NASA Winds - Publications

Publications

This database catalogues publications of the Ocean Vector Winds Science Team (OVWST) and those that employ our products. Click the read more buttons for full citation and abstract. Please acknowledge the OVWST when utilizing our products.

Publications: 870

Martin-Blanco, C., Scapin, N., Wu, J., Popinet, S., Farrar, J.T., Chapron, B., and L. Deike, L. (2026). Kinematics of gravity-capillary waves above an evolving underwater current, Journal of Fluid Mechanics, 1935, 10.1017/jfm.2026.11523. Journal Article »
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Title: Kinematics of gravity-capillary waves above an evolving underwater current
Type: Journal Article
Publication: Journal of Fluid Mechanics
Author(s): Martin-Blanco, C., Scapin, N., Wu, J., Popinet, S., Farrar, J.T., Chapron, B., and L. Deike, L.
Year: 2026
Formatted Citation: Martin-Blanco, C., Scapin, N., Wu, J., Popinet, S., Farrar, J.T., Chapron, B., and L. Deike, L., 2026: Kinematics of gravity-capillary waves above an evolving underwater current, Journal of Fluid Mechanics, 1935, 10.1017/jfm.2026.11523.
Abstract: We perform direct numerical simulations of continuously growing broadband surface waves forced by a turbulent atmospheric boundary layer coupled with a developing underwater current. We resolve and analyse the multiscale space–time evolution of the waves by considering the wave spectrum in frequency and wavenumber space and describe the kinematics of nonlinear gravity–capillary waves under a current initially described by a viscous boundary layer and transitioning to turbulence at later times under the wind-wave forcing. The wave speed experiences a scale-dependent Doppler shift, with shorter waves shifted by currents closer to the surface, in agreement with the framework from Stewart & Joy (1974 Deep Sea Res. Oceanogr. Abstracts 21(12), 1039–1049). At low wave slopes, the wave energy concentrates along the linear dispersion relation. When the wave slope is high enough, we observe wave energy located in multiple branches associated with nonlinear bound harmonics travelling at the speed of a carrier mode. These nonlinear branches are well described by a generalized nonlinear dispersion relation that links each harmonic to the effective velocity of the carrier mode to which they are bound, and are found to be Doppler shifted with the carrier mode. The generalized Doppler-shifted nonlinear dispersion relation remains valid as the underwater current becomes turbulent, and the depth-varying mean current profile can be systematically reconstructed from the measured phase velocities from waves at different scales.
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URL: https://doi.org/10.1017/jfm.2026.11523
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Scapin, N., Wu, J., Farrar, J.T., Chapron, B., Popinet, S., and Deike, L. (2026). Growth Rate and Dissipation in Wind-Forced Breaking Waves, Geophysical Research Letters, 53(1), e2025GL117901, 10.1029/2025GL117901. Journal Article »
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Title: Growth Rate and Dissipation in Wind-Forced Breaking Waves
Type: Journal Article
Publication: Geophysical Research Letters
Author(s): Scapin, N., Wu, J., Farrar, J.T., Chapron, B., Popinet, S., and Deike, L.
Year: 2026
Formatted Citation: Scapin, N., Wu, J., Farrar, J.T., Chapron, B., Popinet, S., and Deike, L., 2026: Growth Rate and Dissipation in Wind-Forced Breaking Waves, Geophysical Research Letters, 53(1), e2025GL117901, 10.1029/2025GL117901.
Abstract: Ocean waves grow and eventually break under the action of strong winds, a process that plays a key role in transferring energy from the atmosphere to the ocean and limiting wave heights. In this study, we used high-resolution computer simulations to examine how wind causes waves to grow and how breaking waves transfer energy into ocean currents under high wind speed conditions. Waves grow mainly due to wind pressure on their surface, but once they become steep enough, they break and generate underwater turbulence that carries energy into the ocean. We confirm that the rate at which waves grow and break depends on their steepness and the wind strength. By analyzing the energy lost during breaking, we confirm a universal dissipation pattern that is independent of the specific mechanism leading to breaking. Finally, we propose a new way to describe how this energy is transferred below the surface, which agrees well with both our simulations and open ocean field measurements.
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URL: https://doi.org/10.1029/2025GL117901
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Yang, R., Liu, Z., Kumar Farsoiya, P., Popinet, S., and Deike, L. (2026). Surfactant effects on gravity-capillary waves, Journal of Fluid Mechanics, 1031, 10.1017/jfm.2026.11260. Journal Article »
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Title: Surfactant effects on gravity-capillary waves
Type: Journal Article
Publication: Journal of Fluid Mechanics
Author(s): Yang, R., Liu, Z., Kumar Farsoiya, P., Popinet, S., and Deike, L.
Year: 2026
Formatted Citation: Yang, R., Liu, Z., Kumar Farsoiya, P., Popinet, S., and Deike, L., 2026: Surfactant effects on gravity-capillary waves, Journal of Fluid Mechanics, 1031, 10.1017/jfm.2026.11260.
Abstract: Surfactants at the air–sea interface are known to alter surface wave dynamics by modifying surface tension and Marangoni stresses. In this study, we perform two-dimensional direct numerical simulations of gravity-capillary waves with insoluble surfactants using a coupled phase field and volume-of-fluid method. We consider a nonlinear equation of state for surface tension and resolve Marangoni stresses induced by surfactant concentration gradients. We explore a broad parameter space characterised by initial wave steepness, Bond number (comparing gravity and surface tension), Reynolds number (comparing inertia and viscosity), and the importance of surfactant concentration and strength of the gradient, characterised by a surfactant parameter. We analyse the impact of surfactants on wave patterns, surface roughness, wave breaking, energy dissipation and surface vorticity.
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URL: https://doi.org/10.1017/jfm.2026.11260
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Bohé, A., Chen, A., Chen, C., Dubois, P., Fore, A., Molero, B., Peral, E., Raynal, M., Stiley, B., Ardhuin, F., Hay, A., Legresy, B., Lenain, L., and Villas Bôas, A.B. (2025). Measuring Significant Wave Height Fields in Two Dimensions at Kilometric Scales with SWOT, IEEE Transactions on Geoscience and Remote Sensing, 10.1109/TGRS.2025.3551605. Journal Article »
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Title: Measuring Significant Wave Height Fields in Two Dimensions at Kilometric Scales with SWOT
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Bohé, A., Chen, A., Chen, C., Dubois, P., Fore, A., Molero, B., Peral, E., Raynal, M., Stiley, B., Ardhuin, F., Hay, A., Legresy, B., Lenain, L., and Villas Bôas, A.B.
Year: 2025
Formatted Citation: Bohé, A., Chen, A., Chen, C., Dubois, P., Fore, A., Molero, B., Peral, E., Raynal, M., Stiley, B., Ardhuin, F., Hay, A., Legresy, B., Lenain, L., and Villas Bôas, A.B., 2025: Measuring Significant Wave Height Fields in Two Dimensions at Kilometric Scales with SWOT, IEEE Transactions on Geoscience and Remote Sensing, 10.1109/TGRS.2025.3551605.
Abstract: We demonstrate that spatial maps of Significant Wave Height (SWH) with kilometric resolutions can be derived from the data acquired by the KaRIn instrument on-board the SWOT mission by exploiting the measured interferometric decorrelation. We discuss the sensitivity to errors in the volumetric decorrelation estimates and show that a succesful inversion of SWH, particularly in the outer part of KaRIn’s swath and for low values of SWH, requires factoring out all sources of decorrelation of instrumental origin to an exquisite precision. We then validate KaRIn’s SWH measurement against independent data, namely GPS buoys, airborne lidar, Sentinel3, SWOT’s nadir altimeter and the ECMWF global wave model. We show that biases between KaRIn and the other sensors are centimetric and that KaRIn is able to capture features in the two dimensional SWH field of only a few kilometers. While KaRIn’s SWH measurement error is difficult to fully characterize due the absence of two-dimensional ground truth data valid at such fine spatial scales and spanning a wide range of sea states, we argue that the retrieved fields are dominated by signal rather than noise, except possibly in the last few kilometers of the swath at low SWH. We briefly discuss the implications in terms of advancing our understanding of the phenomena that shape the wave fields at small scales. The algorithm and calibration described in this paper will be the basis for version D of the operational SWOT products.
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URL: https://doi.org/10.1109/TGRS.2025.3551605
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Liu, C., and Yu, L. (2025). Satellite-Based Evidence of Winter Intensification of Ocean Surface Stress and Ekman Downwelling in the Beaufort Gyre Since the 2010s, Journal of Geophysical Research: Oceans, 130(11), e2025JC022521, 10.1029/2025JC022521. Journal Article »
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Title: Satellite-Based Evidence of Winter Intensification of Ocean Surface Stress and Ekman Downwelling in the Beaufort Gyre Since the 2010s
Type: Journal Article
Publication: Journal of Geophysical Research: Oceans
Author(s): Liu, C., and Yu, L.
Year: 2025
Formatted Citation: Liu, C., and Yu, L., 2025: Satellite-Based Evidence of Winter Intensification of Ocean Surface Stress and Ekman Downwelling in the Beaufort Gyre Since the 2010s, Journal of Geophysical Research: Oceans, 130(11), e2025JC022521, 10.1029/2025JC022521.
Abstract: The Beaufort Gyre (BG) is a critical reservoir of Arctic freshwater, its stability governed by interactions between atmospheric forcing, sea ice motion, and ocean surface stress. Over the past 2 decades, surface stress and stress curl patterns have undergone marked changes shaped by shifting atmospheric modes and thinning sea ice. Although both atmospheric forcing and ice stress contribute to Ekman transport, neither alone fully captures the changing momentum transfer dynamics. Although atmospheric winds remained relatively stable, enhanced momentum transfer across the ice-ocean interface, driven by faster ice drift and reduced ice thickness, led to increased surface stress and amplified variability. This strengthened the influence of the Arctic Oscillation and elevated the role of the Arctic Dipole, which now contributes more predominantly to Beaufort Sea downwelling. These shifts produced a spatially asymmetric stress curl pattern with stronger anticyclonic forcing in the southeast and sustained cyclonic anomalies in the northwest. The resulting increase in Ekman downwelling is linked to deepening winter mixed layers potentially weakening the gyre's ability to store freshwater. As the Arctic transitions toward thinner more mobile ice, the evolving balance between atmospheric variability, ice-ocean coupling, and Ekman dynamics will be critical for future understanding of BG circulation and freshwater retention.
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URL: https://doi.org/10.1029/2025JC022521
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Liu, C., and Yu, L. (2025). Satellite-Based Analysis of Ocean-Surface Stress Across the Ice-Free and Ice-Covered Polar Oceans, Earth System Science Data, 17(8), 4159–4184, 10.5194/essd-17-4159-2025. Journal Article »
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Title: Satellite-Based Analysis of Ocean-Surface Stress Across the Ice-Free and Ice-Covered Polar Oceans
Type: Journal Article
Publication: Earth System Science Data
Author(s): Liu, C., and Yu, L.
Year: 2025
Formatted Citation: Liu, C., and Yu, L., 2025: Satellite-Based Analysis of Ocean-Surface Stress Across the Ice-Free and Ice-Covered Polar Oceans, Earth System Science Data, 17(8), 4159–4184, 10.5194/essd-17-4159-2025.
Abstract: Ocean-surface stress is a critical driver of polar sea-ice dynamics, air–sea interactions, and ocean circulation. This work provides a daily analysis of ocean-surface stress on 25 km Equal-Area Scalable Earth (EASE) grids across the ice-free and ice-covered regions of the polar oceans (2011–2021 for the Arctic, 2013–2021 for the Antarctic), covering latitudes north of 60° N in the Arctic and south of 50° S in the Antarctic and Southern Ocean. Ocean-surface stress is calculated using a bulk parameterization approach that combines ocean-surface winds, ice motion vectors, and sea surface height (SSH) data from multiple satellite platforms. The analysis captures significant spatial and temporal variability in ocean-surface wind stress and the resultant wind-driven Ekman transport, while providing enhanced spatiotemporal resolution. Two sensitivity analyses are conducted to address key sources of uncertainty. The first addresses the fine-scale variability in SSH fields, which was mitigated using a 150 km Gaussian filter to smooth 3 d SSH datasets and enhance compatibility with the other monthly product, followed by linear interpolation to achieve daily resolution. The second investigates uncertainty in the ice–water drag coefficient, which revealed that variations in the coefficient have a proportional influence on the computed ocean-surface stress under the tested conditions. These uncertainties are most pronounced during winter, with median values reaching 20 % in the Arctic and 40 % in the Southern Ocean. Validation efforts using ice-tethered profiler velocity records revealed weak to moderate correlations with satellite-derived stress (r= 0.4–0.8) between observed surface velocities and satellite-derived estimates (Ekman + geostrophic) at daily resolution, with significantly improved agreement when averaged to weekly means. This dataset is publicly available at https://doi.org/10.5281/zenodo.15534576 (Liu and Yu, 2024).
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URL: https://doi.org/10.5194/essd-17-4159-2025
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Liu, T., and Hu, S. (2025). An Algorithm to Develop a Satellite-Based Atmospheric River Database, Geophysical Research Letters, 52(5), e2024GL111316, 10.1029/2024GL111316. Journal Article »
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Title: An Algorithm to Develop a Satellite-Based Atmospheric River Database
Type: Journal Article
Publication: Geophysical Research Letters
Author(s): Liu, T., and Hu, S.
Year: 2025
Formatted Citation: Liu, T., and Hu, S., 2025: An Algorithm to Develop a Satellite-Based Atmospheric River Database, Geophysical Research Letters, 52(5), e2024GL111316, 10.1029/2024GL111316.
Abstract: Atmospheric rivers (ARs) are long, narrow corridors of strong water vapor transports and can lead to intense rainfall and flooding when they reach continents. So far, most studies of ARs rely on atmospheric reanalyses or dropsonde observations. Since reanalyses are mixed products of observations and climate models, they may differ from the real world due to the influence of model biases and high-frequency atmospheric variabilities produced by models. Dropsonde observations are limited in time and space. Given those limitations, it will be ideal to construct an observation-based, global AR database using satellite measurements with high spatial-temporal resolutions and global coverage. In this study, we propose an algorithm that can successfully reconstruct the global field of vertically IVT using two satellite observed quantities, vertically integrated water vapor and sea surface winds. The developed satellite-based AR database shows similar large-scale statistics with major atmospheric reanalyses but distinct regional and local features, and therefore has a great potential of advancing our understanding to observed ARs.
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URL: https://doi.org/10.1029/2024GL111316
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Pan, M., Hu, S., Zaitchik, B., and Pan, W. (2025). Contrasting historical trends of atmospheric rivers in the Northern Hemisphere, npj Clim. Atmos. Sci., 307, 10.1038/s41612-025-01191-w. Journal Article »
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Title: Contrasting historical trends of atmospheric rivers in the Northern Hemisphere
Type: Journal Article
Publication: npj Clim. Atmos. Sci.
Author(s): Pan, M., Hu, S., Zaitchik, B., and Pan, W.
Year: 2025
Formatted Citation: Pan, M., Hu, S., Zaitchik, B., and Pan, W., 2025: Contrasting historical trends of atmospheric rivers in the Northern Hemisphere, npj Clim. Atmos. Sci., 307, 10.1038/s41612-025-01191-w.
Abstract: Previous modeling studies have indicated that Atmospheric rivers (ARs) will become more frequent in the warming climate. However, whether we have experienced more ARs during historical period is less studied. Here, we show that winter AR frequency has significantly increased over the mid-latitude NorthernHemisphere from 1950—2022. Using station-based observations, we confirm that ARs have driven coherent long-term trends in both total and extreme precipitation over land. The warming induced rise in atmospheric moisture alone accounts for an AR frequency increase of ~0.6–0.8% per decade. AR trends exhibit meridional dipolar patterns over western North America and Europe, governed by positive trends of the Pacific-North America Pattern and North Atlantic Oscillation. The “Pineapple Express” ARs have been suppressed, declining of AR landfalling over the Pacific Northwest. Through atmospheric model analyses, we demonstrate that observed sea surface temperature changes dominate Atlantic AR trends, while exerting minor effects on Pacific AR trends.
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URL: https://doi.org/10.1038/s41612-025-01191-w
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Ricciardulli, L., Manaster, A., and Lindsley, R. (2025). Investigation of a Calibration Change in the Ocean Surface Wind Measurements from the TAO Buoy Array, Bulletin of the American Meteorological Society, 106(2), E242–E260, 10.1175/BAMS-D-24-0072.1. Journal Article »
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Title: Investigation of a Calibration Change in the Ocean Surface Wind Measurements from the TAO Buoy Array
Type: Journal Article
Publication: Bulletin of the American Meteorological Society
Author(s): Ricciardulli, L., Manaster, A., and Lindsley, R.
Year: 2025
Formatted Citation: Ricciardulli, L., Manaster, A., and Lindsley, R., 2025: Investigation of a Calibration Change in the Ocean Surface Wind Measurements from the TAO Buoy Array, Bulletin of the American Meteorological Society, 106(2), E242–E260, 10.1175/BAMS-D-24-0072.1.
Abstract: During routine analyses of the calibration stability of ocean surface wind retrievals from satellites, we identified a significant bias between satellite measurements and wind observations from the Tropical Atmosphere Ocean (TAO) buoy array, starting in mid-2020 until the present. After extensive investigation, we determined that the bias did not arise from anomalies in the satellites’ calibration or coding errors, as it appeared regardless of which satellite these buoys were compared to. A sudden increase of about 10% (0.5–0.8 m s⁻¹) in wind speed observations was first identified in over 40 TAO buoys that were serviced between March and September 2020. Our concerns were shared with scientists at the National Data Buoy Center (NDBC), who confirmed our estimates. The exact source of this sudden change is still under investigation, but it appears to be related to changes in the calibration of buoy anemometers installed during recent service trips. By 2024, all currently operating TAO buoys under NDBC management have been serviced since 2020, and they all manifest a sudden wind speed increase postservice in the public-facing buoy data. This change is a source of concern because the stability of the integrated satellite–buoy system is vital for international ocean observation programs. The aim of this paper is to inform the research community about this spurious wind signal in the TAO array, discuss the impact it could have on the research community, and prevent it from being misinterpreted as climate variability, impacting the calibration of other observing systems, or affecting derived data products such as ocean surface fluxes.
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URL: https://doi.org/10.1175/BAMS-D-24-0072.1
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Wang H., Villas Bôas A.B., Vanneste J., and Young, W.R. (2025). Scattering of Surface Waves by Ocean Currents: The U2H Map, Journal of Fluid Mechanics, 1005, A12, 10.1017/jfm.2024.964. Journal Article »
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Title: Scattering of Surface Waves by Ocean Currents: The U2H Map
Type: Journal Article
Publication: Journal of Fluid Mechanics
Author(s): Wang H., Villas Bôas A.B., Vanneste J., and Young, W.R.
Year: 2025
Formatted Citation: Wang H., Villas Bôas A.B., Vanneste J., and Young, W.R., 2025: Scattering of Surface Waves by Ocean Currents: The U2H Map, Journal of Fluid Mechanics, 1005, A12, 10.1017/jfm.2024.964.
Abstract: Ocean turbulence at meso- and submesocales affects the propagation of surface waves through refraction and scattering, inducing spatial modulations in significant wave height (SWH). We develop a theoretical framework that relates these modulations to the current that induces them. We exploit the asymptotic smallness of the ratio of typical current speed to wave group speed to derive a linear map – the U2H map – between surface current velocity and SWH anomaly. The U2H map is a convolution, non-local in space, expressible as a product in Fourier space by a factor independent of the magnitude of the wavenumber vector. Analytic expressions of the U2H map show how the SWH responds differently to the vortical and divergent parts of the current, and how the anisotropy of the wave spectrum is key to large current-induced SWH anomalies. We implement the U2H map numerically and test its predictions against WAVEWATCH III numerical simulations for both idealised and realistic current configurations.
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URL: https://doi.org/10.1017/jfm.2024.964
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Yang, S., Bae, H.-J., Bourassa, M., Nam, C.C., Cocke, S., Shin, D.W., Barr, B.W., Seo, H., Cha, D.-H., Kwon, M.-H., Kim, D., Park, M.-S., Jeong, K.-Y., and Kim, B.-M. (2025). Sea Spray Effects on Typhoon Prediction in the Yellow and East China Seas: Case Studies Using a Coupled Atmosphere-Ocean-Wave Model for Lingling (2019) and Maysak (2020), Environmental Research Letters, 20(5), 054028, 10.1088/1748-9326/adc616. Journal Article »
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Title: Sea Spray Effects on Typhoon Prediction in the Yellow and East China Seas: Case Studies Using a Coupled Atmosphere-Ocean-Wave Model for Lingling (2019) and Maysak (2020)
Type: Journal Article
Publication: Environmental Research Letters
Author(s): Yang, S., Bae, H.-J., Bourassa, M., Nam, C.C., Cocke, S., Shin, D.W., Barr, B.W., Seo, H., Cha, D.-H., Kwon, M.-H., Kim, D., Park, M.-S., Jeong, K.-Y., and Kim, B.-M.
Year: 2025
Formatted Citation: Yang, S., Bae, H.-J., Bourassa, M., Nam, C.C., Cocke, S., Shin, D.W., Barr, B.W., Seo, H., Cha, D.-H., Kwon, M.-H., Kim, D., Park, M.-S., Jeong, K.-Y., and Kim, B.-M., 2025: Sea Spray Effects on Typhoon Prediction in the Yellow and East China Seas: Case Studies Using a Coupled Atmosphere-Ocean-Wave Model for Lingling (2019) and Maysak (2020), Environmental Research Letters, 20(5), 054028, 10.1088/1748-9326/adc616.
Abstract: This study investigates the impact of sea spray parameterization on typhoon prediction in the Yellow and East China Seas (YECS) region. Using an air-sea-wave coupled model, we evaluate changes due to sea spray effects in the simulated intensity and structure of Typhoons Lingling (2019) and Maysak (2020). Enabling sea spray effect enhances surface turbulent heat fluxes considerably around the typhoon centers (74% increase for Lingling, 92% for Maysak), leading to a better representation of typhoon intensification phases. Analysis of thermodynamic processes reveals that sea spray-induced warming emerges before rapid intensification, with enhanced temperature and moisture profiles throughout the troposphere supporting stronger secondary circulation. As a result, key aspects of typhoon prediction exhibit significant improvements: root-mean-squared errors decreased by 63% in minimum central pressure and 60% for maximum wind speed in the case of Maysak. The results demonstrate that sea spray effects are strongly modulated by sub-surface ocean conditions, with a greater surface heat flux enhancement for Maysak that moved along warmer Kuroshio and Tsushima currents than for Lingling which passed over Yellow Sea Bottom Cold Water. Our findings demonstrate the significant potential to improve typhoon predictions in the YECS region by incorporating sea spray effects.
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URL: https://doi.org/10.1088/1748-9326/adc616
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Azorin-Molina, C., Dunn, R.J.H., Ricciardulli, L., Mears, C.A., Nicolas, J.P., McVicar, T.R., Zeng, Z., and Bosilovich, M.G. (2024). Chapter 2 Global Climate: Land and Ocean Surface Winds, Bulletin of the American Meteorological Society, State of the Climate in 2023, 105(8), S76-S79, 10.1175/BAMS-D-24-0116.1. Journal Article »
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Title: Chapter 2 Global Climate: Land and Ocean Surface Winds
Type: Journal Article
Publication: Bulletin of the American Meteorological Society, State of the Climate in 2023
Author(s): Azorin-Molina, C., Dunn, R.J.H., Ricciardulli, L., Mears, C.A., Nicolas, J.P., McVicar, T.R., Zeng, Z., and Bosilovich, M.G.
Year: 2024
Formatted Citation: Azorin-Molina, C., Dunn, R.J.H., Ricciardulli, L., Mears, C.A., Nicolas, J.P., McVicar, T.R., Zeng, Z., and Bosilovich, M.G., 2024: Chapter 2 Global Climate: Land and Ocean Surface Winds, Bulletin of the American Meteorological Society, State of the Climate in 2023, 105(8), S76-S79, 10.1175/BAMS-D-24-0116.1.
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URL: https://doi.org/10.1175/BAMS-D-24-0116.1
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Kamp, W., Han, W., Zhang, L., Kido, S., and McCreary, J. (2024). Tropical Atmospheric Intraseasonal Oscillations Leading to Sea Level Extremes in Coastal Indonesia during Recent Decades, Journal of Climate, 37(9), 2867–2880, 10.1175/JCLI-D-23-0374.1. Journal Article »
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Title: Tropical Atmospheric Intraseasonal Oscillations Leading to Sea Level Extremes in Coastal Indonesia during Recent Decades
Type: Journal Article
Publication: Journal of Climate
Author(s): Kamp, W., Han, W., Zhang, L., Kido, S., and McCreary, J.
Year: 2024
Formatted Citation: Kamp, W., Han, W., Zhang, L., Kido, S., and McCreary, J., 2024: Tropical Atmospheric Intraseasonal Oscillations Leading to Sea Level Extremes in Coastal Indonesia during Recent Decades, Journal of Climate, 37(9), 2867–2880, 10.1175/JCLI-D-23-0374.1.
Abstract: Coastal flooding induced by sea surface high extreme (HEX) events is an increasing risk to human society and infrastructure as both urban growth in coastal areas and anthropogenic sea level rise continue, especially for island nations like Indonesia. This paper investigates the role of atmospheric intraseasonal oscillations (ISOs), which are dominated by the Madden–Julian oscillation (MJO), in forcing HEXs on the coasts of Indonesia bordering the Indian Ocean. We use satellite altimetry data from 1993 to 2021 and tide gauge observations to detect HEXs, and modeling experiments using both the Regional Ocean Modeling System and a Bayesian dynamic linear model to understand the forcing and processes. We find that HEXs exhibit strong seasonality, with most events occurring during boreal winter (December–February) and spring (March–May) that are dominated by seasonal-to-decadal and intraseasonal variability respectively. In 32% of the 56 HEX events detected, the amplitude of ISO-induced sea level anomalies (SLAs) exceeds that of seasonal-to-decadal SLAs. Surface wind stress associated with atmospheric ISOs is the major forcing for intraseasonal SLAs, and both the remote westerly wind stress from the Indian Ocean equator and northwesterly longshore wind stress at the Indonesian coasts play important roles in driving the HEXs. The MJO is the dominant cause of ISO-dominated HEXs and its impact shows strong seasonal differences. Spring MJOs are associated with stronger convective anomalies over the eastern Indian Ocean equator that drive stronger zonal winds across the equatorial basin that lead to more HEX events compared to winter MJOs when the convection is shifted southward.
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URL: https://doi.org/10.1175/JCLI-D-23-0374.1
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May, J. and Bourassa, M.A. (2024). Upper Ocean Thermodynamic Response to Coupling Currents to Wind Stress over the Gulf Stream, Journal of Marine Science and Engineering, 12(11), 1994, 10.3390/jmse12111994. Journal Article »
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Title: Upper Ocean Thermodynamic Response to Coupling Currents to Wind Stress over the Gulf Stream
Type: Journal Article
Publication: Journal of Marine Science and Engineering
Author(s): May, J. and Bourassa, M.A.
Year: 2024
Formatted Citation: May, J. and Bourassa, M.A., 2024: Upper Ocean Thermodynamic Response to Coupling Currents to Wind Stress over the Gulf Stream, Journal of Marine Science and Engineering, 12(11), 1994, 10.3390/jmse12111994.
Abstract: We use high-resolution coupled atmosphere–ocean model simulations over the Gulf Stream extension region during a winter season to examine the upper ocean thermodynamic response to including current feedback to atmospheric wind stress. We demonstrate that a model that includes current feedback leads to significant changes in the structure and transport of heat throughout the upper ocean in comparison to the same model without current feedback. We find that including the current feedback leads to changes in the upper ocean temperature pattern that match the vorticity pattern. Areas with cyclonic ocean vorticity, typically north of the Gulf Stream extension, correspond to areas with warmer temperatures throughout the water column. Areas with anticyclonic ocean vorticity, typically south of the Gulf Stream extension, correspond to areas with cooler temperatures throughout the water column. We also find that including current feedback leads to an overall reduction in the submesoscale vertical heat flux spectra across all spatial scales, with differences in the submesoscale vertical heat flux corresponding to SST minus mixed layer temperature differences. The direct impact of current feedback on the thermodynamic structure within the upper ocean also has indirect impacts on other aspects of the ocean, such as the energy transfer between the ocean and the atmosphere, ocean stratification, and acoustic parameters.
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URL: https://doi.org/10.3390/jmse12111994
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Samelson, R.M., Durski, S.M., Chelton, D.B., Skyllingstad, E.D., and Barbour, P.L. (2024). Surface Currents and Relative-Wind Stress in Coupled Ocean–Atmosphere Simulations of the Northern California Current System, Monthly Weather Review, 152(9), 2033–2054 , 10.1175/MWR-D-23-0279.1. Journal Article »
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Title: Surface Currents and Relative-Wind Stress in Coupled Ocean–Atmosphere Simulations of the Northern California Current System
Type: Journal Article
Publication: Monthly Weather Review
Author(s): Samelson, R.M., Durski, S.M., Chelton, D.B., Skyllingstad, E.D., and Barbour, P.L.
Year: 2024
Formatted Citation: Samelson, R.M., Durski, S.M., Chelton, D.B., Skyllingstad, E.D., and Barbour, P.L., 2024: Surface Currents and Relative-Wind Stress in Coupled Ocean–Atmosphere Simulations of the Northern California Current System, Monthly Weather Review, 152(9), 2033–2054 , 10.1175/MWR-D-23-0279.1.
Abstract: The dependence of surface-current damping on the definition of surface current for the relative wind is examined in coupled ocean–atmosphere numerical simulations of the northern California Current System (nCCS) during March–October 2009. The model response is analyzed for wind stress computed from relative wind for six different choices of effective model surface velocity. Simulations without surface-current coupling are also considered. As a function of the geographically varying uppermost grid-level depth, the model uppermost grid-level velocity is found to have a wind-drift component with a log-layer structure. Mean geostrophic wind work is concentrated in the shelf and slope regions during March–May (MAM) and in the deep offshore region in June–September (JJAS). The surface-current damping effect on ocean kinetic energy depends more strongly on the parameterization of atmospheric planetary boundary layer (PBL) turbulence than on the surface-current coupling formulation: weaker PBL mixing gives stronger surface-current damping. The damping effect is stronger in the less energetic offshore region than in the more energetic region closer to the coast. During MAM, the changes in kinetic energy and geostrophic wind work in the shelf and slope regions are spatially correlated, while during JJAS, the changes in geostrophic wind work are strongly modulated by SST–stress coupling. The wind-drift-corrected surface-current formulations result in large changes in the effective wind work based on the product of stress and relative-wind surface current but result in only small changes in the kinetic energy of the circulation.
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URL: https://doi.org/10.1175/MWR-D-23-0279.1
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Blair, D., Zheng, Y., and Bourassa, M.A. (2023). The Effect of Surface Oil on Ocean Wind Stress, Earth, 4(2), 345-364, 10.3390/earth4020019. Journal Article »
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Title: The Effect of Surface Oil on Ocean Wind Stress
Type: Journal Article
Publication: Earth
Author(s): Blair, D., Zheng, Y., and Bourassa, M.A.
Year: 2023
Formatted Citation: Blair, D., Zheng, Y., and Bourassa, M.A., 2023: The Effect of Surface Oil on Ocean Wind Stress, Earth, 4(2), 345-364, 10.3390/earth4020019.
Abstract: This study provides, to the best of our knowledge, the first detailed analysis of how surface oil modifies air–sea interactions in a two-way coupled model, i.e., the coupled–ocean–atmosphere–wave–sediment–transport (COAWST) model, modified to account for oil-related changes in air–sea fluxes. This study investigates the effects of oil on surface roughness, surface wind, surface and near-surface temperature differences, and boundary-layer stability and how those conditions ultimately affect surface stress. We first conducted twin-coupled modeling simulations with and without the influence of oil over the Deepwater Horizon (DWH) oil spill period (20 April to 5 May 2010) in the Gulf of Mexico. Then, we compared the results by using a modularized flux model with parameterizations selected to match those selected in the coupled model adapted to either ignore or account for different atmospheric/oceanic processes in calculating surface stress. When non-oil inputs to the bulk formula were treated as being unchanged by oil, the surface stress changes were always negative because of oil-related dampening of the surface roughness alone. However, the oil-related changes to 10 m wind speeds and boundary-layer stability were found to play a dominant role in surface stress changes relative to those due to the oil-related surface roughness changes, highlighting that most of the changes in surface stress were due to oil-related changes in wind speed and boundary-layer stability. Finally, the oil-related changes in surface stress due to the combined oil-related changes in surface roughness, surface wind, and boundary-layer stability were not large enough to have a major impact on the surface current and surface oil transport, indicating that the feedback from the surface oil to the surface oil movement itself is insignificant in forecasting surface oil transport unless the fractional oil coverage is much larger than the value found in this study.
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URL: https://doi.org/10.3390/earth4020019
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Hauser, D., Abdalla, S., Ardhuin, F., Bidlot, J.-R., Bourassa, M., Cotton, D., Gommenginger, C., Evers-King, H., Johnsen, H., Knaff, J., Lavender, S., Mouche, A., Reul, N., Sampson, C., Steele, E.C.C., and Stoffelen, A. (2023). Satellite Remote Sensing of Surface Winds, Waves, and Currents: Where are we Now?, Surveys in Geophysics, 44(5), 1357-1446, 10.1007/s10712-023-09771-2. Journal Article »
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Title: Satellite Remote Sensing of Surface Winds, Waves, and Currents: Where are we Now?
Type: Journal Article
Publication: Surveys in Geophysics
Author(s): Hauser, D., Abdalla, S., Ardhuin, F., Bidlot, J.-R., Bourassa, M., Cotton, D., Gommenginger, C., Evers-King, H., Johnsen, H., Knaff, J., Lavender, S., Mouche, A., Reul, N., Sampson, C., Steele, E.C.C., and Stoffelen, A.
Year: 2023
Formatted Citation: Hauser, D., Abdalla, S., Ardhuin, F., Bidlot, J.-R., Bourassa, M., Cotton, D., Gommenginger, C., Evers-King, H., Johnsen, H., Knaff, J., Lavender, S., Mouche, A., Reul, N., Sampson, C., Steele, E.C.C., and Stoffelen, A., 2023: Satellite Remote Sensing of Surface Winds, Waves, and Currents: Where are we Now?, Surveys in Geophysics, 44(5), 1357-1446, 10.1007/s10712-023-09771-2.
Abstract: This review paper reports on the state-of-the-art concerning observations of surface winds, waves, and currents from space and their use for scientific research and subsequent applications. The development of observations of sea state parameters from space dates back to the 1970s, with a significant increase in the number and diversity of space missions since the 1990s. Sensors used to monitor the sea-state parameters from space are mainly based on microwave techniques. They are either specifically designed to monitor surface parameters or are used for their abilities to provide opportunistic measurements complementary to their primary purpose. The principles on which is based on the estimation of the sea surface parameters are first described, including the performance and limitations of each method. Numerous examples and references on the use of these observations for scientific and operational applications are then given. The richness and diversity of these applications are linked to the importance of knowledge of the sea state in many fields. Firstly, surface wind, waves, and currents are significant factors influencing exchanges at the air/sea interface, impacting oceanic and atmospheric boundary layers, contributing to sea level rise at the coasts, and interacting with the sea-ice formation or destruction in the polar zones. Secondly, ocean surface currents combined with wind- and wave- induced drift contribute to the transport of heat, salt, and pollutants. Waves and surface currents also impact sediment transport and erosion in coastal areas. For operational applications, observations of surface parameters are necessary on the one hand to constrain the numerical solutions of predictive models (numerical wave, oceanic, or atmospheric models), and on the other hand to validate their results. In turn, these predictive models are used to guarantee safe, efficient, and successful offshore operations, including the commercial shipping and energy sector, as well as tourism and coastal activities. Long-time series of global sea-state observations are also becoming increasingly important to analyze the impact of climate change on our environment. All these aspects are recalled in the article, relating to both historical and contemporary activities in these fields.
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URL: https://doi.org/10.1007/s10712-023-09771-2
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May, J.C. and Bourassa, M.A. (2023). Atmospheric Dynamic Response to Coupling Currents to Wind Stress over the Gulf Stream, Atmosphere, 14(8), 1216, 10.3390/atmos14081216. Journal Article »
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Title: Atmospheric Dynamic Response to Coupling Currents to Wind Stress over the Gulf Stream
Type: Journal Article
Publication: Atmosphere
Author(s): May, J.C. and Bourassa, M.A.
Year: 2023
Formatted Citation: May, J.C. and Bourassa, M.A., 2023: Atmospheric Dynamic Response to Coupling Currents to Wind Stress over the Gulf Stream, Atmosphere, 14(8), 1216, 10.3390/atmos14081216.
Abstract: Atmospheric near-surface stress and boundary layer wind responses to surface currents are examined with high resolution coupled atmosphere–ocean models over the Gulf Stream during winter. Because the ocean and atmosphere are linked through surface stress, the two fluids can cause dramatic changes through feedback processes. When the current feedback is included, we find that the current gradient in the cross-wind direction drives the stress curl pattern and wind curl pattern to have minima and maxima at locations matching those of the ocean surface vorticity pattern. Furthermore, we find the large- (>30 km) and small-scale, or submesoscale (<30 km), stress curl and wind curl responses to ocean surface vorticity are complimentary; however, the large- and small-scale wind divergence responses are counteractive. These responses (commonly called coupling coefficients) are found to depend on the relative position to the Gulf Stream maximum current. Throughout the atmospheric boundary layer, we find including the current feedback also leads to changes in the atmospheric secondary circulation on either side of the Gulf Stream extension. The winter seasonal means suggest the current feedback will impact climate, and investigating individual events, such as an atmospheric front passing over the Gulf Stream, suggests the current feedback will also impact the intensity of weather.
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URL: https://doi.org/10.3390/atmos14081216
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Seo, H., O'Neill, L.W., Bourassa, M.A., Czaja, A., Drushka, K., Edson, J.B., Fox-Kemper, B., Frenger, I., Gille, S.T., Kirtman, B.P., Minobe, S., Pendergrass, A.G., Renault, L., Roberts, M.J., Schneider, N., Small, R.J., Stoffelen, A., and Wang, Q. (2023). Ocean Mesoscale and Frontal-Scale Ocean-Atmosphere Interactions and Influence on Large-Scale Climate: A Review, Journal of Climate, 36(7), 1981–2013 , 10.1175/JCLI-D-21-0982.1. Journal Article »
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Title: Ocean Mesoscale and Frontal-Scale Ocean-Atmosphere Interactions and Influence on Large-Scale Climate: A Review
Type: Journal Article
Publication: Journal of Climate
Author(s): Seo, H., O'Neill, L.W., Bourassa, M.A., Czaja, A., Drushka, K., Edson, J.B., Fox-Kemper, B., Frenger, I., Gille, S.T., Kirtman, B.P., Minobe, S., Pendergrass, A.G., Renault, L., Roberts, M.J., Schneider, N., Small, R.J., Stoffelen, A., and Wang, Q.
Year: 2023
Formatted Citation: Seo, H., O'Neill, L.W., Bourassa, M.A., Czaja, A., Drushka, K., Edson, J.B., Fox-Kemper, B., Frenger, I., Gille, S.T., Kirtman, B.P., Minobe, S., Pendergrass, A.G., Renault, L., Roberts, M.J., Schneider, N., Small, R.J., Stoffelen, A., and Wang, Q., 2023: Ocean Mesoscale and Frontal-Scale Ocean-Atmosphere Interactions and Influence on Large-Scale Climate: A Review, Journal of Climate, 36(7), 1981–2013 , 10.1175/JCLI-D-21-0982.1.
Abstract: Two decades of high-resolution satellite observations and climate modeling studies have indicated strong ocean–atmosphere coupled feedback mediated by ocean mesoscale processes, including semipermanent and meandrous SST fronts, mesoscale eddies, and filaments. The air–sea exchanges in latent heat, sensible heat, momentum, and carbon dioxide associated with this so-called mesoscale air–sea interaction are robust near the major western boundary currents, Southern Ocean fronts, and equatorial and coastal upwelling zones, but they are also ubiquitous over the global oceans wherever ocean mesoscale processes are active. Current theories, informed by rapidly advancing observational and modeling capabilities, have established the importance of mesoscale and frontal-scale air–sea interaction processes for understanding large-scale ocean circulation, biogeochemistry, and weather and climate variability. However, numerous challenges remain to accurately diagnose, observe, and simulate mesoscale air–sea interaction to quantify its impacts on large-scale processes. This article provides a comprehensive review of key aspects pertinent to mesoscale air–sea interaction, synthesizes current understanding with remaining gaps and uncertainties, and provides recommendations on theoretical, observational, and modeling strategies for future air–sea interaction research.
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URL: https://doi.org/10.1175/JCLI-D-21-0982.1
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Wang, X., Lee, T., and Mears, C. (2023). Evaluation of Blended Wind Products and Their Implications for Offshore Wind Power Estimation, Remote Sensing, 15(10), 2620, 10.3390/rs15102620. Journal Article »
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Title: Evaluation of Blended Wind Products and Their Implications for Offshore Wind Power Estimation
Type: Journal Article
Publication: Remote Sensing
Author(s): Wang, X., Lee, T., and Mears, C.
Year: 2023
Formatted Citation: Wang, X., Lee, T., and Mears, C., 2023: Evaluation of Blended Wind Products and Their Implications for Offshore Wind Power Estimation, Remote Sensing, 15(10), 2620, 10.3390/rs15102620.
Abstract: The Cross-Calibrated Multi-Platform (CCMP) wind analysis is a satellite-based blended wind product produced using a two-dimensional variational method. The current version available publicly is Version 2 (CCMP2.0), which includes buoy winds in addition to satellite winds. Version 3 of the product (CCMP3.0) is being produced with several improvements in analysis algorithms, without including buoy winds. Here, we compare CCMP3.0 with a special version of CCMP2.0 that did not include buoy winds, so both versions are independent of buoy measurements. We evaluate them using wind data from buoys around the coasts of the United States and discuss the implications for the wind power industry and offshore wind farms. CCMP2.0 uses ERA-Interim 10 m winds as the background to fill observational gaps. CCMP3.0 uses ERA5 10 m neutral winds as the background. Because ERA5 winds are biased towards lower values at higher wind conditions, CCMP3.0 corrected this bias by matching ERA5 wind speeds with satellite scatterometer wind speeds using a histogram matching method. Our evaluation indicates that CCMP3.0 has better agreement with the independent buoy winds, primarily for higher winds (>10 m/s). This is reflected by the higher correlation and lower root-mean-squared differences of CCMP3.0 versus buoy winds, especially for higher wind conditions. For the U.S. coastal region (within 200 km), the mean wind speed of CCMP3.0 is enhanced by 1–2%, and the wind speed standard deviation is enhanced by around 3–5%. These changes in wind speed and its standard deviation from CCMP2.0 to CCMP3.0 cause an 8–12% increase in wind power density. The wind power density along the U.S. coastal region is also correlated with various climate indices depending on locations, providing a useful approach for predicting wind power on subseasonal to interannual timescales.
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URL: https://doi.org/10.3390/rs15102620
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Fore, A.G., Stiles, B.W., Strub, P.T., and West, R.D. (2022). QuikSCAT Climatological Data Record: Land Contamination Flagging and Correction, Remote Sensing, 14(10), 2487, 10.3390/rs14102487. Journal Article »
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Title: QuikSCAT Climatological Data Record: Land Contamination Flagging and Correction
Type: Journal Article
Publication: Remote Sensing
Author(s): Fore, A.G., Stiles, B.W., Strub, P.T., and West, R.D.
Year: 2022
Formatted Citation: Fore, A.G., Stiles, B.W., Strub, P.T., and West, R.D., 2022: QuikSCAT Climatological Data Record: Land Contamination Flagging and Correction, Remote Sensing, 14(10), 2487, 10.3390/rs14102487.
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URL: https://doi.org/10.3390/rs14102487
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Giglio, D., Gille, S.T., Cornuelle, B.D., Subramanian, A.C., Turk, F.J., Hristova-Veleva, S., and Northcott, D. (2022). Annual Modulation of Diurnal Winds in the Tropical Oceans, Remote Sensing, 14(3), 459, 10.3390/rs14030459. Journal Article »
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Title: Annual Modulation of Diurnal Winds in the Tropical Oceans
Type: Journal Article
Publication: Remote Sensing
Author(s): Giglio, D., Gille, S.T., Cornuelle, B.D., Subramanian, A.C., Turk, F.J., Hristova-Veleva, S., and Northcott, D.
Year: 2022
Formatted Citation: Giglio, D., Gille, S.T., Cornuelle, B.D., Subramanian, A.C., Turk, F.J., Hristova-Veleva, S., and Northcott, D., 2022: Annual Modulation of Diurnal Winds in the Tropical Oceans, Remote Sensing, 14(3), 459, 10.3390/rs14030459.
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URL: https://doi.org/10.3390/rs14030459
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Miao, Y., Dong, X., Bourassa, M.A., and Zhu, D. (2022). Effects of Ocean Wave Directional Spectra on Doppler Retrievals of Ocean Surface Current, IEEE Transactions on Geoscience and Remote Sensing, 60, 1-12, 10.1109/Tgrs.2021.3126327. Journal Article »
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Title: Effects of Ocean Wave Directional Spectra on Doppler Retrievals of Ocean Surface Current
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Miao, Y., Dong, X., Bourassa, M.A., and Zhu, D.
Year: 2022
Formatted Citation: Miao, Y., Dong, X., Bourassa, M.A., and Zhu, D., 2022: Effects of Ocean Wave Directional Spectra on Doppler Retrievals of Ocean Surface Current, IEEE Transactions on Geoscience and Remote Sensing, 60, 1-12, 10.1109/Tgrs.2021.3126327.
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URL: https://doi.org/10.1109/Tgrs.2021.3126327
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Polverari, F., Wineteer, A., Rodríguez, E., Perkovic-Martin, D., Siqueira, P., Farrar, J.T., Adam, M., Closa Tarrés, M., and Edson, J.B. (2022). A Ka-Band Wind Geophysical Model Function Using Doppler Scatterometer Measurements from the Air-Sea Interaction Tower Experiment, Remote Sensing, 14(9), 2067, 10.3390/rs14092067. Journal Article »
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Title: A Ka-Band Wind Geophysical Model Function Using Doppler Scatterometer Measurements from the Air-Sea Interaction Tower Experiment
Type: Journal Article
Publication: Remote Sensing
Author(s): Polverari, F., Wineteer, A., Rodríguez, E., Perkovic-Martin, D., Siqueira, P., Farrar, J.T., Adam, M., Closa Tarrés, M., and Edson, J.B.
Year: 2022
Formatted Citation: Polverari, F., Wineteer, A., Rodríguez, E., Perkovic-Martin, D., Siqueira, P., Farrar, J.T., Adam, M., Closa Tarrés, M., and Edson, J.B., 2022: A Ka-Band Wind Geophysical Model Function Using Doppler Scatterometer Measurements from the Air-Sea Interaction Tower Experiment, Remote Sensing, 14(9), 2067, 10.3390/rs14092067.
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URL: https://doi.org/10.3390/rs14092067
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Ricciardulli, L., Foltz, G.R., Manaster, A., and Meissner, T. (2022). Assessment of Saildrone Extreme Wind Measurements in Hurricane Sam Using MW Satellite Sensors, Remote Sensing, 14(12), 2726, 10.3390/rs14122726. Journal Article »
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Title: Assessment of Saildrone Extreme Wind Measurements in Hurricane Sam Using MW Satellite Sensors
Type: Journal Article
Publication: Remote Sensing
Author(s): Ricciardulli, L., Foltz, G.R., Manaster, A., and Meissner, T.
Year: 2022
Formatted Citation: Ricciardulli, L., Foltz, G.R., Manaster, A., and Meissner, T., 2022: Assessment of Saildrone Extreme Wind Measurements in Hurricane Sam Using MW Satellite Sensors, Remote Sensing, 14(12), 2726, 10.3390/rs14122726.
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URL: https://doi.org/10.3390/rs14122726
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Ahern, K., Hart, R.E., and Bourassa, M.A. (2021). Asymmetric Hurricane Boundary Layer Structure during Storm Decay. Part I: Formation of Descending Inflow, Monthly Weather Review, 149(11), 3851-3874, 10.1175/Mwr-D-21-0030.1. Journal Article »
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Title: Asymmetric Hurricane Boundary Layer Structure during Storm Decay. Part I: Formation of Descending Inflow
Type: Journal Article
Publication: Monthly Weather Review
Author(s): Ahern, K., Hart, R.E., and Bourassa, M.A.
Year: 2021
Formatted Citation: Ahern, K., Hart, R.E., and Bourassa, M.A., 2021: Asymmetric Hurricane Boundary Layer Structure during Storm Decay. Part I: Formation of Descending Inflow, Monthly Weather Review, 149(11), 3851-3874, 10.1175/Mwr-D-21-0030.1.
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URL: https://doi.org/10.1175/Mwr-D-21-0030.1
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Bentamy, A., Grodsky, S. A., Cambon, G., Tandeo, P., Capet, X., Roy, C., and Grouazel, A. (2021). Twenty-Seven Years of Scatterometer Surface Wind Analysis over Eastern Boundary Upwelling Systems, Remote Sensing, 12(1), 10.3390/rs13050940. Journal Article »
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Title: Twenty-Seven Years of Scatterometer Surface Wind Analysis over Eastern Boundary Upwelling Systems
Type: Journal Article
Publication: Remote Sensing
Author(s): Bentamy, A., Grodsky, S. A., Cambon, G., Tandeo, P., Capet, X., Roy, C., and Grouazel, A.
Year: 2021
Formatted Citation: Bentamy, A., Grodsky, S. A., Cambon, G., Tandeo, P., Capet, X., Roy, C., and Grouazel, A., 2021: Twenty-Seven Years of Scatterometer Surface Wind Analysis over Eastern Boundary Upwelling Systems, Remote Sensing, 12(1), 10.3390/rs13050940.
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URL: https://doi.org/10.3390/rs13050940
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Capotondi, A. and Ricciardulli, L. (2021). The Influence of Pacific Winds on ENSO Diversity, Scientific Reports, 11(1), 18672, 10.1038/s41598-021-97963-4. Journal Article »
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Title: The Influence of Pacific Winds on ENSO Diversity
Type: Journal Article
Publication: Scientific Reports
Author(s): Capotondi, A. and Ricciardulli, L.
Year: 2021
Formatted Citation: Capotondi, A. and Ricciardulli, L., 2021: The Influence of Pacific Winds on ENSO Diversity, Scientific Reports, 11(1), 18672, 10.1038/s41598-021-97963-4.
Abstract: The differences in ENSO sea surface temperature (SST) spatial patterns, whether centered in the Eastern Pacific (EP), Central Pacific (CP) or in the eastern-central equatorial region ("canonical") have been associated to differences in atmospheric teleconnections and global impacts. However, predicting different types of ENSO events has proved challenging, highlighting the need for a deeper understanding of their predictability. Given the key role played by wind variations in the development and evolution of ENSO events, this study examines the relationship between the leading modes of Pacific surface wind speed variability and ENSO diversity using three different state-of-the-art wind products, including satellite observations and atmospheric reanalyses. Although previous studies have associated different ENSO precursors to either EP or CP events, our results indicate that the most prominent of those ENSO precursors are primarily related to canonical and CP events, and show little correlation with EP events. The latter are associated with tropical Pacific conditions favoring equatorial westerly wind and precipitation anomalies that extend all the way to the eastern Pacific. Results over the entire twentieth century period versus those during the satellite era also suggest that the influences from the Southern Hemisphere may be more robust than those from the Northern Hemisphere.
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URL: https://doi.org/10.1038/s41598-021-97963-4
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Colosi, L.V., Villas Bôas, A.B., and Gille, S.T. (2021). The Seasonal Cycle of Significant Wave Height in the Ocean: Local Versus Remote Forcing, Journal of Geophysical Research: Oceans, 126(8), e2021JC017198, 10.1029/2021JC017198. Journal Article »
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Title: The Seasonal Cycle of Significant Wave Height in the Ocean: Local Versus Remote Forcing
Type: Journal Article
Publication: Journal of Geophysical Research: Oceans
Author(s): Colosi, L.V., Villas Bôas, A.B., and Gille, S.T.
Year: 2021
Formatted Citation: Colosi, L.V., Villas Bôas, A.B., and Gille, S.T., 2021: The Seasonal Cycle of Significant Wave Height in the Ocean: Local Versus Remote Forcing, Journal of Geophysical Research: Oceans, 126(8), e2021JC017198, 10.1029/2021JC017198.
Abstract: Significant wave height (SWH) stems from a combination of locally generated “wind-sea” and remotely generated “swell” waves. In the Northern and Southern Hemispheres, wave heights typically undergo a sinusoidal annual cycle, with larger SWH in winter in response to seasonal changes in high-latitude storm patterns that generate equatorward propagating swell. However, some locations deviate from this hemispheric-scale seasonal pattern in SWH. For example, in the California coastal region, local wind events occur in boreal spring and summer, leading to a wind speed (WSP) annual cycle with a distinct maximum in boreal spring and a corresponding local response in SWH. Here ocean regions with a WSP annual cycle reaching a maximum in late spring, summer, or early fall are designated as seasonal wind anomaly regions (SWARs). Intra-annual variability of surface gravity waves is analyzed globally using two decades of satellite-derived SWH and WSP data. The phasing of the WSP annual cycle is used as a metric to identify SWARs. Global maps of probability of swell based on wave age confirm that during the spring and summer months, locally forced waves are statistically more likely in SWARs than in surrounding regions. The magnitude of the deviation in the SWH annual cycle is determined by the exposure to swell and characteristics of the wave field within the region. Local winds have a more identifiable impact on Northern Hemisphere SWARs than on Southern Hemisphere SWARs due to the larger seasonality of Northern Hemisphere winds.
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URL: https://doi.org/10.1029/2021JC017198
Other URLs:
Dunn, R.J.H., Aldred, F., Gobron, N., Miller, J.B., Willett, K.M., Ades, M., Adler, R., Allan, R.P., Allan, R., Anderson, J., Argüez, A., Arosio, C., Augustine, J.A., Azorin-Molina, C., Barichivich, J., Beck, H.E., Becker, A., Bellouin, N., Benedetti, A., Berry, D.I., Blenkinsop, S., Bock, O., Bodin, X., Bosilovich, M.G., Boucher, O., Buehler, S.A., Calmettes, B., Carrea, L., Castia, L., Christiansen, H.H., Christy, J.R., Chung, E.-S., Coldewey-Egbers, M., Cooper, O.R., Cornes, R.C., Covey, C., Cretaux, J.-F., Crotwell, M., Davis, S.M., de Jeu, R.A.M., Degenstein, D., Delaloye, R., Di Girolamo, L., Donat, M.G., Dorigo, W.A., Durre, I., Dutton, G.S., Duveiller, G., Elkins, J.W., Fioletov, V.E., Flemming, J., Foster, M.J., Frith, S.M., Froidevaux, L., Garforth, J., Gentry, M., Gupta, S.K., Hahn, S., Haimberger, L., Hall, B.D., Harris, I., Hemming, D.L., Hirschi, M., Ho, S.-pen(B.), Hrbacek, F., Hubert, D., Hurst, D.F., Inness, A., Isaksen, K., John, V.O., Jones, P.D., Junod, R., Kaiser, J.W., Kaufmann, V., Kellerer-Pirklbauer, A., Kent, E.C., Kidd, R., Kim, H., Kipling, Z., Koppa, A., Kraemer, B.M., Kratz, D.P., Lan, X., Lantz, K.O., Lavers, D., Loeb, N.G., Loyola, D., Madelon, R., Mayer, M., McCabe, M.F., McVicar, T.R., Mears, C.A., Merchant, C.J., Miralles, D.G., Moesinger, L., Montzka, S.A., Morice, C., Mösinger, L., Mühle, J., Nicolas, J.P., Noetzli, J., Noll, B., O'Keefe, J., Osborn, T.J., Park, T., Pasik, A.J., Pellet, C., Pelto, M.S., Perkins-Kirkpatrick, S.E., Petron, G., Phillips, C., Po-Chedley, S., Polvani, L., Preimesberger, W., Rains, D.G., Randel, W.J., Rayner, N.A., Rémy, S., Ricciardulli, L., Richardson, A.D., Robinson, D.A., Rodell, M., Rodríguez-Fernández, N.J., Rosenlof, K.H., Roth, C., Rozanov, A., Rutishäuser, T., Sánchez-Lugo, A., Sawaengphokhai, P., Scanlon, T., Schenzinger, V., Schlegel, R.W., Sharma, S., Shi, L., Simmons, A.J., Siso, C., Smith, S.L., Soden, B.J., Sofieva, V., Sparks, T.H., Stackhouse, P.W., Steinbrecht, W., Stengel, M., Streletskiy, D.A., Sun-Mack, S., Tans, P., Thackeray, S.J., Thibert, E., Tokuda, D., Tourpali, K., Tye, M.R., van der A, R., van der Schalie, R., van der Schrier, G., van der Vliet, M., van der Werf, G.R., Vance, A., Vernier, J.-P., Vimont, I.J., Vömel, H., Vose, R.S., Wang, R., Weber, M., Wiese, D., Wilber, A.C., Wild, J.D., Wong, T., Woolway, R.I., Zhou, X., Yin, X., Zhao, G., Zhao, L., Ziemke, J.R., Ziese, M., and Zotta, R.M. (2021). Global Climate, Bulletin of the American Meteorological Society, 102(8), S11-S142, 10.1175/BAMS-D-21-0098.1. Journal Article »
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Title: Global Climate
Type: Journal Article
Publication: Bulletin of the American Meteorological Society
Author(s): Dunn, R.J.H., Aldred, F., Gobron, N., Miller, J.B., Willett, K.M., Ades, M., Adler, R., Allan, R.P., Allan, R., Anderson, J., Argüez, A., Arosio, C., Augustine, J.A., Azorin-Molina, C., Barichivich, J., Beck, H.E., Becker, A., Bellouin, N., Benedetti, A., Berry, D.I., Blenkinsop, S., Bock, O., Bodin, X., Bosilovich, M.G., Boucher, O., Buehler, S.A., Calmettes, B., Carrea, L., Castia, L., Christiansen, H.H., Christy, J.R., Chung, E.-S., Coldewey-Egbers, M., Cooper, O.R., Cornes, R.C., Covey, C., Cretaux, J.-F., Crotwell, M., Davis, S.M., de Jeu, R.A.M., Degenstein, D., Delaloye, R., Di Girolamo, L., Donat, M.G., Dorigo, W.A., Durre, I., Dutton, G.S., Duveiller, G., Elkins, J.W., Fioletov, V.E., Flemming, J., Foster, M.J., Frith, S.M., Froidevaux, L., Garforth, J., Gentry, M., Gupta, S.K., Hahn, S., Haimberger, L., Hall, B.D., Harris, I., Hemming, D.L., Hirschi, M., Ho, S.-pen(B.), Hrbacek, F., Hubert, D., Hurst, D.F., Inness, A., Isaksen, K., John, V.O., Jones, P.D., Junod, R., Kaiser, J.W., Kaufmann, V., Kellerer-Pirklbauer, A., Kent, E.C., Kidd, R., Kim, H., Kipling, Z., Koppa, A., Kraemer, B.M., Kratz, D.P., Lan, X., Lantz, K.O., Lavers, D., Loeb, N.G., Loyola, D., Madelon, R., Mayer, M., McCabe, M.F., McVicar, T.R., Mears, C.A., Merchant, C.J., Miralles, D.G., Moesinger, L., Montzka, S.A., Morice, C., Mösinger, L., Mühle, J., Nicolas, J.P., Noetzli, J., Noll, B., O'Keefe, J., Osborn, T.J., Park, T., Pasik, A.J., Pellet, C., Pelto, M.S., Perkins-Kirkpatrick, S.E., Petron, G., Phillips, C., Po-Chedley, S., Polvani, L., Preimesberger, W., Rains, D.G., Randel, W.J., Rayner, N.A., Rémy, S., Ricciardulli, L., Richardson, A.D., Robinson, D.A., Rodell, M., Rodríguez-Fernández, N.J., Rosenlof, K.H., Roth, C., Rozanov, A., Rutishäuser, T., Sánchez-Lugo, A., Sawaengphokhai, P., Scanlon, T., Schenzinger, V., Schlegel, R.W., Sharma, S., Shi, L., Simmons, A.J., Siso, C., Smith, S.L., Soden, B.J., Sofieva, V., Sparks, T.H., Stackhouse, P.W., Steinbrecht, W., Stengel, M., Streletskiy, D.A., Sun-Mack, S., Tans, P., Thackeray, S.J., Thibert, E., Tokuda, D., Tourpali, K., Tye, M.R., van der A, R., van der Schalie, R., van der Schrier, G., van der Vliet, M., van der Werf, G.R., Vance, A., Vernier, J.-P., Vimont, I.J., Vömel, H., Vose, R.S., Wang, R., Weber, M., Wiese, D., Wilber, A.C., Wild, J.D., Wong, T., Woolway, R.I., Zhou, X., Yin, X., Zhao, G., Zhao, L., Ziemke, J.R., Ziese, M., and Zotta, R.M.
Year: 2021
Formatted Citation: Dunn, R.J.H., Aldred, F., Gobron, N., Miller, J.B., Willett, K.M., Ades, M., Adler, R., Allan, R.P., Allan, R., Anderson, J., Argüez, A., Arosio, C., Augustine, J.A., Azorin-Molina, C., Barichivich, J., Beck, H.E., Becker, A., Bellouin, N., Benedetti, A., Berry, D.I., Blenkinsop, S., Bock, O., Bodin, X., Bosilovich, M.G., Boucher, O., Buehler, S.A., Calmettes, B., Carrea, L., Castia, L., Christiansen, H.H., Christy, J.R., Chung, E.-S., Coldewey-Egbers, M., Cooper, O.R., Cornes, R.C., Covey, C., Cretaux, J.-F., Crotwell, M., Davis, S.M., de Jeu, R.A.M., Degenstein, D., Delaloye, R., Di Girolamo, L., Donat, M.G., Dorigo, W.A., Durre, I., Dutton, G.S., Duveiller, G., Elkins, J.W., Fioletov, V.E., Flemming, J., Foster, M.J., Frith, S.M., Froidevaux, L., Garforth, J., Gentry, M., Gupta, S.K., Hahn, S., Haimberger, L., Hall, B.D., Harris, I., Hemming, D.L., Hirschi, M., Ho, S.-pen(B.), Hrbacek, F., Hubert, D., Hurst, D.F., Inness, A., Isaksen, K., John, V.O., Jones, P.D., Junod, R., Kaiser, J.W., Kaufmann, V., Kellerer-Pirklbauer, A., Kent, E.C., Kidd, R., Kim, H., Kipling, Z., Koppa, A., Kraemer, B.M., Kratz, D.P., Lan, X., Lantz, K.O., Lavers, D., Loeb, N.G., Loyola, D., Madelon, R., Mayer, M., McCabe, M.F., McVicar, T.R., Mears, C.A., Merchant, C.J., Miralles, D.G., Moesinger, L., Montzka, S.A., Morice, C., Mösinger, L., Mühle, J., Nicolas, J.P., Noetzli, J., Noll, B., O'Keefe, J., Osborn, T.J., Park, T., Pasik, A.J., Pellet, C., Pelto, M.S., Perkins-Kirkpatrick, S.E., Petron, G., Phillips, C., Po-Chedley, S., Polvani, L., Preimesberger, W., Rains, D.G., Randel, W.J., Rayner, N.A., Rémy, S., Ricciardulli, L., Richardson, A.D., Robinson, D.A., Rodell, M., Rodríguez-Fernández, N.J., Rosenlof, K.H., Roth, C., Rozanov, A., Rutishäuser, T., Sánchez-Lugo, A., Sawaengphokhai, P., Scanlon, T., Schenzinger, V., Schlegel, R.W., Sharma, S., Shi, L., Simmons, A.J., Siso, C., Smith, S.L., Soden, B.J., Sofieva, V., Sparks, T.H., Stackhouse, P.W., Steinbrecht, W., Stengel, M., Streletskiy, D.A., Sun-Mack, S., Tans, P., Thackeray, S.J., Thibert, E., Tokuda, D., Tourpali, K., Tye, M.R., van der A, R., van der Schalie, R., van der Schrier, G., van der Vliet, M., van der Werf, G.R., Vance, A., Vernier, J.-P., Vimont, I.J., Vömel, H., Vose, R.S., Wang, R., Weber, M., Wiese, D., Wilber, A.C., Wild, J.D., Wong, T., Woolway, R.I., Zhou, X., Yin, X., Zhao, G., Zhao, L., Ziemke, J.R., Ziese, M., and Zotta, R.M., 2021: Global Climate, Bulletin of the American Meteorological Society, 102(8), S11-S142, 10.1175/BAMS-D-21-0098.1.
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URL: https://doi.org/10.1175/BAMS-D-21-0098.1
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Hristova-Veleva, S., Haddad, Z., Chau, A., Stiles, B.W., Turk, F.J., Li, P.P., Knosp, B., Vu, Q., Shen, T.-P., Lambrigtsen, B., Seo, E.-K., and Su, H. (2021). Impact of Microphysical Parameterizations on Simulated Hurricanes: Using Multiparameter Satellite Data to Determine the Particle Size Distributions that Produce Most Realistic Storms, Atmosphere, 12(2), 154, 10.3390/atmos12020154. Journal Article »
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Title: Impact of Microphysical Parameterizations on Simulated Hurricanes: Using Multiparameter Satellite Data to Determine the Particle Size Distributions that Produce Most Realistic Storms
Type: Journal Article
Publication: Atmosphere
Author(s): Hristova-Veleva, S., Haddad, Z., Chau, A., Stiles, B.W., Turk, F.J., Li, P.P., Knosp, B., Vu, Q., Shen, T.-P., Lambrigtsen, B., Seo, E.-K., and Su, H.
Year: 2021
Formatted Citation: Hristova-Veleva, S., Haddad, Z., Chau, A., Stiles, B.W., Turk, F.J., Li, P.P., Knosp, B., Vu, Q., Shen, T.-P., Lambrigtsen, B., Seo, E.-K., and Su, H., 2021: Impact of Microphysical Parameterizations on Simulated Hurricanes: Using Multiparameter Satellite Data to Determine the Particle Size Distributions that Produce Most Realistic Storms, Atmosphere, 12(2), 154, 10.3390/atmos12020154.
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URL: https://doi.org/10.3390/atmos12020154
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Knaff, J.A., Sampson, C.R., Kucas, M.E., Slocum, C.J., Brennan, M.J., Meissner, T., Ricciardulli, L., Mouche, A., Reul, N., Morris, M., Chirokova, G., and Caroff, P. (2021). Estimating Tropical Cyclone Surface Winds: Current Status, Emerging Technologies, Historical Evolution, and a Look to the Future, Tropical Cyclone Research and Review, 10(3), 125-150, 10.1016/j.tcrr.2021.09.002. Journal Article »
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Title: Estimating Tropical Cyclone Surface Winds: Current Status, Emerging Technologies, Historical Evolution, and a Look to the Future
Type: Journal Article
Publication: Tropical Cyclone Research and Review
Author(s): Knaff, J.A., Sampson, C.R., Kucas, M.E., Slocum, C.J., Brennan, M.J., Meissner, T., Ricciardulli, L., Mouche, A., Reul, N., Morris, M., Chirokova, G., and Caroff, P.
Year: 2021
Formatted Citation: Knaff, J.A., Sampson, C.R., Kucas, M.E., Slocum, C.J., Brennan, M.J., Meissner, T., Ricciardulli, L., Mouche, A., Reul, N., Morris, M., Chirokova, G., and Caroff, P., 2021: Estimating Tropical Cyclone Surface Winds: Current Status, Emerging Technologies, Historical Evolution, and a Look to the Future, Tropical Cyclone Research and Review, 10(3), 125-150, 10.1016/j.tcrr.2021.09.002.
Abstract: This article provides a review of tropical cyclone (TC) surface wind estimation from an operational forecasting perspective. First, we provide a summary of operational forecast center practices and historical databases. Next, we discuss current and emerging objective estimates of TC surface winds, including algorithms, archive datasets, and individual algorithm strengths and weaknesses as applied to operational TC surface wind forecast parameters. Our review leads to recommendations about required surface coverage - an area covering at least 1100 km from center of TC at a 2-km resolution in the inner-core, and at a frequency of at least once every 6 h. This is enough coverage to support a complete analysis of the TC surface wind field from center to the extent of the 34-kt (17 m s-1) winds at 6-h intervals. We also suggest future designs of TC surface wind capabilities include funding to ensure near real-time data delivery to operators so that operational evaluation and use are feasible within proposed budgets. Finally, we suggest that users of archived operational wind radii datasets contact operational organizations to ensure these datasets are appropriate for their needs as the datasets vary in quality through time and space, even from a single organisation.
Keywords: Tropical cyclone; Surface wind; Satellite; Best track; Operations
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URL: https://doi.org/10.1016/j.tcrr.2021.09.002
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Manaster, A., Ricciardulli, L., and Meissner, T. (2021). Tropical Cyclone Winds from WindSat, AMSR2, and SMAP: Comparison with the HWRF Model, Remote Sensing, 13(12), 2347, 10.3390/rs13122347. Journal Article »
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Title: Tropical Cyclone Winds from WindSat, AMSR2, and SMAP: Comparison with the HWRF Model
Type: Journal Article
Publication: Remote Sensing
Author(s): Manaster, A., Ricciardulli, L., and Meissner, T.
Year: 2021
Formatted Citation: Manaster, A., Ricciardulli, L., and Meissner, T., 2021: Tropical Cyclone Winds from WindSat, AMSR2, and SMAP: Comparison with the HWRF Model, Remote Sensing, 13(12), 2347, 10.3390/rs13122347.
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URL: https://doi.org/10.3390/rs13122347
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Meissner, T., Ricciardulli, L., and Manaster, A. (2021). Tropical Cyclone Wind Speeds from WindSat, AMSR and SMAP: Algorithm Development and Testing, Remote Sensing, 13(9), 1641, 10.3390/rs13091641. Journal Article »
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Title: Tropical Cyclone Wind Speeds from WindSat, AMSR and SMAP: Algorithm Development and Testing
Type: Journal Article
Publication: Remote Sensing
Author(s): Meissner, T., Ricciardulli, L., and Manaster, A.
Year: 2021
Formatted Citation: Meissner, T., Ricciardulli, L., and Manaster, A., 2021: Tropical Cyclone Wind Speeds from WindSat, AMSR and SMAP: Algorithm Development and Testing, Remote Sensing, 13(9), 1641, 10.3390/rs13091641.
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URL: https://doi.org/10.3390/rs13091641
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Polverari F., Portabella M., Lin W., Sapp J. W., Stoffelen A., Jelenak Z. and Chang P.S. (2021). On High and Extreme Wind Calibration Using ASCAT, IEEE Transactions on Geoscience and Remote Sensing, 10.1109/TGRS.2021.3079898. Journal Article »
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Title: On High and Extreme Wind Calibration Using ASCAT
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Polverari F., Portabella M., Lin W., Sapp J. W., Stoffelen A., Jelenak Z. and Chang P.S.
Year: 2021
Formatted Citation: Polverari F., Portabella M., Lin W., Sapp J. W., Stoffelen A., Jelenak Z. and Chang P.S., 2021: On High and Extreme Wind Calibration Using ASCAT, IEEE Transactions on Geoscience and Remote Sensing, 10.1109/TGRS.2021.3079898.
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Mission: |ASCAT|
URL: https://doi.org/10.1109/TGRS.2021.3079898
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Polverari, F., Wineteer, A., Rodriguez, E., Perkovic-Martin, D., Siqueira, P., Farrar, J.T., Adam, J.M., and Edson, J. (2021). Towards a Characterization of the Ka-band Ocean Surface Backscattering Mechanisms, Proc. of International Geoscience and Remote Sensing Symposium, 10.1109/IGARSS47720.2021.9554576. Journal Article »
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Title: Towards a Characterization of the Ka-band Ocean Surface Backscattering Mechanisms
Type: Journal Article
Publication: Proc. of International Geoscience and Remote Sensing Symposium
Author(s): Polverari, F., Wineteer, A., Rodriguez, E., Perkovic-Martin, D., Siqueira, P., Farrar, J.T., Adam, J.M., and Edson, J.
Year: 2021
Formatted Citation: Polverari, F., Wineteer, A., Rodriguez, E., Perkovic-Martin, D., Siqueira, P., Farrar, J.T., Adam, J.M., and Edson, J., 2021: Towards a Characterization of the Ka-band Ocean Surface Backscattering Mechanisms, Proc. of International Geoscience and Remote Sensing Symposium, 10.1109/IGARSS47720.2021.9554576.
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URL: https://doi.org/10.1109/IGARSS47720.2021.9554576
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Ricciardulli, L. and Manaster, A. (2021). Intercalibration of ASCAT Scatterometer Winds from MetOp-A, -B, and -C, for a Stable Climate Data Record, Remote Sensing, 13, 3678, 10.3390/rs13183678. Journal Article »
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Title: Intercalibration of ASCAT Scatterometer Winds from MetOp-A, -B, and -C, for a Stable Climate Data Record
Type: Journal Article
Publication: Remote Sensing
Author(s): Ricciardulli, L. and Manaster, A.
Year: 2021
Formatted Citation: Ricciardulli, L. and Manaster, A., 2021: Intercalibration of ASCAT Scatterometer Winds from MetOp-A, -B, and -C, for a Stable Climate Data Record, Remote Sensing, 13, 3678, 10.3390/rs13183678.
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URL: https://doi.org/10.3390/rs13183678
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Ricciardulli, L., Mears, C., Manaster, A., and Meissner, T. (2021). Assessment of CYGNSS Wind Speed Retrievals in Tropical Cyclones, Remote Sensing, 13(24), 5110, 10.3390/rs13245110. Journal Article »
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Title: Assessment of CYGNSS Wind Speed Retrievals in Tropical Cyclones
Type: Journal Article
Publication: Remote Sensing
Author(s): Ricciardulli, L., Mears, C., Manaster, A., and Meissner, T.
Year: 2021
Formatted Citation: Ricciardulli, L., Mears, C., Manaster, A., and Meissner, T., 2021: Assessment of CYGNSS Wind Speed Retrievals in Tropical Cyclones, Remote Sensing, 13(24), 5110, 10.3390/rs13245110.
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URL: https://doi.org/10.3390/rs13245110
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Turk, F.J., Hristova-Veleva, S. and Giglio, D. (2021). Examination of the Daily Cycle Wind Vector Modes of Variability from the Constellation of Microwave Scatterometers and Radiometers, Remote Sensing, 13, 141, 10.3390/rs13010141.
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Title: Examination of the Daily Cycle Wind Vector Modes of Variability from the Constellation of Microwave Scatterometers and Radiometers
Type: Journal Article
Publication: Remote Sensing
Author(s): Turk, F.J., Hristova-Veleva, S. and Giglio, D.
Year: 2021
Formatted Citation: Turk, F.J., Hristova-Veleva, S. and Giglio, D., 2021: Examination of the Daily Cycle Wind Vector Modes of Variability from the Constellation of Microwave Scatterometers and Radiometers, Remote Sensing, 13, 141, 10.3390/rs13010141.
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Wright, E.E., Bourassa, M.A., Stoffelen, A., and Bidlot, J.-R. (2021). Characterizing Buoy Wind Speed Error in High Winds and Varying Sea State with ASCAT and ERA5, Remote Sensing, 13(22), 4558, 10.3390/rs13224558. Journal Article »
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Title: Characterizing Buoy Wind Speed Error in High Winds and Varying Sea State with ASCAT and ERA5
Type: Journal Article
Publication: Remote Sensing
Author(s): Wright, E.E., Bourassa, M.A., Stoffelen, A., and Bidlot, J.-R.
Year: 2021
Formatted Citation: Wright, E.E., Bourassa, M.A., Stoffelen, A., and Bidlot, J.-R., 2021: Characterizing Buoy Wind Speed Error in High Winds and Varying Sea State with ASCAT and ERA5, Remote Sensing, 13(22), 4558, 10.3390/rs13224558.
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URL: https://doi.org/10.3390/rs13224558
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Yu, L. (2021). Emerging Pattern of Wind Change over the Eurasian Marginal Seas Revealed by Three Decades of Satellite Ocean-Surface Wind Observations, Remote Sensing, 13(9), 10.3390/rs13091707. Journal Article »
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Title: Emerging Pattern of Wind Change over the Eurasian Marginal Seas Revealed by Three Decades of Satellite Ocean-Surface Wind Observations
Type: Journal Article
Publication: Remote Sensing
Author(s): Yu, L.
Year: 2021
Formatted Citation: Yu, L., 2021: Emerging Pattern of Wind Change over the Eurasian Marginal Seas Revealed by Three Decades of Satellite Ocean-Surface Wind Observations, Remote Sensing, 13(9), 10.3390/rs13091707.
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Mission: |SeaWinds|
URL: https://doi.org/10.3390/rs13091707
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Beal, L.M., Vialard, J., Roxy, M.K., Li, J., Andres, M., Annamalai, H., Feng, M., Han, W., Hood, R., Lee, T., Lengaigne, M., Lumpkin, R., Masumoto, Y., McPhaden, M.J., Ravichandran, M., Shinoda, T., Sloyan, B.M., Strutton, P.G., Subramanian, A.C., Tozuka, T., Ummenhofer, C.C., Unnikrishnan, A.S., Wiggert, J., Yu, L., Cheng, L., Desbruyères, D.G., Parvathi, and V. (2020). A Road Map to IndOOS-2: Better Observations of the Rapidly Warming Indian Ocean, Bulletin of the American Meteorological Society, 101(11), E1891–E1913, 10.1175/BAMS-D-19-0209.1. Journal Article »
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Title: A Road Map to IndOOS-2: Better Observations of the Rapidly Warming Indian Ocean
Type: Journal Article
Publication: Bulletin of the American Meteorological Society
Author(s): Beal, L.M., Vialard, J., Roxy, M.K., Li, J., Andres, M., Annamalai, H., Feng, M., Han, W., Hood, R., Lee, T., Lengaigne, M., Lumpkin, R., Masumoto, Y., McPhaden, M.J., Ravichandran, M., Shinoda, T., Sloyan, B.M., Strutton, P.G., Subramanian, A.C., Tozuka, T., Ummenhofer, C.C., Unnikrishnan, A.S., Wiggert, J., Yu, L., Cheng, L., Desbruyères, D.G., Parvathi, and V.
Year: 2020
Formatted Citation: Beal, L.M., Vialard, J., Roxy, M.K., Li, J., Andres, M., Annamalai, H., Feng, M., Han, W., Hood, R., Lee, T., Lengaigne, M., Lumpkin, R., Masumoto, Y., McPhaden, M.J., Ravichandran, M., Shinoda, T., Sloyan, B.M., Strutton, P.G., Subramanian, A.C., Tozuka, T., Ummenhofer, C.C., Unnikrishnan, A.S., Wiggert, J., Yu, L., Cheng, L., Desbruyères, D.G., Parvathi, and V., 2020: A Road Map to IndOOS-2: Better Observations of the Rapidly Warming Indian Ocean, Bulletin of the American Meteorological Society, 101(11), E1891–E1913, 10.1175/BAMS-D-19-0209.1.
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URL: https://doi.org/10.1175/BAMS-D-19-0209.1
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Dunn, R.J.H., Stanitski, D.M., Gobron, N., Willett, K.M., Ades, M., Adler, R., Allan, R., Allan, R.P., Anderson, J., Argüez, A., Arosio, C., Augustine, J.A., Azorin-Molina, C., Barichivich, J., Barnes, J., Beck, H.E., Becker, A., Bellouin, N., Benedetti, A., Berry, D.I., Blenkinsop, S., Bock, O., Bosilovich, M.G., Boucher, O., Buehler, S.A., Carrea, L., Christiansen, H.H., Chouza, F., Christy, J.R., Chung, E.-S., Coldewey-Egbers, M., Compo, G.P., Cooper, O.R., Covey, C., Crotwell, A., Davis, S.M., de Eyto, E., de Jeu, R.A.M., VanderSat, B.V., DeGasperi, C.L., Degenstein, D., Di Girolamo, L., Dokulil, M.T., Donat, M.G., Dorigo, W.A., Durre, I., Dutton, G.S., Duveiller, G., Elkins, J.W., Fioletov, V.E., Flemming, J., Foster, M.J., Frey, R.A., Frith, S.M., Froidevaux, L., Garforth, J., Gupta, S.K., Haimberger, L., Hall, B.D., Harris, I., Heidinger, A.K., Hemming, D.L., Ho, S.-peng(B.), Hubert, D., Hurst, D.F., Hüser, I., Inness, A., Isaksen, K., John, V., Jones, P.D., Kaiser, J.W., Kelly, S., Khaykin, S., Kidd, R., Kim, H., Kipling, Z., Kraemer, B.M., Kratz, D.P., La Fuente, R.S., Lan, X., Lantz, K.O., Leblanc, T., Li, B., Loeb, N.G., Long, C.S., Loyola, D., Marszelewski, W., Martens, B., May, L., Mayer, M., McCabe, M.F., McVicar, T.R., Mears, C.A., Menzel, W.P., Merchant, C.J., Miller, B.R., Miralles, D.G., Montzka, S.A., Morice, C., Muhle, J., Myneni, R., Nicolas, J.P., Noetzli, J., Osborn, T.J., Park, T., Pasik, A., Paterson, A.M., Pelto, M.S., Perkins-Kirkpatrick, S., Pétron, G., Phillips, C., Pinty, B., Po-Chedley, S., Polvani, L., Preimesberger, W., Pulkkanen, M., Randel, W.J., Rémy, S., Ricciardulli, L., Richardson, A.D., Rieger, L., Robinson, D.A., Rodell, M., Rosenlof, K.H., Roth, C., Rozanov, A., Rusak, J.A., Rusanovskaya, O., Rutishäuser, T., Sánchez-Lugo, A., Sawaengphokhai, P., Scanlon, T., Schenzinger, V., Schladow, S.G., Schlegel, R.W., Schmid, M., Selkirk, H.B., Sharma, S., Shi, L., Shimaraeva, S.V., Silow, E.A., Simmons, A.J., Smith, C.A., Smith, S.L., Soden, B.J., Sofieva, V., Sparks, T.H., Stackhouse, P.W., Steinbrecht, W., Streletskiy, D.A., Taha, G., Telg, H., Thackeray, S.J., Timofeyev, M.A., Tourpali, K., Tye, M.R., van der A, R.J., van der Schalie, R., van der Schrier, G., van der Werf, G.R., Verburg, P., Vernier, J.-P., Vömel, H., Vose, R.S., Wang, R., Watanabe, S.G., Weber, M., Weyhenmeyer, G.A., Wiese, D., Wilber, A.C., Wild, J.D., Wong, T., Woolway, R.I., Yin, X., Zhao, L., Zhao, G., Zhou, X., Ziemke, J.R., and Ziese, M. (2020). Global Climate, Bulletin of the American Meteorological Society, 101(8), S9-S128, 10.1175/Bams-D-20-0104.1. Journal Article »
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Title: Global Climate
Type: Journal Article
Publication: Bulletin of the American Meteorological Society
Author(s): Dunn, R.J.H., Stanitski, D.M., Gobron, N., Willett, K.M., Ades, M., Adler, R., Allan, R., Allan, R.P., Anderson, J., Argüez, A., Arosio, C., Augustine, J.A., Azorin-Molina, C., Barichivich, J., Barnes, J., Beck, H.E., Becker, A., Bellouin, N., Benedetti, A., Berry, D.I., Blenkinsop, S., Bock, O., Bosilovich, M.G., Boucher, O., Buehler, S.A., Carrea, L., Christiansen, H.H., Chouza, F., Christy, J.R., Chung, E.-S., Coldewey-Egbers, M., Compo, G.P., Cooper, O.R., Covey, C., Crotwell, A., Davis, S.M., de Eyto, E., de Jeu, R.A.M., VanderSat, B.V., DeGasperi, C.L., Degenstein, D., Di Girolamo, L., Dokulil, M.T., Donat, M.G., Dorigo, W.A., Durre, I., Dutton, G.S., Duveiller, G., Elkins, J.W., Fioletov, V.E., Flemming, J., Foster, M.J., Frey, R.A., Frith, S.M., Froidevaux, L., Garforth, J., Gupta, S.K., Haimberger, L., Hall, B.D., Harris, I., Heidinger, A.K., Hemming, D.L., Ho, S.-peng(B.), Hubert, D., Hurst, D.F., Hüser, I., Inness, A., Isaksen, K., John, V., Jones, P.D., Kaiser, J.W., Kelly, S., Khaykin, S., Kidd, R., Kim, H., Kipling, Z., Kraemer, B.M., Kratz, D.P., La Fuente, R.S., Lan, X., Lantz, K.O., Leblanc, T., Li, B., Loeb, N.G., Long, C.S., Loyola, D., Marszelewski, W., Martens, B., May, L., Mayer, M., McCabe, M.F., McVicar, T.R., Mears, C.A., Menzel, W.P., Merchant, C.J., Miller, B.R., Miralles, D.G., Montzka, S.A., Morice, C., Muhle, J., Myneni, R., Nicolas, J.P., Noetzli, J., Osborn, T.J., Park, T., Pasik, A., Paterson, A.M., Pelto, M.S., Perkins-Kirkpatrick, S., Pétron, G., Phillips, C., Pinty, B., Po-Chedley, S., Polvani, L., Preimesberger, W., Pulkkanen, M., Randel, W.J., Rémy, S., Ricciardulli, L., Richardson, A.D., Rieger, L., Robinson, D.A., Rodell, M., Rosenlof, K.H., Roth, C., Rozanov, A., Rusak, J.A., Rusanovskaya, O., Rutishäuser, T., Sánchez-Lugo, A., Sawaengphokhai, P., Scanlon, T., Schenzinger, V., Schladow, S.G., Schlegel, R.W., Schmid, M., Selkirk, H.B., Sharma, S., Shi, L., Shimaraeva, S.V., Silow, E.A., Simmons, A.J., Smith, C.A., Smith, S.L., Soden, B.J., Sofieva, V., Sparks, T.H., Stackhouse, P.W., Steinbrecht, W., Streletskiy, D.A., Taha, G., Telg, H., Thackeray, S.J., Timofeyev, M.A., Tourpali, K., Tye, M.R., van der A, R.J., van der Schalie, R., van der Schrier, G., van der Werf, G.R., Verburg, P., Vernier, J.-P., Vömel, H., Vose, R.S., Wang, R., Watanabe, S.G., Weber, M., Weyhenmeyer, G.A., Wiese, D., Wilber, A.C., Wild, J.D., Wong, T., Woolway, R.I., Yin, X., Zhao, L., Zhao, G., Zhou, X., Ziemke, J.R., and Ziese, M.
Year: 2020
Formatted Citation: Dunn, R.J.H., Stanitski, D.M., Gobron, N., Willett, K.M., Ades, M., Adler, R., Allan, R., Allan, R.P., Anderson, J., Argüez, A., Arosio, C., Augustine, J.A., Azorin-Molina, C., Barichivich, J., Barnes, J., Beck, H.E., Becker, A., Bellouin, N., Benedetti, A., Berry, D.I., Blenkinsop, S., Bock, O., Bosilovich, M.G., Boucher, O., Buehler, S.A., Carrea, L., Christiansen, H.H., Chouza, F., Christy, J.R., Chung, E.-S., Coldewey-Egbers, M., Compo, G.P., Cooper, O.R., Covey, C., Crotwell, A., Davis, S.M., de Eyto, E., de Jeu, R.A.M., VanderSat, B.V., DeGasperi, C.L., Degenstein, D., Di Girolamo, L., Dokulil, M.T., Donat, M.G., Dorigo, W.A., Durre, I., Dutton, G.S., Duveiller, G., Elkins, J.W., Fioletov, V.E., Flemming, J., Foster, M.J., Frey, R.A., Frith, S.M., Froidevaux, L., Garforth, J., Gupta, S.K., Haimberger, L., Hall, B.D., Harris, I., Heidinger, A.K., Hemming, D.L., Ho, S.-peng(B.), Hubert, D., Hurst, D.F., Hüser, I., Inness, A., Isaksen, K., John, V., Jones, P.D., Kaiser, J.W., Kelly, S., Khaykin, S., Kidd, R., Kim, H., Kipling, Z., Kraemer, B.M., Kratz, D.P., La Fuente, R.S., Lan, X., Lantz, K.O., Leblanc, T., Li, B., Loeb, N.G., Long, C.S., Loyola, D., Marszelewski, W., Martens, B., May, L., Mayer, M., McCabe, M.F., McVicar, T.R., Mears, C.A., Menzel, W.P., Merchant, C.J., Miller, B.R., Miralles, D.G., Montzka, S.A., Morice, C., Muhle, J., Myneni, R., Nicolas, J.P., Noetzli, J., Osborn, T.J., Park, T., Pasik, A., Paterson, A.M., Pelto, M.S., Perkins-Kirkpatrick, S., Pétron, G., Phillips, C., Pinty, B., Po-Chedley, S., Polvani, L., Preimesberger, W., Pulkkanen, M., Randel, W.J., Rémy, S., Ricciardulli, L., Richardson, A.D., Rieger, L., Robinson, D.A., Rodell, M., Rosenlof, K.H., Roth, C., Rozanov, A., Rusak, J.A., Rusanovskaya, O., Rutishäuser, T., Sánchez-Lugo, A., Sawaengphokhai, P., Scanlon, T., Schenzinger, V., Schladow, S.G., Schlegel, R.W., Schmid, M., Selkirk, H.B., Sharma, S., Shi, L., Shimaraeva, S.V., Silow, E.A., Simmons, A.J., Smith, C.A., Smith, S.L., Soden, B.J., Sofieva, V., Sparks, T.H., Stackhouse, P.W., Steinbrecht, W., Streletskiy, D.A., Taha, G., Telg, H., Thackeray, S.J., Timofeyev, M.A., Tourpali, K., Tye, M.R., van der A, R.J., van der Schalie, R., van der Schrier, G., van der Werf, G.R., Verburg, P., Vernier, J.-P., Vömel, H., Vose, R.S., Wang, R., Watanabe, S.G., Weber, M., Weyhenmeyer, G.A., Wiese, D., Wilber, A.C., Wild, J.D., Wong, T., Woolway, R.I., Yin, X., Zhao, L., Zhao, G., Zhou, X., Ziemke, J.R., and Ziese, M., 2020: Global Climate, Bulletin of the American Meteorological Society, 101(8), S9-S128, 10.1175/Bams-D-20-0104.1.
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URL: https://doi.org/10.1175/Bams-D-20-0104.1
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Hristova-Veleva, S.M., Li, P.P., Knosp, B., Vu, Q., Turk, F.J., Poulsen, W.L., Haddad, Z.,Lambrigtsen, B., Stiles, B.W., Shen, T.-P., Niamsuwan, N., Tanelli, S., Sy, O., Seo, E.-K., Su, H., Vane, D.G., Chao, Y., Callahan, P.S., Dunbar, R.S., Montgomery, M., Boothe, M., Tallapragada, V., Trahan, S., Wimmers, A.J., Holz, R., Reid, J.S., Marks, F., Vukicevic, T., Bhalachandran, S., Leighton, H., Gopalakrishnan, S., Navarro, A., and Tapiador, F.J. (2020). An Eye on the Storm: Integrating a Wealth of Data for Quickly Advancing the Physical Understanding and Forecasting of Tropical Cyclones, Bulletin of the American Meteorological Society, 101(10), E1718–E1742, 10.1175/BAMS-D-19-0020.1. Journal Article »
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Title: An Eye on the Storm: Integrating a Wealth of Data for Quickly Advancing the Physical Understanding and Forecasting of Tropical Cyclones
Type: Journal Article
Publication: Bulletin of the American Meteorological Society
Author(s): Hristova-Veleva, S.M., Li, P.P., Knosp, B., Vu, Q., Turk, F.J., Poulsen, W.L., Haddad, Z.,Lambrigtsen, B., Stiles, B.W., Shen, T.-P., Niamsuwan, N., Tanelli, S., Sy, O., Seo, E.-K., Su, H., Vane, D.G., Chao, Y., Callahan, P.S., Dunbar, R.S., Montgomery, M., Boothe, M., Tallapragada, V., Trahan, S., Wimmers, A.J., Holz, R., Reid, J.S., Marks, F., Vukicevic, T., Bhalachandran, S., Leighton, H., Gopalakrishnan, S., Navarro, A., and Tapiador, F.J.
Year: 2020
Formatted Citation: Hristova-Veleva, S.M., Li, P.P., Knosp, B., Vu, Q., Turk, F.J., Poulsen, W.L., Haddad, Z.,Lambrigtsen, B., Stiles, B.W., Shen, T.-P., Niamsuwan, N., Tanelli, S., Sy, O., Seo, E.-K., Su, H., Vane, D.G., Chao, Y., Callahan, P.S., Dunbar, R.S., Montgomery, M., Boothe, M., Tallapragada, V., Trahan, S., Wimmers, A.J., Holz, R., Reid, J.S., Marks, F., Vukicevic, T., Bhalachandran, S., Leighton, H., Gopalakrishnan, S., Navarro, A., and Tapiador, F.J., 2020: An Eye on the Storm: Integrating a Wealth of Data for Quickly Advancing the Physical Understanding and Forecasting of Tropical Cyclones, Bulletin of the American Meteorological Society, 101(10), E1718–E1742, 10.1175/BAMS-D-19-0020.1.
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URL: https://doi.org/10.1175/BAMS-D-19-0020.1
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Robertson, F.R., Roberts, J.B., Bosilovich, M.G., Bentamy, A., Clayson, C.A., Fennig, K., Schröder, M., Tomita, H., Compo, G.P., Gutenstein, M., Hersbach, H., Kobayashi, C., Ricciardulli, L., Sardeshmukh, P., and Slivinski, L.C. (2020). Uncertainties in Ocean Latent Heat Flux Variations over Recent Decades in Satellite-Based Estimates and Reduced Observation Reanalyses, Journal Of Climate, 33(19), 8415-8437, 10.1175/Jcli-D-19-0954.1. Journal Article »
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Title: Uncertainties in Ocean Latent Heat Flux Variations over Recent Decades in Satellite-Based Estimates and Reduced Observation Reanalyses
Type: Journal Article
Publication: Journal Of Climate
Author(s): Robertson, F.R., Roberts, J.B., Bosilovich, M.G., Bentamy, A., Clayson, C.A., Fennig, K., Schröder, M., Tomita, H., Compo, G.P., Gutenstein, M., Hersbach, H., Kobayashi, C., Ricciardulli, L., Sardeshmukh, P., and Slivinski, L.C.
Year: 2020
Formatted Citation: Robertson, F.R., Roberts, J.B., Bosilovich, M.G., Bentamy, A., Clayson, C.A., Fennig, K., Schröder, M., Tomita, H., Compo, G.P., Gutenstein, M., Hersbach, H., Kobayashi, C., Ricciardulli, L., Sardeshmukh, P., and Slivinski, L.C., 2020: Uncertainties in Ocean Latent Heat Flux Variations over Recent Decades in Satellite-Based Estimates and Reduced Observation Reanalyses, Journal Of Climate, 33(19), 8415-8437, 10.1175/Jcli-D-19-0954.1.
Abstract: Four state-of-the-art satellite-based estimates of ocean surface latent heat fluxes (LHFs) extending over three decades are analyzed, focusing on the interannual variability and trends of near-global averages and regional patterns. Detailed intercomparisons are made with other datasets including 1) reduced observation reanalyses (RedObs) whose exclusion of satellite data renders them an important independent diagnostic tool; 2) a moisture budget residual LHF estimate using reanalysis moisture transport, atmospheric storage, and satellite precipitation; 3) the ECMWF Reanalysis 5 (ERA5); 4) Remote Sensing Systems (RSS) singlesensor passive microwave and scatterometer wind speed retrievals; and 5) several sea surface temperature (SST) datasets. Large disparities remain in near-global satellite LHF trends and their regional expression over the 1990-2010 period, during which time the interdecadal Pacific oscillation changed sign. The budget residual diagnostics support the smaller RedObs LHF trends. The satellites, ERA5, and RedObs are reasonably consistent in identifying contributions by the 10-m wind speed variations to the LHF trend patterns. However, contributions by the near-surface vertical humidity gradient from satellites and ERA5 trend upward in time with respect to the RedObs ensemble and show less agreement in trend patterns. Problems with wind speed retrievals from Special Sensor Microwave Imager/Sounder satellite sensors, excessive upward trends in trends in Optimal Interpolation Sea Surface Temperature (OISST AVHRR-Only) data used in most satellite LHF estimates, and uncertainties associated with poor satellite coverage before the mid-1990s are noted. Possibly erroneous trends are also identified in ERA5 LHF associated with the onset of scatterometer wind data assimilation in the early 1990s.
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URL: https://doi.org/10.1175/Jcli-D-19-0954.1
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Samelson, R. M., L. W. O'Neill, D. B. Chelton, E. D. Skyllingstad, P. L. Barbour, and S. M. Durski, (2020). Surface Stress and Atmospheric Boundary Layer Response to Mesoscale SST Structure in Coupled Simulations of the Northern California Current System, American Meteorological Society, 10.1175/MWR-D-19-0200.1.
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Title: Surface Stress and Atmospheric Boundary Layer Response to Mesoscale SST Structure in Coupled Simulations of the Northern California Current System
Type: Journal Article
Publication: American Meteorological Society
Author(s): Samelson, R. M., L. W. O'Neill, D. B. Chelton, E. D. Skyllingstad, P. L. Barbour, and S. M. Durski,
Year: 2020
Formatted Citation: Samelson, R. M., L. W. O'Neill, D. B. Chelton, E. D. Skyllingstad, P. L. Barbour, and S. M. Durski,, 2020: Surface Stress and Atmospheric Boundary Layer Response to Mesoscale SST Structure in Coupled Simulations of the Northern California Current System, American Meteorological Society, 10.1175/MWR-D-19-0200.1.
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Steffen, J. and Bourassa, M. (2020). Upper-Ocean Response to Precipitation Forcing in an Ocean Model Hindcast of Hurricane Gonzalo, Journal of Physical Oceanography, 50(11), 3219-3234, 10.1175/JPO-D-19-0277.1. Journal Article »
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Title: Upper-Ocean Response to Precipitation Forcing in an Ocean Model Hindcast of Hurricane Gonzalo
Type: Journal Article
Publication: Journal of Physical Oceanography
Author(s): Steffen, J. and Bourassa, M.
Year: 2020
Formatted Citation: Steffen, J. and Bourassa, M., 2020: Upper-Ocean Response to Precipitation Forcing in an Ocean Model Hindcast of Hurricane Gonzalo, Journal of Physical Oceanography, 50(11), 3219-3234, 10.1175/JPO-D-19-0277.1.
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URL: https://doi.org/10.1175/JPO-D-19-0277.1
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Stow, J.P., Bourassa, M.A., and Holbach, H.M. (2020). Analyzing Gaps in Hurricane Rain Coverage to Inform Future Satellite Proposals, Remote Sensing, 12(17), 2673, 10.3390/rs12172673. Journal Article »
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Title: Analyzing Gaps in Hurricane Rain Coverage to Inform Future Satellite Proposals
Type: Journal Article
Publication: Remote Sensing
Author(s): Stow, J.P., Bourassa, M.A., and Holbach, H.M.
Year: 2020
Formatted Citation: Stow, J.P., Bourassa, M.A., and Holbach, H.M., 2020: Analyzing Gaps in Hurricane Rain Coverage to Inform Future Satellite Proposals, Remote Sensing, 12(17), 2673, 10.3390/rs12172673.
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URL: https://doi.org/10.3390/rs12172673
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Zheng, Y., Bourassa, M.A., and Ali, M.M. (2020). Statistical Evidence on Distinct Impacts of Short- and Long-Time Fluctuations of Indian Ocean Surface Wwind Fields on Indian Summer Monsoon Rainfall During 1991-2014, Climate Dynamics, 54(5-6), 3053-3076, 10.1007/s00382-020-05156-y. Journal Article »
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Title: Statistical Evidence on Distinct Impacts of Short- and Long-Time Fluctuations of Indian Ocean Surface Wwind Fields on Indian Summer Monsoon Rainfall During 1991-2014
Type: Journal Article
Publication: Climate Dynamics
Author(s): Zheng, Y., Bourassa, M.A., and Ali, M.M.
Year: 2020
Formatted Citation: Zheng, Y., Bourassa, M.A., and Ali, M.M., 2020: Statistical Evidence on Distinct Impacts of Short- and Long-Time Fluctuations of Indian Ocean Surface Wwind Fields on Indian Summer Monsoon Rainfall During 1991-2014, Climate Dynamics, 54(5-6), 3053-3076, 10.1007/s00382-020-05156-y.
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URL: https://doi.org/10.1007/s00382-020-05156-y
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Ahern, K., Bourassa, M.A., Hart, R.E., Zhang, J.A., and Rogers, R.F. (2019). Observed Kinematic and Thermodynamic Structure in the Hurricane Boundary Layer During Intensity Change, Monthly Weather Review, 147(8), 2765-2785, 10.1175/Mwr-D-18-0380.1. Journal Article »
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Title: Observed Kinematic and Thermodynamic Structure in the Hurricane Boundary Layer During Intensity Change
Type: Journal Article
Publication: Monthly Weather Review
Author(s): Ahern, K., Bourassa, M.A., Hart, R.E., Zhang, J.A., and Rogers, R.F.
Year: 2019
Formatted Citation: Ahern, K., Bourassa, M.A., Hart, R.E., Zhang, J.A., and Rogers, R.F., 2019: Observed Kinematic and Thermodynamic Structure in the Hurricane Boundary Layer During Intensity Change, Monthly Weather Review, 147(8), 2765-2785, 10.1175/Mwr-D-18-0380.1.
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URL: https://doi.org/10.1175/Mwr-D-18-0380.1
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Ardhuin, F., Chapron, B., Maes, C., Romeiser, R., Gommenginger, C., Cravatte, S., Morrow, R., Donlon, C., and Bourassa, M. (2019). Satellite Doppler Observations for the Motions of the Oceans, Bulletin of the American Meteorological Society, 100(8), Es215-Es219, 10.1175/Bams-D-19-0039.1. Journal Article »
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Title: Satellite Doppler Observations for the Motions of the Oceans
Type: Journal Article
Publication: Bulletin of the American Meteorological Society
Author(s): Ardhuin, F., Chapron, B., Maes, C., Romeiser, R., Gommenginger, C., Cravatte, S., Morrow, R., Donlon, C., and Bourassa, M.
Year: 2019
Formatted Citation: Ardhuin, F., Chapron, B., Maes, C., Romeiser, R., Gommenginger, C., Cravatte, S., Morrow, R., Donlon, C., and Bourassa, M., 2019: Satellite Doppler Observations for the Motions of the Oceans, Bulletin of the American Meteorological Society, 100(8), Es215-Es219, 10.1175/Bams-D-19-0039.1.
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URL: https://doi.org/10.1175/Bams-D-19-0039.1
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Armstrong, E.M., Bourassa, M.A., Cram, T.A., DeBellis, M., Elya, J., Greguska, F.R., Huang, T., Jacob, J.C., Ji, Z., Jiang, Y., Li, Y., Quach, N., McGibbney, L., Smith, S., Tsontos, V.M., Wilson, B., Worley, S.J., Yang, C., and Yam, E. (2019). An Integrated Data Analytics Platform, Frontiers in Marine Science, 6, 10.3389/fmars.2019.00354. Journal Article »
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Title: An Integrated Data Analytics Platform
Type: Journal Article
Publication: Frontiers in Marine Science
Author(s): Armstrong, E.M., Bourassa, M.A., Cram, T.A., DeBellis, M., Elya, J., Greguska, F.R., Huang, T., Jacob, J.C., Ji, Z., Jiang, Y., Li, Y., Quach, N., McGibbney, L., Smith, S., Tsontos, V.M., Wilson, B., Worley, S.J., Yang, C., and Yam, E.
Year: 2019
Formatted Citation: Armstrong, E.M., Bourassa, M.A., Cram, T.A., DeBellis, M., Elya, J., Greguska, F.R., Huang, T., Jacob, J.C., Ji, Z., Jiang, Y., Li, Y., Quach, N., McGibbney, L., Smith, S., Tsontos, V.M., Wilson, B., Worley, S.J., Yang, C., and Yam, E., 2019: An Integrated Data Analytics Platform, Frontiers in Marine Science, 6, 10.3389/fmars.2019.00354.
Abstract: An Integrated Science Data Analytics Platform is an environment that enables the confluence of resources for scientific investigation. It harmonizes data, tools and computational resources to enable the research community to focus on the investigation rather than spending time on security, data preparation, management, etc. OceanWorks is a NASA technology integration project to establish a cloud-based Integrated Ocean Science Data Analytics Platform for big ocean science at NASA's Physical Oceanography Distributed Active Archive Center (PO.DAAC) for big ocean science. It focuses on advancement and maturity by bringing together several NASA open-source, big data projects for parallel analytics, anomaly detection, in situ to satellite data matchup, quality-screened data subsetting, search relevancy, and data discovery. Our communities are relying on data available through distributed data centers to conduct their research. In typical investigations, scientists would (1) search for data, (2) evaluate the relevance of that data, (3) download it, and (4) then apply algorithms to identify trends, anomalies, or other attributes of the data. Such a workflow cannot scale if the research involves a massive amount of data or multi-variate measurements. With the upcoming NASA Surface Water and Ocean Topography (SWOT) mission expected to produce over 20PB of observational data during its 3-year nominal mission, the volume of data will challenge all existing Earth Science data archival, distribution and analysis paradigms. This paper discusses how OceanWorks enhances the analysis of physical ocean data where the computation is done on an elastic cloud platform next to the archive to deliver fast, web-accessible services for working with oceanographic measurements.
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URL: https://doi.org/10.3389/fmars.2019.00354
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Chelton, D.B., Schlax, M.G., Samelson, R.M., Farrar, J.T., Molemaker, M.J., McWilliams, J.C., and Gula, J. (2019). Prospects for Future Satellite Estimation of Small-Scale Variability of Ocean Surface Velocity and Vorticity, Progress in Oceanography, 173, 256-350, 10.1016/j.pocean.2018.10.012. Journal Article »
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Title: Prospects for Future Satellite Estimation of Small-Scale Variability of Ocean Surface Velocity and Vorticity
Type: Journal Article
Publication: Progress in Oceanography
Author(s): Chelton, D.B., Schlax, M.G., Samelson, R.M., Farrar, J.T., Molemaker, M.J., McWilliams, J.C., and Gula, J.
Year: 2019
Formatted Citation: Chelton, D.B., Schlax, M.G., Samelson, R.M., Farrar, J.T., Molemaker, M.J., McWilliams, J.C., and Gula, J., 2019: Prospects for Future Satellite Estimation of Small-Scale Variability of Ocean Surface Velocity and Vorticity, Progress in Oceanography, 173, 256-350, 10.1016/j.pocean.2018.10.012.
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URL: https://doi.org/10.1016/j.pocean.2018.10.012
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Hell, M.C., Cornuelle, B.D., Gille, S.T., Miller, A.J., and Bromirski, P.D. (2019). Identifying Ocean Swell Generation Events from Ross Ice Shelf Seismic Data, Journal of Atmospheric and Oceanic Technology, 36, 2171–2189, 10.1175/JTECH-D-19-0093.1. Journal Article »
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Title: Identifying Ocean Swell Generation Events from Ross Ice Shelf Seismic Data
Type: Journal Article
Publication: Journal of Atmospheric and Oceanic Technology
Author(s): Hell, M.C., Cornuelle, B.D., Gille, S.T., Miller, A.J., and Bromirski, P.D.
Year: 2019
Formatted Citation: Hell, M.C., Cornuelle, B.D., Gille, S.T., Miller, A.J., and Bromirski, P.D., 2019: Identifying Ocean Swell Generation Events from Ross Ice Shelf Seismic Data, Journal of Atmospheric and Oceanic Technology, 36, 2171–2189, 10.1175/JTECH-D-19-0093.1.
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URL: https://doi.org/10.1175/JTECH-D-19-0093.1
Other URLs:
Hutchings, N. and Long, D.G. (2019). Improved Ultrahigh-Resolution Wind Retrieval for RapidScat, IEEE Transactions on Geoscience and Remote Sensing, 57(6), 3370-3379, 10.1109/TGRS.2018.2884128. Journal Article »
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Title: Improved Ultrahigh-Resolution Wind Retrieval for RapidScat
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Hutchings, N. and Long, D.G.
Year: 2019
Formatted Citation: Hutchings, N. and Long, D.G., 2019: Improved Ultrahigh-Resolution Wind Retrieval for RapidScat, IEEE Transactions on Geoscience and Remote Sensing, 57(6), 3370-3379, 10.1109/TGRS.2018.2884128.
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URL: https://doi.org/10.1109/TGRS.2018.2884128
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Long, D.G. (2019). Scatterometer Backscatter Imaging Using Backus-Gilbert Inversion, IEEE Transactions on Geoscience and Remote Sensing, 57(6), 3179-3190, 10.1109/TGRS.2018.2882136. Journal Article »
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Title: Scatterometer Backscatter Imaging Using Backus-Gilbert Inversion
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Long, D.G.
Year: 2019
Formatted Citation: Long, D.G., 2019: Scatterometer Backscatter Imaging Using Backus-Gilbert Inversion, IEEE Transactions on Geoscience and Remote Sensing, 57(6), 3179-3190, 10.1109/TGRS.2018.2882136.
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URL: https://doi.org/10.1109/TGRS.2018.2882136
Other URLs:
Long, D.G., Brodzik, M.J., and Hardman, M.A. (2019). Enhanced-Resolution SMAP Brightness Temperature Image Products, IEEE Transactions on Geoscience and Remote Sensing, 57(7), 4151-4163, 10.1109/TGRS.2018.2889427. Journal Article »
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Title: Enhanced-Resolution SMAP Brightness Temperature Image Products
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Long, D.G., Brodzik, M.J., and Hardman, M.A.
Year: 2019
Formatted Citation: Long, D.G., Brodzik, M.J., and Hardman, M.A., 2019: Enhanced-Resolution SMAP Brightness Temperature Image Products, IEEE Transactions on Geoscience and Remote Sensing, 57(7), 4151-4163, 10.1109/TGRS.2018.2889427.
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URL: https://doi.org/10.1109/TGRS.2018.2889427
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Manaster, A., Ricciardulli, L., and Meissner, T. (2019). Validation of High Ocean Surface Winds from Satellites Using Oil Platform Anemometers, Journal of Atmospheric and Oceanic Technology, 36(5), 803-818, 10.1175/JTECH-D-18-0116.1. Journal Article »
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Title: Validation of High Ocean Surface Winds from Satellites Using Oil Platform Anemometers
Type: Journal Article
Publication: Journal of Atmospheric and Oceanic Technology
Author(s): Manaster, A., Ricciardulli, L., and Meissner, T.
Year: 2019
Formatted Citation: Manaster, A., Ricciardulli, L., and Meissner, T., 2019: Validation of High Ocean Surface Winds from Satellites Using Oil Platform Anemometers, Journal of Atmospheric and Oceanic Technology, 36(5), 803-818, 10.1175/JTECH-D-18-0116.1.
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URL: https://doi.org/10.1175/JTECH-D-18-0116.1
Other URLs:
Mears, C.A., Scott, J., Wentz, F.J., Ricciardulli, L., Leidner, S.M., Hoffman, R., and Atlas, R. (2019). A Near-Real-Time Version of the Cross-Calibrated Multiplatform (CCMP) Ocean Surface Wind Velocity Data Set, Journal of Geophysical Research: Oceans, 124(10), 6997-7010, 10.1029/2019JC015367. Journal Article »
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Title: A Near-Real-Time Version of the Cross-Calibrated Multiplatform (CCMP) Ocean Surface Wind Velocity Data Set
Type: Journal Article
Publication: Journal of Geophysical Research: Oceans
Author(s): Mears, C.A., Scott, J., Wentz, F.J., Ricciardulli, L., Leidner, S.M., Hoffman, R., and Atlas, R.
Year: 2019
Formatted Citation: Mears, C.A., Scott, J., Wentz, F.J., Ricciardulli, L., Leidner, S.M., Hoffman, R., and Atlas, R., 2019: A Near-Real-Time Version of the Cross-Calibrated Multiplatform (CCMP) Ocean Surface Wind Velocity Data Set, Journal of Geophysical Research: Oceans, 124(10), 6997-7010, 10.1029/2019JC015367.
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URL: https://doi.org/10.1029/2019JC015367
Other URLs:
Menezes, V.V., Farrar, J.T., and Bower, A.S. (2019). Evaporative Implications of Dry-Air Outbreaks Over the Northern Red Sea, Journal of Geophysical Research: Atmospheres, 124(9), 4829-4861, 10.1029/2018JD028853. Journal Article »
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Title: Evaporative Implications of Dry-Air Outbreaks Over the Northern Red Sea
Type: Journal Article
Publication: Journal of Geophysical Research: Atmospheres
Author(s): Menezes, V.V., Farrar, J.T., and Bower, A.S.
Year: 2019
Formatted Citation: Menezes, V.V., Farrar, J.T., and Bower, A.S., 2019: Evaporative Implications of Dry-Air Outbreaks Over the Northern Red Sea, Journal of Geophysical Research: Atmospheres, 124(9), 4829-4861, 10.1029/2018JD028853.
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URL: https://doi.org/10.1029/2018JD028853
Other URLs:
Rodríguez, E., Bourassa, M., Chelton, D., Farrar, J.T., Long, D., Perkovic-Martin, D., and Samelson, R. (2019). The Winds and Currents Mission Concept, Frontiers in Marine Science, 6, 10.3389/fmars.2019.00438. Journal Article »
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Title: The Winds and Currents Mission Concept
Type: Journal Article
Publication: Frontiers in Marine Science
Author(s): Rodríguez, E., Bourassa, M., Chelton, D., Farrar, J.T., Long, D., Perkovic-Martin, D., and Samelson, R.
Year: 2019
Formatted Citation: Rodríguez, E., Bourassa, M., Chelton, D., Farrar, J.T., Long, D., Perkovic-Martin, D., and Samelson, R., 2019: The Winds and Currents Mission Concept, Frontiers in Marine Science, 6, 10.3389/fmars.2019.00438.
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URL: https://doi.org/10.3389/fmars.2019.00438
Other URLs:
Shi, Q. and Bourassa, M.A. (2019). Coupling Ocean Currents and Waves with Wind Stress over the Gulf Stream, Remote Sensing, 11(12), 1476, 10.3390/rs11121476. Journal Article »
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Title: Coupling Ocean Currents and Waves with Wind Stress over the Gulf Stream
Type: Journal Article
Publication: Remote Sensing
Author(s): Shi, Q. and Bourassa, M.A.
Year: 2019
Formatted Citation: Shi, Q. and Bourassa, M.A., 2019: Coupling Ocean Currents and Waves with Wind Stress over the Gulf Stream, Remote Sensing, 11(12), 1476, 10.3390/rs11121476.
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URL: https://doi.org/10.3390/rs11121476
Other URLs:
Strub, P.T., James, C., Montecino, V., Rutllant, J.A., and Blanco, J.L. (2019). Ocean Circulation Along the Southern Chile Transition Region (38°-46°S): Mean, Seasonal and Interannual Variability, with a Focus on 2014-2016, Progress in Oceanography, 172, 159-198, 10.1016/j.pocean.2019.01.004. Journal Article »
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Title: Ocean Circulation Along the Southern Chile Transition Region (38°-46°S): Mean, Seasonal and Interannual Variability, with a Focus on 2014-2016
Type: Journal Article
Publication: Progress in Oceanography
Author(s): Strub, P.T., James, C., Montecino, V., Rutllant, J.A., and Blanco, J.L.
Year: 2019
Formatted Citation: Strub, P.T., James, C., Montecino, V., Rutllant, J.A., and Blanco, J.L., 2019: Ocean Circulation Along the Southern Chile Transition Region (38°-46°S): Mean, Seasonal and Interannual Variability, with a Focus on 2014-2016, Progress in Oceanography, 172, 159-198, 10.1016/j.pocean.2019.01.004.
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URL: https://doi.org/10.1016/j.pocean.2019.01.004
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Villas Bôas, A.B., Ardhuin, F., Ayet, A., Bourassa, M.A., Brandt, P., Chapron, B., Cornuelle, B.D., Farrar, J.T., Fewings, M.R., Fox-Kemper, B., Gille, S.T., Gommenginger, C., Heimbach, P., Hell, M.C., Li, Q., Mazloff, M.R., Merrifield, S.T., Mouche, A., Rio, M.H., Rodriguez, E., Shutler, J.D., Subramanian, A.C., Terrill, E.J., Tsamados, M., Ubelmann, C., and van Sebille, E. (2019). Integrated Observations of Global Surface Winds, Currents, and Waves: Requirements and Challenges for the Next Decade, Frontiers in Marine Science, 6, 10.3389/fmars.2019.00425. Journal Article »
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Title: Integrated Observations of Global Surface Winds, Currents, and Waves: Requirements and Challenges for the Next Decade
Type: Journal Article
Publication: Frontiers in Marine Science
Author(s): Villas Bôas, A.B., Ardhuin, F., Ayet, A., Bourassa, M.A., Brandt, P., Chapron, B., Cornuelle, B.D., Farrar, J.T., Fewings, M.R., Fox-Kemper, B., Gille, S.T., Gommenginger, C., Heimbach, P., Hell, M.C., Li, Q., Mazloff, M.R., Merrifield, S.T., Mouche, A., Rio, M.H., Rodriguez, E., Shutler, J.D., Subramanian, A.C., Terrill, E.J., Tsamados, M., Ubelmann, C., and van Sebille, E.
Year: 2019
Formatted Citation: Villas Bôas, A.B., Ardhuin, F., Ayet, A., Bourassa, M.A., Brandt, P., Chapron, B., Cornuelle, B.D., Farrar, J.T., Fewings, M.R., Fox-Kemper, B., Gille, S.T., Gommenginger, C., Heimbach, P., Hell, M.C., Li, Q., Mazloff, M.R., Merrifield, S.T., Mouche, A., Rio, M.H., Rodriguez, E., Shutler, J.D., Subramanian, A.C., Terrill, E.J., Tsamados, M., Ubelmann, C., and van Sebille, E., 2019: Integrated Observations of Global Surface Winds, Currents, and Waves: Requirements and Challenges for the Next Decade, Frontiers in Marine Science, 6, 10.3389/fmars.2019.00425.
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URL: https://doi.org/10.3389/fmars.2019.00425
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Walton, P. and Long, D. (2019). Space of Solutions to Ocean Surface Wind Measurement Using Scatterometer Constellations, Journal of Applied Remote Sensing, 13(03), 1, 10.1117/1.JRS.13.032506. Journal Article »
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Title: Space of Solutions to Ocean Surface Wind Measurement Using Scatterometer Constellations
Type: Journal Article
Publication: Journal of Applied Remote Sensing
Author(s): Walton, P. and Long, D.
Year: 2019
Formatted Citation: Walton, P. and Long, D., 2019: Space of Solutions to Ocean Surface Wind Measurement Using Scatterometer Constellations, Journal of Applied Remote Sensing, 13(03), 1, 10.1117/1.JRS.13.032506.
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URL: https://doi.org/10.1117/1.JRS.13.032506
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Budge, J.S. and Long, D.G. (2018). A Comprehensive Database for Antarctic Iceberg Tracking Using Scatterometer Data, IEEE Journal of Selected Topics in Applied Earth Observations, 11(2), 434-442, 10.1109/JSTARS.2017.2784186. Journal Article »
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Title: A Comprehensive Database for Antarctic Iceberg Tracking Using Scatterometer Data
Type: Journal Article
Publication: IEEE Journal of Selected Topics in Applied Earth Observations
Author(s): Budge, J.S. and Long, D.G.
Year: 2018
Formatted Citation: Budge, J.S. and Long, D.G., 2018: A Comprehensive Database for Antarctic Iceberg Tracking Using Scatterometer Data, IEEE Journal of Selected Topics in Applied Earth Observations, 11(2), 434-442, 10.1109/JSTARS.2017.2784186.
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URL: https://doi.org/10.1109/JSTARS.2017.2784186
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Capotondi, A., Sardeshmukh, P.D., and Ricciardulli, L. (2018). The Nature of the Stochastic Wind Forcing of ENSO, Journal of Climate, 31(19), 8081-8099, 10.1175/Jcli-D-17-0842.1. Journal Article »
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Title: The Nature of the Stochastic Wind Forcing of ENSO
Type: Journal Article
Publication: Journal of Climate
Author(s): Capotondi, A., Sardeshmukh, P.D., and Ricciardulli, L.
Year: 2018
Formatted Citation: Capotondi, A., Sardeshmukh, P.D., and Ricciardulli, L., 2018: The Nature of the Stochastic Wind Forcing of ENSO, Journal of Climate, 31(19), 8081-8099, 10.1175/Jcli-D-17-0842.1.
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URL: https://doi.org/10.1175/Jcli-D-17-0842.1
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Delman, A.S., Lee, T., and Qiu, B. (2018). Interannual to Multidecadal Forcing of Mesoscale Eddy Kinetic Energy in the Subtropical Southern Indian Ocean, Journal of Geophysical Research: Oceans, 123(11), 8180-8202, 10.1029/2018JC013945. Journal Article »
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Title: Interannual to Multidecadal Forcing of Mesoscale Eddy Kinetic Energy in the Subtropical Southern Indian Ocean
Type: Journal Article
Publication: Journal of Geophysical Research: Oceans
Author(s): Delman, A.S., Lee, T., and Qiu, B.
Year: 2018
Formatted Citation: Delman, A.S., Lee, T., and Qiu, B., 2018: Interannual to Multidecadal Forcing of Mesoscale Eddy Kinetic Energy in the Subtropical Southern Indian Ocean, Journal of Geophysical Research: Oceans, 123(11), 8180-8202, 10.1029/2018JC013945.
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URL: https://doi.org/10.1029/2018JC013945
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Fu, L.-L., Lee, T., Liu, W.T., and Kwok, R. (2018). 50 Years of Satellite Remote Sensing of the Ocean, Meteorological Monographs, 59, 5.1-5.46, 10.1175/AMSMONOGRAPHS-D-18-0010.1. Journal Article »
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Title: 50 Years of Satellite Remote Sensing of the Ocean
Type: Journal Article
Publication: Meteorological Monographs
Author(s): Fu, L.-L., Lee, T., Liu, W.T., and Kwok, R.
Year: 2018
Formatted Citation: Fu, L.-L., Lee, T., Liu, W.T., and Kwok, R., 2018: 50 Years of Satellite Remote Sensing of the Ocean, Meteorological Monographs, 59, 5.1-5.46, 10.1175/AMSMONOGRAPHS-D-18-0010.1.
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URL: https://doi.org/10.1175/AMSMONOGRAPHS-D-18-0010.1
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Holbach, H.M., Uhlhorn, E.W., and Bourassa, M.A. (2018). Off-Nadir SFMR Brightness Temperature Measurements in High-Wind Conditions, Journal of Atmospheric and Oceanic Technology, 35(9), 1865-1879, 10.1175/Jtech-D-18-0005.1. Journal Article »
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Title: Off-Nadir SFMR Brightness Temperature Measurements in High-Wind Conditions
Type: Journal Article
Publication: Journal of Atmospheric and Oceanic Technology
Author(s): Holbach, H.M., Uhlhorn, E.W., and Bourassa, M.A.
Year: 2018
Formatted Citation: Holbach, H.M., Uhlhorn, E.W., and Bourassa, M.A., 2018: Off-Nadir SFMR Brightness Temperature Measurements in High-Wind Conditions, Journal of Atmospheric and Oceanic Technology, 35(9), 1865-1879, 10.1175/Jtech-D-18-0005.1.
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URL: https://doi.org/10.1175/Jtech-D-18-0005.1
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Li, J., Suhas, E., Lee, W., Richardson, M., Wang, Y., Yu, J., Lee, T., Fetzer, E., Stephens, G., and Shen, M.H. (2018). The Impacts of Bias in Cloud-Radiation-Dynamics Interactions on Central Pacific Seasonal and El Niño Simulations in Contemporary GCMs, Earth and Space Science, 5, 50–60, 10.1002/2017EA000304. Journal Article »
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Title: The Impacts of Bias in Cloud-Radiation-Dynamics Interactions on Central Pacific Seasonal and El Niño Simulations in Contemporary GCMs
Type: Journal Article
Publication: Earth and Space Science
Author(s): Li, J., Suhas, E., Lee, W., Richardson, M., Wang, Y., Yu, J., Lee, T., Fetzer, E., Stephens, G., and Shen, M.H.
Year: 2018
Formatted Citation: Li, J., Suhas, E., Lee, W., Richardson, M., Wang, Y., Yu, J., Lee, T., Fetzer, E., Stephens, G., and Shen, M.H., 2018: The Impacts of Bias in Cloud-Radiation-Dynamics Interactions on Central Pacific Seasonal and El Niño Simulations in Contemporary GCMs, Earth and Space Science, 5, 50–60, 10.1002/2017EA000304.
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URL: https://doi.org/10.1002/2017EA000304
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Li, Y., Han, W., Wang, W., Zhang, L., and Ravichandran, M. (2018). The Indian Summer Monsoon Intraseasonal Oscillations in CFSv2 Forecasts: Biases and Importance of Improving Air-Sea Interaction Processes, Journal of Climate, 31, 5351–5370, 10.1175/JCLI-D-17-0623.1. Journal Article »
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Title: The Indian Summer Monsoon Intraseasonal Oscillations in CFSv2 Forecasts: Biases and Importance of Improving Air-Sea Interaction Processes
Type: Journal Article
Publication: Journal of Climate
Author(s): Li, Y., Han, W., Wang, W., Zhang, L., and Ravichandran, M.
Year: 2018
Formatted Citation: Li, Y., Han, W., Wang, W., Zhang, L., and Ravichandran, M., 2018: The Indian Summer Monsoon Intraseasonal Oscillations in CFSv2 Forecasts: Biases and Importance of Improving Air-Sea Interaction Processes, Journal of Climate, 31, 5351–5370, 10.1175/JCLI-D-17-0623.1.
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URL: https://doi.org/10.1175/JCLI-D-17-0623.1
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Menezes, V.V. , Farrar, J.T., and Bower, A.S. (2018). Westward Mountain-Gap Wind Jets of the Northern Red Sea as Seen by QuikSCAT, Remote Sensing of Environment, 209, 677-699, 10.1016/j.rse.2018.02.075. Journal Article »
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Title: Westward Mountain-Gap Wind Jets of the Northern Red Sea as Seen by QuikSCAT
Type: Journal Article
Publication: Remote Sensing of Environment
Author(s): Menezes, V.V. , Farrar, J.T., and Bower, A.S.
Year: 2018
Formatted Citation: Menezes, V.V. , Farrar, J.T., and Bower, A.S., 2018: Westward Mountain-Gap Wind Jets of the Northern Red Sea as Seen by QuikSCAT, Remote Sensing of Environment, 209, 677-699, 10.1016/j.rse.2018.02.075.
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URL: https://doi.org/10.1016/j.rse.2018.02.075
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Morey, S., Wienders, N., Dukhovskoy, D., and Bourassa, M. (2018). Measurement Characteristics of Near-Surface Currents from Ultra-Thin Drifters, Drogued Drifters, and HF Radar, Remote Sensing, 10(10), 1633, 10.3390/rs10101633. Journal Article »
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Title: Measurement Characteristics of Near-Surface Currents from Ultra-Thin Drifters, Drogued Drifters, and HF Radar
Type: Journal Article
Publication: Remote Sensing
Author(s): Morey, S., Wienders, N., Dukhovskoy, D., and Bourassa, M.
Year: 2018
Formatted Citation: Morey, S., Wienders, N., Dukhovskoy, D., and Bourassa, M., 2018: Measurement Characteristics of Near-Surface Currents from Ultra-Thin Drifters, Drogued Drifters, and HF Radar, Remote Sensing, 10(10), 1633, 10.3390/rs10101633.
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URL: https://doi.org/10.3390/rs10101633
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Rodríguez, E., Wineteer, A., Perkovic-Martin, D., Gál, T., Stiles, B.W., Niamsuwan, N., and Monje, R.R. (2018). Estimating Ocean Vector Winds and Currents Using a Ka-Band Pencil-Beam Doppler Scatterometer, Remote Sensing, 10(4), 576, 10.3390/rs10040576. Journal Article »
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Title: Estimating Ocean Vector Winds and Currents Using a Ka-Band Pencil-Beam Doppler Scatterometer
Type: Journal Article
Publication: Remote Sensing
Author(s): Rodríguez, E., Wineteer, A., Perkovic-Martin, D., Gál, T., Stiles, B.W., Niamsuwan, N., and Monje, R.R.
Year: 2018
Formatted Citation: Rodríguez, E., Wineteer, A., Perkovic-Martin, D., Gál, T., Stiles, B.W., Niamsuwan, N., and Monje, R.R., 2018: Estimating Ocean Vector Winds and Currents Using a Ka-Band Pencil-Beam Doppler Scatterometer, Remote Sensing, 10(4), 576, 10.3390/rs10040576.
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URL: https://doi.org/10.3390/rs10040576
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T. Lee, J.T. Farrar, S. Arnault, D. Meyssignac, W. Han, and T. Durland (2018). Monitoring and Interpreting the Tropical Oceans by Satellite Altimetry, Satellite Altimetry Over Ocean and Land Surfaces.
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Title: Monitoring and Interpreting the Tropical Oceans by Satellite Altimetry
Type: Book Chapter
Publication: Satellite Altimetry Over Ocean and Land Surfaces
Author(s): T. Lee, J.T. Farrar, S. Arnault, D. Meyssignac, W. Han, and T. Durland
Year: 2018
Formatted Citation: T. Lee, J.T. Farrar, S. Arnault, D. Meyssignac, W. Han, and T. Durland, 2018: Monitoring and Interpreting the Tropical Oceans by Satellite Altimetry, Satellite Altimetry Over Ocean and Land Surfaces.
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Zhang, L., Han, W. , Li, Y., and Maloney, E. (2018). Role of North Indian Ocean Air-Sea Interaction in Summer Monsoon Intraseasonal Oscillation, Journal of Climate, 31(19), 7885–7908 , 10.1175/JCLI-D-17-0691.1. Journal Article »
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Title: Role of North Indian Ocean Air-Sea Interaction in Summer Monsoon Intraseasonal Oscillation
Type: Journal Article
Publication: Journal of Climate
Author(s): Zhang, L., Han, W. , Li, Y., and Maloney, E.
Year: 2018
Formatted Citation: Zhang, L., Han, W. , Li, Y., and Maloney, E., 2018: Role of North Indian Ocean Air-Sea Interaction in Summer Monsoon Intraseasonal Oscillation, Journal of Climate, 31(19), 7885–7908 , 10.1175/JCLI-D-17-0691.1.
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URL: https://doi.org/10.1175/JCLI-D-17-0691.1
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Bentamy, A., Grodsky, S.A., Elyouncha, A., Chapron, B., and Desbiolles, F. (2017). Homogenization of Scatterometer Wind Retrievals, International Journal of Climatology, 37(2), 870-889, 10.1002/joc.4746. Journal Article »
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Title: Homogenization of Scatterometer Wind Retrievals
Type: Journal Article
Publication: International Journal of Climatology
Author(s): Bentamy, A., Grodsky, S.A., Elyouncha, A., Chapron, B., and Desbiolles, F.
Year: 2017
Formatted Citation: Bentamy, A., Grodsky, S.A., Elyouncha, A., Chapron, B., and Desbiolles, F., 2017: Homogenization of Scatterometer Wind Retrievals, International Journal of Climatology, 37(2), 870-889, 10.1002/joc.4746.
Abstract:
Keywords: scatterometer; surface wind; homogenization
Mission: |ASCAT|
URL: https://doi.org/10.1002/joc.4746
Other URLs:
Bentamy, A., Piollé, J.F., Grouazel, A., Danielson, R., Gulev, S., Paul, F., Azelmat, H., Mathieu, P.P., von Schuckmann, K., Sathyendranath, S., Evers-King, H., Esau, I., Johannessen, J.A., Clayson, C.A., Pinker, R.T., Grodsky, S.A., Bourassa, M., Smith, S.R., Haines, K., Valdivieso, M., Merchant, C.J., Chapron, B., Anderson, A., Hollmann, R., and Josey, S.A. (2017). Review and Assessment of Latent and Sensible Heat Flux Accuracy Over the Global Oceans, Remote Sensing of Environment, 201, 196-218, 10.1016/j.rse.2017.08.016. Journal Article »
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Title: Review and Assessment of Latent and Sensible Heat Flux Accuracy Over the Global Oceans
Type: Journal Article
Publication: Remote Sensing of Environment
Author(s): Bentamy, A., Piollé, J.F., Grouazel, A., Danielson, R., Gulev, S., Paul, F., Azelmat, H., Mathieu, P.P., von Schuckmann, K., Sathyendranath, S., Evers-King, H., Esau, I., Johannessen, J.A., Clayson, C.A., Pinker, R.T., Grodsky, S.A., Bourassa, M., Smith, S.R., Haines, K., Valdivieso, M., Merchant, C.J., Chapron, B., Anderson, A., Hollmann, R., and Josey, S.A.
Year: 2017
Formatted Citation: Bentamy, A., Piollé, J.F., Grouazel, A., Danielson, R., Gulev, S., Paul, F., Azelmat, H., Mathieu, P.P., von Schuckmann, K., Sathyendranath, S., Evers-King, H., Esau, I., Johannessen, J.A., Clayson, C.A., Pinker, R.T., Grodsky, S.A., Bourassa, M., Smith, S.R., Haines, K., Valdivieso, M., Merchant, C.J., Chapron, B., Anderson, A., Hollmann, R., and Josey, S.A., 2017: Review and Assessment of Latent and Sensible Heat Flux Accuracy Over the Global Oceans, Remote Sensing of Environment, 201, 196-218, 10.1016/j.rse.2017.08.016.
Abstract:
Keywords: Ocean Heat Flux; Latent heat flux; Sensible heat flux; Ocean heat content; Scatterometer; Surface wind; Specfic air humidity; OceanSites; Remotely sensed data
Mission:
URL: https://doi.org/10.1016/j.rse.2017.08.016
Other URLs:
Desbiolles, F., Bentamy, A., Blanke, B., Roy, C., Mestas-Nuñez, A.M., Grodsky, S.A., Herbette, S., Cambon, G., and Maes, C. (2017). Two Decades [1992-2012] of Surface Wind Analyses Based on Satellite Scatterometer Observations, Journal of Marine Systems, 168, 38-56, 10.1016/j.jmarsys.2017.01.003. Journal Article »
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Title: Two Decades [1992-2012] of Surface Wind Analyses Based on Satellite Scatterometer Observations
Type: Journal Article
Publication: Journal of Marine Systems
Author(s): Desbiolles, F., Bentamy, A., Blanke, B., Roy, C., Mestas-Nuñez, A.M., Grodsky, S.A., Herbette, S., Cambon, G., and Maes, C.
Year: 2017
Formatted Citation: Desbiolles, F., Bentamy, A., Blanke, B., Roy, C., Mestas-Nuñez, A.M., Grodsky, S.A., Herbette, S., Cambon, G., and Maes, C., 2017: Two Decades [1992-2012] of Surface Wind Analyses Based on Satellite Scatterometer Observations, Journal of Marine Systems, 168, 38-56, 10.1016/j.jmarsys.2017.01.003.
Abstract:
Keywords:
Mission:
URL: https://doi.org/10.1016/j.jmarsys.2017.01.003
Other URLs:
Dukhovskoy, D.S., Bourassa, M.A., Petersen, G.N., and Steffen, J. (2017). Comparison of the Ocean Surface Vector Winds from Atmospheric Reanalysis and Scatterometer-Base Wind Products over the Subpolar North Atlantic and Their Applications for Ocean Forcing, Journal of Geophysical Research, 122, 1943–1973, 10.1002/2016JC012453. Journal Article »
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Title: Comparison of the Ocean Surface Vector Winds from Atmospheric Reanalysis and Scatterometer-Base Wind Products over the Subpolar North Atlantic and Their Applications for Ocean Forcing
Type: Journal Article
Publication: Journal of Geophysical Research
Author(s): Dukhovskoy, D.S., Bourassa, M.A., Petersen, G.N., and Steffen, J.
Year: 2017
Formatted Citation: Dukhovskoy, D.S., Bourassa, M.A., Petersen, G.N., and Steffen, J., 2017: Comparison of the Ocean Surface Vector Winds from Atmospheric Reanalysis and Scatterometer-Base Wind Products over the Subpolar North Atlantic and Their Applications for Ocean Forcing, Journal of Geophysical Research, 122, 1943–1973, 10.1002/2016JC012453.
Abstract:
Keywords:
Mission:
URL: https://doi.org/10.1002/2016JC012453
Other URLs:
Durden, S.L. and Perkovic-Martin, D. (2017). The RapidScat Ocean Winds Scatterometer: A Radar System Engineering Perspective, IEEE Geoscience and Remote Sensing Magazine, 5(3), 36-43, 10.1109/MGRS.2017.2678999. Journal Article »
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Title: The RapidScat Ocean Winds Scatterometer: A Radar System Engineering Perspective
Type: Journal Article
Publication: IEEE Geoscience and Remote Sensing Magazine
Author(s): Durden, S.L. and Perkovic-Martin, D.
Year: 2017
Formatted Citation: Durden, S.L. and Perkovic-Martin, D., 2017: The RapidScat Ocean Winds Scatterometer: A Radar System Engineering Perspective, IEEE Geoscience and Remote Sensing Magazine, 5(3), 36-43, 10.1109/MGRS.2017.2678999.
Abstract:
Keywords:
Mission:
URL: https://doi.org/10.1109/MGRS.2017.2678999
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Fewings, M.R. (2017). Large-Scale Structure in Wind Forcing over the California Current System in Summer, Monthly Weather Review, 145(10), 4227-4247, 10.1175/MWR-D-17-0106.1. Journal Article »
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Title: Large-Scale Structure in Wind Forcing over the California Current System in Summer
Type: Journal Article
Publication: Monthly Weather Review
Author(s): Fewings, M.R.
Year: 2017
Formatted Citation: Fewings, M.R., 2017: Large-Scale Structure in Wind Forcing over the California Current System in Summer, Monthly Weather Review, 145(10), 4227-4247, 10.1175/MWR-D-17-0106.1.
Abstract:
Keywords:
Mission:
URL: https://doi.org/10.1175/MWR-D-17-0106.1
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Flynn, K.R., Fewings, M.R., Gotschalk, C., and Lombardo, K. (2017). Large-Scale Anomalies in Sea-Surface Temperature and Air-Sea Fluxes During Wind Relaxation Events off the United States West Coast in Summer, Journal of Geophysical Research: Oceans, 122(3), 2574-2594, 10.1002/2016JC012613. Journal Article »
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Title: Large-Scale Anomalies in Sea-Surface Temperature and Air-Sea Fluxes During Wind Relaxation Events off the United States West Coast in Summer
Type: Journal Article
Publication: Journal of Geophysical Research: Oceans
Author(s): Flynn, K.R., Fewings, M.R., Gotschalk, C., and Lombardo, K.
Year: 2017
Formatted Citation: Flynn, K.R., Fewings, M.R., Gotschalk, C., and Lombardo, K., 2017: Large-Scale Anomalies in Sea-Surface Temperature and Air-Sea Fluxes During Wind Relaxation Events off the United States West Coast in Summer, Journal of Geophysical Research: Oceans, 122(3), 2574-2594, 10.1002/2016JC012613.
Abstract:
Keywords:
Mission:
URL: https://doi.org/10.1002/2016JC012613
Other URLs:
Gentemann, C., Fewings, M.R., and García-Reyes, M. (2017). Satellite Sea Surface Temperatures Along the West Coast of the United States During the 2014-2016 Northeast Pacific Marine Heat Wave, Geophysical Research Letters, 43, 312-319, 10.1002/2016GL071039. Journal Article »
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Title: Satellite Sea Surface Temperatures Along the West Coast of the United States During the 2014-2016 Northeast Pacific Marine Heat Wave
Type: Journal Article
Publication: Geophysical Research Letters
Author(s): Gentemann, C., Fewings, M.R., and García-Reyes, M.
Year: 2017
Formatted Citation: Gentemann, C., Fewings, M.R., and García-Reyes, M., 2017: Satellite Sea Surface Temperatures Along the West Coast of the United States During the 2014-2016 Northeast Pacific Marine Heat Wave, Geophysical Research Letters, 43, 312-319, 10.1002/2016GL071039.
Abstract:
Keywords:
Mission:
URL: https://doi.org/10.1002/2016GL071039
Other URLs:
Giglio, D., Gille, S.T., Subramanian, A.C., Nguyen, S. (2017). The Role of Wind Gusts in Upper Ocean Diurnal Variability, Journal of Geophysical Research - Oceans, 122, 7751–7764, 10.1002/2017JC012794. Journal Article »
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Title: The Role of Wind Gusts in Upper Ocean Diurnal Variability
Type: Journal Article
Publication: Journal of Geophysical Research - Oceans
Author(s): Giglio, D., Gille, S.T., Subramanian, A.C., Nguyen, S.
Year: 2017
Formatted Citation: Giglio, D., Gille, S.T., Subramanian, A.C., Nguyen, S., 2017: The Role of Wind Gusts in Upper Ocean Diurnal Variability, Journal of Geophysical Research - Oceans, 122, 7751–7764, 10.1002/2017JC012794.
Abstract:
Keywords:
Mission:
URL: https://doi.org/10.1002/2017JC012794
Other URLs:
Han, W., Meehl, G.A., Hu, A., Zheng, J., Kenigson, J., Vialard, J., Rajagopalan, B., and Yanto (2017). Decadal Variability of the Indian and Pacific Walker Cells Since the 1960s: Do They Co-vary on Decadal Timescales?, Journal of Climate, 30, 8447–8468, 10.1175/JCLI-D-16-0783.1. Journal Article »
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Title: Decadal Variability of the Indian and Pacific Walker Cells Since the 1960s: Do They Co-vary on Decadal Timescales?
Type: Journal Article
Publication: Journal of Climate
Author(s): Han, W., Meehl, G.A., Hu, A., Zheng, J., Kenigson, J., Vialard, J., Rajagopalan, B., and Yanto
Year: 2017
Formatted Citation: Han, W., Meehl, G.A., Hu, A., Zheng, J., Kenigson, J., Vialard, J., Rajagopalan, B., and Yanto, 2017: Decadal Variability of the Indian and Pacific Walker Cells Since the 1960s: Do They Co-vary on Decadal Timescales?, Journal of Climate, 30, 8447–8468, 10.1175/JCLI-D-16-0783.1.
Abstract:
Keywords:
Mission:
URL: https://doi.org/10.1175/JCLI-D-16-0783.1
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Hill, J.C. and Long, D.G. (2017). Extension of the QuikSCAT Sea Ice Extent Data Set With OSCAT Data, IEEE Geoscience and Remote Sensing Letters, 14(1), 92-96, 10.1109/LGRS.2016.2630010. Journal Article »
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Title: Extension of the QuikSCAT Sea Ice Extent Data Set With OSCAT Data
Type: Journal Article
Publication: IEEE Geoscience and Remote Sensing Letters
Author(s): Hill, J.C. and Long, D.G.
Year: 2017
Formatted Citation: Hill, J.C. and Long, D.G., 2017: Extension of the QuikSCAT Sea Ice Extent Data Set With OSCAT Data, IEEE Geoscience and Remote Sensing Letters, 14(1), 92-96, 10.1109/LGRS.2016.2630010.
Abstract:
Keywords:
Mission:
URL: https://doi.org/10.1109/LGRS.2016.2630010
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Hoffman, R.N., Privé, N., and Bourassa, M. (2017). Comments on "Reanalyses and Observations: What's the Difference?", Bulletin of the American Meteorological Society, 98(11), 2455-2459, 10.1175/BAMS-D-17-0008.1. Journal Article »
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Title: Comments on "Reanalyses and Observations: What's the Difference?"
Type: Journal Article
Publication: Bulletin of the American Meteorological Society
Author(s): Hoffman, R.N., Privé, N., and Bourassa, M.
Year: 2017
Formatted Citation: Hoffman, R.N., Privé, N., and Bourassa, M., 2017: Comments on "Reanalyses and Observations: What's the Difference?", Bulletin of the American Meteorological Society, 98(11), 2455-2459, 10.1175/BAMS-D-17-0008.1.
Abstract:
Keywords:
Mission:
URL: https://doi.org/10.1175/BAMS-D-17-0008.1
Other URLs:
Holbach, H.M. and Bourassa, M.A. (2017). Platform and Across-Swath Comparison of Vorticity Spectra From QuikSCAT, ASCAT-A, OSCAT, and ASCAT-B Scatterometers, IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 10(5), 2205-2213, 10.1109/JSTARS.2016.2642583. Journal Article »
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Title: Platform and Across-Swath Comparison of Vorticity Spectra From QuikSCAT, ASCAT-A, OSCAT, and ASCAT-B Scatterometers
Type: Journal Article
Publication: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Author(s): Holbach, H.M. and Bourassa, M.A.
Year: 2017
Formatted Citation: Holbach, H.M. and Bourassa, M.A., 2017: Platform and Across-Swath Comparison of Vorticity Spectra From QuikSCAT, ASCAT-A, OSCAT, and ASCAT-B Scatterometers, IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 10(5), 2205-2213, 10.1109/JSTARS.2016.2642583.
Abstract:
Keywords: vorticity; Consistency; intercalibration; scatterometer
Mission: |ASCAT|
URL: https://doi.org/10.1109/JSTARS.2016.2642583
Other URLs:
Krishnamurti, T.N., Jana, S., Krishnamurti, R., Kumar, V., Deepa, R., Papa, F., Bourassa, M.A., and Ali, M.M. (2017). Monsoonal Intraseasonal Oscillations in the Ocean Heat Content over the Surface Layers of the Bay of Bengal, Journal of Marine Systems, 167, 19-32, 10.1016/j.jmarsys.2016.11.002. Journal Article »
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Title: Monsoonal Intraseasonal Oscillations in the Ocean Heat Content over the Surface Layers of the Bay of Bengal
Type: Journal Article
Publication: Journal of Marine Systems
Author(s): Krishnamurti, T.N., Jana, S., Krishnamurti, R., Kumar, V., Deepa, R., Papa, F., Bourassa, M.A., and Ali, M.M.
Year: 2017
Formatted Citation: Krishnamurti, T.N., Jana, S., Krishnamurti, R., Kumar, V., Deepa, R., Papa, F., Bourassa, M.A., and Ali, M.M., 2017: Monsoonal Intraseasonal Oscillations in the Ocean Heat Content over the Surface Layers of the Bay of Bengal, Journal of Marine Systems, 167, 19-32, 10.1016/j.jmarsys.2016.11.002.
Abstract:
Keywords:
Mission:
URL: https://doi.org/10.1016/j.jmarsys.2016.11.002
Other URLs:
Li, Y., Guan, K., Gentine, P., Konings, A.G., Meinzer, F.C., Kimball, J.S., Xu, X., Anderegg, W.R.L., McDowell, N.G., Martinez-Vilalta, J., Long, D.G., and Good, S.P. (2017). Estimating Global Ecosystem Isohydry/Anisohydry Using Active and Passive Microwave Satellite Data, Journal of Geophysical Research: Biogeosciences, 122(12), 3306-3321, 10.1002/2017JG003958. Journal Article »
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Title: Estimating Global Ecosystem Isohydry/Anisohydry Using Active and Passive Microwave Satellite Data
Type: Journal Article
Publication: Journal of Geophysical Research: Biogeosciences
Author(s): Li, Y., Guan, K., Gentine, P., Konings, A.G., Meinzer, F.C., Kimball, J.S., Xu, X., Anderegg, W.R.L., McDowell, N.G., Martinez-Vilalta, J., Long, D.G., and Good, S.P.
Year: 2017
Formatted Citation: Li, Y., Guan, K., Gentine, P., Konings, A.G., Meinzer, F.C., Kimball, J.S., Xu, X., Anderegg, W.R.L., McDowell, N.G., Martinez-Vilalta, J., Long, D.G., and Good, S.P., 2017: Estimating Global Ecosystem Isohydry/Anisohydry Using Active and Passive Microwave Satellite Data, Journal of Geophysical Research: Biogeosciences, 122(12), 3306-3321, 10.1002/2017JG003958.
Abstract:
Keywords:
Mission:
URL: https://doi.org/10.1002/2017JG003958
Other URLs:
Li, Y., Han, W., Ravichandran, M., Wang, W., Shinoda, T., and Lee, T. (2017). Bay of Bengal Salinity Stratification and Indian Summer Monsoon Intraseasonal Oscillation: 1. Intraseasonal Variability and Causes, Journal of Geophysical Research: Oceans, 122(5), 4291-4311, 10.1002/2017JC012691. Journal Article »
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Title: Bay of Bengal Salinity Stratification and Indian Summer Monsoon Intraseasonal Oscillation: 1. Intraseasonal Variability and Causes
Type: Journal Article
Publication: Journal of Geophysical Research: Oceans
Author(s): Li, Y., Han, W., Ravichandran, M., Wang, W., Shinoda, T., and Lee, T.
Year: 2017
Formatted Citation: Li, Y., Han, W., Ravichandran, M., Wang, W., Shinoda, T., and Lee, T., 2017: Bay of Bengal Salinity Stratification and Indian Summer Monsoon Intraseasonal Oscillation: 1. Intraseasonal Variability and Causes, Journal of Geophysical Research: Oceans, 122(5), 4291-4311, 10.1002/2017JC012691.
Abstract:
Keywords:
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URL: https://doi.org/10.1002/2017JC012691
Other URLs:
Li, Y., Han, W., Wang, W., Ravichandran, M., Lee, T., and Shinoda, T. (2017). Bay of Bengal Salinity Stratification and Indian Summer Monsoon Intraseasonal Oscillation: 2. Impact on SST and Convection, Journal of Geophysical Research: Oceans, 122(5), 4312-4328, 10.1002/2017JC012692. Journal Article »
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Title: Bay of Bengal Salinity Stratification and Indian Summer Monsoon Intraseasonal Oscillation: 2. Impact on SST and Convection
Type: Journal Article
Publication: Journal of Geophysical Research: Oceans
Author(s): Li, Y., Han, W., Wang, W., Ravichandran, M., Lee, T., and Shinoda, T.
Year: 2017
Formatted Citation: Li, Y., Han, W., Wang, W., Ravichandran, M., Lee, T., and Shinoda, T., 2017: Bay of Bengal Salinity Stratification and Indian Summer Monsoon Intraseasonal Oscillation: 2. Impact on SST and Convection, Journal of Geophysical Research: Oceans, 122(5), 4312-4328, 10.1002/2017JC012692.
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Keywords:
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URL: https://doi.org/10.1002/2017JC012692
Other URLs:
Liu, W.T. and Xie, X. (2017). Premonsoon Drought in India Observed from Space, Journal of Hydrometeorology, 18(3), 683-692, 10.1175/JHM-D-16-0014.1. Journal Article »
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Title: Premonsoon Drought in India Observed from Space
Type: Journal Article
Publication: Journal of Hydrometeorology
Author(s): Liu, W.T. and Xie, X.
Year: 2017
Formatted Citation: Liu, W.T. and Xie, X., 2017: Premonsoon Drought in India Observed from Space, Journal of Hydrometeorology, 18(3), 683-692, 10.1175/JHM-D-16-0014.1.
Abstract:
Keywords:
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URL: https://doi.org/10.1175/JHM-D-16-0014.1
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Long, D.G. (2017). Comparison of SeaWinds Backscatter Imaging Algorithms, IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 10(5), 2214-2231, 10.1109/JSTARS.2016.2626966. Journal Article »
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Title: Comparison of SeaWinds Backscatter Imaging Algorithms
Type: Journal Article
Publication: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Author(s): Long, D.G.
Year: 2017
Formatted Citation: Long, D.G., 2017: Comparison of SeaWinds Backscatter Imaging Algorithms, IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 10(5), 2214-2231, 10.1109/JSTARS.2016.2626966.
Abstract:
Keywords:
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URL: https://doi.org/10.1109/JSTARS.2016.2626966
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Long, D.G. (2017). Polar Applications of Spaceborne Scatterometers, IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 10(5), 2307-2320, 10.1109/JSTARS.2016.2629418. Journal Article »
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Title: Polar Applications of Spaceborne Scatterometers
Type: Journal Article
Publication: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Author(s): Long, D.G.
Year: 2017
Formatted Citation: Long, D.G., 2017: Polar Applications of Spaceborne Scatterometers, IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 10(5), 2307-2320, 10.1109/JSTARS.2016.2629418.
Abstract:
Keywords:
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URL: https://doi.org/10.1109/JSTARS.2016.2629418
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Manning, C.C., Stanley, R., Nicholson, D., Smith, J., Pennington, J.T., Fewings, M., Squibb, M., and Chavez, F. (2017). Impact of Recently Upwelled Water on Productivity Investigated Using In Situ and Incubation-Based Methods in Monterey Bay, Journal of Geophysical Research: Oceans, 122(3), 1901-1926, 10.1002/2016JC012306. Journal Article »
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Title: Impact of Recently Upwelled Water on Productivity Investigated Using In Situ and Incubation-Based Methods in Monterey Bay
Type: Journal Article
Publication: Journal of Geophysical Research: Oceans
Author(s): Manning, C.C., Stanley, R., Nicholson, D., Smith, J., Pennington, J.T., Fewings, M., Squibb, M., and Chavez, F.
Year: 2017
Formatted Citation: Manning, C.C., Stanley, R., Nicholson, D., Smith, J., Pennington, J.T., Fewings, M., Squibb, M., and Chavez, F., 2017: Impact of Recently Upwelled Water on Productivity Investigated Using In Situ and Incubation-Based Methods in Monterey Bay, Journal of Geophysical Research: Oceans, 122(3), 1901-1926, 10.1002/2016JC012306.
Abstract:
Keywords:
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URL: https://doi.org/10.1002/2016JC012306
Other URLs:
Meissner, T., Ricciardulli, L., and Wentz, F.J. (2017). Capability of the SMAP Mission to Measure Ocean Surface Winds in Storms, Bulletin of the American Meteorological Society, 98, 1660–1677, 10.1175/BAMS-D-16-0052.1. Journal Article »
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Title: Capability of the SMAP Mission to Measure Ocean Surface Winds in Storms
Type: Journal Article
Publication: Bulletin of the American Meteorological Society
Author(s): Meissner, T., Ricciardulli, L., and Wentz, F.J.
Year: 2017
Formatted Citation: Meissner, T., Ricciardulli, L., and Wentz, F.J., 2017: Capability of the SMAP Mission to Measure Ocean Surface Winds in Storms, Bulletin of the American Meteorological Society, 98, 1660–1677, 10.1175/BAMS-D-16-0052.1.
Abstract:
Keywords:
Mission:
URL: https://doi.org/10.1175/BAMS-D-16-0052.1
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O'Neill, L.W., Haack, T., Chelton, D.B., and Skyllingstad, E. (2017). The Gulf Stream Convergence Zone in the Time-Mean Winds, Journal of the Atmospheric Sciences, 74, 2383–2412, 10.1175/JAS-D-16-0213.1. Journal Article »
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Title: The Gulf Stream Convergence Zone in the Time-Mean Winds
Type: Journal Article
Publication: Journal of the Atmospheric Sciences
Author(s): O'Neill, L.W., Haack, T., Chelton, D.B., and Skyllingstad, E.
Year: 2017
Formatted Citation: O'Neill, L.W., Haack, T., Chelton, D.B., and Skyllingstad, E., 2017: The Gulf Stream Convergence Zone in the Time-Mean Winds, Journal of the Atmospheric Sciences, 74, 2383–2412, 10.1175/JAS-D-16-0213.1.
Abstract:
Keywords:
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URL: https://doi.org/10.1175/JAS-D-16-0213.1
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Samelson, R.M. (2017). Time-Dependent Linear Theory for the Generation of Poleward Undercurrents on Eastern Boundaries, Journal of Physical Oceanography, 47, 3037–3059, 10.1175/JPO-D-17-0077.1. Journal Article »
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Title: Time-Dependent Linear Theory for the Generation of Poleward Undercurrents on Eastern Boundaries
Type: Journal Article
Publication: Journal of Physical Oceanography
Author(s): Samelson, R.M.
Year: 2017
Formatted Citation: Samelson, R.M., 2017: Time-Dependent Linear Theory for the Generation of Poleward Undercurrents on Eastern Boundaries, Journal of Physical Oceanography, 47, 3037–3059, 10.1175/JPO-D-17-0077.1.
Abstract:
Keywords:
Mission:
URL: https://doi.org/10.1175/JPO-D-17-0077.1
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Srinivasu, U., Ravichandran, M., Han, W., Sivareddy, S., Rahman, H., Li, Y., and Nayak, S. (2017). Causes for the Reversal of North Indian Ocean Decadal Sea Level Trend in Recent Two Decades, Climate Dynamics, 49(11-12), 3887-3904, 10.1007/s00382-017-3551-y. Journal Article »
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Title: Causes for the Reversal of North Indian Ocean Decadal Sea Level Trend in Recent Two Decades
Type: Journal Article
Publication: Climate Dynamics
Author(s): Srinivasu, U., Ravichandran, M., Han, W., Sivareddy, S., Rahman, H., Li, Y., and Nayak, S.
Year: 2017
Formatted Citation: Srinivasu, U., Ravichandran, M., Han, W., Sivareddy, S., Rahman, H., Li, Y., and Nayak, S., 2017: Causes for the Reversal of North Indian Ocean Decadal Sea Level Trend in Recent Two Decades, Climate Dynamics, 49(11-12), 3887-3904, 10.1007/s00382-017-3551-y.
Abstract:
Keywords:
Mission:
URL: https://doi.org/10.1007/s00382-017-3551-y
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van der Wiel, K., Gille, S.T., Llewellyn Smith, S.G., Linden, P.F., and Cenedese, C. (2017). Characteristics of Colliding Sea Breeze Gravity Current Fronts: A Laboratory Study, Quarterly Journal of the Royal Meteorological Society, 143, 1434-1441, 10.1002/qj.3015. Journal Article »
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Title: Characteristics of Colliding Sea Breeze Gravity Current Fronts: A Laboratory Study
Type: Journal Article
Publication: Quarterly Journal of the Royal Meteorological Society
Author(s): van der Wiel, K., Gille, S.T., Llewellyn Smith, S.G., Linden, P.F., and Cenedese, C.
Year: 2017
Formatted Citation: van der Wiel, K., Gille, S.T., Llewellyn Smith, S.G., Linden, P.F., and Cenedese, C., 2017: Characteristics of Colliding Sea Breeze Gravity Current Fronts: A Laboratory Study, Quarterly Journal of the Royal Meteorological Society, 143, 1434-1441, 10.1002/qj.3015.
Abstract:
Keywords:
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URL: https://doi.org/10.1002/qj.3015
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Wentz, F.J., Ricciardulli, L., Rodriguez, E., Stiles, B., Bourassa, M., Long, D., Hoffman, R., Stoffelen, A., Verhoef, A., O'Neill, L., Farrar, T., Vandemark, D., Fore, A., Hristova Veleva, S., Turk, J., Gaston, R., and Tyler, D. (2017). Evaluating and Extending the Ocean Wind Climate Data Record, IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 10(5), 2165 - 2185, 10.1109/JSTARS.2016.2643641. Journal Article »
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Title: Evaluating and Extending the Ocean Wind Climate Data Record
Type: Journal Article
Publication: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Author(s): Wentz, F.J., Ricciardulli, L., Rodriguez, E., Stiles, B., Bourassa, M., Long, D., Hoffman, R., Stoffelen, A., Verhoef, A., O'Neill, L., Farrar, T., Vandemark, D., Fore, A., Hristova Veleva, S., Turk, J., Gaston, R., and Tyler, D.
Year: 2017
Formatted Citation: Wentz, F.J., Ricciardulli, L., Rodriguez, E., Stiles, B., Bourassa, M., Long, D., Hoffman, R., Stoffelen, A., Verhoef, A., O'Neill, L., Farrar, T., Vandemark, D., Fore, A., Hristova Veleva, S., Turk, J., Gaston, R., and Tyler, D., 2017: Evaluating and Extending the Ocean Wind Climate Data Record, IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 10(5), 2165 - 2185, 10.1109/JSTARS.2016.2643641.
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URL: https://doi.org/10.1109/JSTARS.2016.2643641
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Yurovsky, Y.Y., Kudryavtsev, V.N., Grodsky, S.A., and Chapron, B. (2017). Ka-Band Dual Copolarized Empirical Model for the Sea Surface Radar Cross Section, IEEE Transactions on Geoscience and Remote Sensing, 55(3), 1629-1647, 10.1109/TGRS.2016.2628640. Journal Article »
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Title: Ka-Band Dual Copolarized Empirical Model for the Sea Surface Radar Cross Section
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Yurovsky, Y.Y., Kudryavtsev, V.N., Grodsky, S.A., and Chapron, B.
Year: 2017
Formatted Citation: Yurovsky, Y.Y., Kudryavtsev, V.N., Grodsky, S.A., and Chapron, B., 2017: Ka-Band Dual Copolarized Empirical Model for the Sea Surface Radar Cross Section, IEEE Transactions on Geoscience and Remote Sensing, 55(3), 1629-1647, 10.1109/TGRS.2016.2628640.
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URL: https://doi.org/10.1109/TGRS.2016.2628640
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Ali, M.M., Bourassa, M.A., Bhowmick, S.A., Sharma, R., and Niharika, K. (2016). Retrieval of Wind Stress at the Ocean Surface From AltiKa Measurements, IEEE Geoscience and Remote Sensing Letters, 13(6), 821-825, 10.1109/LGRS.2016.2547969. Journal Article »
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Title: Retrieval of Wind Stress at the Ocean Surface From AltiKa Measurements
Type: Journal Article
Publication: IEEE Geoscience and Remote Sensing Letters
Author(s): Ali, M.M., Bourassa, M.A., Bhowmick, S.A., Sharma, R., and Niharika, K.
Year: 2016
Formatted Citation: Ali, M.M., Bourassa, M.A., Bhowmick, S.A., Sharma, R., and Niharika, K., 2016: Retrieval of Wind Stress at the Ocean Surface From AltiKa Measurements, IEEE Geoscience and Remote Sensing Letters, 13(6), 821-825, 10.1109/LGRS.2016.2547969.
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URL: https://doi.org/10.1109/LGRS.2016.2547969
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Ali, M.M., Neetu, S., Suresh Kumar, M., Zheng, Y., Bourassa, M., and Rao, C.V. (2016). Dominant Thermal Interaction with Atmospheric Processes Occurs in the Upper 50m of the Indian Ocean, Geophysical Research Letters, 13, 821-825.
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Title: Dominant Thermal Interaction with Atmospheric Processes Occurs in the Upper 50m of the Indian Ocean
Type: Journal Article
Publication: Geophysical Research Letters
Author(s): Ali, M.M., Neetu, S., Suresh Kumar, M., Zheng, Y., Bourassa, M., and Rao, C.V.
Year: 2016
Formatted Citation: Ali, M.M., Neetu, S., Suresh Kumar, M., Zheng, Y., Bourassa, M., and Rao, C.V., 2016: Dominant Thermal Interaction with Atmospheric Processes Occurs in the Upper 50m of the Indian Ocean, Geophysical Research Letters, 13, 821-825.
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Aristizábal, M., Fewings, M.R., and Washburn, L. (2016). Contrasting Spatial Patterns in the Diurnal and Semidiurnal Temperature Variability in the Santa Barbara Channel, California, Journal of Geophysical Research, 121(1), 427-440, 10.1002/2015JC011239. Journal Article »
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Title: Contrasting Spatial Patterns in the Diurnal and Semidiurnal Temperature Variability in the Santa Barbara Channel, California
Type: Journal Article
Publication: Journal of Geophysical Research
Author(s): Aristizábal, M., Fewings, M.R., and Washburn, L.
Year: 2016
Formatted Citation: Aristizábal, M., Fewings, M.R., and Washburn, L., 2016: Contrasting Spatial Patterns in the Diurnal and Semidiurnal Temperature Variability in the Santa Barbara Channel, California, Journal of Geophysical Research, 121(1), 427-440, 10.1002/2015JC011239.
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URL: https://doi.org/10.1002/2015JC011239
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Bentamy, A., Piollé, J.F., Grouazel, A., Paul, F., Azelmat, H., Mathieu, P.P., Schuchmann, K.V., Sathyendranah, S., King, H.E., Danielson, R., Esau, I., Johannessen, J., Gulev, S., Clayson, C. A., Pinker, R., Grodsky, S., Bourassa, M., Smith, S. R., Haines, K., Valdivieso, M., Merchant, C., Chapron, B., Anderson, A., Hollmann, R., and Simon, J. (2016). Towards Improved Estimation of Turbulent Heat Flux over the Global Oceans, Remote Sensing of Environment.
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Title: Towards Improved Estimation of Turbulent Heat Flux over the Global Oceans
Type: Journal Article
Publication: Remote Sensing of Environment
Author(s): Bentamy, A., Piollé, J.F., Grouazel, A., Paul, F., Azelmat, H., Mathieu, P.P., Schuchmann, K.V., Sathyendranah, S., King, H.E., Danielson, R., Esau, I., Johannessen, J., Gulev, S., Clayson, C. A., Pinker, R., Grodsky, S., Bourassa, M., Smith, S. R., Haines, K., Valdivieso, M., Merchant, C., Chapron, B., Anderson, A., Hollmann, R., and Simon, J.
Year: 2016
Formatted Citation: Bentamy, A., Piollé, J.F., Grouazel, A., Paul, F., Azelmat, H., Mathieu, P.P., Schuchmann, K.V., Sathyendranah, S., King, H.E., Danielson, R., Esau, I., Johannessen, J., Gulev, S., Clayson, C. A., Pinker, R., Grodsky, S., Bourassa, M., Smith, S. R., Haines, K., Valdivieso, M., Merchant, C., Chapron, B., Anderson, A., Hollmann, R., and Simon, J., 2016: Towards Improved Estimation of Turbulent Heat Flux over the Global Oceans, Remote Sensing of Environment.
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Brocca, L., Massari, C., Ciabatta, L., Wagner, W., and Stoffelen, A. (2016). Remote Sensing of Terrestrial Rainfall From Ku-Band Scatterometers, IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 9(1), 533-539, 10.1109/JSTARS.2015.2508065. Journal Article »
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Title: Remote Sensing of Terrestrial Rainfall From Ku-Band Scatterometers
Type: Journal Article
Publication: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Author(s): Brocca, L., Massari, C., Ciabatta, L., Wagner, W., and Stoffelen, A.
Year: 2016
Formatted Citation: Brocca, L., Massari, C., Ciabatta, L., Wagner, W., and Stoffelen, A., 2016: Remote Sensing of Terrestrial Rainfall From Ku-Band Scatterometers, IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 9(1), 533-539, 10.1109/JSTARS.2015.2508065.
Abstract: Rainfall is the most fundamental variable of the terrestrial hydrological cycle. However, in many regions of the world, ground observations are still very scarce or even missing. Recently, a bottom-up approach, named SM2RAIN, for terrestrial rainfall estimation from satellite soil moisture (SM) products was proposed and successfully applied to C- and L-band products from scatterometers and radiometers. Thanks to the multiple Ku-band scatterometers launched in the recent years and a number of new sensors expected in the near future, accurate rainfall estimation at subdaily time scale could be obtained. We present here a first attempt to estimate terrestrial rainfall from Ku-band scatterometers using SM2RAIN. To this end, backscattering data (sigma-0) collected in central Italy from the RapidScat instrument on board the International Space Station are compared with the Advanced SCATterometer (ASCAT, C-band) SM product and in situ observations for assessing its sensitivity to SM variations. Then, RapidScat sigma-0 is used for rainfall retrieval and compared with ground observations over a regular grid of 15-km spacing. The 8-month period from Nov 2014 to Jun 2015 is considered. Results show a very good agreement between ASCAT SM and RapidScat SM index with a median temporal correlation coefficient R of similar to 0.9 and a reasonable performance (R > 0.52) against in situ data. More interestingly, the performance of RapidScat in 1-day rainfall estimation is found to be satisfactory with median R-values equal to similar to 0.6. These promising results highlight the large potential of using the constellation of scatterometers for providing an accurate rainfall product with high spatial-temporal resolution.
Keywords: Hydrology; radar applications; rain; soil measurements
Mission: |ASCAT|
URL: https://doi.org/10.1109/JSTARS.2015.2508065
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Cahill, B., Wilkin, J., Fennel, K., Vandemark, D., and Friedrichs, M.A.M. (2016). Interannual and Seasonal Variabilities in Air-Sea CO₂ Fluxes Along the U.S. Eastern Continental Shelf and Their Sensitivity to Increasing Air Temperatures and Variable Winds: U.S. East Coast Shelf Air-Sea CO₂ Fluxes, Journal of Geophysical Research: Biogeosciences, 121(2), 295-311, 10.1002/2015JG002939. Journal Article »
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Title: Interannual and Seasonal Variabilities in Air-Sea CO₂ Fluxes Along the U.S. Eastern Continental Shelf and Their Sensitivity to Increasing Air Temperatures and Variable Winds: U.S. East Coast Shelf Air-Sea CO₂ Fluxes
Type: Journal Article
Publication: Journal of Geophysical Research: Biogeosciences
Author(s): Cahill, B., Wilkin, J., Fennel, K., Vandemark, D., and Friedrichs, M.A.M.
Year: 2016
Formatted Citation: Cahill, B., Wilkin, J., Fennel, K., Vandemark, D., and Friedrichs, M.A.M., 2016: Interannual and Seasonal Variabilities in Air-Sea CO₂ Fluxes Along the U.S. Eastern Continental Shelf and Their Sensitivity to Increasing Air Temperatures and Variable Winds: U.S. East Coast Shelf Air-Sea CO₂ Fluxes, Journal of Geophysical Research: Biogeosciences, 121(2), 295-311, 10.1002/2015JG002939.
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URL: https://doi.org/10.1002/2015JG002939
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Chen, S.S. and Curcic, M. (2016). Ocean Surface Waves in Hurricane Ike (2008) and Superstorm Sandy (2012): Coupled Model Predictions and Observations, Ocean Modeling, 103, 161-176, 10.1016/j.ocemod.2015.08.005. Journal Article »
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Title: Ocean Surface Waves in Hurricane Ike (2008) and Superstorm Sandy (2012): Coupled Model Predictions and Observations
Type: Journal Article
Publication: Ocean Modeling
Author(s): Chen, S.S. and Curcic, M.
Year: 2016
Formatted Citation: Chen, S.S. and Curcic, M., 2016: Ocean Surface Waves in Hurricane Ike (2008) and Superstorm Sandy (2012): Coupled Model Predictions and Observations, Ocean Modeling, 103, 161-176, 10.1016/j.ocemod.2015.08.005.
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URL: https://doi.org/10.1016/j.ocemod.2015.08.005
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Dong, Z.Q., Liu S.Y., Chen, X.G., Shi, Y.T., Zhang, C.W., and Jiang, H. (2016). Optimization of Measurement Configuration in Pptical Scatterometry for One-Dimensional Nanostructure Based on Sensitivity Analysis, GEC Journal of Research Incorporating the Marconi Reviewfrared and Millimeter Waves, 35(1), 116-122.
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Title: Optimization of Measurement Configuration in Pptical Scatterometry for One-Dimensional Nanostructure Based on Sensitivity Analysis
Type: Journal Article
Publication: GEC Journal of Research Incorporating the Marconi Reviewfrared and Millimeter Waves
Author(s): Dong, Z.Q., Liu S.Y., Chen, X.G., Shi, Y.T., Zhang, C.W., and Jiang, H.
Year: 2016
Formatted Citation: Dong, Z.Q., Liu S.Y., Chen, X.G., Shi, Y.T., Zhang, C.W., and Jiang, H., 2016: Optimization of Measurement Configuration in Pptical Scatterometry for One-Dimensional Nanostructure Based on Sensitivity Analysis, GEC Journal of Research Incorporating the Marconi Reviewfrared and Millimeter Waves, 35(1), 116-122.
Abstract: In optical scatterometry, the sensitivity has a significant impact on the precision of the extracted structral parameters in addition to the quality of the measured signatures. As the sensitivity of structral parameters can be improved with the proper selection of measurement configuration (a combination of wavelengths, incidence, and azimuthal angles), we proposed a method to determine an optimal one for optical scatterometry based on sensitivity analysis. Experiments performed on a one-dimensional periodic grating show agreement between the theoretically predicted and experimentally obtained optimal measurement configurations, which demonstrates the validity of the proposed optimization method.
Keywords: optical scatterometry; sensitivity analysis; measurement configuration; precision
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Fang, L., Hain, C.R., Zhan, X.W. and Anderson, M.C. (2016). An Inter-Comparison of Soil Moisture Data Products from Satellite Remote Sensing and a Land Surface Model, International Journal of Applied Earth Observation and Geoinformation, 48, 37-50, 10.1016/j.jag.2015.10.006. Journal Article »
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Title: An Inter-Comparison of Soil Moisture Data Products from Satellite Remote Sensing and a Land Surface Model
Type: Journal Article
Publication: International Journal of Applied Earth Observation and Geoinformation
Author(s): Fang, L., Hain, C.R., Zhan, X.W. and Anderson, M.C.
Year: 2016
Formatted Citation: Fang, L., Hain, C.R., Zhan, X.W. and Anderson, M.C., 2016: An Inter-Comparison of Soil Moisture Data Products from Satellite Remote Sensing and a Land Surface Model, International Journal of Applied Earth Observation and Geoinformation, 48, 37-50, 10.1016/j.jag.2015.10.006.
Abstract: Significant advances have been achieved in generating soil moisture (SM) products from satellite remote sensing and/or land surface modeling with reasonably good accuracy in recent years. However, the discrepancies among the different SM data products can be considerably large, which hampers their usage in various applications. The bias of one SM product from another is well recognized in the literature. Bias estimation and spatial correction methods have been documented for assimilating satellite SM product into land surface and hydrologic models. Nevertheless, understanding the characteristics of each of these SM data products is required for many applications where the most accurate data products are desirable. This study inter-compares five SM data products from three different sources with each other, and evaluates them against in situ SM measurements over 14-year period from 2000 to 2013. Specifically, three microwave (MW) satellite based data sets provided by ESA's Climate Change Initiative (CCI) (CCI-merged, -active and -passive products), one thermal infrared (TIR) satellite based product (ALEXI), and the Noah land surface model (LSM) simulations. The in-situ SM measurements are collected from the North American Soil Moisture Database - NASMD, which involves more than 600 ground sites from a variety of networks. They are used to evaluate the accuracies of these five SM data products. In general, each of the five SM products is capable of capturing the dry/wet patterns over the study period. However, the absolute SM values among the five products vary significantly. SM simulations from Noah LSM are more stable relative to the satellite-based products. All TIR and MW satellite based products are relatively noisier than the Noah LSM simulations. Even though MW satellite based SM retrievals have been predominantly used in the past years, SM retrievals of the ALEXI model based on TIR satellite observations demonstrate skills equivalent to all the MW satellite retrievals and even slightly better over certain regions. Compared to the individual active and passive MW products, the merged CCI product exhibits higher anomaly correlation with both Noah LSM simulations and in-situ SM measurements.
Keywords: Soil moisture product; Validation; Active and passive microwave; Thermal infrared remote sensing
Mission: |ASCAT|
URL: https://doi.org/10.1016/j.jag.2015.10.006
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Fewings, M.R., Washburn, L., Dorman, C.E., Gotschalk, C., and Lombardo, K. (2016). Synoptic Forcing of Wind Relaxations at Pt. Conception, California, Journal of Geophysical Research: Oceans, 121(8), 5711-5730, 10.1002/2016JC011699. Journal Article »
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Title: Synoptic Forcing of Wind Relaxations at Pt. Conception, California
Type: Journal Article
Publication: Journal of Geophysical Research: Oceans
Author(s): Fewings, M.R., Washburn, L., Dorman, C.E., Gotschalk, C., and Lombardo, K.
Year: 2016
Formatted Citation: Fewings, M.R., Washburn, L., Dorman, C.E., Gotschalk, C., and Lombardo, K., 2016: Synoptic Forcing of Wind Relaxations at Pt. Conception, California, Journal of Geophysical Research: Oceans, 121(8), 5711-5730, 10.1002/2016JC011699.
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URL: https://doi.org/10.1002/2016JC011699
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Flynn, K. (2016). The Causes of Regional Sea-Surface Temperature Anomalies During Wind Relaxation Events Off the U.S. West Coast in Summer, Thesis »
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Title: The Causes of Regional Sea-Surface Temperature Anomalies During Wind Relaxation Events Off the U.S. West Coast in Summer
Type: Thesis
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Author(s): Flynn, K.
Year: 2016
Formatted Citation: Flynn, K., 2016: The Causes of Regional Sea-Surface Temperature Anomalies During Wind Relaxation Events Off the U.S. West Coast in Summer,
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URL: http://opencommons.uconn.edu/gs_theses/984
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Guo, J., Zhang, H., Cui, T.W., He, Y.J., Zhang, J., Guo, K., Hou, C.W., and Liu, R.J. (2016). Remote Sensing Observations of the Winter Yellow Sea Warm Current Invasion into the Bohai Sea, China, Advances in Meterology, 2016, 10.1155/2016/8170296. Journal Article »
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Title: Remote Sensing Observations of the Winter Yellow Sea Warm Current Invasion into the Bohai Sea, China
Type: Journal Article
Publication: Advances in Meterology
Author(s): Guo, J., Zhang, H., Cui, T.W., He, Y.J., Zhang, J., Guo, K., Hou, C.W., and Liu, R.J.
Year: 2016
Formatted Citation: Guo, J., Zhang, H., Cui, T.W., He, Y.J., Zhang, J., Guo, K., Hou, C.W., and Liu, R.J., 2016: Remote Sensing Observations of the Winter Yellow Sea Warm Current Invasion into the Bohai Sea, China, Advances in Meterology, 2016, 10.1155/2016/8170296.
Abstract: Using ASCAT, QuikSCAT, and MODIS data, we analyzed the sea surface wind field, temperature, salinity, and chlorophyll concentrations in the mixed zone between the Bohai Sea and Yellow Sea in the winter (the period of winter 2013 included December 2013 and January-February 2014) from 2002 to 2013. We found that the intrusion of the Yellow Sea Warm Current into the Bohai Sea occurred three times in the winters of 2007 (strongest), 2004, and 2013 (weakest) during this 12-year period. We present detailed validation of the intrusion in 2013. This study shows that the intrusion of the Yellow Sea Warm Current into the Bohai Sea occurred when the wind speed, sea surface temperature, and salinity were above (or close to) the multiyear average and the chlorophyll concentration was less than the multiyear average.
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Mission: |ASCAT|
URL: https://doi.org/10.1155/2016/8170296
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Hilburn, K.A., Meissner, T., Wentz, F.J., and Brown, S.T. (2016). Ocean Vector Winds From WindSat Two-Look Polarmetric Radiances, Journal Article »
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Title: Ocean Vector Winds From WindSat Two-Look Polarmetric Radiances
Type: Journal Article
Publication:
Author(s): Hilburn, K.A., Meissner, T., Wentz, F.J., and Brown, S.T.
Year: 2016
Formatted Citation: Hilburn, K.A., Meissner, T., Wentz, F.J., and Brown, S.T., 2016: Ocean Vector Winds From WindSat Two-Look Polarmetric Radiances,
Abstract: WindSat has been providing accurate ocean vector winds (OVWs) for over a decade. WindSat makes polarimetric brightness temperature measurements of Earth looking forwards and backwards. However, because the overlap of these two swaths is relatively narrow, the benefit of two-look polarimetric (2LP) retrieval accuracy has not been utilized. This paper derives OVW from WindSat 2LP measurements using a radiative transfermodel and maximum-likelihood estimation. The purpose of this paper is a comparison of WindSat 2LP wind direction accuracy with WindSat one-look, QuikSCAT, and Advanced Scatterometer (ASCAT) wind directions. Retrievals are compared with anemometer measurements on collocated moored buoys. Statistics are examined for both the first-ranked wind direction ambiguity and the selected ambiguity after median filtering initialized with a numerical weather prediction wind field. For winds above 8 m/s, WindSat 2LP retrievals have the most accurate first-ranked direction compared with all other sensors. For winds of 6-9 m/s, the standard deviation relative to buoys is 17 degrees, and for 9-20 m/s, it is less than 10 degrees. One-look standard deviations are nearly twice as large. At low winds, QuikSCAT provides the most accurate wind directions, for first-ranked and selected ambiguity. Thus, scatterometer and radiometer OVW measurements provide complementary capabilities. The accuracy of 2LP OVW is particularly relevant now that new internal calibration technology allows for a 360 degrees conical scan of earth observations. Moreover, new low-cost designs would make it possible to affordably deploy a constellation of OVW sensors capable of providing accurate winds under a wide range of conditions, described herein.
Keywords: Advanced Scatterometer (ASCAT); maximum-likelihood estimation; microwave radiometer; multilook radiometry; ocean vector winds (OVW); passive microwave remote sensing; polarimetric radiometry; QuikSCAT; scatterometer; WindSat
Mission: |WindSat|ASCAT|
URL: https://doi.org/10.1109/TGRS.2015.2469633
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Keclik, A.M., Powell, M.D., Smith, S.R., and Bourassa, M.A. (2016). Comparing U.S. Tropical Cyclone Landfall Statistics to Landfalls Interpolated from NHC Forecasts (2001-2012), Natural Hazards.
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Title: Comparing U.S. Tropical Cyclone Landfall Statistics to Landfalls Interpolated from NHC Forecasts (2001-2012)
Type: Journal Article
Publication: Natural Hazards
Author(s): Keclik, A.M., Powell, M.D., Smith, S.R., and Bourassa, M.A.
Year: 2016
Formatted Citation: Keclik, A.M., Powell, M.D., Smith, S.R., and Bourassa, M.A., 2016: Comparing U.S. Tropical Cyclone Landfall Statistics to Landfalls Interpolated from NHC Forecasts (2001-2012), Natural Hazards.
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Kidwell, A., Lee, T., Jo, Y.-H., and Yan, X.-H. (2016). Characterization of the Variability of the South Pacific Convergence Zone Using Satellite and Reanalysis Wind Products, Journal of Climate, 29(5), 1717-1732, 10.1175/JCLI-D-15-0536.1. Journal Article »
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Title: Characterization of the Variability of the South Pacific Convergence Zone Using Satellite and Reanalysis Wind Products
Type: Journal Article
Publication: Journal of Climate
Author(s): Kidwell, A., Lee, T., Jo, Y.-H., and Yan, X.-H.
Year: 2016
Formatted Citation: Kidwell, A., Lee, T., Jo, Y.-H., and Yan, X.-H., 2016: Characterization of the Variability of the South Pacific Convergence Zone Using Satellite and Reanalysis Wind Products, Journal of Climate, 29(5), 1717-1732, 10.1175/JCLI-D-15-0536.1.
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URL: https://doi.org/10.1175/JCLI-D-15-0536.1
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Kilpatrick, T., Schneider, N., and Qiu, B. (2016). Atmospheric Response to a Midlatitude SST Front: Alongfront Winds, Journal of the Atmospheric Sciences, 73(9), 3489-3509, 10.1175/JAS-D-15-0312.1. Journal Article »
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Title: Atmospheric Response to a Midlatitude SST Front: Alongfront Winds
Type: Journal Article
Publication: Journal of the Atmospheric Sciences
Author(s): Kilpatrick, T., Schneider, N., and Qiu, B.
Year: 2016
Formatted Citation: Kilpatrick, T., Schneider, N., and Qiu, B., 2016: Atmospheric Response to a Midlatitude SST Front: Alongfront Winds, Journal of the Atmospheric Sciences, 73(9), 3489-3509, 10.1175/JAS-D-15-0312.1.
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URL: https://doi.org/10.1175/JAS-D-15-0312.1
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Kilpatrick, T.J. and Xie, S.-P. (2016). Circumventing Rain-Related Errors in Scatterometer Wind Observations, Journal of Geophysical Research: Atmospheres, 121(16), 9422-9440, 10.1002/2016JD025105. Journal Article »
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Title: Circumventing Rain-Related Errors in Scatterometer Wind Observations
Type: Journal Article
Publication: Journal of Geophysical Research: Atmospheres
Author(s): Kilpatrick, T.J. and Xie, S.-P.
Year: 2016
Formatted Citation: Kilpatrick, T.J. and Xie, S.-P., 2016: Circumventing Rain-Related Errors in Scatterometer Wind Observations, Journal of Geophysical Research: Atmospheres, 121(16), 9422-9440, 10.1002/2016JD025105.
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URL: https://doi.org/10.1002/2016JD025105
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Koster, R.D., Brocca, L., Crow, W.T., Burgin, M.S., and De Lannoy, G.J.M. (2016). Precipitation Estimation Using L-band and C-band Soil Moisture Retrievals: Precipitation Estimation from Soil Moisture Retrievals, Water Resources Research, 52(9), 7213-7225, 10.1002/2016WR019024. Journal Article »
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Title: Precipitation Estimation Using L-band and C-band Soil Moisture Retrievals: Precipitation Estimation from Soil Moisture Retrievals
Type: Journal Article
Publication: Water Resources Research
Author(s): Koster, R.D., Brocca, L., Crow, W.T., Burgin, M.S., and De Lannoy, G.J.M.
Year: 2016
Formatted Citation: Koster, R.D., Brocca, L., Crow, W.T., Burgin, M.S., and De Lannoy, G.J.M., 2016: Precipitation Estimation Using L-band and C-band Soil Moisture Retrievals: Precipitation Estimation from Soil Moisture Retrievals, Water Resources Research, 52(9), 7213-7225, 10.1002/2016WR019024.
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Keywords: precipitation; soil moisture; remote sensing
Mission: |ASCAT|
URL: https://doi.org/10.1002/2016WR019024
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Kwok, R., Comiso, J.C., Lee, T., and Holland, P.R. (2016). Linked Trends in the South Pacific Sea Ice Edge and Southern Oscillation Index, Geophysical Research Letters, 43(19), 10,295-10,302, 10.1002/2016GL070655. Journal Article »
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Title: Linked Trends in the South Pacific Sea Ice Edge and Southern Oscillation Index
Type: Journal Article
Publication: Geophysical Research Letters
Author(s): Kwok, R., Comiso, J.C., Lee, T., and Holland, P.R.
Year: 2016
Formatted Citation: Kwok, R., Comiso, J.C., Lee, T., and Holland, P.R., 2016: Linked Trends in the South Pacific Sea Ice Edge and Southern Oscillation Index, Geophysical Research Letters, 43(19), 10,295-10,302, 10.1002/2016GL070655.
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URL: https://doi.org/10.1002/2016GL070655
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Li, D.L., von Storch, H., and Geyer, B. (2016). High-Resolution Wind Hindmost Over the Bohai Sea and the Yellow Sea in East Asia: Evaluation and Wind Climatology Analysis, Journal Article »
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Title: High-Resolution Wind Hindmost Over the Bohai Sea and the Yellow Sea in East Asia: Evaluation and Wind Climatology Analysis
Type: Journal Article
Publication:
Author(s): Li, D.L., von Storch, H., and Geyer, B.
Year: 2016
Formatted Citation: Li, D.L., von Storch, H., and Geyer, B., 2016: High-Resolution Wind Hindmost Over the Bohai Sea and the Yellow Sea in East Asia: Evaluation and Wind Climatology Analysis,
Abstract: A 34year (1979-2012) high-resolution (7km grid) atmospheric hindcast over the Bohai Sea and the Yellow Sea (BYS) has been performed using COSMO-CLM (CCLM) forced by ERA-Interim reanalysis data (ERA-I). The accuracy of CCLM in surface wind reproduction and the added value of dynamical downscaling to ERA-I have been investigated through comparisons with the QuikSCAT Level2B 12.5km version 3 (L2B12v3) swath data and in situ observations. The results revealed that CCLM has a reliable ability to reproduce the regional wind characteristics over the BYS. Added value to ERA-I has been detected in the coastal areas with complex orography. CCLM wind quality had strong seasonal variability, with better performance in the summer relative to ERA-I, even in the offshore areas. CCLM was better able to represent light and moderate winds but had even more added value for strong winds relative to ERA-I. The spatial digital filter method was used to investigate the scale of the added value, and the results show that CCLM adds value to ERA-I mainly in medium scales of wind variability. Furthermore, wind climatology was investigated, and significant increasing trends in the south Yellow Sea especially in winter and spring were found for seasonal mean wind speeds.
Keywords: surface wind; COSMO-CLM; added value; dynamical downscaling; Bohai Sea and Yellow Sea
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URL: https://doi.org/10.1002/2015JD024177
Other URLs:
Li, Y. and Han, W. (2016). Causes for Intraseasonal Sea Surface Salinity Variability in the Western Tropical Pacific Ocean and Its Seasonality, Journal of Geophysical Research: Oceans, 121(1), 85-103, 10.1002/2015JC011413. Journal Article »
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Title: Causes for Intraseasonal Sea Surface Salinity Variability in the Western Tropical Pacific Ocean and Its Seasonality
Type: Journal Article
Publication: Journal of Geophysical Research: Oceans
Author(s): Li, Y. and Han, W.
Year: 2016
Formatted Citation: Li, Y. and Han, W., 2016: Causes for Intraseasonal Sea Surface Salinity Variability in the Western Tropical Pacific Ocean and Its Seasonality, Journal of Geophysical Research: Oceans, 121(1), 85-103, 10.1002/2015JC011413.
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URL: https://doi.org/10.1002/2015JC011413
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Li, Y., Han, W., Wang, W., and Ravichandran, M. (2016). Intraseasonal Variability of SST and Precipitation in the Arabian Sea during Indian Summer Monsoon: Impact of Ocean Mixed Layer Depth, Journal of Climate, 29, 7889-7910, 10.1175/JCLI-D-16-0238.1. Journal Article »
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Title: Intraseasonal Variability of SST and Precipitation in the Arabian Sea during Indian Summer Monsoon: Impact of Ocean Mixed Layer Depth
Type: Journal Article
Publication: Journal of Climate
Author(s): Li, Y., Han, W., Wang, W., and Ravichandran, M.
Year: 2016
Formatted Citation: Li, Y., Han, W., Wang, W., and Ravichandran, M., 2016: Intraseasonal Variability of SST and Precipitation in the Arabian Sea during Indian Summer Monsoon: Impact of Ocean Mixed Layer Depth, Journal of Climate, 29, 7889-7910, 10.1175/JCLI-D-16-0238.1.
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URL: https://doi.org/10.1175/JCLI-D-16-0238.1
Other URLs:
Li, Y., Han, W., Wang, W., and Ravichandran, M. (2016). Intraseasonal Variability of SST and Precipitation in the Arabian Sea During the Indian Summer Monsoon: Impact of Ocean Mixed Layer Depth, Journal of Climate, 29(21), 7889-7910, 10.1175/JCLI-D-16-0238.1. Journal Article »
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Title: Intraseasonal Variability of SST and Precipitation in the Arabian Sea During the Indian Summer Monsoon: Impact of Ocean Mixed Layer Depth
Type: Journal Article
Publication: Journal of Climate
Author(s): Li, Y., Han, W., Wang, W., and Ravichandran, M.
Year: 2016
Formatted Citation: Li, Y., Han, W., Wang, W., and Ravichandran, M., 2016: Intraseasonal Variability of SST and Precipitation in the Arabian Sea During the Indian Summer Monsoon: Impact of Ocean Mixed Layer Depth, Journal of Climate, 29(21), 7889-7910, 10.1175/JCLI-D-16-0238.1.
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URL: https://doi.org/10.1175/JCLI-D-16-0238.1
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Lindell, D. and Long, D. (2016). Multiyear Arctic Ice Classification Using ASCAT and SSMIS, Remote Sensing, 8(4), 294, 10.3390/rs8040294. Journal Article »
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Title: Multiyear Arctic Ice Classification Using ASCAT and SSMIS
Type: Journal Article
Publication: Remote Sensing
Author(s): Lindell, D. and Long, D.
Year: 2016
Formatted Citation: Lindell, D. and Long, D., 2016: Multiyear Arctic Ice Classification Using ASCAT and SSMIS, Remote Sensing, 8(4), 294, 10.3390/rs8040294.
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URL: https://doi.org/10.3390/rs8040294
Other URLs:
Lindell, D.B. and Long, D.G. (2016). High-Resolution Soil Moisture Retrieval With ASCAT, IEEE Geoscience and Remote Sensing Letters, 13(7), 972-976, 10.1109/LGRS.2016.2557321. Journal Article »
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Title: High-Resolution Soil Moisture Retrieval With ASCAT
Type: Journal Article
Publication: IEEE Geoscience and Remote Sensing Letters
Author(s): Lindell, D.B. and Long, D.G.
Year: 2016
Formatted Citation: Lindell, D.B. and Long, D.G., 2016: High-Resolution Soil Moisture Retrieval With ASCAT, IEEE Geoscience and Remote Sensing Letters, 13(7), 972-976, 10.1109/LGRS.2016.2557321.
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URL: https://doi.org/10.1109/LGRS.2016.2557321
Other URLs:
Lindell, D.B. and Long, D.G. (2016). Multiyear Arctic Sea Ice Classification Using OSCAT and QuikSCAT, IEEE Transactions on Geoscience and Remote Sensing, 54(1), 167-175, 10.1109/TGRS.2015.2452215. Journal Article »
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Title: Multiyear Arctic Sea Ice Classification Using OSCAT and QuikSCAT
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Lindell, D.B. and Long, D.G.
Year: 2016
Formatted Citation: Lindell, D.B. and Long, D.G., 2016: Multiyear Arctic Sea Ice Classification Using OSCAT and QuikSCAT, IEEE Transactions on Geoscience and Remote Sensing, 54(1), 167-175, 10.1109/TGRS.2015.2452215.
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URL: https://doi.org/10.1109/TGRS.2015.2452215
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Lindsley, R.D. and Long, D.G. (2016). ASCAT and QuikSCAT Azimuth Modulation of Backscatter Over East Antarctica, IEEE Geoscience and Remote Sensing Letters, 13(8), 1134-1138, 10.1109/LGRS.2016.2572101. Journal Article »
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Title: ASCAT and QuikSCAT Azimuth Modulation of Backscatter Over East Antarctica
Type: Journal Article
Publication: IEEE Geoscience and Remote Sensing Letters
Author(s): Lindsley, R.D. and Long, D.G.
Year: 2016
Formatted Citation: Lindsley, R.D. and Long, D.G., 2016: ASCAT and QuikSCAT Azimuth Modulation of Backscatter Over East Antarctica, IEEE Geoscience and Remote Sensing Letters, 13(8), 1134-1138, 10.1109/LGRS.2016.2572101.
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URL: https://doi.org/10.1109/LGRS.2016.2572101
Other URLs:
Lindsley, R.D. and Long, D.G. (2016). Enhanced-Resolution Reconstruction of ASCAT Backscatter Measurements, IEEE Transactions on Geoscience and Remote Sensing, 54(5), 2589-2601, 10.1109/TGRS.2015.2503762. Journal Article »
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Title: Enhanced-Resolution Reconstruction of ASCAT Backscatter Measurements
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Lindsley, R.D. and Long, D.G.
Year: 2016
Formatted Citation: Lindsley, R.D. and Long, D.G., 2016: Enhanced-Resolution Reconstruction of ASCAT Backscatter Measurements, IEEE Transactions on Geoscience and Remote Sensing, 54(5), 2589-2601, 10.1109/TGRS.2015.2503762.
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URL: https://doi.org/10.1109/TGRS.2015.2503762
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Lindsley, R.D., Anderson, C., Figa-Saldana, J., and Long, D.G. (2016). A Parameterized ASCAT Measurement Spatial Response Function, IEEE Transactions on Geoscience and Remote Sensing, 54(8), 4570-4579, 10.1109/TGRS.2016.2544835. Journal Article »
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Title: A Parameterized ASCAT Measurement Spatial Response Function
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Lindsley, R.D., Anderson, C., Figa-Saldana, J., and Long, D.G.
Year: 2016
Formatted Citation: Lindsley, R.D., Anderson, C., Figa-Saldana, J., and Long, D.G., 2016: A Parameterized ASCAT Measurement Spatial Response Function, IEEE Transactions on Geoscience and Remote Sensing, 54(8), 4570-4579, 10.1109/TGRS.2016.2544835.
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URL: https://doi.org/10.1109/TGRS.2016.2544835
Other URLs:
Lindsley, R.D., Blodgett, J.R., and Long, D.G. (2016). Analysis and Validation of High-Resolution Wind From ASCAT, IEEE Transactions on Geoscience and Remote Sensing, 54(10), 5699-5711, 10.1109/TGRS.2016.2570245. Journal Article »
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Title: Analysis and Validation of High-Resolution Wind From ASCAT
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Lindsley, R.D., Blodgett, J.R., and Long, D.G.
Year: 2016
Formatted Citation: Lindsley, R.D., Blodgett, J.R., and Long, D.G., 2016: Analysis and Validation of High-Resolution Wind From ASCAT, IEEE Transactions on Geoscience and Remote Sensing, 54(10), 5699-5711, 10.1109/TGRS.2016.2570245.
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URL: https://doi.org/10.1109/TGRS.2016.2570245
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Liu, J.-W., Xie, S.-P., Yang, S., and Zhang, S.-P. (2016). Low-Cloud Transitions across the Kuroshio Front in the East China Sea, Journal of Climate, 29(12), 4429-4443, 10.1175/JCLI-D-15-0589.1. Journal Article »
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Title: Low-Cloud Transitions across the Kuroshio Front in the East China Sea
Type: Journal Article
Publication: Journal of Climate
Author(s): Liu, J.-W., Xie, S.-P., Yang, S., and Zhang, S.-P.
Year: 2016
Formatted Citation: Liu, J.-W., Xie, S.-P., Yang, S., and Zhang, S.-P., 2016: Low-Cloud Transitions across the Kuroshio Front in the East China Sea, Journal of Climate, 29(12), 4429-4443, 10.1175/JCLI-D-15-0589.1.
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URL: https://doi.org/10.1175/JCLI-D-15-0589.1
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Long, D.G. and Brodzik, M.J. (2016). Optimum Image Formation for Spaceborne Microwave Radiometer Products, IEEE Transactions on Geoscience and Remote Sensing, 54(5), 2763-2779, 10.1109/TGRS.2015.2505677. Journal Article »
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Title: Optimum Image Formation for Spaceborne Microwave Radiometer Products
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Long, D.G. and Brodzik, M.J.
Year: 2016
Formatted Citation: Long, D.G. and Brodzik, M.J., 2016: Optimum Image Formation for Spaceborne Microwave Radiometer Products, IEEE Transactions on Geoscience and Remote Sensing, 54(5), 2763-2779, 10.1109/TGRS.2015.2505677.
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URL: https://doi.org/10.1109/TGRS.2015.2505677
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Long, D.G. and Franz, R.O.W. (2016). Band-Limited Signal Reconstruction From Irregular Samples With Variable Apertures, IEEE Transactions on Geoscience and Remote Sensing, 54(4), 2424-2436, 10.1109/TGRS.2015.2501366. Journal Article »
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Title: Band-Limited Signal Reconstruction From Irregular Samples With Variable Apertures
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Long, D.G. and Franz, R.O.W.
Year: 2016
Formatted Citation: Long, D.G. and Franz, R.O.W., 2016: Band-Limited Signal Reconstruction From Irregular Samples With Variable Apertures, IEEE Transactions on Geoscience and Remote Sensing, 54(4), 2424-2436, 10.1109/TGRS.2015.2501366.
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URL: https://doi.org/10.1109/TGRS.2015.2501366
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Madsen, M.H. and Hansen, P.E. (2016). Imaging Scatterometry for Flexible Measurements of Patterned Areas, Optics Express, 24(2), 1109-1117, 10.1364/OE.24.001109. Journal Article »
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Title: Imaging Scatterometry for Flexible Measurements of Patterned Areas
Type: Journal Article
Publication: Optics Express
Author(s): Madsen, M.H. and Hansen, P.E.
Year: 2016
Formatted Citation: Madsen, M.H. and Hansen, P.E., 2016: Imaging Scatterometry for Flexible Measurements of Patterned Areas, Optics Express, 24(2), 1109-1117, 10.1364/OE.24.001109.
Abstract: Characterization of micro/nano-textured surfaces is time consuming using scanning probe and electron microscopy techniques. Scatterometry, where the intensity of scattered light is used as a 'fingerprint' to reconstruct a surface, is a fast and robust method for characterization of gratings. However, most scatterometry techniques are measuring the averaged signal over an area equal to the spot size of the light source. In this paper we present the imaging scatterometry technique, which is capable of locally measuring topographic parameters of gratings spanning an area down to a few mu m(2) with nm accuracy. The imaging scatterometer can easily find areas of interest on the cm scale and measure multiple segments simultaneously. We demonstrate two imaging scatterometers, one built into an optical microscope and one in a split configuration. The two scatterometers are targeted characterization of mm(2) and cm(2) areas, respectively, and both setups are validated using nano-textured samples. (C) 2016 Optical Society of America
Keywords: SPECTROSCOPIC SCATTEROMETRY; SURFACES
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URL: https://doi.org/10.1364/OE.24.001109
Other URLs:
Madsen, N.M. and Long, D.G. (2016). Calibration and Validation of the RapidScat Scatterometer Using Tropical Rainforests, IEEE Transactions on Geoscience and Remote Sensing, 54(5), 2846-2854, 10.1109/TGRS.2015.2506463. Journal Article »
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Title: Calibration and Validation of the RapidScat Scatterometer Using Tropical Rainforests
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Madsen, N.M. and Long, D.G.
Year: 2016
Formatted Citation: Madsen, N.M. and Long, D.G., 2016: Calibration and Validation of the RapidScat Scatterometer Using Tropical Rainforests, IEEE Transactions on Geoscience and Remote Sensing, 54(5), 2846-2854, 10.1109/TGRS.2015.2506463.
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URL: https://doi.org/10.1109/TGRS.2015.2506463
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McGregor, S., Gupta, A.S., Dommenget, D., Lee, T., McPhaden, M.J., and Kessler, W.S. (2016). Factors Influencing the Skill of Synthesized Satellite Wind Products in the Tropical Pacific, Journal of Geophysical Research: Oceans, 122(2), 1072-1089, 10.1002/2016JC012340. Journal Article »
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Title: Factors Influencing the Skill of Synthesized Satellite Wind Products in the Tropical Pacific
Type: Journal Article
Publication: Journal of Geophysical Research: Oceans
Author(s): McGregor, S., Gupta, A.S., Dommenget, D., Lee, T., McPhaden, M.J., and Kessler, W.S.
Year: 2016
Formatted Citation: McGregor, S., Gupta, A.S., Dommenget, D., Lee, T., McPhaden, M.J., and Kessler, W.S., 2016: Factors Influencing the Skill of Synthesized Satellite Wind Products in the Tropical Pacific, Journal of Geophysical Research: Oceans, 122(2), 1072-1089, 10.1002/2016JC012340.
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URL: https://doi.org/10.1002/2016JC012340
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Nouguier, F., Mouche, A., Rascle, N., Chapron, B., and Vandemark, D. (2016). Analysis of Dual-Frequency Ocean Backscatter Measurements at Ku- and Ka-Bands Using Near-Nadir Incidence GPM Radar Data, IEEE Geoscience and Remote Sensing Letters, 13(9), 1310-1314, 10.1109/LGRS.2016.2583198. Journal Article »
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Title: Analysis of Dual-Frequency Ocean Backscatter Measurements at Ku- and Ka-Bands Using Near-Nadir Incidence GPM Radar Data
Type: Journal Article
Publication: IEEE Geoscience and Remote Sensing Letters
Author(s): Nouguier, F., Mouche, A., Rascle, N., Chapron, B., and Vandemark, D.
Year: 2016
Formatted Citation: Nouguier, F., Mouche, A., Rascle, N., Chapron, B., and Vandemark, D., 2016: Analysis of Dual-Frequency Ocean Backscatter Measurements at Ku- and Ka-Bands Using Near-Nadir Incidence GPM Radar Data, IEEE Geoscience and Remote Sensing Letters, 13(9), 1310-1314, 10.1109/LGRS.2016.2583198.
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URL: https://doi.org/10.1109/LGRS.2016.2583198
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Paget, A., Brodzik, M., Long, D., and Hardman, M. (2016). Bringing Earth's Microwave Maps into Sharper Focus, EOS, 7, 10.1029/2016EO063675. Journal Article »
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Title: Bringing Earth's Microwave Maps into Sharper Focus
Type: Journal Article
Publication: EOS
Author(s): Paget, A., Brodzik, M., Long, D., and Hardman, M.
Year: 2016
Formatted Citation: Paget, A., Brodzik, M., Long, D., and Hardman, M., 2016: Bringing Earth's Microwave Maps into Sharper Focus, EOS, 7, 10.1029/2016EO063675.
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URL: https://doi.org/10.1029/2016EO063675
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Paget, A.C., Long, D.G., and Madsen, N.M. (2016). RapidScat Diurnal Cycles Over Land, IEEE Transactions on Geoscience and Remote Sensing, 54(6), 3336-3344, 10.1109/TGRS.2016.2515022. Journal Article »
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Title: RapidScat Diurnal Cycles Over Land
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Paget, A.C., Long, D.G., and Madsen, N.M.
Year: 2016
Formatted Citation: Paget, A.C., Long, D.G., and Madsen, N.M., 2016: RapidScat Diurnal Cycles Over Land, IEEE Transactions on Geoscience and Remote Sensing, 54(6), 3336-3344, 10.1109/TGRS.2016.2515022.
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URL: https://doi.org/10.1109/TGRS.2016.2515022
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Park, H., Yoshikawa, Y., Oshima, K., Kim, Y., Thanh, N.D., Kimball, J.S., and Yang, D. (2016). Quantification of Warming Climate-Induced Changes in Terrestrial Arctic River Ice Thickness and Phenology, Journal of Climate, 29(5), 1733-1754, 10.1175/JCLI-D-15-0569.1. Journal Article »
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Title: Quantification of Warming Climate-Induced Changes in Terrestrial Arctic River Ice Thickness and Phenology
Type: Journal Article
Publication: Journal of Climate
Author(s): Park, H., Yoshikawa, Y., Oshima, K., Kim, Y., Thanh, N.D., Kimball, J.S., and Yang, D.
Year: 2016
Formatted Citation: Park, H., Yoshikawa, Y., Oshima, K., Kim, Y., Thanh, N.D., Kimball, J.S., and Yang, D., 2016: Quantification of Warming Climate-Induced Changes in Terrestrial Arctic River Ice Thickness and Phenology, Journal of Climate, 29(5), 1733-1754, 10.1175/JCLI-D-15-0569.1.
Abstract: A land process model [the coupled hydrological and biogeochemical model (CHANGE)] is used to quantitatively assess changes in the ice phenology, thickness, and volume of terrestrial Arctic rivers from 1979 to 2009. The CHANGE model was coupled with a river routing and discharge model enabling explicit representation of river ice and water temperature dynamics. Model-simulated river ice phenological dates and thickness were generally consistent with in situ river ice data and landscape freeze-thaw (FT) satellite observations. Climate data indicated an increasing trend in winter surface air temperature (SAT) over the pan-Arctic during the study period. Nevertheless, the river ice thickness simulations exhibited a thickening regional trend independent of SAT warming, and associated with less insulation and cooling of underlying river ice by thinning snow cover. Deeper snow depth (SND) combined with SAT warming decreased simulated ice thickness, especially for Siberian rivers, where ice thickness is more strongly correlated with SND than SAT. Overall, the Arctic river ice simulations indicated regional trends toward later fall freezeup, earlier spring breakup, and consequently a longer annual ice-free period. The simulated ice phenological dates were significantly correlated with seasonal SAT warming. It is found that SND is an important factor for winter river ice growth, while ice phenological timing is dominated by seasonal SAT. The mean total Arctic river ice volume simulated from CHANGE was 54.1 km(3) based on the annual maximum ice thickness in individual grid cells, while river ice volume for the pan-Arctic rivers decreased by 2.82 km(3) (0.5%) over the 1979-2009 record. Arctic river ice is shrinking as a consequence of regional climate warming and coincident with other cryospheric components, including permafrost, glaciers, and sea ice.
Keywords: Streamflow; Land surface model; Hydrologic models; Circulation/ Dynamics; Hydrologic cycle; Models and modeling
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URL: https://doi.org/10.1175/JCLI-D-15-0569.1
Other URLs:
Plagge, A.M., Edson, J.B., and Vandemark, D. (2016). In Situ and Satellite Evaluation of Air-Sea Flux Variation Near Ocean Temperature Gradients, Journal of Climate, 29(4), 1583-1601, 10.1175/JCLI-D-15-0489.1. Journal Article »
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Title: In Situ and Satellite Evaluation of Air-Sea Flux Variation Near Ocean Temperature Gradients
Type: Journal Article
Publication: Journal of Climate
Author(s): Plagge, A.M., Edson, J.B., and Vandemark, D.
Year: 2016
Formatted Citation: Plagge, A.M., Edson, J.B., and Vandemark, D., 2016: In Situ and Satellite Evaluation of Air-Sea Flux Variation Near Ocean Temperature Gradients, Journal of Climate, 29(4), 1583-1601, 10.1175/JCLI-D-15-0489.1.
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URL: https://doi.org/10.1175/JCLI-D-15-0489.1
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Ruf, C.S., Atlas, R., Chang, P.S., Clarizia, M.P., Garrison, J.L., Gleason, S., Katzberg, S.J., Jelenak, Z., Johnson, J.T., Majumdar, S.J., O'Brien, A., Posselt, D.J., Ridley, A.J., Rose, R.J., and Zavorotny, V.U. (2016). New Ocean Winds Satellite Mission to Probe Hurricanes and Tropical Convection, Bulletin of the American Meteorological Society, 97(3), 385–395, 10.1175/BAMS-D-14-00218.1. Journal Article »
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Title: New Ocean Winds Satellite Mission to Probe Hurricanes and Tropical Convection
Type: Journal Article
Publication: Bulletin of the American Meteorological Society
Author(s): Ruf, C.S., Atlas, R., Chang, P.S., Clarizia, M.P., Garrison, J.L., Gleason, S., Katzberg, S.J., Jelenak, Z., Johnson, J.T., Majumdar, S.J., O'Brien, A., Posselt, D.J., Ridley, A.J., Rose, R.J., and Zavorotny, V.U.
Year: 2016
Formatted Citation: Ruf, C.S., Atlas, R., Chang, P.S., Clarizia, M.P., Garrison, J.L., Gleason, S., Katzberg, S.J., Jelenak, Z., Johnson, J.T., Majumdar, S.J., O'Brien, A., Posselt, D.J., Ridley, A.J., Rose, R.J., and Zavorotny, V.U., 2016: New Ocean Winds Satellite Mission to Probe Hurricanes and Tropical Convection, Bulletin of the American Meteorological Society, 97(3), 385–395, 10.1175/BAMS-D-14-00218.1.
Abstract: The Cyclone Global Navigation Satellite System (CYGNSS) is a new NASA earth science mission scheduled to be launched in 2016 that focuses on tropical cyclones (TCs) and tropical convection. The mission's two primary objectives are the measurement of ocean surface wind speed with sufficient temporal resolution to resolve short-time-scale processes such as the rapid intensification phase of TC development and the ability of the surface measurements to penetrate through the extremely high precipitation rates typically encountered in the TC inner core. The mission's goal is to support significant improvements in our ability to forecast TC track, intensity, and storm surge through better observations and, ultimately, better understanding of inner-core processes. CYGNSS meets its temporal sampling objective by deploying a constellation of eight satellites. Its ability to see through heavy precipitation is enabled by its operation as a bistatic radar using low-frequency GPS signals. The mission will deploy an eight-spacecraft constellation in a low-inclination (35 degrees) circular orbit to maximize coverage and sampling in the tropics. Each CYGNSS spacecraft carries a four-channel radar receiver that measures GPS navigation signals scattered by the ocean surface. The mission will measure inner-core surface winds with high temporal resolution and spatial coverage, under all precipitating conditions, and over the full dynamic range of TC wind speeds.
Keywords: GPS SIGNALS; SCATTEROMETER; SCATTERING; GNSS
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URL: https://doi.org/10.1175/BAMS-D-14-00218.1
Other URLs:
Schroder, R., McDonald, K.C., Azarderakhsh, M., and Zimmermann, R. (2016). ASCAT MetOp-A Diurnal Backscatter Observations of Recent Vegetation Drought Patterns Over the Contiguous US: An Assessment of Spatial Extent and Relationship with Precipitation and Crop Yield, Remote Sensing of Environment, 177, 153-159, 10.1016/j.rse.2016.01.008. Journal Article »
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Title: ASCAT MetOp-A Diurnal Backscatter Observations of Recent Vegetation Drought Patterns Over the Contiguous US: An Assessment of Spatial Extent and Relationship with Precipitation and Crop Yield
Type: Journal Article
Publication: Remote Sensing of Environment
Author(s): Schroder, R., McDonald, K.C., Azarderakhsh, M., and Zimmermann, R.
Year: 2016
Formatted Citation: Schroder, R., McDonald, K.C., Azarderakhsh, M., and Zimmermann, R., 2016: ASCAT MetOp-A Diurnal Backscatter Observations of Recent Vegetation Drought Patterns Over the Contiguous US: An Assessment of Spatial Extent and Relationship with Precipitation and Crop Yield, Remote Sensing of Environment, 177, 153-159, 10.1016/j.rse.2016.01.008.
Abstract: We analyzed 4-years of Advanced Scatterometer (ASCAT) incidence angle normalized C-band backscatter, Next-Generation Radar (NEXRAD) precipitation and United States Department of Agriculture (USDA) crop yield data over the contiguous United States (U.S.). Large negative anomalies in backscatter are evident over the U.S. during the 2011 and 2012 growing seasons, coincident with two instances of severe drought. The backscatter anomalies were correlated with diminished growing season precipitation and with reduced crop yields reflecting where drought-induced impacts on above-ground biomass production occurred. During periods of acute drought, differences in diurnal backscatter were reduced and in some cases reversed reflecting diminished nocturnal leave rehydration. The results indicate that the C-band, VV-polarized ASCAT backscatter data is sensitive to interannual variability in agricultural productivity rather than soil moisture, and can offer an important geophysical monitoring tool capable of identifying and assessing drought-related vegetation responses independent of and complementary to satellite optical/near-infrared remote sensing data. This technique is flexible and adaptable, providing a capability to address region-specific needs. The twice-daily, weather independent and near-real time global monitoring capabilities of ASCAT and similar microwave instruments (e.g. RapidSCAT, Sentinel-1) can help improve drought preparedness and mitigation planning allowing improved water resource management for agriculture on the local as well as the state level. (C) 2016 Elsevier Inc. All rights reserved.
Keywords: WIND SCATTEROMETER DATA; ERS SCATTEROMETER; SOIL-MOISTURE; SEASAT SCATTEROMETER; SURFACE
Mission: |ASCAT|
URL: https://doi.org/10.1016/j.rse.2016.01.008
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Shinoda, T., Han, W., Jensen, T.G., Zamudio, L., Joseph Metzger, E., and Lien, R.-C. (2016). Impact of the Madden-Julian Oscillation on the Indonesian Throughflow in the Makassar Strait During the CINDY/DYNAMO Field Campaign, Journal of Climate, 29(17), 6085-6108, 10.1175/JCLI-D-15-0711.1. Journal Article »
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Title: Impact of the Madden-Julian Oscillation on the Indonesian Throughflow in the Makassar Strait During the CINDY/DYNAMO Field Campaign
Type: Journal Article
Publication: Journal of Climate
Author(s): Shinoda, T., Han, W., Jensen, T.G., Zamudio, L., Joseph Metzger, E., and Lien, R.-C.
Year: 2016
Formatted Citation: Shinoda, T., Han, W., Jensen, T.G., Zamudio, L., Joseph Metzger, E., and Lien, R.-C., 2016: Impact of the Madden-Julian Oscillation on the Indonesian Throughflow in the Makassar Strait During the CINDY/DYNAMO Field Campaign, Journal of Climate, 29(17), 6085-6108, 10.1175/JCLI-D-15-0711.1.
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URL: https://doi.org/10.1175/JCLI-D-15-0711.1
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Suanda, S., Kumar, N., Miller, A., Di Lorenzo, E., Haas, K., Cai, D., Edwards, C., Washburn, L, Fewings, M. R., Torres, R., and Feddersen, F. (2016). Wind Relaxation and a Coastal Buoyant Plume North of Pt. Conception, CA: Observations, Simulations, and Scalings, Journal of Geophysical Research - Oceans, 121, 7455-7475, 10.1002/2016JC011919. Journal Article »
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Title: Wind Relaxation and a Coastal Buoyant Plume North of Pt. Conception, CA: Observations, Simulations, and Scalings
Type: Journal Article
Publication: Journal of Geophysical Research - Oceans
Author(s): Suanda, S., Kumar, N., Miller, A., Di Lorenzo, E., Haas, K., Cai, D., Edwards, C., Washburn, L, Fewings, M. R., Torres, R., and Feddersen, F.
Year: 2016
Formatted Citation: Suanda, S., Kumar, N., Miller, A., Di Lorenzo, E., Haas, K., Cai, D., Edwards, C., Washburn, L, Fewings, M. R., Torres, R., and Feddersen, F., 2016: Wind Relaxation and a Coastal Buoyant Plume North of Pt. Conception, CA: Observations, Simulations, and Scalings, Journal of Geophysical Research - Oceans, 121, 7455-7475, 10.1002/2016JC011919.
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URL: https://doi.org/10.1002/2016JC011919
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Suresh, I., Vialard, J., Izumo, T., Lengaigne, M., Han, W., McCreary, J., and Muraleedharan, P.M. (2016). Dominant Role of Winds Near Sri Lanka in Driving Seasonal Sea Level Variations Along the West Coast of India: Drivers of WCI Seasonal Sea Level, Geophysical Research Letters, 43(13), 7028-7035, 10.1002/2016GL069976. Journal Article »
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Title: Dominant Role of Winds Near Sri Lanka in Driving Seasonal Sea Level Variations Along the West Coast of India: Drivers of WCI Seasonal Sea Level
Type: Journal Article
Publication: Geophysical Research Letters
Author(s): Suresh, I., Vialard, J., Izumo, T., Lengaigne, M., Han, W., McCreary, J., and Muraleedharan, P.M.
Year: 2016
Formatted Citation: Suresh, I., Vialard, J., Izumo, T., Lengaigne, M., Han, W., McCreary, J., and Muraleedharan, P.M., 2016: Dominant Role of Winds Near Sri Lanka in Driving Seasonal Sea Level Variations Along the West Coast of India: Drivers of WCI Seasonal Sea Level, Geophysical Research Letters, 43(13), 7028-7035, 10.1002/2016GL069976.
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URL: https://doi.org/10.1002/2016GL069976
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Vandemark, D., Chapron, B., Feng H., and Mouche, A. (2016). Sea Surface Reflectivity Variation with Ocean Temperature at Ka-band Observed Using Near Nadir Satellite Radar Data, IEEE Geoscience and Remote Sensing Letters, 13(4), 510-514, 10.1109/LGRS.2016.2520823. Journal Article »
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Title: Sea Surface Reflectivity Variation with Ocean Temperature at Ka-band Observed Using Near Nadir Satellite Radar Data
Type: Journal Article
Publication: IEEE Geoscience and Remote Sensing Letters
Author(s): Vandemark, D., Chapron, B., Feng H., and Mouche, A.
Year: 2016
Formatted Citation: Vandemark, D., Chapron, B., Feng H., and Mouche, A., 2016: Sea Surface Reflectivity Variation with Ocean Temperature at Ka-band Observed Using Near Nadir Satellite Radar Data, IEEE Geoscience and Remote Sensing Letters, 13(4), 510-514, 10.1109/LGRS.2016.2520823.
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URL: https://doi.org/10.1109/LGRS.2016.2520823
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Vandemark, D., Feng, H., and Greenslade, M. (2016). Field Assessment of Optical Transparency in the Low-Level Marine Boundary Layer: Preliminary Data from Coastal New England Sites, Proc. SPIE 9825, Sensors, and Command, Control, Communications, and Intelligence (C3I) Technologies for Homeland Security, Defense, and Law Enforcement Applications XV, 982513, 982513, 10.1117/12.2230728. Conference Paper »
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Title: Field Assessment of Optical Transparency in the Low-Level Marine Boundary Layer: Preliminary Data from Coastal New England Sites
Type: Conference Paper
Publication: Proc. SPIE 9825, Sensors, and Command, Control, Communications, and Intelligence (C3I) Technologies for Homeland Security, Defense, and Law Enforcement Applications XV, 982513
Author(s): Vandemark, D., Feng, H., and Greenslade, M.
Year: 2016
Formatted Citation: Vandemark, D., Feng, H., and Greenslade, M., 2016: Field Assessment of Optical Transparency in the Low-Level Marine Boundary Layer: Preliminary Data from Coastal New England Sites, Proc. SPIE 9825, Sensors, and Command, Control, Communications, and Intelligence (C3I) Technologies for Homeland Security, Defense, and Law Enforcement Applications XV, 982513, 982513, 10.1117/12.2230728.
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URL: https://doi.org/10.1117/12.2230728
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Yueh, S., Fore, A., Tang, W.Q., Hayashi, A., Stiles, B., Zhang, F.Q., Weng, Y.H., and Reul, N. (2016). Applications of SMAP Data to Retrieval of Ocean Surface Wind and Salinity, Remote Sensing of the Ocean, Sea Ice, Coastal Waters, and Large Water Regions 2016, 9999, 10.1117/12.2240710. Conference Paper »
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Title: Applications of SMAP Data to Retrieval of Ocean Surface Wind and Salinity
Type: Conference Paper
Publication: Remote Sensing of the Ocean, Sea Ice, Coastal Waters, and Large Water Regions 2016
Author(s): Yueh, S., Fore, A., Tang, W.Q., Hayashi, A., Stiles, B., Zhang, F.Q., Weng, Y.H., and Reul, N.
Year: 2016
Formatted Citation: Yueh, S., Fore, A., Tang, W.Q., Hayashi, A., Stiles, B., Zhang, F.Q., Weng, Y.H., and Reul, N., 2016: Applications of SMAP Data to Retrieval of Ocean Surface Wind and Salinity, Remote Sensing of the Ocean, Sea Ice, Coastal Waters, and Large Water Regions 2016, 9999, 10.1117/12.2240710.
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Keywords: hurricane; microwave remote sensing; ocean surface wind; sea surface salinity; radar; radiometer
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URL: https://doi.org/10.1117/12.2240710
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Yueh, S.H., Fore, A.G., Tang, W., Hayashi, A., Stiles, B., Reul, N., Weng, Y., and Zhang, F. (2016). SMAP L-Band Passive Microwave Observations of Ocean Surface Wind During Severe Storms, IEEE Transactions on Geoscience and Remote Sensing, 54(12), 7339-7350, 10.1109/TGRS.2016.2600239. Journal Article »
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Title: SMAP L-Band Passive Microwave Observations of Ocean Surface Wind During Severe Storms
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Yueh, S.H., Fore, A.G., Tang, W., Hayashi, A., Stiles, B., Reul, N., Weng, Y., and Zhang, F.
Year: 2016
Formatted Citation: Yueh, S.H., Fore, A.G., Tang, W., Hayashi, A., Stiles, B., Reul, N., Weng, Y., and Zhang, F., 2016: SMAP L-Band Passive Microwave Observations of Ocean Surface Wind During Severe Storms, IEEE Transactions on Geoscience and Remote Sensing, 54(12), 7339-7350, 10.1109/TGRS.2016.2600239.
Abstract: The L-band passive microwave data from the Soil Moisture Active Passive (SMAP) observatory are investigated for remote sensing of ocean surface winds during severe storms. The surface winds of Joaquin derived from the real-time analysis of the Center for Advanced Data Assimilation and Predictability Techniques at Penn State support the linear extrapolation of the Aquarius and SMAP geophysical model functions (GMFs) to hurricane force winds. We apply the SMAP and Aquarius GMFs to the retrieval of ocean surface wind vectors from the SMAP radiometer data to take advantage of SMAP's two-look geometry. The SMAP radiometer winds are compared with the winds from other satellites and numerical weather models for validation. The root-mean-square difference (RMSD) with WindSat or Special Sensor Microwave Imager/Sounder is 1.7 m/s below 20-m/s wind speeds. The RMSD with the European Center for Medium-Range Weather Forecasts direction is 18. for wind speeds between 12 and 30 m/s. We find that the correlation is sufficiently high between the maximum wind speeds retrieved by SMAP with a 60-km resolution and the best track peak winds estimated by the National Hurricane Center and the Joint Typhoon Warning Center to allow them to be estimated by SMAP with a correlation coefficient of 0.8 and an underestimation by 8%-18% on average, which is likely due to the effects of spatial averaging. There is also a good agreement with the airborne Stepped-Frequency Radiometer wind speeds with an RMSD of 4.6 m/s for wind speeds in the range of 20-40 m/s.
Keywords: Hurricane; microwave remote sensing; ocean surface wind; radar; radiometer
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URL: https://doi.org/10.1109/TGRS.2016.2600239
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Ali, M.M., Bhowmick, S.A., Sharma, R., Chaudhury, A., Pessullo, J.C., Bourassa, M.A., Ramana, I.V., and Niharika, K. (2015). An Artificial Neural Network Model Function for SARAL-Altika Winds, IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 8(11), 5317-5323, 10.1109/JSTARS.2015.2437896. Journal Article »
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Title: An Artificial Neural Network Model Function for SARAL-Altika Winds
Type: Journal Article
Publication: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Author(s): Ali, M.M., Bhowmick, S.A., Sharma, R., Chaudhury, A., Pessullo, J.C., Bourassa, M.A., Ramana, I.V., and Niharika, K.
Year: 2015
Formatted Citation: Ali, M.M., Bhowmick, S.A., Sharma, R., Chaudhury, A., Pessullo, J.C., Bourassa, M.A., Ramana, I.V., and Niharika, K., 2015: An Artificial Neural Network Model Function for SARAL-Altika Winds, IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 8(11), 5317-5323, 10.1109/JSTARS.2015.2437896.
Abstract: High-quality winds over the ocean surface, at an enhanced spatio-temporal resolution are required for a better understanding of the dynamics of the ocean and atmosphere. Altimetry helps in increasing the frequency of satellite observations. Traditional algorithms for wind speed retrievals from altimeter consider only the backscatter (sigma-0) and possibly the significant wave height (SWH). In this study, we propose an artificial neural network (ANN) model function for AltiKa on board Satellite for ARgos and ALtiKa (SARAL) to relate wind speed to sigma-0, SWH, the width of the waveform leading edge, the two brightness temperatures (TBK and TBKa), and the amplitude of the 1-Hz echo. These parameters influence either the backscatter from the ocean or the propagation of the altimeter radar signal. The wind estimates have significantly improved by incorporating these parameters.
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URL: https://doi.org/10.1109/JSTARS.2015.2437896
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Ali, M.M., Nagamani, P.V., Sharma, N., Venu Gopal, R.T., Rajeevan, M., Goni, G.J., and Bourassa, M.A. (2015). Relationship Between Ocean Mean Temperatures and Indian Summer Monsoon Rainfall, Atmospheric Science Letters, 16(3), 408-413, 10.1002/asl2.576. Journal Article »
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Title: Relationship Between Ocean Mean Temperatures and Indian Summer Monsoon Rainfall
Type: Journal Article
Publication: Atmospheric Science Letters
Author(s): Ali, M.M., Nagamani, P.V., Sharma, N., Venu Gopal, R.T., Rajeevan, M., Goni, G.J., and Bourassa, M.A.
Year: 2015
Formatted Citation: Ali, M.M., Nagamani, P.V., Sharma, N., Venu Gopal, R.T., Rajeevan, M., Goni, G.J., and Bourassa, M.A., 2015: Relationship Between Ocean Mean Temperatures and Indian Summer Monsoon Rainfall, Atmospheric Science Letters, 16(3), 408-413, 10.1002/asl2.576.
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URL: https://doi.org/10.1002/asl2.576
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Chow, C.H., Liu, Q., and Xie, S.-P. (2015). Effects of Kuroshio Intrusions on the Atmosphere Northeast of Taiwan Island: Kuroshio-Intrusion Atmospheric Effects, Geophysical Research Letters, 42(5), 1465-1470, 10.1002/2014GL062796. Journal Article »
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Title: Effects of Kuroshio Intrusions on the Atmosphere Northeast of Taiwan Island: Kuroshio-Intrusion Atmospheric Effects
Type: Journal Article
Publication: Geophysical Research Letters
Author(s): Chow, C.H., Liu, Q., and Xie, S.-P.
Year: 2015
Formatted Citation: Chow, C.H., Liu, Q., and Xie, S.-P., 2015: Effects of Kuroshio Intrusions on the Atmosphere Northeast of Taiwan Island: Kuroshio-Intrusion Atmospheric Effects, Geophysical Research Letters, 42(5), 1465-1470, 10.1002/2014GL062796.
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URL: https://doi.org/10.1002/2014GL062796
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Clark, M., Heath, N., and Bourassa, M.A. (2015). Quantification of Stokes Drift as a Mechanism for Surface Oil Advection in the Gulf of Mexico,
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Title: Quantification of Stokes Drift as a Mechanism for Surface Oil Advection in the Gulf of Mexico
Type: Journal Article
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Author(s): Clark, M., Heath, N., and Bourassa, M.A.
Year: 2015
Formatted Citation: Clark, M., Heath, N., and Bourassa, M.A., 2015: Quantification of Stokes Drift as a Mechanism for Surface Oil Advection in the Gulf of Mexico,
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Dukhovskoy, D.S., Ubnoske, J., Blanchard-Wrigglesworth, E., Hiester, H.R., and Proshutinsky, A. (2015). Skill Metrics for Evaluation and Comparison of Sea Ice Models, Journal of Geophysical Research: Oceans, 120(9), 5910–5931, 10.1002/2015JC010989. Journal Article »
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Title: Skill Metrics for Evaluation and Comparison of Sea Ice Models
Type: Journal Article
Publication: Journal of Geophysical Research: Oceans
Author(s): Dukhovskoy, D.S., Ubnoske, J., Blanchard-Wrigglesworth, E., Hiester, H.R., and Proshutinsky, A.
Year: 2015
Formatted Citation: Dukhovskoy, D.S., Ubnoske, J., Blanchard-Wrigglesworth, E., Hiester, H.R., and Proshutinsky, A., 2015: Skill Metrics for Evaluation and Comparison of Sea Ice Models, Journal of Geophysical Research: Oceans, 120(9), 5910–5931, 10.1002/2015JC010989.
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URL: https://doi.org/10.1002/2015JC010989
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Fewings, M.R., Washburn, L., and Ohlmann, J.C. (2015). Coastal Water Circulation Patterns Around the Northern Channel Islands and Point Conception, California, Progress in Oceanography, 138, 283-304, 10.1016/j.pocean.2015.10.001. Journal Article »
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Title: Coastal Water Circulation Patterns Around the Northern Channel Islands and Point Conception, California
Type: Journal Article
Publication: Progress in Oceanography
Author(s): Fewings, M.R., Washburn, L., and Ohlmann, J.C.
Year: 2015
Formatted Citation: Fewings, M.R., Washburn, L., and Ohlmann, J.C., 2015: Coastal Water Circulation Patterns Around the Northern Channel Islands and Point Conception, California, Progress in Oceanography, 138, 283-304, 10.1016/j.pocean.2015.10.001.
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URL: https://doi.org/10.1016/j.pocean.2015.10.001
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Judt, F. and Chen, S.S. (2015). A New Aircraft Hurricane Wind Climatology and Applications in Assessing the Predictive Skill of Tropical Cyclone Intensity Using High-Resolution Ensemble Forecasts, Geophysical Research Letters, 42(14), 6043-6050, 10.1002/2015GL064609. Journal Article »
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Title: A New Aircraft Hurricane Wind Climatology and Applications in Assessing the Predictive Skill of Tropical Cyclone Intensity Using High-Resolution Ensemble Forecasts
Type: Journal Article
Publication: Geophysical Research Letters
Author(s): Judt, F. and Chen, S.S.
Year: 2015
Formatted Citation: Judt, F. and Chen, S.S., 2015: A New Aircraft Hurricane Wind Climatology and Applications in Assessing the Predictive Skill of Tropical Cyclone Intensity Using High-Resolution Ensemble Forecasts, Geophysical Research Letters, 42(14), 6043-6050, 10.1002/2015GL064609.
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URL: https://doi.org/10.1002/2015GL064609
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Kruk, M.C., Hilburn, K., and Marra, J.J. (2015). Using Microwave Satellite Data to Assess Changes in Storminess Over the Pacific Ocean, Monthly Weather Review, 143(8), 3214–3229, 10.1175/MWR-D-14-00280.1. Journal Article »
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Title: Using Microwave Satellite Data to Assess Changes in Storminess Over the Pacific Ocean
Type: Journal Article
Publication: Monthly Weather Review
Author(s): Kruk, M.C., Hilburn, K., and Marra, J.J.
Year: 2015
Formatted Citation: Kruk, M.C., Hilburn, K., and Marra, J.J., 2015: Using Microwave Satellite Data to Assess Changes in Storminess Over the Pacific Ocean, Monthly Weather Review, 143(8), 3214–3229, 10.1175/MWR-D-14-00280.1.
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URL: https://doi.org/10.1175/MWR-D-14-00280.1
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Li, Y. and Han, W. (2015). Understanding the Intraseasonal Variability of Sea Surface Salinity in the Western Tropical Pacific Ocean, Journal of Geophysical Research - Oceans.
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Title: Understanding the Intraseasonal Variability of Sea Surface Salinity in the Western Tropical Pacific Ocean
Type: Journal Article
Publication: Journal of Geophysical Research - Oceans
Author(s): Li, Y. and Han, W.
Year: 2015
Formatted Citation: Li, Y. and Han, W., 2015: Understanding the Intraseasonal Variability of Sea Surface Salinity in the Western Tropical Pacific Ocean, Journal of Geophysical Research - Oceans.
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Li, Y. and Han, W. (2015). Decadal Sea Level Variations in the Indian Ocean Investigated with HYCOM: Roles of Climate Modes, Ocean Internal Variability, and Stochastic Wind Forcing, Journal of Climate, 28(23), 9143-9165, 10.1175/JCLI-D-15-0252.1. Journal Article »
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Title: Decadal Sea Level Variations in the Indian Ocean Investigated with HYCOM: Roles of Climate Modes, Ocean Internal Variability, and Stochastic Wind Forcing
Type: Journal Article
Publication: Journal of Climate
Author(s): Li, Y. and Han, W.
Year: 2015
Formatted Citation: Li, Y. and Han, W., 2015: Decadal Sea Level Variations in the Indian Ocean Investigated with HYCOM: Roles of Climate Modes, Ocean Internal Variability, and Stochastic Wind Forcing, Journal of Climate, 28(23), 9143-9165, 10.1175/JCLI-D-15-0252.1.
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URL: https://doi.org/10.1175/JCLI-D-15-0252.1
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Liu, J.-W.; Xie, S.-P.; Zhang, S.-P. (2015). Effects of the Hawaiian Islands on the vertical structure of low-level clouds from CALIPSO lidar: Hawaiian Clouds, Journal of Geophysical Research: Atmospheres, 120(1), 215-228, 10.1002/2014JD022410. Journal Article »
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Title: Effects of the Hawaiian Islands on the vertical structure of low-level clouds from CALIPSO lidar: Hawaiian Clouds
Type: Journal Article
Publication: Journal of Geophysical Research: Atmospheres
Author(s): Liu, J.-W.; Xie, S.-P.; Zhang, S.-P.
Year: 2015
Formatted Citation: Liu, J.-W.; Xie, S.-P.; Zhang, S.-P., 2015: Effects of the Hawaiian Islands on the vertical structure of low-level clouds from CALIPSO lidar: Hawaiian Clouds, Journal of Geophysical Research: Atmospheres, 120(1), 215-228, 10.1002/2014JD022410.
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URL: https://doi.org/10.1002/2014JD022410
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Liu, W.T. (2015). Surface Wind and Stress, Encyclopedia of Atmospheric Science (Second Edition), 138-144, 10.1016/B978-0-12-382225-3.00359-5. Book Chapter »
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Title: Surface Wind and Stress
Type: Book Chapter
Publication: Encyclopedia of Atmospheric Science (Second Edition)
Author(s): Liu, W.T.
Year: 2015
Formatted Citation: Liu, W.T., 2015: Surface Wind and Stress, Encyclopedia of Atmospheric Science (Second Edition), 138-144, 10.1016/B978-0-12-382225-3.00359-5.
Abstract: The basics of scatterometry and air–sea turbulence transfer are discussed to bring out the capabilities of space sensors in measuring ocean surface stress and wind vectors. The scientific significance of wind and stress are described. Past knowledge of stress characteristics was based on those of wind, because of the lack of stress measurements. Using the unique measurement of stress by the scatterometer, the differences between stress and wind over oceanfronts and in hurricanes are revealed. Wind speed retrieval from measurements of radar altimeter, microwave radiometer, and synthetic aperture radar is summarized. Potential improvements in measuring wind and stress are suggested.
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URL: https://doi.org/10.1016/B978-0-12-382225-3.00359-5
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Milliff, R., Fiechter, J., Leeds, W., Herbel, R., Wikle, C., Hooten, M., Moore, A., Powell, T., and Brown, J. (2015). Uncertainty Management in Coupled Physical-Biological Lower Trophic Level Ocean Ecosystem Models, Oceanography, 26(4), 98-115, 10.5670/oceanog.2013.78. Journal Article »
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Title: Uncertainty Management in Coupled Physical-Biological Lower Trophic Level Ocean Ecosystem Models
Type: Journal Article
Publication: Oceanography
Author(s): Milliff, R., Fiechter, J., Leeds, W., Herbel, R., Wikle, C., Hooten, M., Moore, A., Powell, T., and Brown, J.
Year: 2015
Formatted Citation: Milliff, R., Fiechter, J., Leeds, W., Herbel, R., Wikle, C., Hooten, M., Moore, A., Powell, T., and Brown, J., 2015: Uncertainty Management in Coupled Physical-Biological Lower Trophic Level Ocean Ecosystem Models, Oceanography, 26(4), 98-115, 10.5670/oceanog.2013.78.
Abstract: Lower trophic level (LTL) ocean ecosystem models are important tools for understanding ocean biogeochemical variability and its role in Earth's climate system. These models are often replete with parameters that cannot be well constrained by the sparse observational data available. LTL ocean ecosystem model parameter estimation is examined from a probabilistic perspective, using a Bayesian hierarchical model (BHM), in the coastal Gulf of Alaska (CGOA) domain that benefits from ocean station observations obtained in repeated US GLOBEC cruises. Data entering the BHM include daily average SeaWiFS satellite estimates of surface chlorophyll and GLOBEC observations of nutrient and phytoplankton profiles at inner and outer shelf stations on the Seward Line. The final form of the BHM process model component is comprised of a discrete version of the Nutrient-Phytoplankton-Zooplankton-Detritus LTL ecosystem model equations augmented to address iron limitation in the CGOA (i.e., NPZDFe), and including a vertical diffusion term to constrain the timing of the phytoplankton bloom in spring. Even in the relatively data-rich GLOBEC context, parameter estimation in the BHM requires guidance from a suite of calculations in a coupled physical-biological deterministic model—the Regional Ocean Model System coupled to an NPZDFe component (ROMS-NPZDFe). ROMS-NPZDFe simulations are used to: (1) validate the BHM formulation, (2) separate BHM limitations due to sampling from those due to LTL model approximations, and (3) obtain output distributions for zooplankton grazing rate and phytoplankton nutrient uptake rate using GLOBEC and SeaWiFS data for 2001. Uncertainty is evident from the spreads in output distributions for model parameters in the BHM. Experiments driven by simulated data from ROMS-NPZDFe helped to optimize the utility of GLOBEC observations for LTL ocean ecosystem model parameter estimation, given ever-present uncertainty issues. The ROMS-NPZDFe simulations are also used to build Bayesian statistical models as surrogates for the deterministic model. Two applications are briefly described. One estimates output distributions for selected ocean ecosystem parameters while accounting for spatial variability across the GLOBEC stations in the CGOA. A second application assimilates SeaWiFS data and simulated data from a ROMS-NPZDFe control run for 2002 to estimate complete fields of surface phytoplankton concentration, with associated spatial and temporal uncertainties.
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URL: https://doi.org/10.5670/oceanog.2013.78
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O'Neill, L.W., Haack, T., and Durland, T. (2015). Estimation of Time-Averaged Surface Divergence and Vorticity from Satellite Ocean Vector Winds, Journal of Climate, 28(19), 7596-7620, 10.1175/JCLI-D-15-0119.1. Journal Article »
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Title: Estimation of Time-Averaged Surface Divergence and Vorticity from Satellite Ocean Vector Winds
Type: Journal Article
Publication: Journal of Climate
Author(s): O'Neill, L.W., Haack, T., and Durland, T.
Year: 2015
Formatted Citation: O'Neill, L.W., Haack, T., and Durland, T., 2015: Estimation of Time-Averaged Surface Divergence and Vorticity from Satellite Ocean Vector Winds, Journal of Climate, 28(19), 7596-7620, 10.1175/JCLI-D-15-0119.1.
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URL: https://doi.org/10.1175/JCLI-D-15-0119.1
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Paget, A., Bourassa, M.A., and Anguelova, M.D. (2015). Comparing In Situ and Satellite-Based Observations of Oceanic Whitecaps, Journal of Geophysical Research: Oceans, 120(4), 2826–2843, 10.1002/2014JC010328. Journal Article »
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Title: Comparing In Situ and Satellite-Based Observations of Oceanic Whitecaps
Type: Journal Article
Publication: Journal of Geophysical Research: Oceans
Author(s): Paget, A., Bourassa, M.A., and Anguelova, M.D.
Year: 2015
Formatted Citation: Paget, A., Bourassa, M.A., and Anguelova, M.D., 2015: Comparing In Situ and Satellite-Based Observations of Oceanic Whitecaps, Journal of Geophysical Research: Oceans, 120(4), 2826–2843, 10.1002/2014JC010328.
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URL: https://doi.org/10.1002/2014JC010328
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Paget, A.C., Frolking, S., Long, D.G., and Milliman, T. (2015). Satellite Radar Anisotropy Observed in Urban Areas, International Journal of Remote Sensing, 36(2), 665-679, 10.1080/01431161.2014.999883. Journal Article »
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Title: Satellite Radar Anisotropy Observed in Urban Areas
Type: Journal Article
Publication: International Journal of Remote Sensing
Author(s): Paget, A.C., Frolking, S., Long, D.G., and Milliman, T.
Year: 2015
Formatted Citation: Paget, A.C., Frolking, S., Long, D.G., and Milliman, T., 2015: Satellite Radar Anisotropy Observed in Urban Areas, International Journal of Remote Sensing, 36(2), 665-679, 10.1080/01431161.2014.999883.
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URL: https://doi.org/10.1080/01431161.2014.999883
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Ricciardulli, L. and Wentz, F. (2015). A Scatterometer Geophysical Model Function for High Winds: QuikSCAT Ku-2011, Journal of Atmospheric and Oceanic Technology, 32(10), 1829–1846, 10.1175/JTECH-D-15-0008.1. Journal Article »
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Title: A Scatterometer Geophysical Model Function for High Winds: QuikSCAT Ku-2011
Type: Journal Article
Publication: Journal of Atmospheric and Oceanic Technology
Author(s): Ricciardulli, L. and Wentz, F.
Year: 2015
Formatted Citation: Ricciardulli, L. and Wentz, F., 2015: A Scatterometer Geophysical Model Function for High Winds: QuikSCAT Ku-2011, Journal of Atmospheric and Oceanic Technology, 32(10), 1829–1846, 10.1175/JTECH-D-15-0008.1.
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URL: https://doi.org/10.1175/JTECH-D-15-0008.1
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Smyth, W.D., Durland, T.S., and Moum, J.N. (2015). Energy and Heat Fluxes Due to Vertically Propagating Yanai Waves Observed in the Equatorial Indian Ocean, Journal of Geophysical Research: Oceans, 120(1), 1-15, 10.1002/2014JC010152. Journal Article »
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Title: Energy and Heat Fluxes Due to Vertically Propagating Yanai Waves Observed in the Equatorial Indian Ocean
Type: Journal Article
Publication: Journal of Geophysical Research: Oceans
Author(s): Smyth, W.D., Durland, T.S., and Moum, J.N.
Year: 2015
Formatted Citation: Smyth, W.D., Durland, T.S., and Moum, J.N., 2015: Energy and Heat Fluxes Due to Vertically Propagating Yanai Waves Observed in the Equatorial Indian Ocean, Journal of Geophysical Research: Oceans, 120(1), 1-15, 10.1002/2014JC010152.
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URL: https://doi.org/10.1002/2014JC010152
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Steffen, J., Bourassa, M.A., and Hughes, P.J. (2015). The Effects of Sea Surface Temperature Gradients On Surface Turbulent Fluxes, Journal of Geophysical Research.
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Title: The Effects of Sea Surface Temperature Gradients On Surface Turbulent Fluxes
Type: Journal Article
Publication: Journal of Geophysical Research
Author(s): Steffen, J., Bourassa, M.A., and Hughes, P.J.
Year: 2015
Formatted Citation: Steffen, J., Bourassa, M.A., and Hughes, P.J., 2015: The Effects of Sea Surface Temperature Gradients On Surface Turbulent Fluxes, Journal of Geophysical Research.
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van der Wiel, K., Cenedese, C., Gille, S.T., Linden, P.F., and Llewellyn Smith, S.G. (2015). On the Collision of Sea Breeze Gravity Currents, Journal of Fluid Mechanics.
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Title: On the Collision of Sea Breeze Gravity Currents
Type: Journal Article
Publication: Journal of Fluid Mechanics
Author(s): van der Wiel, K., Cenedese, C., Gille, S.T., Linden, P.F., and Llewellyn Smith, S.G.
Year: 2015
Formatted Citation: van der Wiel, K., Cenedese, C., Gille, S.T., Linden, P.F., and Llewellyn Smith, S.G., 2015: On the Collision of Sea Breeze Gravity Currents, Journal of Fluid Mechanics.
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Wentz, F.J. (2015). A 17-Year Climate Record of Environmental Parameters Derived from the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager, Journal of Climate, 28, 6882–6902, 10.1175/JCLI-D-15-0155.1. Journal Article »
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Title: A 17-Year Climate Record of Environmental Parameters Derived from the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager
Type: Journal Article
Publication: Journal of Climate
Author(s): Wentz, F.J.
Year: 2015
Formatted Citation: Wentz, F.J., 2015: A 17-Year Climate Record of Environmental Parameters Derived from the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager, Journal of Climate, 28, 6882–6902, 10.1175/JCLI-D-15-0155.1.
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URL: https://doi.org/10.1175/JCLI-D-15-0155.1
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Yueh, S.H., Tang, W.Q., Fore, A.G., and Hayashi, A. (2015). Impact of Ocean Wave Height on L-band Passive and Active Microwave Observation of Sea Surfaces, IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 8(12), 5491-5499, 10.1109/JSTARS.2015.2432134. Journal Article »
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Title: Impact of Ocean Wave Height on L-band Passive and Active Microwave Observation of Sea Surfaces
Type: Journal Article
Publication: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Author(s): Yueh, S.H., Tang, W.Q., Fore, A.G., and Hayashi, A.
Year: 2015
Formatted Citation: Yueh, S.H., Tang, W.Q., Fore, A.G., and Hayashi, A., 2015: Impact of Ocean Wave Height on L-band Passive and Active Microwave Observation of Sea Surfaces, IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 8(12), 5491-5499, 10.1109/JSTARS.2015.2432134.
Abstract: The impact of ocean waves on L-band brightness temperatures and backscatter from the ocean surface was analyzed using Aquarius data. Matchups of Aquarius data with significant wave height (SWH) from National Oceanic and Atmospheric Administration (NOAA) WaveWatch3 reanalysis and the ocean surface wind are generated. We perform the analysis using two different wind speed products: special sensor microwave imager/sounder (SSMI/S) and National Center for Environmental Prediction (NCEP) operational data. Interestingly, the influence of SWH manifests itself differently for these two wind speed products. Conditionally, averaged normalized radar cross-section (sigma(0)) and brightness temperatures (T-B) by NCEP wind speed show strong influence by SWH over the entire range of NCEP wind speeds with a larger impact at lower wind speeds. However, performing the same analysis conditioned on the SSMI/S wind speed, the conclusion becomes entirely different: the SWH effects appear small at low wind speeds (<5 ms(-1)) and increase with increasing wind speed. The apparent contradiction is a result of the differing characteristics of NCEP and SSMI/S wind speeds. NCEP wind is an atmospheric model estimate of surface wind velocity, whereas the SSMI/S wind is a microwave remote sensing product, representing the characteristics of sea surface roughness. The impact of SWH needs to be considered when the SSMI/S wind speed is assimilated into the numerical weather prediction models, such as the NCEP.
Keywords: Microwave remote sensing; ocean wave; ocean wind; radar; radiometer
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URL: https://doi.org/10.1109/JSTARS.2015.2432134
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Zheng, Y., Ali, M.M., and Bourassa, M.A. (2015). Contribution of Monthly and Regional Rainfall to the Strength of Indian Summer Monsoon, Monthly Weather Review, 144, 3037-3055, 10.1175/MWR-D-15-0318.1. Journal Article »
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Title: Contribution of Monthly and Regional Rainfall to the Strength of Indian Summer Monsoon
Type: Journal Article
Publication: Monthly Weather Review
Author(s): Zheng, Y., Ali, M.M., and Bourassa, M.A.
Year: 2015
Formatted Citation: Zheng, Y., Ali, M.M., and Bourassa, M.A., 2015: Contribution of Monthly and Regional Rainfall to the Strength of Indian Summer Monsoon, Monthly Weather Review, 144, 3037-3055, 10.1175/MWR-D-15-0318.1.
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URL: https://doi.org/10.1175/MWR-D-15-0318.1
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Adames, A.F., Patoux, J., and Foster, R.C. (2014). The Contribution of Extratropical Waves to the MJO Wind Field, Journal of the Atmospheric Sciences, 71(1), 155-176, 10.1175/JAS-D-13-084.1. Journal Article »
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Title: The Contribution of Extratropical Waves to the MJO Wind Field
Type: Journal Article
Publication: Journal of the Atmospheric Sciences
Author(s): Adames, A.F., Patoux, J., and Foster, R.C.
Year: 2014
Formatted Citation: Adames, A.F., Patoux, J., and Foster, R.C., 2014: The Contribution of Extratropical Waves to the MJO Wind Field, Journal of the Atmospheric Sciences, 71(1), 155-176, 10.1175/JAS-D-13-084.1.
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URL: https://doi.org/10.1175/JAS-D-13-084.1
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Alsweiss, S., Hanna, R., Laupattarakasem, P., Jones, W., Hennon, C., and Chen, R. (2014). A Non-MLE Approach for Satellite Scatterometer Wind Vector Retrievals in Tropical Cyclones, Remote Sensing, 6(5), 4133-4148, 10.3390/rs6054133. Journal Article »
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Title: A Non-MLE Approach for Satellite Scatterometer Wind Vector Retrievals in Tropical Cyclones
Type: Journal Article
Publication: Remote Sensing
Author(s): Alsweiss, S., Hanna, R., Laupattarakasem, P., Jones, W., Hennon, C., and Chen, R.
Year: 2014
Formatted Citation: Alsweiss, S., Hanna, R., Laupattarakasem, P., Jones, W., Hennon, C., and Chen, R., 2014: A Non-MLE Approach for Satellite Scatterometer Wind Vector Retrievals in Tropical Cyclones, Remote Sensing, 6(5), 4133-4148, 10.3390/rs6054133.
Abstract: Satellite microwave scatterometers are the principal source of global synoptic-scale ocean vector wind (OVW) measurements for a number of scientific and operational oceanic wind applications. However, for extreme wind events such as tropical cyclones, their performance is significantly degraded. This paper presents a novel OVW retrieval algorithm for tropical cyclones which improves the accuracy of scatterometer based ocean surface winds when compared to low-flying aircraft with in-situ and remotely sensed observations. Unlike the traditional maximum likelihood estimation (MLE) wind vector retrieval technique, this new approach sequentially estimates scalar wind directions and wind speeds. A detailed description of the algorithm is provided along with results for ten QuikSCAT hurricane overpasses (from 2003–2008) to evaluate the performance of the new algorithm. Results are compared with independent surface wind analyses from the National Oceanic and Atmospheric Administration (NOAA) Hurricane Research Division’s H*Wind surface analyses and with the corresponding SeaWinds Project’s L2B-12.5 km OVW products. They demonstrate that the proposed algorithm extends the SeaWinds capability to retrieve wind speeds beyond the current range of approximately 35 m/s (minimal hurricane category-1) with improved wind direction accuracy, making this new approach a potential candidate for current and future conically scanning scatterometer wind retrieval algorithms.
Keywords: SeaWinds; conical scanning; scatterometers; wind vector retrievals; MLE; tropical cyclones; H*Wind
Mission: |SeaWinds|
URL: https://doi.org/10.3390/rs6054133
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Bradley, J.P. and Long, D.G. (2014). Estimation of the OSCAT Spatial Response Function Using Island Targets, IEEE Transactions on Geoscience and Remote Sensing, 52(4), 1924-1934, 10.1109/TGRS.2013.2256429. Journal Article »
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Title: Estimation of the OSCAT Spatial Response Function Using Island Targets
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Bradley, J.P. and Long, D.G.
Year: 2014
Formatted Citation: Bradley, J.P. and Long, D.G., 2014: Estimation of the OSCAT Spatial Response Function Using Island Targets, IEEE Transactions on Geoscience and Remote Sensing, 52(4), 1924-1934, 10.1109/TGRS.2013.2256429.
Abstract: Originally designed for wind velocity estimation over the ocean, scatterometers have been applied to weather forecasting, global climatological studies, and monitoring of large-scale human interaction on the planet. Launched in September of 2009, the Oceansat-2 Ku-band scatterometer (OSCAT) is an excellent candidate for continuing the data time series begun with QuikSCAT, which was the SeaWinds scatterometer flown on the QuikSCAT mission 1999-2009. Some processing algorithms require knowledge of the spatial response function (SRF) of the scatterometer. With limited knowledge of OSCAT implementation, and thus its SRF, a procedure is developed for estimating the SRF. The estimation procedure uses scatterometer measurements over islands to invert the radar equation. A mathematical model is developed that reduces the solution to rank-reduced least-squares estimation. The geographic sampling region is discussed, and a simulation is performed to verify the efficacy of the method, while also providing guidelines for island choice and the number of singular values used in rank reduction. The utility of OSCAT SRF estimates is demonstrated through the construction of an enhanced-resolution radar backscatter image over the Amazon rainforest.
Keywords: Oceansat-2 scatterometer; remote sensing; scatterometry; spatial response function (SRF)
Mission: |SeaWinds|
URL: https://doi.org/10.1109/TGRS.2013.2256429
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Bradley, J.P. and Long, D.G. (2014). Correction to "Estimation of the OSCAT Spatial Response Function Using Island Targets", IEEE Transactions on Geoscience and Remote Sensing, 52(4), 2288-2288, 10.1109/TGRS.2013.2281336. Journal Article »
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Title: Correction to "Estimation of the OSCAT Spatial Response Function Using Island Targets"
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Bradley, J.P. and Long, D.G.
Year: 2014
Formatted Citation: Bradley, J.P. and Long, D.G., 2014: Correction to "Estimation of the OSCAT Spatial Response Function Using Island Targets", IEEE Transactions on Geoscience and Remote Sensing, 52(4), 2288-2288, 10.1109/TGRS.2013.2281336.
Abstract: In the above-named article [ibid., vol. 51, no. 5, pp 1924-1934, April 2014] there are errors in Table I. The corrected table is published here.
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URL: https://doi.org/10.1109/TGRS.2013.2281336
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Carranza, M.M. and Gille, S.T. (2014). Southern Ocean Wind-Driven Entrainment Enhances Satellite Chlorophyll-a Through the Summer, Journal of Geophysical Research - Oceans, 120(1), 304-323, 10.1002/2014JC010203. Journal Article »
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Title: Southern Ocean Wind-Driven Entrainment Enhances Satellite Chlorophyll-a Through the Summer
Type: Journal Article
Publication: Journal of Geophysical Research - Oceans
Author(s): Carranza, M.M. and Gille, S.T.
Year: 2014
Formatted Citation: Carranza, M.M. and Gille, S.T., 2014: Southern Ocean Wind-Driven Entrainment Enhances Satellite Chlorophyll-a Through the Summer, Journal of Geophysical Research - Oceans, 120(1), 304-323, 10.1002/2014JC010203.
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URL: https://doi.org/10.1002/2014JC010203
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Das, N.N., Colliander, A., Chan, S.K., Njoku, E.G., and Li, L. (2014). Intercomparisons of Brightness Temperature Observations Over Land From AMSR-E and WindSat, IEEE Transactions on Geoscience and Remote Sensing, 52(1), 452-464, 10.1109/TGRS.2013.2241445. Journal Article »
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Title: Intercomparisons of Brightness Temperature Observations Over Land From AMSR-E and WindSat
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Das, N.N., Colliander, A., Chan, S.K., Njoku, E.G., and Li, L.
Year: 2014
Formatted Citation: Das, N.N., Colliander, A., Chan, S.K., Njoku, E.G., and Li, L., 2014: Intercomparisons of Brightness Temperature Observations Over Land From AMSR-E and WindSat, IEEE Transactions on Geoscience and Remote Sensing, 52(1), 452-464, 10.1109/TGRS.2013.2241445.
Abstract: The Advanced Microwave Scanning Radiometer-EOS (AMSR-E) on Aqua and WindSat on Coriolis instruments have collected multichannel passive microwave data over the global land and oceans since 2002 and 2003, respectively. AMSR-E on Aqua ceased operation in October 2011 due to a malfunction in the antenna scanning mechanism. AMSR-E and WindSat have similar frequencies, bandwidths, polarizations, incidence angles and instantaneous fields of view (IFOVs), but there are some differences in their configurations. The altitudes and local overpass times also differ between the AMSR-E and WindSat sensors. The time series of data from the two instruments have a long period of overlap, which can be used to intercompare and cross-calibrate the instrument data sets taking into account the instrument differences. This would allow retrieval of geophysical parameters using common algorithms that could take advantage of the increased time duration and sampling coverage afforded by combining data from the two sensors. In this paper, we focus on land applications and compare the multichannel data from these two sensors over land. Channels useful primarily for soil moisture and vegetation water content studies (i.e., similar to 6, similar to 10, similar to 18, and similar to 37 GHz at H- and V-pol) are used in the comparisons. To minimize differences caused by surface temperature effects related to local overpass times, only descending passes (with Equator crossing times for AMSR-E of 1: 30 A. M. and WindSat 6: 00 A. M.) are considered. Homogeneous and temporally stable sites such as Dome-C, Antarctica and the Amazon forest, and a flat and bare region in the Sahara desert are chosen to evaluate similarities and differences among comparable channel observations. Taking into consideration the sensor configurations and geophysical conditions during the descending overpasses, reasonably good agreement is observed between AMSR-E and WindSat measurements over the globe.
Keywords: Passive microwave remote sensing; radiometers; soil moisture
Mission: |WindSat|
URL: https://doi.org/10.1109/TGRS.2013.2241445
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Dobricic, S., Wikle, C.K., Milliff, R.F., Pinardi, N., and Berliner, L.M. (2014). Assimilation of Oceanographic Observations with Estimates of Vertical Background-Error Covariances by a Bayesian Hierarchical Model, Quarterly Journal of the Royal Meteorological Society, 141(686), 182-194, 10.1002/qj.2348. Journal Article »
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Title: Assimilation of Oceanographic Observations with Estimates of Vertical Background-Error Covariances by a Bayesian Hierarchical Model
Type: Journal Article
Publication: Quarterly Journal of the Royal Meteorological Society
Author(s): Dobricic, S., Wikle, C.K., Milliff, R.F., Pinardi, N., and Berliner, L.M.
Year: 2014
Formatted Citation: Dobricic, S., Wikle, C.K., Milliff, R.F., Pinardi, N., and Berliner, L.M., 2014: Assimilation of Oceanographic Observations with Estimates of Vertical Background-Error Covariances by a Bayesian Hierarchical Model, Quarterly Journal of the Royal Meteorological Society, 141(686), 182-194, 10.1002/qj.2348.
Abstract: A new method to estimate the vertical part of the background-error covariance matrix for an ocean variational data assimilation system is presented and tested in the Mediterranean operational daily analysis system. The operational, seasonally varying error covariances are compared with high-frequency estimates from a Bayesian Hierarchical Model (BHM) which estimates distributions for the vertical error covariances from two data-stage inputs: model anomalies and differences between model background and observations, i.e. so-called misfits. It is found that the posterior mean BHM-error covariance estimates that vary on 5-day time-scales reduce the misfits root mean square of the analysis vertical profiles of temperature and salinity by 10�20% versus analyses arising from covariances that vary on seasonal time-scales or those from the BHM given only model anomalies as data stage inputs.
Keywords: Bayesian hierarhical model; data assimilation; oceanography
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URL: https://doi.org/10.1002/qj.2348
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Fore, A.G., Stiles, B.W., Chau, A.H., Williams, B.A., Dunbar, R.S., and Rodríguez E. (2014). Point-Wise Wind Retrieval and Ambiguity Removal Improvements for the QuikSCAT Climatological Data Set, IEEE Trans. Geoscience and Remote Sensing, 52(1), 51-59, 10.1109/TGRS.2012.2235843. Journal Article »
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Title: Point-Wise Wind Retrieval and Ambiguity Removal Improvements for the QuikSCAT Climatological Data Set
Type: Journal Article
Publication: IEEE Trans. Geoscience and Remote Sensing
Author(s): Fore, A.G., Stiles, B.W., Chau, A.H., Williams, B.A., Dunbar, R.S., and Rodríguez E.
Year: 2014
Formatted Citation: Fore, A.G., Stiles, B.W., Chau, A.H., Williams, B.A., Dunbar, R.S., and Rodríguez E., 2014: Point-Wise Wind Retrieval and Ambiguity Removal Improvements for the QuikSCAT Climatological Data Set, IEEE Trans. Geoscience and Remote Sensing, 52(1), 51-59, 10.1109/TGRS.2012.2235843.
Abstract: In this paper we introduce a reprocessing of the entire SeaWinds on QuikSCAT mission. The goal of the reprocessing is to create a climate data record suitable for climate studies and to incorporate recent algorithm improvements. Three different levels of QuikSCAT data are produced at the Jet Propulsion Laboratory (JPL): L1B, geo-located, calibrated, backscatter measurements in chronological order by acquisition time; L2A, backscatter measurements binned into a geographical grid; and L2B, gridded ocean surface wind vectors. The reprocessing begins with the L1B data � we have not adjusted the geo-location or calibration of the 0 data at all. We introduce new algorithms at the L1B to level L2A processing level and at the L2A to L2B processing level. After introducing our new algorithms, we show the validation studies performed to date, which include comparisons to numerical weather products, comparisons to buoy datasets, comparisons to other remote sensing instruments, as well as spectral considerations.
Keywords: Ocean winds, radar, rain, remote sensing, scatterometery
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URL: https://doi.org/10.1109/TGRS.2012.2235843
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Gille, S.T. and Llewellyn Smith, S.G. (2014). When Land Breezes Collide: Converging Diurnal Winds Over Small Bodies of Water, Quarterly Journal of the Royal Meteorological Society, 140(685), 2573-2581, 10.1002/qj.2322. Journal Article »
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Title: When Land Breezes Collide: Converging Diurnal Winds Over Small Bodies of Water
Type: Journal Article
Publication: Quarterly Journal of the Royal Meteorological Society
Author(s): Gille, S.T. and Llewellyn Smith, S.G.
Year: 2014
Formatted Citation: Gille, S.T. and Llewellyn Smith, S.G., 2014: When Land Breezes Collide: Converging Diurnal Winds Over Small Bodies of Water, Quarterly Journal of the Royal Meteorological Society, 140(685), 2573-2581, 10.1002/qj.2322.
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URL: https://doi.org/10.1002/qj.2322
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Gille, S.T., Carranza, M.M., Cambra, R., and Morrow, R. (2014). Wind-Induced Upwelling in the Kerguelen Plateau Region, Biogeosciences, 11(22), 6389-6400, 10.5194/bg-11-6389-2014. Journal Article »
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Title: Wind-Induced Upwelling in the Kerguelen Plateau Region
Type: Journal Article
Publication: Biogeosciences
Author(s): Gille, S.T., Carranza, M.M., Cambra, R., and Morrow, R.
Year: 2014
Formatted Citation: Gille, S.T., Carranza, M.M., Cambra, R., and Morrow, R., 2014: Wind-Induced Upwelling in the Kerguelen Plateau Region, Biogeosciences, 11(22), 6389-6400, 10.5194/bg-11-6389-2014.
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URL: https://doi.org/10.5194/bg-11-6389-2014
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Grodsky, S.A., Carton, J.A., and Bentamy, A. (2014). Salty Anomalies Forced by Tehuantepec and Papagayo Gap Winds: Aquarius Observations, Remote Sensing Letters, 5(6), 568-574, 10.1080/2150704X.2014.935522. Journal Article »
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Title: Salty Anomalies Forced by Tehuantepec and Papagayo Gap Winds: Aquarius Observations
Type: Journal Article
Publication: Remote Sensing Letters
Author(s): Grodsky, S.A., Carton, J.A., and Bentamy, A.
Year: 2014
Formatted Citation: Grodsky, S.A., Carton, J.A., and Bentamy, A., 2014: Salty Anomalies Forced by Tehuantepec and Papagayo Gap Winds: Aquarius Observations, Remote Sensing Letters, 5(6), 568-574, 10.1080/2150704X.2014.935522.
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URL: https://doi.org/10.1080/2150704X.2014.935522
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Grodsky, S.A., Reverdin, G., Carton, J.A., and Coles, V.J. (2014). Year-to-Year Salinity Changes in the Amazon Plume: Contrasting 2011 and 2012 Aquarius/SACD and SMOS Satellite Data, Remote Sensing of Environment, 140, 14-22, 10.1016/j.rse.2013.08.033. Journal Article »
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Title: Year-to-Year Salinity Changes in the Amazon Plume: Contrasting 2011 and 2012 Aquarius/SACD and SMOS Satellite Data
Type: Journal Article
Publication: Remote Sensing of Environment
Author(s): Grodsky, S.A., Reverdin, G., Carton, J.A., and Coles, V.J.
Year: 2014
Formatted Citation: Grodsky, S.A., Reverdin, G., Carton, J.A., and Coles, V.J., 2014: Year-to-Year Salinity Changes in the Amazon Plume: Contrasting 2011 and 2012 Aquarius/SACD and SMOS Satellite Data, Remote Sensing of Environment, 140, 14-22, 10.1016/j.rse.2013.08.033.
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URL: https://doi.org/10.1016/j.rse.2013.08.033
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Han, W., Vialard, J., McPhaden, M., Lee, T., Masumoto, Y., Feng, M., and de Ruijter, W. (2014). Indian Ocean Decadal Variability: A Review, Bulletin of the American Meteorological Society, 95(11), 1679–1703, 10.1175/BAMS-D-13-00028.1. Journal Article »
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Title: Indian Ocean Decadal Variability: A Review
Type: Journal Article
Publication: Bulletin of the American Meteorological Society
Author(s): Han, W., Vialard, J., McPhaden, M., Lee, T., Masumoto, Y., Feng, M., and de Ruijter, W.
Year: 2014
Formatted Citation: Han, W., Vialard, J., McPhaden, M., Lee, T., Masumoto, Y., Feng, M., and de Ruijter, W., 2014: Indian Ocean Decadal Variability: A Review, Bulletin of the American Meteorological Society, 95(11), 1679–1703, 10.1175/BAMS-D-13-00028.1.
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URL: https://doi.org/10.1175/BAMS-D-13-00028.1
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Holbach, H.M. and Bourassa, M.A. (2014). The Effects of Gap-Wind-Induced Vorticity, the Monsoon Trough, and the ITCZ on East Pacific Tropical Cyclogenesis, Monthly Weather Review, 142(3), 1312-1325, 10.1175/MWR-D-13-00218.1. Journal Article »
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Title: The Effects of Gap-Wind-Induced Vorticity, the Monsoon Trough, and the ITCZ on East Pacific Tropical Cyclogenesis
Type: Journal Article
Publication: Monthly Weather Review
Author(s): Holbach, H.M. and Bourassa, M.A.
Year: 2014
Formatted Citation: Holbach, H.M. and Bourassa, M.A., 2014: The Effects of Gap-Wind-Induced Vorticity, the Monsoon Trough, and the ITCZ on East Pacific Tropical Cyclogenesis, Monthly Weather Review, 142(3), 1312-1325, 10.1175/MWR-D-13-00218.1.
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URL: https://doi.org/10.1175/MWR-D-13-00218.1
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Hullinger, W.J. and Long, D.G. (2014). Mitigation of Sea Ice Contamination in QuikSCAT Wind Retrieval, IEEE Transactions on Geoscience and Remote Sensing, 52(4), 2149-2158, 10.1109/TGRS.2013.2258400. Journal Article »
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Title: Mitigation of Sea Ice Contamination in QuikSCAT Wind Retrieval
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Hullinger, W.J. and Long, D.G.
Year: 2014
Formatted Citation: Hullinger, W.J. and Long, D.G., 2014: Mitigation of Sea Ice Contamination in QuikSCAT Wind Retrieval, IEEE Transactions on Geoscience and Remote Sensing, 52(4), 2149-2158, 10.1109/TGRS.2013.2258400.
Abstract: Scatterometers provide frequent estimates of near-surface wind vectors over the Earth's oceans. However, in the polar oceans, the presence of sea ice in or near the measurement footprint can adversely affect scatterometer measurements, resulting in inaccurate wind estimates. Currently, such ice contamination is mitigated by discarding measurements within 50 km of the detected sea ice. This approach is imperfect and causes loss of coverage. We present a new algorithm that detects ice-contaminated measurements based on a metric called the ice contribution ratio (ICR), which measures the spatial ice contribution for each measurement. Determined by simulation, we threshold the ICR depending on local wind, ice backscatter, and cross-track location. Using ICR processing, wind is retrieved almost 40 km closer to sea ice than has been previously possible, while ensuring wind accuracy. Using ICR processing, retrieved wind distributions more closely resemble uncontaminated distributions than winds retrieved using previous methods. The algorithm is applied to QuikSCAT in this paper, but could be applied to other scatterometers such as the Oceansat-2 scatterometer.
Keywords: QuikCSAT; remote sensing; scatterometry; sea ice; wind; wind retrieval
Mission: |SeaWinds|
URL: https://doi.org/10.1109/TGRS.2013.2258400
Other URLs:
Jaruwatanadilok, S. and Stiles, B.W. (2014). Trends and Variation in Ku-band Backscatter of Natural Targets on Land Observed in QuikSCAT Data, IEEE Transactions on Geoscience and Remote Sensing, 52(7), 4383-4390, 10.1109/TGRS.2013.2281722. Journal Article »
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Title: Trends and Variation in Ku-band Backscatter of Natural Targets on Land Observed in QuikSCAT Data
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Jaruwatanadilok, S. and Stiles, B.W.
Year: 2014
Formatted Citation: Jaruwatanadilok, S. and Stiles, B.W., 2014: Trends and Variation in Ku-band Backscatter of Natural Targets on Land Observed in QuikSCAT Data, IEEE Transactions on Geoscience and Remote Sensing, 52(7), 4383-4390, 10.1109/TGRS.2013.2281722.
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URL: https://doi.org/10.1109/TGRS.2013.2281722
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Jaruwatanadilok, S., Stiles, B.W., and Fore, A.G. (2014). Cross Calibration Between QuikSCAT and OceanSAT-2, IEEE Transactions on Geoscience and Remote Sensing, 52(10), 6197 - 6204, 10.1109/TGRS.2013.2295539. Journal Article »
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Title: Cross Calibration Between QuikSCAT and OceanSAT-2
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Jaruwatanadilok, S., Stiles, B.W., and Fore, A.G.
Year: 2014
Formatted Citation: Jaruwatanadilok, S., Stiles, B.W., and Fore, A.G., 2014: Cross Calibration Between QuikSCAT and OceanSAT-2, IEEE Transactions on Geoscience and Remote Sensing, 52(10), 6197 - 6204, 10.1109/TGRS.2013.2295539.
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URL: https://doi.org/10.1109/TGRS.2013.2295539
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Li, J.-L.F., Lee, W.-L., Waliser, D.E., David Neelin, J., Stachnik, J.P., and Lee, T. (2014). Cloud-Precipitation-Radiation-Dynamics Interaction in Global Climate Models: A Snow and Radiation Interaction Sensitivity Experiment, Journal of Geophysical Research: Atmospheres, 119(7), 3809-3824, 10.1002/2013JD021038. Journal Article »
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Title: Cloud-Precipitation-Radiation-Dynamics Interaction in Global Climate Models: A Snow and Radiation Interaction Sensitivity Experiment
Type: Journal Article
Publication: Journal of Geophysical Research: Atmospheres
Author(s): Li, J.-L.F., Lee, W.-L., Waliser, D.E., David Neelin, J., Stachnik, J.P., and Lee, T.
Year: 2014
Formatted Citation: Li, J.-L.F., Lee, W.-L., Waliser, D.E., David Neelin, J., Stachnik, J.P., and Lee, T., 2014: Cloud-Precipitation-Radiation-Dynamics Interaction in Global Climate Models: A Snow and Radiation Interaction Sensitivity Experiment, Journal of Geophysical Research: Atmospheres, 119(7), 3809-3824, 10.1002/2013JD021038.
Abstract: Conventional global climate models (GCMs) often consider radiation interactions only with small-particle/suspended cloud mass, ignoring large-particle/falling and convective core cloud mass. We characterize the radiation and atmospheric circulation impacts of frozen precipitating hydrometeors (i.e., snow), using the National Center for Atmospheric Research (NCAR)-coupled GCM, by conducting sensitivity experiments that turn off the radiation interaction with snow. The changes associated with the exclusion of precipitating hydrometeors exhibit a number differences consistent with biases in CMIP3 and CMIP5, including more outgoing longwave (LW) flux at the top of atmosphere (TOA) and downward shortwave (SW) flux at the surface in the heavily precipitating regions. Neglecting the radiation interaction of snow increases the net radiative cooling near the cloud top with the resulting increased instability triggering more convection in the heavily precipitating regions of the tropics. In addition, the increased differential vertical heating leads to a weakening of the low-level mean flow and an apparent low-level eastward advection from the warm pool resulting in moisture convergence south of the ITCZ and north of the SPCZ. This westerly bias, with effective warm and moist air transport, might be a contributing factor in the model's northeastward overextension of the SPCZ and the concomitant changes in sea surface temperatures, upward motion, and precipitation. Broader dynamical impacts include a stronger local meridional overturning circulation over the mid- and east Pacific, and commensurate changes in low- and upper-level winds, large-scale ascending motion, with a notable similarity to the systematic bias in this region in CMIP5 upper-level zonal winds.
Keywords: coupled-GCM; cloud-radiation; atmospheric dynamics; SSTs
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URL: https://doi.org/10.1002/2013JD021038
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Liu, J.-W., Xie, S.-P., Norris, J., and Zhang, S. (2014). Low-Level Cloud Response to the Gulf Stream Front in Winter Using CALIPSO, Journal of Climate, 27, 4421-4432, 10.1175/JCLI-D-13-00469.1. Journal Article »
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Title: Low-Level Cloud Response to the Gulf Stream Front in Winter Using CALIPSO
Type: Journal Article
Publication: Journal of Climate
Author(s): Liu, J.-W., Xie, S.-P., Norris, J., and Zhang, S.
Year: 2014
Formatted Citation: Liu, J.-W., Xie, S.-P., Norris, J., and Zhang, S., 2014: Low-Level Cloud Response to the Gulf Stream Front in Winter Using CALIPSO, Journal of Climate, 27, 4421-4432, 10.1175/JCLI-D-13-00469.1.
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URL: https://doi.org/10.1175/JCLI-D-13-00469.1
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Meissner, T., Wentz, F., and Ricciardulli, L (2014). The Emission and Scattering of L-Band Microwave Radiation from Rough Ocean Surfaces and Wind Speed Measurements from the Aquarius Sensor, Journal of Geophysical Research: Oceans, 119(9), 6499-6522, 10.1002/2014JC009837. Journal Article »
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Title: The Emission and Scattering of L-Band Microwave Radiation from Rough Ocean Surfaces and Wind Speed Measurements from the Aquarius Sensor
Type: Journal Article
Publication: Journal of Geophysical Research: Oceans
Author(s): Meissner, T., Wentz, F., and Ricciardulli, L
Year: 2014
Formatted Citation: Meissner, T., Wentz, F., and Ricciardulli, L, 2014: The Emission and Scattering of L-Band Microwave Radiation from Rough Ocean Surfaces and Wind Speed Measurements from the Aquarius Sensor, Journal of Geophysical Research: Oceans, 119(9), 6499-6522, 10.1002/2014JC009837.
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URL: https://doi.org/10.1002/2014JC009837
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Mortin, J., Howell, S.E.L., Wang, L., Derksen, C., Svensson, G., Graversen, R.G., and Schrøder, T.M. (2014). Extending the QuikSCAT Record of Seasonal Melt-Freeze Transitions Over Arctic Sea Ice Using ASCAT, Remote Sensing of Environment, 141, 214-230, 10.1016/j.rse.2013.11.004. Journal Article »
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Title: Extending the QuikSCAT Record of Seasonal Melt-Freeze Transitions Over Arctic Sea Ice Using ASCAT
Type: Journal Article
Publication: Remote Sensing of Environment
Author(s): Mortin, J., Howell, S.E.L., Wang, L., Derksen, C., Svensson, G., Graversen, R.G., and Schrøder, T.M.
Year: 2014
Formatted Citation: Mortin, J., Howell, S.E.L., Wang, L., Derksen, C., Svensson, G., Graversen, R.G., and Schrøder, T.M., 2014: Extending the QuikSCAT Record of Seasonal Melt-Freeze Transitions Over Arctic Sea Ice Using ASCAT, Remote Sensing of Environment, 141, 214-230, 10.1016/j.rse.2013.11.004.
Abstract: The seasonal melt-freeze transitions are important to continuously monitor over Arctic sea ice in order to better understand Arctic climate variability. The K-u-band scatterometer QuikSCAT (13.4 GHz), widely used to retrieve pan-Arctic seasonal transitions, discontinued its decadal long record in 2009. In this study, we show that the C-band scatterometer ASCAT (5.3 GHz), in orbit since 2006 and with an anticipated lifetime through 2021, can be used to extend the QuikSCAT record of seasonal melt-freeze transitions. This is done by (1) comparing backscatter measurements over multiyear and first-year ice, and by (2) retrieving seasonal transitions from resolution-enhanced ASCAT and QuikSCAT measurements and comparing the results with independent datasets. Despite operating in different frequencies, ASCAT and QuikSCAT respond similarly to surface transitions. However, QuikSCAT measurements respond slightly stronger to the early melt of first-year ice, making it less sensitive to sea-ice dynamics. To retrieve the transitions, we employed an improved edge-detector algorithm, which was iterated and constrained using sea-ice concentration data, efficiently alleviating unreasonable outliers. This gives melt-freeze transitions over all Arctic sea ice north of 60 degrees N at a 4.45 km resolution during 1999-2009 and 2009-2012 for QuikSCAT and ASCAT, respectively. Using the sensor overlap period, we show that the retrieved transitions retrieved from the different instruments are largely consistent across all regions in the Arctic sea-ice domain, indicating a robust consistency.
Keywords: Active microwave measurements; Satelliteborne scatterometry; Arctic sea ice and snow; Surface processes; Melt-freeze retrieval; Arctic climate
Mission: |ASCAT|
URL: https://doi.org/10.1016/j.rse.2013.11.004
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Nedbor-Gross, R., Dukhovskoy, D.S., Bourassa, M.A., Morey, S.L., and Chassignet, E.P. (2014). Investigation of the Relationship Between the Yucatan Channel Transport and the Loop Current Area in a Multi-Decadal Numerical Simulation, Marine Technology Society Journal, 48(4), 15-26, 10.4031/MTSJ.48.4.8. Journal Article »
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Title: Investigation of the Relationship Between the Yucatan Channel Transport and the Loop Current Area in a Multi-Decadal Numerical Simulation
Type: Journal Article
Publication: Marine Technology Society Journal
Author(s): Nedbor-Gross, R., Dukhovskoy, D.S., Bourassa, M.A., Morey, S.L., and Chassignet, E.P.
Year: 2014
Formatted Citation: Nedbor-Gross, R., Dukhovskoy, D.S., Bourassa, M.A., Morey, S.L., and Chassignet, E.P., 2014: Investigation of the Relationship Between the Yucatan Channel Transport and the Loop Current Area in a Multi-Decadal Numerical Simulation, Marine Technology Society Journal, 48(4), 15-26, 10.4031/MTSJ.48.4.8.
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URL: https://doi.org/10.4031/MTSJ.48.4.8
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Purna Chand, C., Rao, M.V., Ramana, I.V., Ali, M.M., Patoux, J., and Bourassa, M.A. (2014). Estimation of Sea Level Pressure Fields During Cyclone Nilam from Oceansat-2 Scatterometer Winds: Presssure Fields from OSCAT, Atmospheric Science Letters, 15(1), 65-71, 10.1002/asl2.473. Journal Article »
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Title: Estimation of Sea Level Pressure Fields During Cyclone Nilam from Oceansat-2 Scatterometer Winds: Presssure Fields from OSCAT
Type: Journal Article
Publication: Atmospheric Science Letters
Author(s): Purna Chand, C., Rao, M.V., Ramana, I.V., Ali, M.M., Patoux, J., and Bourassa, M.A.
Year: 2014
Formatted Citation: Purna Chand, C., Rao, M.V., Ramana, I.V., Ali, M.M., Patoux, J., and Bourassa, M.A., 2014: Estimation of Sea Level Pressure Fields During Cyclone Nilam from Oceansat-2 Scatterometer Winds: Presssure Fields from OSCAT, Atmospheric Science Letters, 15(1), 65-71, 10.1002/asl2.473.
Abstract: Sea level pressure observations are rarely available over most of the oceans and no remote sensing instrument can measure it directly. Here, we explore the estimation of sea level pressure fields using surface wind observations from OSCAT, the scatterometer onboard Oceansat-2, during the 27 October-2 November 2012 passage of Cyclone Nilam over the Bay of Bengal. The estimated pressure is validated with moored-buoy observations. Scatterometer-derived pressure differences are closer to in situ observations than those in examined numerical model estimations. The estimated pressure is more accurate than European Centre for Medium-range Weather Forecasting re-analysis values in location, track, and intensity.
Keywords: scatterometer; sea level pressure; OSCAT
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URL: https://doi.org/10.1002/asl2.473
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Remund, Q.P. and Long, D.G. (2014). A Decade of QuikSCAT Scatterometer Sea Ice Extent Data, IEEE Transactions on Geoscience and Remote Sensing, 52(7), 4281-4290, 10.1109/TGRS.2013.2281056. Journal Article »
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Title: A Decade of QuikSCAT Scatterometer Sea Ice Extent Data
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Remund, Q.P. and Long, D.G.
Year: 2014
Formatted Citation: Remund, Q.P. and Long, D.G., 2014: A Decade of QuikSCAT Scatterometer Sea Ice Extent Data, IEEE Transactions on Geoscience and Remote Sensing, 52(7), 4281-4290, 10.1109/TGRS.2013.2281056.
Abstract: Polar sea ice is an important input to global climate models and is considered to be a sensitive indicator of climate change. While originally designed only for wind estimation, radar backscatter measurements collected by wind scatterometers have proven useful for estimating the extent of sea ice. During the Quick Scatterometer (QuikSCAT) mission, SeaWinds data were used to operationally map the sea ice extent. The resulting sea ice maps were used to mask near-surface winds to support SeaWinds' primary mission of measuring near-surface winds over the ocean. This paper describes the operational SeaWinds sea ice extent mapping algorithm, provides validation comparisons, and presents results from the ten-year data product. Starting with enhanced resolution horizontal polarization and vertical polarization backscatter images, the algorithm employs an iterative maximum-likelihood classifier with fixed thresholds to segment sea ice and open ocean pixels. Residual classification errors are reduced through binary image processing techniques and sea ice growth/retreat constraint methods. The algorithm results are compared with sea ice concentrations derived from Special Sensor Microwave/Imager data and with RADARSAT synthetic aperture radar imagery. The results suggest differences in the sensitivities of active and passive products given their channel sets and specific algorithms. Derived sea ice extents over the full decade-long QuikSCAT mission data set are analyzed to show important trends in sea ice extent for the Antarctic and Arctic regions.
Keywords: Antarctica; Arctic; QuikSCAT; SeaWinds; maximum likelihood (ML) detection; microwave radiometry; microwave sensors; radar remote sensing; sea ice
Mission: |SeaWinds|
URL: https://doi.org/10.1109/TGRS.2013.2281056
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Stiles, B.W., Danielson, R.E., Poulsen, W.L., Brennan, M.J., Hristova-Veleva, S., Shen, T.-P., and Fore, A.G. (2014). Optimized Tropical Cyclone Winds From QuikSCAT: A Neural Network Approach, IEEE Transactions on Geoscience and Remote Sensing, 52(11), 7418-7434, 10.1109/TGRS.2014.2312333. Journal Article »
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Title: Optimized Tropical Cyclone Winds From QuikSCAT: A Neural Network Approach
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Stiles, B.W., Danielson, R.E., Poulsen, W.L., Brennan, M.J., Hristova-Veleva, S., Shen, T.-P., and Fore, A.G.
Year: 2014
Formatted Citation: Stiles, B.W., Danielson, R.E., Poulsen, W.L., Brennan, M.J., Hristova-Veleva, S., Shen, T.-P., and Fore, A.G., 2014: Optimized Tropical Cyclone Winds From QuikSCAT: A Neural Network Approach, IEEE Transactions on Geoscience and Remote Sensing, 52(11), 7418-7434, 10.1109/TGRS.2014.2312333.
Abstract: We have developed a neural network technique for retrieving accurate 12.5-km resolution wind speeds from Ku-band scatterometer measurements in tropical cyclone conditions including typical rain events in such storms. The method was shown to retrieve accurate wind speeds up to 40 m/s when compared with aircraft reconnaissance data, including GPS dropwindsondes and Stepped-Frequency Microwave Radiometer surface wind speed measurements, and when compared to global best track maximum wind speeds. Wind directions were unchanged from the current (version 3) Jet Propulsion Laboratory (JPL) global wind vector product. The technique removes positive biases with respect to best track winds in the developing phase of tropical cyclones that occurred in the nominal (version 2) JPL QuikSCAT product. The new technique also reduces negative biases with respect to best track wind speeds that occurred in the nominal product (both versions 2 and 3) during the most extreme period of the lifetime of intense storms. The wind regime with the most notable improvement is 20–40 m/s (40–80 kn), with more modest improvement for higher winds and the improvement at lower winds comparable to that achieved previously by the version 3 JPL global rain-corrected product. The net effect of all the wind speed improvements is a much better measurement of storm intensity over time in the new product than what has been previously available. When compared with speed data from aircraft flights in Atlantic hurricanes, the new product exhibited a 1–2-m/s positive overall bias and a 3-m/s mean absolute error. The random error and systematic positive bias in the new scatterometer wind product is similar to that of the Hurricane Research Division H*WIND analyses when aircraft data are available for assimilation. This similarity may be explained by the fact that H*WIND data are used as ground truth to fit the coefficients used by the new technique to map radar measure- ents to wind speed. The fact that H*WIND was designed to match maximum winds while preserving radial symmetry may explain the overall positive biases that we observe in both H*WIND and the new scatterometer wind product which compared to aircraft reconnaissance data. The new scatterometer product could also be inheriting systematic biases in the presence of rain from H*WIND. Under the most extreme rain conditions, the radar signal from the surface can be lost. In such cases, the technique makes use of measurements in the 87.5-km region comprising the 7 $times$ 7 neighboring cells around the target 12.5-km wind vector cell. In so doing, we sacrifice resolution in cases where the highest resolution region has no useful measurements. Even so, the most extreme rain conditions can result in reduced accuracy. The new technique has been used to retrieve wind fields for every tropical cyclone of tropical storm force or above that has been observed by QuikSCAT during the period of time from October 1999 to November 2009. The resulting data set has been made available online for use by the tropical cyclone research community.
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Mission: |SeaWinds|
URL: https://doi.org/10.1109/TGRS.2014.2312333
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Ulaby, F. and Long, D. (2014). Microwave Radar and Radiometric Remote Sensing, Book »
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Title: Microwave Radar and Radiometric Remote Sensing
Type: Book
Publication:
Author(s): Ulaby, F. and Long, D.
Year: 2014
Formatted Citation: Ulaby, F. and Long, D., 2014: Microwave Radar and Radiometric Remote Sensing,
Abstract: The 1000-page book covers theoretical models, system design and operation, and geoscientific applications of active and passive microwave remote sensing systems. It is designed as a textbook for a postgraduate course, as well as a reference for the practicing professional. To facilitate understanding and use of the material, the book includes 50 MATLAB-based computer codes and the book's website includes interactive modules based on theoretical and empirical models. The book is a must-have for every scientist and engineer with interest in microwave remote sensing.
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URL: https://mrs.eecs.umich.edu/
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Vose, R.S., Applequist, S., Bourassa, M.A., Pryor, S.C., Barthelmie, R.J., Blanton, B., Bromirski, P.D., Brooks, H.E., DeGaetano, A.T., Dole, R.M., Easterling, D.R., Jensen, R.E., Karl, T.R., Katz, R.W., Klink, K., Kruk, M.C., Kunkel, K.E., MacCracken, M.C., Peterson, T.C., Shein, K., Thomas, B.R., Walsh, J.E., Wang, X.L., Wehner, M.F., Wuebbles, D.J., and Young, R.S. (2014). Monitoring and Understanding Changes in Extremes: Extratropical Storms, Winds, and Waves, Bulletin of the American Meteorological Society, 95(3), 377-386, 10.1175/BAMS-D-12-00162.1. Journal Article »
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Title: Monitoring and Understanding Changes in Extremes: Extratropical Storms, Winds, and Waves
Type: Journal Article
Publication: Bulletin of the American Meteorological Society
Author(s): Vose, R.S., Applequist, S., Bourassa, M.A., Pryor, S.C., Barthelmie, R.J., Blanton, B., Bromirski, P.D., Brooks, H.E., DeGaetano, A.T., Dole, R.M., Easterling, D.R., Jensen, R.E., Karl, T.R., Katz, R.W., Klink, K., Kruk, M.C., Kunkel, K.E., MacCracken, M.C., Peterson, T.C., Shein, K., Thomas, B.R., Walsh, J.E., Wang, X.L., Wehner, M.F., Wuebbles, D.J., and Young, R.S.
Year: 2014
Formatted Citation: Vose, R.S., Applequist, S., Bourassa, M.A., Pryor, S.C., Barthelmie, R.J., Blanton, B., Bromirski, P.D., Brooks, H.E., DeGaetano, A.T., Dole, R.M., Easterling, D.R., Jensen, R.E., Karl, T.R., Katz, R.W., Klink, K., Kruk, M.C., Kunkel, K.E., MacCracken, M.C., Peterson, T.C., Shein, K., Thomas, B.R., Walsh, J.E., Wang, X.L., Wehner, M.F., Wuebbles, D.J., and Young, R.S., 2014: Monitoring and Understanding Changes in Extremes: Extratropical Storms, Winds, and Waves, Bulletin of the American Meteorological Society, 95(3), 377-386, 10.1175/BAMS-D-12-00162.1.
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URL: https://doi.org/10.1175/BAMS-D-12-00162.1
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Weihs, R.R. and Bourassa, M.A. (2014). Modeled Diurnally Varying Sea Surface Temperatures and Their Influence on Surface Heat Fluxes, Journal of Geophysical Research: Oceans, 119(7), 4101-4123, 10.1002/2013JC009489. Journal Article »
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Title: Modeled Diurnally Varying Sea Surface Temperatures and Their Influence on Surface Heat Fluxes
Type: Journal Article
Publication: Journal of Geophysical Research: Oceans
Author(s): Weihs, R.R. and Bourassa, M.A.
Year: 2014
Formatted Citation: Weihs, R.R. and Bourassa, M.A., 2014: Modeled Diurnally Varying Sea Surface Temperatures and Their Influence on Surface Heat Fluxes, Journal of Geophysical Research: Oceans, 119(7), 4101-4123, 10.1002/2013JC009489.
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URL: https://doi.org/10.1002/2013JC009489
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Zheng, Y., Zhang, R., and Bourassa, M.A. (2014). Impact of East Asian Winter and Australian Summer Monsoons on the Enhanced Surface Westerlies over the Western Tropical Pacific Ocean Preceding the El Niño Onset, Journal of Climate, 27(5), 1928-1944, 10.1175/JCLI-D-13-00369.1. Journal Article »
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Title: Impact of East Asian Winter and Australian Summer Monsoons on the Enhanced Surface Westerlies over the Western Tropical Pacific Ocean Preceding the El Niño Onset
Type: Journal Article
Publication: Journal of Climate
Author(s): Zheng, Y., Zhang, R., and Bourassa, M.A.
Year: 2014
Formatted Citation: Zheng, Y., Zhang, R., and Bourassa, M.A., 2014: Impact of East Asian Winter and Australian Summer Monsoons on the Enhanced Surface Westerlies over the Western Tropical Pacific Ocean Preceding the El Niño Onset, Journal of Climate, 27(5), 1928-1944, 10.1175/JCLI-D-13-00369.1.
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URL: https://doi.org/10.1175/JCLI-D-13-00369.1
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Ali, M.M., Bhat, G.S., Long, D.G., Bharadwaj, S., and Bourassa, M.A. (2013). Estimating Wind Stress at the Ocean Surface from Scatterometer Observations, IEEE Geoscience and Remote Sensing Letters, 10(5), 1129-1132, 10.1109/LGRS.2012.2231937. Journal Article »
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Title: Estimating Wind Stress at the Ocean Surface from Scatterometer Observations
Type: Journal Article
Publication: IEEE Geoscience and Remote Sensing Letters
Author(s): Ali, M.M., Bhat, G.S., Long, D.G., Bharadwaj, S., and Bourassa, M.A.
Year: 2013
Formatted Citation: Ali, M.M., Bhat, G.S., Long, D.G., Bharadwaj, S., and Bourassa, M.A., 2013: Estimating Wind Stress at the Ocean Surface from Scatterometer Observations, IEEE Geoscience and Remote Sensing Letters, 10(5), 1129-1132, 10.1109/LGRS.2012.2231937.
Abstract: Wind stress is the most important ocean forcing for driving tropical surface currents. Stress can be estimated from scatterometer-reported wind measurements at 10 m that have been extrapolated to the surface, assuming a neutrally stable atmosphere and no surface current. Scatterometer calibration is designed to account for the assumption of neutral stability; however, the assumption of a particular sea state and negligible current often introduces an error in wind stress estimations. Since the fundamental scatterometer measurement is of the surface radar backscatter (sigma-0) which is related to surface roughness and, thus, stress, we develop a method to estimate wind stress directly from the scatterometer measurements of sigma-0 and their associated azimuth angle and incidence angle using a neural network approach. We compare the results with in situ estimations and observe that the wind stress estimations from this approach are more accurate compared with those obtained from the conventional estimations using 10-m-height wind measurements.
Keywords: Atmospheric stability; neutral stability; scatterometer; wind stress
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URL: https://doi.org/10.1109/LGRS.2012.2231937
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Banzon, V.F. and Reynolds, R.W. (2013). Use of WindSat to Extend a Microwave-Based Daily Optimum Interpolation Sea Surface Temperature Time Series, Journal of Climate, 26(8), 2557-2562, 10.1175/JCLI-D-12-00628.1. Journal Article »
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Title: Use of WindSat to Extend a Microwave-Based Daily Optimum Interpolation Sea Surface Temperature Time Series
Type: Journal Article
Publication: Journal of Climate
Author(s): Banzon, V.F. and Reynolds, R.W.
Year: 2013
Formatted Citation: Banzon, V.F. and Reynolds, R.W., 2013: Use of WindSat to Extend a Microwave-Based Daily Optimum Interpolation Sea Surface Temperature Time Series, Journal of Climate, 26(8), 2557-2562, 10.1175/JCLI-D-12-00628.1.
Abstract: The NOAA 1/4 degrees daily optimum interpolation sea surface temperature analysis (DOISST) is available either as a 31-yr (from 1981 onward) time series based on Advanced Very High Resolution Radiometer (AVHRR) observations or as a 9-yr (2002-11) time series that incorporates additional data from the Advanced Microwave Scanning Radiometer (AMSR) on the Earth Observing System (EOS) platform. In October 2011, AVHRR+AMSR DOISST production was discontinued when the AMSR instrument lost its capability to collect daily, global-coverage data. Sea surface temperatures from the follow-up AMSR2 instrument will not be available until mid-2013. To ensure an uninterrupted consistent long-term microwave-based DOISST time series, this study tested the feasibility of bridging the gap between AMSR and AMSR2 using WindSat Polarimetric Radiometer (WSAT) data. Comparison of WSAT and AMSR SST data during their period of overlap from 2004 to 2011 showed temporal gaps were common for WSAT, especially before 2009. The WSAT daily spatial coverage was slightly inferior to AMSR but still far superior to AVHRR. When satellite SSTs were bias adjusted with respect to in situ data, the resulting AMSR-and WSAT-only analyses were very similar. Monthly zonal averages agreed to within 0.1 K, except when WSAT data were continuously missing for over three weeks. However, if satellite SSTs were not bias adjusted prior to analysis, seasonally varying zonal average differences were observed, with maxima of similar to 0.3 K occurring at midlatitudes. Thus, WSAT can be used to continue the microwave-based DOISST time series because the methodology compensates for the different equatorial crossing times of the two satellites.
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Mission: |WindSat|
URL: https://doi.org/10.1175/JCLI-D-12-00628.1
Other URLs:
Bentamy, A., Grodsky, S.A., Chapron, B., and Carton, J.A. (2013). Compatibility of C- and Ku-band Scatterometer Winds: ERS-2 and QuikSCAT, Journal of Marine Systems, 117-118, 72-80, 10.1016/j.jmarsys.2013.02.008. Journal Article »
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Title: Compatibility of C- and Ku-band Scatterometer Winds: ERS-2 and QuikSCAT
Type: Journal Article
Publication: Journal of Marine Systems
Author(s): Bentamy, A., Grodsky, S.A., Chapron, B., and Carton, J.A.
Year: 2013
Formatted Citation: Bentamy, A., Grodsky, S.A., Chapron, B., and Carton, J.A., 2013: Compatibility of C- and Ku-band Scatterometer Winds: ERS-2 and QuikSCAT, Journal of Marine Systems, 117-118, 72-80, 10.1016/j.jmarsys.2013.02.008.
Abstract: Global winds provided by satellite scatterometry are an important aspect of the ocean observing system. Many applications require well-calibrated time series of winds over time periods spanned by multiple missions. But sensors on individual satellites differ, introducing differences in wind estimates. This study focuses on global winds from two scatterometers, ERS-2 (1996-2001) and QuikSCAT (1999-2009) that show persistent differences during their period of overlap (July-1999 to January 2001). We examine a set of collocated observations during this period to evaluate the causes of these differences. The use of different operating frequencies leads to differences that depend on rain rate, wind velocity, and SST. The enhanced sensitivity to rain rate of the higher frequency QuikSCAT is mitigated by a combined use of the standard rain flag and removing data for which the multidimensional rain probability is >0.05. Generally, ERS-2 wind speeds computed using the IFREMER CMODIFR2 geophysical model function (GMF) are lower than QuikSCAT winds by 0.6 m/s, but wind directions are consistent. This wind speed bias is reduced to -0.2 m/s after partial reprocessing of ERS-2 wind speed using Hersbach's (2010) new CMOD5.n GMF, without altering wind direction. An additional contributor to the difference in wind speed is the biases in the GMFs used in processing the two data sets and is empirically parameterized here as a function of ERS-2 wind speed and direction relative to the mid-beam azimuth. After applying the above corrections, QuikSCAT wind speed then remains systematically lower (by 0.5 m/s) than ERS-2 over regions of very cold SST<5 degrees C. This difference may result from temperature-dependence in the viscous damping of surface waves which has a stronger impact on shorter waves and thus preferentially affects QuikSCAT.
Keywords: Scatterometer winds; SST; Inter-instrument bias
Mission:
URL: https://doi.org/10.1016/j.jmarsys.2013.02.008
Other URLs:
Bentamy, A., Grodsky, S.A., Katsaros, K., Mestas-Nuñez, A.M., Blanke, B., and Desbiolles, F. (2013). Improvement in Air-Sea Flux Estimates Derived from Satellite Observations, International Journal of Remote Sensing, 34(14), 5243-5261, 10.1080/01431161.2013.787502. Journal Article »
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Title: Improvement in Air-Sea Flux Estimates Derived from Satellite Observations
Type: Journal Article
Publication: International Journal of Remote Sensing
Author(s): Bentamy, A., Grodsky, S.A., Katsaros, K., Mestas-Nuñez, A.M., Blanke, B., and Desbiolles, F.
Year: 2013
Formatted Citation: Bentamy, A., Grodsky, S.A., Katsaros, K., Mestas-Nuñez, A.M., Blanke, B., and Desbiolles, F., 2013: Improvement in Air-Sea Flux Estimates Derived from Satellite Observations, International Journal of Remote Sensing, 34(14), 5243-5261, 10.1080/01431161.2013.787502.
Abstract: A new method is developed to estimate daily turbulent airsea fluxes over the global ocean on a 0.25 degrees grid. The required surface wind speed (w(10)) and specific air humidity (q(10)) at 10m height are both estimated from remotely sensed measurements. w(10) is obtained from the SeaWinds scatterometer on board the QuikSCAT satellite. A new empirical model relating brightness temperatures (T-b) from the Special Sensor Microwave Imager (SSM/I) and q(10) is developed. It is an extension of the author's previous q(10) model. In addition to T-b, the empirical model includes sea surface temperature (SST) and airsea temperature difference data. The calibration of the new empirical q(10) model utilizes q(10) from the latest version of the National Oceanography Centre airsea interaction gridded data set (NOCS2.0). Compared with mooring data, the new satellite q(10) exhibits better statistical results than previous estimates. For instance, the bias, the root mean square (RMS), and the correlation coefficient values estimated from comparisons between satellite and moorings in the northeast Atlantic and the Mediterranean Sea are 0.04gkg(1), 0.87gkg(1), and 0.95, respectively. The new satellite q(10) is used in combination with the newly reprocessed QuikSCAT V3, the latest version of SST analyses provided by the National Climatic Data Center (NCDC), and 10m air temperature estimated from the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalyses (ERA-Interim), to determine three daily gridded turbulent quantities at 0.25 degrees spatial resolution: surface wind stress, latent heat flux (LHF), and sensible heat flux (SHF). Validation of the resulting fields is performed through a comprehensive comparison with daily, in situ values of LHF and SHF from buoys. In the northeast Atlantic basin, the satellite-derived daily LHF has bias, RMS, and correlation of 5Wm(2), 27Wm(2), and 0.89, respectively. For SHF, the statistical parameters are 2Wm(2), 10Wm(2), and 0.94, respectively. At global scale, the new satellite LHF and SHF are compared to NOCS2.0 daily estimates. Both daily fluxes exhibit similar spatial and seasonal variability. The main departures are found at latitudes south of 40 degrees S, where satellite latent and sensible heat fluxes are generally larger.
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Mission: |SeaWinds|
URL: https://doi.org/10.1080/01431161.2013.787502
Other URLs:
Bogucki, D.J., Drennan, W.M., Woods, S., Gremes-Cordero, S., Long, D.G., and Mitchell, C. (2013). Short Surface Waves in the Canadian Arctic in 2007 and 2008, Journal of Geophysical Research: Oceans, 118(7), 3712-3722, 10.1002/jgrc.20273. Journal Article »
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Title: Short Surface Waves in the Canadian Arctic in 2007 and 2008
Type: Journal Article
Publication: Journal of Geophysical Research: Oceans
Author(s): Bogucki, D.J., Drennan, W.M., Woods, S., Gremes-Cordero, S., Long, D.G., and Mitchell, C.
Year: 2013
Formatted Citation: Bogucki, D.J., Drennan, W.M., Woods, S., Gremes-Cordero, S., Long, D.G., and Mitchell, C., 2013: Short Surface Waves in the Canadian Arctic in 2007 and 2008, Journal of Geophysical Research: Oceans, 118(7), 3712-3722, 10.1002/jgrc.20273.
Abstract: We have collected time series data of short oceanic waves as a part of the International Polar Year (IPY) 2007-2008. Using a shipboard laser wave slope (LAWAS) system operating at 900 nm, we have obtained wave slopes measurements up to 60 rad m(-1) wave number. We have compared our in situ wave slopes with collocated and concurrent high-resolution upwind Normalized Radar Cross Sections (NRCS) collected by QuikSCAT. The LAWAS measured wave slope spectra were consistent with local wind speeds and QuikSCAT measured NRCS. Our measured short wave mean slopes indicate their enhancement by long waves (0-1 rad m(-1)) at small values of long-wave slope. Concurrent with wave slope measurements, the strength of the reflected LAWAS light beam was analyzed in terms of the light attenuation coefficient at 900 nm. We have observed a correlation between surface elevation and light attenuation. The mechanism of wave modulated beam attenuation was found to be related to the instantaneous long wave skewness.
Keywords: waves; microwave; scatterometer
Mission: |SeaWinds|
URL: https://doi.org/10.1002/jgrc.20273
Other URLs:
Bourassa, M., Gille, S.T., Bitz, C., Carlson, D., Cerovecki, I., Cronin, M., Drennan, W., Fairall, C., Hoffman, R., Magnusdottir, G., Pinker, R., Renfrew, I., Serreze, M., Speer, K., Talley, L., and Wick, G. (2013). High-Latitude Ocean and Sea Ice Surface Fluxes: Requirements and Challenges for Climate Research, Bulletin of the American Meteorological Society, 94(3), 403-423, 10.1175/BAMS-D-11-00244.1. Journal Article »
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Title: High-Latitude Ocean and Sea Ice Surface Fluxes: Requirements and Challenges for Climate Research
Type: Journal Article
Publication: Bulletin of the American Meteorological Society
Author(s): Bourassa, M., Gille, S.T., Bitz, C., Carlson, D., Cerovecki, I., Cronin, M., Drennan, W., Fairall, C., Hoffman, R., Magnusdottir, G., Pinker, R., Renfrew, I., Serreze, M., Speer, K., Talley, L., and Wick, G.
Year: 2013
Formatted Citation: Bourassa, M., Gille, S.T., Bitz, C., Carlson, D., Cerovecki, I., Cronin, M., Drennan, W., Fairall, C., Hoffman, R., Magnusdottir, G., Pinker, R., Renfrew, I., Serreze, M., Speer, K., Talley, L., and Wick, G., 2013: High-Latitude Ocean and Sea Ice Surface Fluxes: Requirements and Challenges for Climate Research, Bulletin of the American Meteorological Society, 94(3), 403-423, 10.1175/BAMS-D-11-00244.1.
Abstract: Polar regions have great sensitivity to climate forcing; however, understanding of the physical processes coupling the atmosphere and ocean in these regions is relatively poor. Improving our knowledge of high-latitude surface fluxes will require close collaboration among meteorologists, oceanographers, ice physicists, and climatologists, and between observationalists and modelers, as well as new combinations of in situ measurements and satellite remote sensing. This article describes the deficiencies in our current state of knowledge about air�sea surface fluxes in high latitudes, the sensitivity of various high-latitude processes to changes in surface fluxes, and the scientific requirements for surface fluxes at high latitudes. We inventory the reasons, both logistical and physical, why existing flux products do not meet these requirements. Capturing an annual cycle in fluxes requires that instruments function through long periods of cold polar darkness, often far from support services, in situations subject to icing and extreme wave conditions. Furthermore, frequent cloud cover at high latitudes restricts the availability of surface and atmospheric data from visible and infrared (IR) wavelength satellite sensors. Recommendations are made for improving high-latitude fluxes, including 1) acquiring more in situ observations, 2) developing improved satellite-flux-observing capabilities, 3) making observations and flux products more accessible, and 4) encouraging flux intercomparisons.
Keywords: flux; white; climate; Arctic; Antarctic
Mission:
URL: https://doi.org/10.1175/BAMS-D-11-00244.1
Other URLs:
Chelton, D. (2013). Mesoscale Eddy Effects, Nature Geoscience, 6(8), 594-595, 10.1038/ngeo1906. Journal Article »
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Title: Mesoscale Eddy Effects
Type: Journal Article
Publication: Nature Geoscience
Author(s): Chelton, D.
Year: 2013
Formatted Citation: Chelton, D., 2013: Mesoscale Eddy Effects, Nature Geoscience, 6(8), 594-595, 10.1038/ngeo1906.
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URL: https://doi.org/10.1038/ngeo1906
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Cheng, X., Xie, S.-P., McCreary, J.P., Qi, Y., and Du, Y. (2013). Intraseasonal variability of sea surface height in the Bay of Bengal, Journal of Geophysical Research: Oceans, 118(2), 816-830, 10.1002/jgrc.20075. Journal Article »
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Title: Intraseasonal variability of sea surface height in the Bay of Bengal
Type: Journal Article
Publication: Journal of Geophysical Research: Oceans
Author(s): Cheng, X., Xie, S.-P., McCreary, J.P., Qi, Y., and Du, Y.
Year: 2013
Formatted Citation: Cheng, X., Xie, S.-P., McCreary, J.P., Qi, Y., and Du, Y., 2013: Intraseasonal variability of sea surface height in the Bay of Bengal, Journal of Geophysical Research: Oceans, 118(2), 816-830, 10.1002/jgrc.20075.
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URL: https://doi.org/10.1002/jgrc.20075
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Gaube, P., Chelton, D.B., Strutton, P.G., and Behrenfeld, M.J. (2013). Satellite Observations of Chlorophyll, Phytoplankton Biomass, and Ekman Pumping in Nonlinear Mesoscale Eddies, Journal of Geophysical Research: Oceans, 118(12), 6349-6370, 10.1002/2013JC009027. Journal Article »
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Title: Satellite Observations of Chlorophyll, Phytoplankton Biomass, and Ekman Pumping in Nonlinear Mesoscale Eddies
Type: Journal Article
Publication: Journal of Geophysical Research: Oceans
Author(s): Gaube, P., Chelton, D.B., Strutton, P.G., and Behrenfeld, M.J.
Year: 2013
Formatted Citation: Gaube, P., Chelton, D.B., Strutton, P.G., and Behrenfeld, M.J., 2013: Satellite Observations of Chlorophyll, Phytoplankton Biomass, and Ekman Pumping in Nonlinear Mesoscale Eddies, Journal of Geophysical Research: Oceans, 118(12), 6349-6370, 10.1002/2013JC009027.
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URL: https://doi.org/10.1002/2013JC009027
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Gierach, M.M., Vazquez-Cuervo, J., Lee, T., and Tsontos, V.M. (2013). Aquarius and SMOS Detect Effects of an Extreme Mississippi River Flooding Event in the Gulf of Mexico, Geophysical Research Letters, 40(19), 5188-5193, 10.1002/grl.50995. Journal Article »
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Title: Aquarius and SMOS Detect Effects of an Extreme Mississippi River Flooding Event in the Gulf of Mexico
Type: Journal Article
Publication: Geophysical Research Letters
Author(s): Gierach, M.M., Vazquez-Cuervo, J., Lee, T., and Tsontos, V.M.
Year: 2013
Formatted Citation: Gierach, M.M., Vazquez-Cuervo, J., Lee, T., and Tsontos, V.M., 2013: Aquarius and SMOS Detect Effects of an Extreme Mississippi River Flooding Event in the Gulf of Mexico, Geophysical Research Letters, 40(19), 5188-5193, 10.1002/grl.50995.
Abstract: Sea surface salinity (SSS) measurements from the Aquarius/Satélite de Aplicaciones Científicas (SAC)-D satellite and Soil Moisture and Ocean Salinity (SMOS) mission were used to document the freshening associated with the record 2011 Mississippi River flooding event in the Gulf of Mexico (GoM). Assessment of the salinity response was aided by additional satellite observations, including chlorophyll-a (chl-a) and ocean surface currents, and a passive tracer simulation. Low SSS values associated with the spreading of the river plume were observed 1–3 months after peak river discharge which then receded and became unidentifiable from satellite observations 5 months after maximum discharge. The seasonal wind pattern and general circulation of the GoM dramatically impacted the observed salinity response, transporting freshwater eastward along the Gulf coast and entraining low salinity waters into the open GoM. The observed salinity response from Aquarius was consistent with SMOS SSS, chl-a concentrations, and the passive tracer simulation in terms of the pathway and transit time of the river plume spreading. This study is the first successful application of satellite SSS to study salinity variation in marginal seas.
Keywords: sea surface salinity; river discharge; Aquarius; SMOS; remote sensing; Gulf of Mexico
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URL: https://doi.org/10.1002/grl.50995
Other URLs:
Landerer, F.W., Gleckler, P.J., and Lee, T. (2013). Evaluation of CMIP5 Dynamic Sea Surface Height Multi-Model Simulations Against Satellite Observations, Climate Dynamics, 43, 1271-1283, 10.1007/s00382-013-1939-x. Journal Article »
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Title: Evaluation of CMIP5 Dynamic Sea Surface Height Multi-Model Simulations Against Satellite Observations
Type: Journal Article
Publication: Climate Dynamics
Author(s): Landerer, F.W., Gleckler, P.J., and Lee, T.
Year: 2013
Formatted Citation: Landerer, F.W., Gleckler, P.J., and Lee, T., 2013: Evaluation of CMIP5 Dynamic Sea Surface Height Multi-Model Simulations Against Satellite Observations, Climate Dynamics, 43, 1271-1283, 10.1007/s00382-013-1939-x.
Abstract: We evaluate the representation of dynamic sea surface height (SSH) fields of 33 global coupled models (GCMs) contributed to the fifth phase of the Coupled Model Intercomparison Project (CMIP5). We use observations from satellite altimetry and basic performance metrics to quantify the ability of the GCMs to replicate observed SSH of the time-mean, seasonal cycle, and inter-annual variability patterns. The time-mean SSH representation has markedly improved from CMIP3 to CMIP5, both in terms of overall reduction in root-mean square differences, and in terms of reduced GCM ensemble spread. Biases of the time-mean SSH field in the Indian and Pacific Ocean equatorial regions are consistent with biases in the zonal surface wind stress fields identified with independent measurements. In the Southern Ocean, the latitude of the maximum meridional gradient of the zonal mean SSH CMIP5 models is shifted equatorward, consistent with the GCMs’ spatial biases in the maximum of the zonal mean westerly surface wind stress fields. However, while the Southern Ocean SSH gradients correlate well with the maximum Antarctic circumpolar current transports, there is no significant correlation with the maximum zonal mean wind stress amplitudes, consistent with recent findings that the eddy parameterisations in GCMs dominate over wind stress amplitudes in this region. There is considerable spread across the CMIP5 ensemble for the seasonal and interannual SSH variability patterns. Because of the short observational period, the interannual variability patterns depend on the time-period over which they are derived, while no such dependency is found for the time-mean patterns. The model performance metrics for SSH presented here provide insight into GCM shortcoming due to inadequate model physics or processes. While the diagnostics of CMIP5 GCM performance relative to observations reveal that some models are clearly better than others, model performance is sensitive to the spatio-temporal scales chosen.
Keywords: Sea surface height; CMIP5; GCM skill; Model evaluation; AR5
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URL: https://doi.org/10.1007/s00382-013-1939-x
Other URLs:
Lee, T., Waliser, D.E., Li, J.-L., Landerer, F.W., and Gierach, M.M. (2013). Evaluation of CMIP3 and CMIP5 Wind Stress Climatology Using Satellite Measurements and Atmospheric Reanalysis Products, Journal of Climate, 26(16), 5810–5826, 10.1175/JCLI-D-12-00591.1. Journal Article »
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Title: Evaluation of CMIP3 and CMIP5 Wind Stress Climatology Using Satellite Measurements and Atmospheric Reanalysis Products
Type: Journal Article
Publication: Journal of Climate
Author(s): Lee, T., Waliser, D.E., Li, J.-L., Landerer, F.W., and Gierach, M.M.
Year: 2013
Formatted Citation: Lee, T., Waliser, D.E., Li, J.-L., Landerer, F.W., and Gierach, M.M., 2013: Evaluation of CMIP3 and CMIP5 Wind Stress Climatology Using Satellite Measurements and Atmospheric Reanalysis Products, Journal of Climate, 26(16), 5810–5826, 10.1175/JCLI-D-12-00591.1.
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URL: https://doi.org/10.1175/JCLI-D-12-00591.1
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Li, X., Zhang, J.A., Yang, X., Pichel, W.G., DeMaria, M., Long, D., and Li, Z. (2013). Tropical Cyclone Morphology from Spaceborne Synthetic Aperture Radar, Bulletin of the American Meteorological Society, 94(2), 215-230, 10.1175/BAMS-D-11-00211.1. Journal Article »
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Title: Tropical Cyclone Morphology from Spaceborne Synthetic Aperture Radar
Type: Journal Article
Publication: Bulletin of the American Meteorological Society
Author(s): Li, X., Zhang, J.A., Yang, X., Pichel, W.G., DeMaria, M., Long, D., and Li, Z.
Year: 2013
Formatted Citation: Li, X., Zhang, J.A., Yang, X., Pichel, W.G., DeMaria, M., Long, D., and Li, Z., 2013: Tropical Cyclone Morphology from Spaceborne Synthetic Aperture Radar, Bulletin of the American Meteorological Society, 94(2), 215-230, 10.1175/BAMS-D-11-00211.1.
Abstract: In 2008, the Canadian Space Agency sponsored the Radarsat Hurricane Applications Project (RHAP), for researching new developments in the application of Radarsat-1 synthetic aperture radar (SAR) data and innovative mapping approaches to better understand the dynamics of tropical cyclone genesis, morphology, and movement. Although tropical cyclones can be detected by many remote sensors, SAR can yield high-resolution (subkilometer) and low-level storm information that cannot be seen below the clouds by other sensors. In addition to the wind field and tropical cyclone eye information, structures associated with atmospheric processes can also be detected by SAR. We have acquired 161 Radarsat-1 SAR images through RHAP between 2001 and 2007. Among these, 73 images show clear tropical cyclone eye structure. In addition, we also acquired 10 images from the European Space Agency's Envisat SAR between 2004 and 2010. Both Atlantic hurricanes and Pacific typhoons are included. In this study, we analyze these 83 (73 Radarsat-1 and 10 Envisat) images with tropical cyclone eye information along with ancillary tropical cyclone intensity information from the archive to generate tropical cyclone morphology statistics. Histograms of wave-number asymmetry and intensity are presented. The statistics show that when the storm has higher intensity, the tropical cyclone eye tends to become more symmetric, and the area of the tropical cyclone eye, defined by the minimum wind area, tends to be smaller. Examples of finescale structures within the tropical cyclone (i.e., eye/eyewall mesovortices, arc clouds, double eyewalls, and abnormally high wind or rain within eyes) are presented and discussed.
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URL: https://doi.org/10.1175/BAMS-D-11-00211.1
Other URLs:
Liu, J.-W., Zhang, S.-P., and Xie, S.-P. (2013). Two Types of Surface Wind Response to the East China Sea Kuroshio Front, Journal of Climate, 26(21), 8616-8627, 10.1175/JCLI-D-12-00092.1. Journal Article »
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Title: Two Types of Surface Wind Response to the East China Sea Kuroshio Front
Type: Journal Article
Publication: Journal of Climate
Author(s): Liu, J.-W., Zhang, S.-P., and Xie, S.-P.
Year: 2013
Formatted Citation: Liu, J.-W., Zhang, S.-P., and Xie, S.-P., 2013: Two Types of Surface Wind Response to the East China Sea Kuroshio Front, Journal of Climate, 26(21), 8616-8627, 10.1175/JCLI-D-12-00092.1.
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URL: https://doi.org/10.1175/JCLI-D-12-00092.1
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Moon, K.R. and Long, D.G. (2013). Considerations for Ku-band Scatterometer Calibration Using the Dry Snow Zone of the Greenland Ice Sheet, IEEE Geoscience and Remote Sensing Letters, 10(6), 1344-1349, 10.1109/LGRS.2013.2241012. Journal Article »
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Title: Considerations for Ku-band Scatterometer Calibration Using the Dry Snow Zone of the Greenland Ice Sheet
Type: Journal Article
Publication: IEEE Geoscience and Remote Sensing Letters
Author(s): Moon, K.R. and Long, D.G.
Year: 2013
Formatted Citation: Moon, K.R. and Long, D.G., 2013: Considerations for Ku-band Scatterometer Calibration Using the Dry Snow Zone of the Greenland Ice Sheet, IEEE Geoscience and Remote Sensing Letters, 10(6), 1344-1349, 10.1109/LGRS.2013.2241012.
Abstract: Postlaunch calibration of satellite-borne scatterometers using backscatter data from natural land targets helps to maintain scatterometer accuracy. Due to its temporal stability, the dry-snow zone of the Greenland ice sheet has been proposed in previous studies as a calibration target. Using QuikSCAT data, this letter examines the backscatter properties of the dry-snow zone that are relevant to Ku-band scatterometer calibration including temporal and spatial variabilities, and azimuth-angle and polarization and incidence-angle dependences. The backscatter is found to seasonally vary throughout the dry-snow zone by 0.4 dB on average. Small interannual variations (less than 1.5 dB over a nine year period) in the backscatter are also present in some regions. Azimuth modulation is generally less than 0.4 dB in magnitude and is not significant in some regions of the dry-snow zone. Melting and refreezing appear to cause the quasi-polarization ratio to temporarily decrease. Spatially consistent and relatively temporally stable regions that are well within the interior of the dry-snow zone are best suited as calibration sites.
Keywords: Greenland; Ice sheet; QuikSCAT; scatterometer calibration; snow
Mission: |SeaWinds|
URL: https://doi.org/10.1109/LGRS.2013.2241012
Other URLs:
Owen, M.P. and Long, D.G. (2013). Prior Selection for QuikSCAT Ultra-High Resolution Wind and Rain Retrieval, IEEE Transactions on Geoscience and Remote Sensing, 51(3), 1555-1567, 10.1109/TGRS.2012.2207904. Journal Article »
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Title: Prior Selection for QuikSCAT Ultra-High Resolution Wind and Rain Retrieval
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Owen, M.P. and Long, D.G.
Year: 2013
Formatted Citation: Owen, M.P. and Long, D.G., 2013: Prior Selection for QuikSCAT Ultra-High Resolution Wind and Rain Retrieval, IEEE Transactions on Geoscience and Remote Sensing, 51(3), 1555-1567, 10.1109/TGRS.2012.2207904.
Abstract: QuikSCAT was designed for ocean wind retrieval. However, its wind estimation performance is limited in rainy conditions. Several estimation techniques have been proposed: wind-only (WO), simultaneous wind and rain (SWR), and rain-only, which are appropriate for different levels of rain contamination. To exploit the strengths of each estimation method at mitigating rain contamination, a Bayes estimator selection (BES) technique has been developed for 25-km wind products to select from among the several estimation techniques for each wind vector cell. This paper adapts the BES concept [1] to QuikSCAT ultra-high resolution (UHR) 2.5-km, products and extends BES to include prior selection and noise reduction. Prior selection and noise reduction exploit general spatial characteristics of wind and rain fields to improve the accuracy of estimator selections. Together these techniques enable improved estimator selection performance so that the probability of selecting the estimate with minimum squared error approaches optimal levels. Optimal estimator selection reduces variability of wind estimates during rainy conditions and provides rain estimates when possible without using additional sources of information. Overall, UHR wind estimation performance with the new technique has improved bias and root mean-squared error, -0.16 m/s and 2.15 m/s, respectively, which are lower than either of the UHR WO and UHR SWR estimates.
Keywords: Remote sensing; resolution enhancement; scatterometry; wind; wind retrieval
Mission: |SeaWinds|
URL: https://doi.org/10.1109/TGRS.2012.2207904
Other URLs:
Patoux, J. and Levy, G. (2013). Space-Time Interpolation of Satellite Winds in the Tropics, Journal of Geophysical Research: Atmospheres, 118(18), 10,405-10,413, 10.1002/jgrd.50811. Journal Article »
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Title: Space-Time Interpolation of Satellite Winds in the Tropics
Type: Journal Article
Publication: Journal of Geophysical Research: Atmospheres
Author(s): Patoux, J. and Levy, G.
Year: 2013
Formatted Citation: Patoux, J. and Levy, G., 2013: Space-Time Interpolation of Satellite Winds in the Tropics, Journal of Geophysical Research: Atmospheres, 118(18), 10,405-10,413, 10.1002/jgrd.50811.
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URL: https://doi.org/10.1002/jgrd.50811
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Rudzin, J., Morey, S., Bourassa, M., and Smith, S. (2013). The Influence of Loop Current Position on Winter Sea Surface Temperatures in the Florida Straits, Earth Interactions, 17(16), 1-9, 10.1175/2013EI000521.1. Journal Article »
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Title: The Influence of Loop Current Position on Winter Sea Surface Temperatures in the Florida Straits
Type: Journal Article
Publication: Earth Interactions
Author(s): Rudzin, J., Morey, S., Bourassa, M., and Smith, S.
Year: 2013
Formatted Citation: Rudzin, J., Morey, S., Bourassa, M., and Smith, S., 2013: The Influence of Loop Current Position on Winter Sea Surface Temperatures in the Florida Straits, Earth Interactions, 17(16), 1-9, 10.1175/2013EI000521.1.
Abstract: Influences of the Gulf of Mexico's Loop Current (LC) position on the sea surface temperature (SST) in the Florida Straits (FS) during the winter season are investigated. Satellite-derived SST data are analyzed on the basis of the LC configuration (mature or immature) as determined by satellite altimetry analyses. Cumulative distributions of FS SSTs for both LC phases during the months of January and February show greater likelihood of cooler SSTs in the FS during a mature LC than during an immature LC. This work suggests that differing transit times of LC water parcels during mature and immature phases result in differences in heat loss of the LC near-surface water. This may contribute to the observed SST differences in FS during mature and immature LC phases via temperature advection.
Keywords: Air-sea interaction; Florida Straits; Loop Current; Sea surface temperature; CAO; Atlantic sailfish
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URL: https://doi.org/10.1175/2013EI000521.1
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Strub, P.T., Combes, V., Shillington, F., and Pizarro, O. (2013). Currents and Processes Along the Eastern Boundaries, Ocean Circulation and Climate: A 21st Century Perspective, 103, 339-384, 10.1016/B978-0-12-391851-2.00014-3. Book Chapter »
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Title: Currents and Processes Along the Eastern Boundaries
Type: Book Chapter
Publication: Ocean Circulation and Climate: A 21st Century Perspective
Author(s): Strub, P.T., Combes, V., Shillington, F., and Pizarro, O.
Year: 2013
Formatted Citation: Strub, P.T., Combes, V., Shillington, F., and Pizarro, O., 2013: Currents and Processes Along the Eastern Boundaries, Ocean Circulation and Climate: A 21st Century Perspective, 103, 339-384, 10.1016/B978-0-12-391851-2.00014-3.
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URL: https://doi.org/10.1016/B978-0-12-391851-2.00014-3
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Todd, A.C. (2013). Circulation Dynamics and Larval Transport Mechanisms in the Florida Big Bend, Thesis »
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Title: Circulation Dynamics and Larval Transport Mechanisms in the Florida Big Bend
Type: Thesis
Publication:
Author(s): Todd, A.C.
Year: 2013
Formatted Citation: Todd, A.C., 2013: Circulation Dynamics and Larval Transport Mechanisms in the Florida Big Bend,
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URL: http://purl.flvc.org/fsu/fd/FSU_migr_etd-7630
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Tomita, H., Xie, S.-P., Tokinaga, H., and Kawai, Y. (2013). Cloud Response to the Meandering Kuroshio Extension Front, Journal of Climate, 26(23), 9393-9398, 10.1175/JCLI-D-13-00133.1. Journal Article »
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Title: Cloud Response to the Meandering Kuroshio Extension Front
Type: Journal Article
Publication: Journal of Climate
Author(s): Tomita, H., Xie, S.-P., Tokinaga, H., and Kawai, Y.
Year: 2013
Formatted Citation: Tomita, H., Xie, S.-P., Tokinaga, H., and Kawai, Y., 2013: Cloud Response to the Meandering Kuroshio Extension Front, Journal of Climate, 26(23), 9393-9398, 10.1175/JCLI-D-13-00133.1.
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URL: https://doi.org/10.1175/JCLI-D-13-00133.1
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Wikle, C.K., Milliff, R.F., Herbei, R., and Leeds, W.B. (2013). Modern Statistical Methods in Oceanography: A Hierarchical Perspective, Statistical Science, 28(4), 466-486, 10.1214/13-STS436. Journal Article »
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Title: Modern Statistical Methods in Oceanography: A Hierarchical Perspective
Type: Journal Article
Publication: Statistical Science
Author(s): Wikle, C.K., Milliff, R.F., Herbei, R., and Leeds, W.B.
Year: 2013
Formatted Citation: Wikle, C.K., Milliff, R.F., Herbei, R., and Leeds, W.B., 2013: Modern Statistical Methods in Oceanography: A Hierarchical Perspective, Statistical Science, 28(4), 466-486, 10.1214/13-STS436.
Abstract: Processes in ocean physics, air–sea interaction and ocean biogeochemistry span enormous ranges in spatial and temporal scales, that is, from molecular to planetary and from seconds to millennia. Identifying and implementing sustainable human practices depend critically on our understandings of key aspects of ocean physics and ecology within these scale ranges. The set of all ocean data is distorted such that three- and four-dimensional (i.e., time-dependent) in situ data are very sparse, while observations of surface and upper ocean properties from space-borne platforms have become abundant in the past few decades. Precisions in observations of all types vary as well. In the face of these challenges, the interface between Statistics and Oceanography has proven to be a fruitful area for research and the development of useful models. With the recognition of the key importance of identifying, quantifying and managing uncertainty in data and models of ocean processes, a hierarchical perspective has become increasingly productive. As examples, we review a heterogeneous mix of studies from our own work demonstrating Bayesian hierarchical model applications in ocean physics, air–sea interaction, ocean forecasting and ocean ecosystem models. This review is by no means exhaustive and we have endeavored to identify hierarchical modeling work reported by others across the broad range of ocean-related topics reported in the statistical literature. We conclude by noting relevant ocean-statistics problems on the immediate research horizon, and some technical challenges they pose, for example, in terms of nonlinearity, dimensionality and computing.
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URL: https://doi.org/10.1214/13-STS436
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Williams, B.A. (2013). A Fieldwise Retrieval Approach to the Noise Versus Resolution Tradeoff in Wind Scatterometry, IEEE Transactions on Geoscience and Remote Sensing, 51(12), 5259-5272, 10.1109/TGRS.2012.2233481. Journal Article »
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Title: A Fieldwise Retrieval Approach to the Noise Versus Resolution Tradeoff in Wind Scatterometry
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Williams, B.A.
Year: 2013
Formatted Citation: Williams, B.A., 2013: A Fieldwise Retrieval Approach to the Noise Versus Resolution Tradeoff in Wind Scatterometry, IEEE Transactions on Geoscience and Remote Sensing, 51(12), 5259-5272, 10.1109/TGRS.2012.2233481.
Abstract: This paper approaches the noise versus resolution tradeoff in wind scatterometry from a fieldwise retrieval perspective. Theoretical considerations are discussed, and a practical implementation is developed and applied to the SeaWinds scatterometer. The approach is compared with conventional approaches, as well as numerical weather predictions and buoys. The new method incorporates knowledge of the wind spectrum to reduce the impact of components of the wind signal that are expected to be noisy while enabling reconstruction of fine-scale features that are distinguishable from noise.
Keywords: Bayes estimation; maximum a posteriori estimation; wind scatterometry
Mission: |NSCAT|
URL: https://doi.org/10.1109/TGRS.2012.2233481
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Zheng, Y., Bourassa, M.A., and Hughes, P.J. (2013). Influences of Sea Surface Temperature Gradients and Surface Roughness Changes on the Motion of Surface Oil: A Simple Idealized Study, Journal of Applied Meteorology and Climatology, 52(7), 1561–1575, 10.1175/JAMC-D-12-0211.1. Journal Article »
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Title: Influences of Sea Surface Temperature Gradients and Surface Roughness Changes on the Motion of Surface Oil: A Simple Idealized Study
Type: Journal Article
Publication: Journal of Applied Meteorology and Climatology
Author(s): Zheng, Y., Bourassa, M.A., and Hughes, P.J.
Year: 2013
Formatted Citation: Zheng, Y., Bourassa, M.A., and Hughes, P.J., 2013: Influences of Sea Surface Temperature Gradients and Surface Roughness Changes on the Motion of Surface Oil: A Simple Idealized Study, Journal of Applied Meteorology and Climatology, 52(7), 1561–1575, 10.1175/JAMC-D-12-0211.1.
Abstract: Our modeling shows that changes in sea surface temperature (SST) gradients and surface roughness between oil-free water and oil slicks influence the motion of the slick. Physically significant changes occur in surface wind speed, surface wind divergence, wind stress curl, and Ekman transport mostly due to SST gradients and changes in surface roughness between the water and the slick. These remarkable changes might affect the speed and direction of surface oil. For example, the strongest surface wind divergence (convergence) occurring in the transition zones owing to the presence of an oil slick will induce an atmospheric secondary circulation over the oil region, which in turn might affect the surface oil movement. SST-related changes to wind stress curl and Ekman transport in the transition zones appear to increase approximately linearly to the magnitude of SST gradients. Both surface roughness difference and SST gradients give rise to a net convergence of Ekman transport for oil cover. The SST gradient could play a more important role than surface roughness in changes of Ekman transport when SST gradients are large enough (e.g., several degrees per 10 km). The resulting changes in Ekman transport also induce the changes of surface oil movement. Sensitivity experiments show that appropriate selections of modeled parameters and geostrophic winds do not change our conclusions. Our results from this idealized study indicate that the feedbacks from the surface oil presence to the oil motion itself are not trivial and should be further investigated for consideration in future oil-tracking modeling systems.
Keywords: Oil Slick; roughness; temperature gradient; secondary circulation; idealized
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URL: https://doi.org/10.1175/JAMC-D-12-0211.1
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Alexander, M.A., Seo, H., Xie, S.-P., and Scott, J.D. (2012). ENSO's Impact on the Gap Wind Regions of the Eastern Tropical Pacific Ocean, Journal of Climate, 25(10), 3549-3565, 10.1175/JCLI-D-11-00320.1. Journal Article »
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Title: ENSO's Impact on the Gap Wind Regions of the Eastern Tropical Pacific Ocean
Type: Journal Article
Publication: Journal of Climate
Author(s): Alexander, M.A., Seo, H., Xie, S.-P., and Scott, J.D.
Year: 2012
Formatted Citation: Alexander, M.A., Seo, H., Xie, S.-P., and Scott, J.D., 2012: ENSO's Impact on the Gap Wind Regions of the Eastern Tropical Pacific Ocean, Journal of Climate, 25(10), 3549-3565, 10.1175/JCLI-D-11-00320.1.
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URL: https://doi.org/10.1175/JCLI-D-11-00320.1
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Bradley, J.P. (2012). Extending the QuikSCAT Data Record with the Oceansat-2 Scatterometer, Thesis »
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Title: Extending the QuikSCAT Data Record with the Oceansat-2 Scatterometer
Type: Thesis
Publication:
Author(s): Bradley, J.P.
Year: 2012
Formatted Citation: Bradley, J.P., 2012: Extending the QuikSCAT Data Record with the Oceansat-2 Scatterometer,
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URL: http://hdl.lib.byu.edu/1877/etd5176
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Chan, K.T.F, and Chan, J.C.L. (2012). Size and Strength of Tropical Cyclones as Inferred from QuikSCAT Data, Monthly Weather Review, 140(3), 811-824, 10.1175/MWR-D-10-05062.1. Journal Article »
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Title: Size and Strength of Tropical Cyclones as Inferred from QuikSCAT Data
Type: Journal Article
Publication: Monthly Weather Review
Author(s): Chan, K.T.F, and Chan, J.C.L.
Year: 2012
Formatted Citation: Chan, K.T.F, and Chan, J.C.L., 2012: Size and Strength of Tropical Cyclones as Inferred from QuikSCAT Data, Monthly Weather Review, 140(3), 811-824, 10.1175/MWR-D-10-05062.1.
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URL: https://doi.org/10.1175/MWR-D-10-05062.1
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DiNapoli, S.M., Bourassa, M.A., and Powell, M.D. (2012). Uncertainty and Intercalibration Analysis of H*Wind, Journal of Atmospheric and Oceanic Technology, 29(6), 822-833, 10.1175/JTECH-D-11-00165.1. Journal Article »
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Title: Uncertainty and Intercalibration Analysis of H*Wind
Type: Journal Article
Publication: Journal of Atmospheric and Oceanic Technology
Author(s): DiNapoli, S.M., Bourassa, M.A., and Powell, M.D.
Year: 2012
Formatted Citation: DiNapoli, S.M., Bourassa, M.A., and Powell, M.D., 2012: Uncertainty and Intercalibration Analysis of H*Wind, Journal of Atmospheric and Oceanic Technology, 29(6), 822-833, 10.1175/JTECH-D-11-00165.1.
Abstract: The HRD Real-time Hurricane Wind Analysis System (H*Wind) is a software application used by NOAA's Hurricane Research Division to create a gridded tropical cyclone wind analysis based on a wide range of observations. These analyses are used in both forecasting and research applications. Although mean bias and RMS errors are listed, H*Wind lacks robust uncertainty information that considers the contributions of random observation errors, relative biases between observation types, temporal drift resulting from combining non-simultaneous measurements into a single analysis, and smoothing and interpolation errors introduced by the H*Wind analysis. This investigation seeks to estimate the total contributions of these sources, and thereby provide an overall uncertainty estimate for the H*Wind product. A series of statistical analyses show that in general, the total uncertainty in the H*Wind product in hurricanes is approximately 6% near the storm center, increasing to nearly 13% near the tropical storm force wind radius. The H*Wind analysis algorithm is found to introduce a positive bias to the wind speeds near the storm center, where the analyzed wind speeds are enhanced to match the highest observations. In addition, spectral analyses are performed to ensure that the filter wavelength of the final analysis product matches user specifications. With increased knowledge of bias and uncertainty sources and their effects, researchers will have a better understanding of the uncertainty in the H*Wind product, and can then judge the suitability of H*Wind for various research applications.
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Mission: |SeaWinds|
URL: https://doi.org/10.1175/JTECH-D-11-00165.1
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Durland, T.S. and Farrar, J.T. (2012). The Wavenumber-Frequency Content of Resonantly Excited Equatorial Waves, Journal of Physical Oceanography, 42(11), 1834-1858, 10.1175/JPO-D-11-0234.1. Journal Article »
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Title: The Wavenumber-Frequency Content of Resonantly Excited Equatorial Waves
Type: Journal Article
Publication: Journal of Physical Oceanography
Author(s): Durland, T.S. and Farrar, J.T.
Year: 2012
Formatted Citation: Durland, T.S. and Farrar, J.T., 2012: The Wavenumber-Frequency Content of Resonantly Excited Equatorial Waves, Journal of Physical Oceanography, 42(11), 1834-1858, 10.1175/JPO-D-11-0234.1.
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URL: https://doi.org/10.1175/JPO-D-11-0234.1
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Fairall, C.W., Bourassa, M.A., Cronin, M.F., Smith, S.R., Weller, R.A., Wick, G., Woodruff, S., Yu, L., and Zhang, H.-M. (2012). Observations to Quantify Air-Sea Fluxes and Their Role in Global Variability and Predictability, Proceedings of the Integrated Ocean Observing System (IOOS) Summit Workshop.
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Title: Observations to Quantify Air-Sea Fluxes and Their Role in Global Variability and Predictability
Type: Conference Paper
Publication: Proceedings of the Integrated Ocean Observing System (IOOS) Summit Workshop
Author(s): Fairall, C.W., Bourassa, M.A., Cronin, M.F., Smith, S.R., Weller, R.A., Wick, G., Woodruff, S., Yu, L., and Zhang, H.-M.
Year: 2012
Formatted Citation: Fairall, C.W., Bourassa, M.A., Cronin, M.F., Smith, S.R., Weller, R.A., Wick, G., Woodruff, S., Yu, L., and Zhang, H.-M., 2012: Observations to Quantify Air-Sea Fluxes and Their Role in Global Variability and Predictability, Proceedings of the Integrated Ocean Observing System (IOOS) Summit Workshop.
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Farrar, J.T. and Durland, T.S. (2012). Wavenumber-Frequency Spectra of Inertia-Gravity and Mixed Rossby-Gravity Waves in the Equatorial Pacific Ocean, Journal of Physical Oceanography, 42(11), 1859-1881, 10.1175/JPO-D-11-0235.1. Journal Article »
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Title: Wavenumber-Frequency Spectra of Inertia-Gravity and Mixed Rossby-Gravity Waves in the Equatorial Pacific Ocean
Type: Journal Article
Publication: Journal of Physical Oceanography
Author(s): Farrar, J.T. and Durland, T.S.
Year: 2012
Formatted Citation: Farrar, J.T. and Durland, T.S., 2012: Wavenumber-Frequency Spectra of Inertia-Gravity and Mixed Rossby-Gravity Waves in the Equatorial Pacific Ocean, Journal of Physical Oceanography, 42(11), 1859-1881, 10.1175/JPO-D-11-0235.1.
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URL: https://doi.org/10.1175/JPO-D-11-0235.1
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Fore, A., Haddad, Z.S., Krishnamurti, T.N., and Rodgridez, E. (2012). Improving Scatterometry Retrievals of Wind in Hurricanes Using Non-Simultaneous Passive Microwave Estimates of Precipitation and a Split-Step Advection/Convection Model, Pure and Applied Geophysics, 169(3), 415-424, 10.1007/s00024-011-0378-z. Journal Article »
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Title: Improving Scatterometry Retrievals of Wind in Hurricanes Using Non-Simultaneous Passive Microwave Estimates of Precipitation and a Split-Step Advection/Convection Model
Type: Journal Article
Publication: Pure and Applied Geophysics
Author(s): Fore, A., Haddad, Z.S., Krishnamurti, T.N., and Rodgridez, E.
Year: 2012
Formatted Citation: Fore, A., Haddad, Z.S., Krishnamurti, T.N., and Rodgridez, E., 2012: Improving Scatterometry Retrievals of Wind in Hurricanes Using Non-Simultaneous Passive Microwave Estimates of Precipitation and a Split-Step Advection/Convection Model, Pure and Applied Geophysics, 169(3), 415-424, 10.1007/s00024-011-0378-z.
Abstract: One of the current problems in the accurate estimation of over-ocean wind from scatterometry observations is the proper accounting for precipitation. Specific cases such as hurricanes are particularly difficult, because precipitation in the eye wall and rain bands can be quite heavy, and therefore, affect the scatterometer signatures so drastically that a category-4 hurricane can appear, to the scatterometer, to have category-1 winds. We have developed an approach to infer and account for the signature of the precipitation from non-simultaneous passive-microwave measurements of rain, with the help of geostationary IR measurements. In this note, we describe the basic approach, and the results of applying it to the data taken by the Tropical Rainfall Measurement Mission Microwave Imager measurements several hours before and after the QuikSCAT observation of Hurricane Rita in September 2005. We also describe how we are enhancing the approach with more realism in the assimilation of the IR information.
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URL: https://doi.org/10.1007/s00024-011-0378-z
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Gierach, M.M., Lee, T., Turk, D., and McPhaden, M.J. (2012). Biological Response to the 1997-98 and 2009-10 El Niño Events in the Equatorial Pacific Ocean, Geophysical Research Letters, 39(10), L10602, 10.1029/2012GL051103. Journal Article »
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Title: Biological Response to the 1997-98 and 2009-10 El Niño Events in the Equatorial Pacific Ocean
Type: Journal Article
Publication: Geophysical Research Letters
Author(s): Gierach, M.M., Lee, T., Turk, D., and McPhaden, M.J.
Year: 2012
Formatted Citation: Gierach, M.M., Lee, T., Turk, D., and McPhaden, M.J., 2012: Biological Response to the 1997-98 and 2009-10 El Niño Events in the Equatorial Pacific Ocean, Geophysical Research Letters, 39(10), L10602, 10.1029/2012GL051103.
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URL: https://doi.org/10.1029/2012GL051103
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Hanafin, J.A., Quilfen, Y., Ardhuin, F., Sienkiewicz, J., Queffeulou, P., Obrebski, M., Chapron, B., Reul, N., Collard, F., Corman, D., de Azevedo, E.B., Vandemark, D., and Stutzmann, E. (2012). Phenomenal Sea States and Swell from a North Atlantic Storm in February 2011: A Comprehensive Analysis, Bulletin of the American Meteorological Society, 93(12), 1825–1832, 10.1175/BAMS-D-11-00128.1. Journal Article »
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Title: Phenomenal Sea States and Swell from a North Atlantic Storm in February 2011: A Comprehensive Analysis
Type: Journal Article
Publication: Bulletin of the American Meteorological Society
Author(s): Hanafin, J.A., Quilfen, Y., Ardhuin, F., Sienkiewicz, J., Queffeulou, P., Obrebski, M., Chapron, B., Reul, N., Collard, F., Corman, D., de Azevedo, E.B., Vandemark, D., and Stutzmann, E.
Year: 2012
Formatted Citation: Hanafin, J.A., Quilfen, Y., Ardhuin, F., Sienkiewicz, J., Queffeulou, P., Obrebski, M., Chapron, B., Reul, N., Collard, F., Corman, D., de Azevedo, E.B., Vandemark, D., and Stutzmann, E., 2012: Phenomenal Sea States and Swell from a North Atlantic Storm in February 2011: A Comprehensive Analysis, Bulletin of the American Meteorological Society, 93(12), 1825–1832, 10.1175/BAMS-D-11-00128.1.
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URL: https://doi.org/10.1175/BAMS-D-11-00128.1
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Holbach, H. (2012). The Effects of Gap-Wind-Induced Vorticity, the Monsoon Trough, and the ITCZ on Tropical Cyclogenesis, Thesis »
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Title: The Effects of Gap-Wind-Induced Vorticity, the Monsoon Trough, and the ITCZ on Tropical Cyclogenesis
Type: Thesis
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Author(s): Holbach, H.
Year: 2012
Formatted Citation: Holbach, H., 2012: The Effects of Gap-Wind-Induced Vorticity, the Monsoon Trough, and the ITCZ on Tropical Cyclogenesis,
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URL: http://purl.flvc.org/fsu/fd/FSU_migr_etd-4913
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Hughes, P.J., Bourassa, M.A., Rolph, J.J., and Smith, S.R. (2012). Averaging-Related Biases in Monthly Latent Heat Fluxes, Journal of Atmospheric and Oceanic Technology, 29(7), 974-986, 10.1175/JTECH-D-11-00184.1. Journal Article »
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Title: Averaging-Related Biases in Monthly Latent Heat Fluxes
Type: Journal Article
Publication: Journal of Atmospheric and Oceanic Technology
Author(s): Hughes, P.J., Bourassa, M.A., Rolph, J.J., and Smith, S.R.
Year: 2012
Formatted Citation: Hughes, P.J., Bourassa, M.A., Rolph, J.J., and Smith, S.R., 2012: Averaging-Related Biases in Monthly Latent Heat Fluxes, Journal of Atmospheric and Oceanic Technology, 29(7), 974-986, 10.1175/JTECH-D-11-00184.1.
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URL: https://doi.org/10.1175/JTECH-D-11-00184.1
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Jo, Y.-H., Yan, X.-H., and Liu, W.T. (2012). A New Insight on Sea Level Trends at Different Time Scales in the North Atlantic, Deep Sea Res., Special Issue.
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Title: A New Insight on Sea Level Trends at Different Time Scales in the North Atlantic
Type: Journal Article
Publication: Deep Sea Res., Special Issue
Author(s): Jo, Y.-H., Yan, X.-H., and Liu, W.T.
Year: 2012
Formatted Citation: Jo, Y.-H., Yan, X.-H., and Liu, W.T., 2012: A New Insight on Sea Level Trends at Different Time Scales in the North Atlantic, Deep Sea Res., Special Issue.
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Lee, T., Lagerloef, G., Gierach, M.M., Kao, H.-Y., Yueh, S., and Dohan, K. (2012). Aquarius Reveals Salinity Structure of Tropical Instability Waves, Geophysical Research Letters, 39(12), L12610, 10.1029/2012GL052232. Journal Article »
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Title: Aquarius Reveals Salinity Structure of Tropical Instability Waves
Type: Journal Article
Publication: Geophysical Research Letters
Author(s): Lee, T., Lagerloef, G., Gierach, M.M., Kao, H.-Y., Yueh, S., and Dohan, K.
Year: 2012
Formatted Citation: Lee, T., Lagerloef, G., Gierach, M.M., Kao, H.-Y., Yueh, S., and Dohan, K., 2012: Aquarius Reveals Salinity Structure of Tropical Instability Waves, Geophysical Research Letters, 39(12), L12610, 10.1029/2012GL052232.
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URL: https://doi.org/10.1029/2012GL052232
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Li, F., Jo, Y.-H., Liu, W.T., and Yan, X.-H. (2012). A Dipole Pattern of the Sea Surface Height Anomaly in the North Atlantic: 1990s-2000s, Geophysical Research Letters, 39(15), L15604, 10.1029/2012GL052556. Journal Article »
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Title: A Dipole Pattern of the Sea Surface Height Anomaly in the North Atlantic: 1990s-2000s
Type: Journal Article
Publication: Geophysical Research Letters
Author(s): Li, F., Jo, Y.-H., Liu, W.T., and Yan, X.-H.
Year: 2012
Formatted Citation: Li, F., Jo, Y.-H., Liu, W.T., and Yan, X.-H., 2012: A Dipole Pattern of the Sea Surface Height Anomaly in the North Atlantic: 1990s-2000s, Geophysical Research Letters, 39(15), L15604, 10.1029/2012GL052556.
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URL: https://doi.org/10.1029/2012GL052556
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Lindsley, R.D. and Long, D.G. (2012). Mapping Surface Oil Extent From the Deepwater Horizon Oil Spill Using ASCAT Backscatter, IEEE Transactions on Geoscience and Remote Sensing, 50(7), 2534-2541, 10.1109/TGRS.2011.2174369. Journal Article »
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Title: Mapping Surface Oil Extent From the Deepwater Horizon Oil Spill Using ASCAT Backscatter
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Lindsley, R.D. and Long, D.G.
Year: 2012
Formatted Citation: Lindsley, R.D. and Long, D.G., 2012: Mapping Surface Oil Extent From the Deepwater Horizon Oil Spill Using ASCAT Backscatter, IEEE Transactions on Geoscience and Remote Sensing, 50(7), 2534-2541, 10.1109/TGRS.2011.2174369.
Abstract: The 2010 Deepwater Horizon oil spill in the Gulf of Mexico covered a sufficiently large area to be observed by the European Space Agency Advanced Scatterometer (ASCAT) on MetOp-A. In this paper, ASCAT data and numerically computed winds from the European Centre for Medium-Range Weather Forecasts (ECMWF) are used to map the spatial extent of oil on the ocean surface over the duration of the spill event. Surface oil alters the ocean radar scattering properties, resulting in a difference between the measured backscatter and the backscatter that would be measured if oil were not present. Wind scatterometers infer the near-surface wind speed and direction using the wind geophysical model function (GMF) in conjunction with measured radar backscatter. The oil-altered backscatter error propagates through the wind retrieval process to create a difference in ASCAT-inferred winds and actual winds. Numerically computed vector winds from ECMWF are compared against ASCAT-inferred vector winds. The GMF is applied to ECMWF winds to create a predicted backscatter value to compare against ASCAT-measured backscatter. Large differences in wind or backscatter indicate areas of the ocean surface affected by oil. An objective function is developed to choose an appropriate threshold level to flag the oil-contaminated regions. Data from other sensors corroborate the ASCAT oil extent mapping.
Keywords: Oil pollution; radar remote sensing; scatterometer; spaceborne radar
Mission: |NSCAT|ASCAT|
URL: https://doi.org/10.1109/TGRS.2011.2174369
Other URLs:
Liu, W.T. and Xie, X. (2012). Sea Surface Wind/Stress Vector, Encyclopedia of Remote Sensing, 759–767, 10.1007/978-0-387-36699-9_168. Book Chapter »
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Title: Sea Surface Wind/Stress Vector
Type: Book Chapter
Publication: Encyclopedia of Remote Sensing
Author(s): Liu, W.T. and Xie, X.
Year: 2012
Formatted Citation: Liu, W.T. and Xie, X., 2012: Sea Surface Wind/Stress Vector, Encyclopedia of Remote Sensing, 759–767, 10.1007/978-0-387-36699-9_168.
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URL: https://doi.org/10.1007/978-0-387-36699-9_168
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Liu, W.T. and Xie, X. (2012). Ocean-Atmosphere Water Flux and Evaporation, Encyclopedia of Remote Sensing, 480–489, 10.1007/978-0-387-36699-9_122. Book Chapter »
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Title: Ocean-Atmosphere Water Flux and Evaporation
Type: Book Chapter
Publication: Encyclopedia of Remote Sensing
Author(s): Liu, W.T. and Xie, X.
Year: 2012
Formatted Citation: Liu, W.T. and Xie, X., 2012: Ocean-Atmosphere Water Flux and Evaporation, Encyclopedia of Remote Sensing, 480–489, 10.1007/978-0-387-36699-9_122.
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URL: https://doi.org/10.1007/978-0-387-36699-9_122
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Liu, W.T. and Xie, X. (2012). Offshore Strong Wind for Electric Power Generation, Wind Energy Conversion System: Technology and Trend, 367-383. Book Chapter »
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Title: Offshore Strong Wind for Electric Power Generation
Type: Book Chapter
Publication: Wind Energy Conversion System: Technology and Trend
Author(s): Liu, W.T. and Xie, X.
Year: 2012
Formatted Citation: Liu, W.T. and Xie, X., 2012: Offshore Strong Wind for Electric Power Generation, Wind Energy Conversion System: Technology and Trend, 367-383.
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URL: https://doi.org/10.1007/978-1-4471-2201-2
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Liu, W.T., Xie, X., and Katsaros, K.B. (2012). Observation of Oceanic Origin of Sahel Precipitation from Space, Remote Sensing of Environment, 123, 593-599, 10.1016/j.rse.2012.04.007. Journal Article »
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Title: Observation of Oceanic Origin of Sahel Precipitation from Space
Type: Journal Article
Publication: Remote Sensing of Environment
Author(s): Liu, W.T., Xie, X., and Katsaros, K.B.
Year: 2012
Formatted Citation: Liu, W.T., Xie, X., and Katsaros, K.B., 2012: Observation of Oceanic Origin of Sahel Precipitation from Space, Remote Sensing of Environment, 123, 593-599, 10.1016/j.rse.2012.04.007.
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URL: https://doi.org/10.1016/j.rse.2012.04.007
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Maneesha, K., Murty, V.S.N., Ravichandran, M., Lee, T., Yu, W., and McPhaden, M. (2012). Upper Ocean Variability in the Bay of Bengal During the Tropical Cyclones Nargis and Laila, Journal Article »
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Title: Upper Ocean Variability in the Bay of Bengal During the Tropical Cyclones Nargis and Laila
Type: Journal Article
Publication:
Author(s): Maneesha, K., Murty, V.S.N., Ravichandran, M., Lee, T., Yu, W., and McPhaden, M.
Year: 2012
Formatted Citation: Maneesha, K., Murty, V.S.N., Ravichandran, M., Lee, T., Yu, W., and McPhaden, M., 2012: Upper Ocean Variability in the Bay of Bengal During the Tropical Cyclones Nargis and Laila,
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URL: https://doi.org/10.1016/j.pocean.2012.06.006
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Meissner, T. and Wentz, F.J. (2012). The Emissivity of the Ocean Surface Between 6 and 90 GHz Over a Large Range of Wind Speeds and Earth Incidence Angles, IEEE Transactions on Geoscience and Remote Sensing, 50(8), 3004-3026, 10.1109/TGRS.2011.2179662. Journal Article »
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Title: The Emissivity of the Ocean Surface Between 6 and 90 GHz Over a Large Range of Wind Speeds and Earth Incidence Angles
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Meissner, T. and Wentz, F.J.
Year: 2012
Formatted Citation: Meissner, T. and Wentz, F.J., 2012: The Emissivity of the Ocean Surface Between 6 and 90 GHz Over a Large Range of Wind Speeds and Earth Incidence Angles, IEEE Transactions on Geoscience and Remote Sensing, 50(8), 3004-3026, 10.1109/TGRS.2011.2179662.
Abstract: We present a model function for the emissivity of the wind roughened ocean surface for microwave frequencies between 6 and 90 GHz. It is an update, refinement, and extension of model functions we had developed previously. The basis of our analysis are brightness temperature (TB) measurements from the spaceborne microwave radiometer WindSat and the Special Sensor Microwave/Imager, which are collocated with independent measurements of surface wind speeds and directions. This allows the determination of the emissivity model function for Earth incidence angles (EIA) around 55°. We demonstrate that an essential part in the model development is the absolute calibration of the radiometer measurements over the ocean to the computed TB of the radiative transfer model, one of whose components the emissivity model function is. We combine our results with other established measurements for lower EIA and finally obtain a model function which can be used over the whole EIA range between 0° and 65°. Results for both the isotropic, wind direction independent part as well as the four Stokes parameters of the wind direction signal are presented. Special emphasis is made on the behavior at high wind speeds between 20 and 40 m/s by conducting a comparison with data from the step frequency microwave radiometer.
Keywords: High wind speeds; Special Sensor Microwave/Imager (SSM/I); Step Frequency Microwave Radiometer (SFMR); Stokes' parameters; WindSat; microwave radiometer calibration; ocean surface emissivity; radiative transfer model (RTM)
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URL: https://doi.org/10.1109/TGRS.2011.2179662
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Moon, K.R. (2012). Investigations of the Dry Snow Zone of the Greenland Ice Sheet Using QuikSCAT, Thesis »
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Title: Investigations of the Dry Snow Zone of the Greenland Ice Sheet Using QuikSCAT
Type: Thesis
Publication:
Author(s): Moon, K.R.
Year: 2012
Formatted Citation: Moon, K.R., 2012: Investigations of the Dry Snow Zone of the Greenland Ice Sheet Using QuikSCAT,
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URL: http://hdl.lib.byu.edu/1877/etd5405
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O'Neill, L.W. (2012). Wind Speed and Stability Effects on the Coupling Between Surface Wind Stress and SST Observed from Buoys and Satellite, Journal of Climate, 26(5), 1544-1569, 10.1175/JCLI-D-11-00121.1. Journal Article »
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Title: Wind Speed and Stability Effects on the Coupling Between Surface Wind Stress and SST Observed from Buoys and Satellite
Type: Journal Article
Publication: Journal of Climate
Author(s): O'Neill, L.W.
Year: 2012
Formatted Citation: O'Neill, L.W., 2012: Wind Speed and Stability Effects on the Coupling Between Surface Wind Stress and SST Observed from Buoys and Satellite, Journal of Climate, 26(5), 1544-1569, 10.1175/JCLI-D-11-00121.1.
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URL: https://doi.org/10.1175/JCLI-D-11-00121.1
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O'Neill, L.W., Chelton, D.B., and Esbensen, S.K. (2012). Covariability of Surface Wind and Stress Responses to Sea-Surface Temperature Fronts, Journal of Climate, 25(17), 5916-5942, 10.1175/JCLI-D-11-00230.1. Journal Article »
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Title: Covariability of Surface Wind and Stress Responses to Sea-Surface Temperature Fronts
Type: Journal Article
Publication: Journal of Climate
Author(s): O'Neill, L.W., Chelton, D.B., and Esbensen, S.K.
Year: 2012
Formatted Citation: O'Neill, L.W., Chelton, D.B., and Esbensen, S.K., 2012: Covariability of Surface Wind and Stress Responses to Sea-Surface Temperature Fronts, Journal of Climate, 25(17), 5916-5942, 10.1175/JCLI-D-11-00230.1.
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URL: https://doi.org/10.1175/JCLI-D-11-00230.1
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Patoux, J. and Foster, R.C. (2012). Cross-Validation of Scatterometer Measurements via Sea-Level Pressure Retrieval, IEEE Transactions on Geoscience and Remote Sensing, 50(7), 2507-2517, 10.1109/TGRS.2011.2172620. Journal Article »
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Title: Cross-Validation of Scatterometer Measurements via Sea-Level Pressure Retrieval
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Patoux, J. and Foster, R.C.
Year: 2012
Formatted Citation: Patoux, J. and Foster, R.C., 2012: Cross-Validation of Scatterometer Measurements via Sea-Level Pressure Retrieval, IEEE Transactions on Geoscience and Remote Sensing, 50(7), 2507-2517, 10.1109/TGRS.2011.2172620.
Abstract: A combined analysis of ocean surface wind vector measurements by the European Advanced Scatterometer (ASCAT) and the National Aeronautics and Space Administration QuikSCAT (QS) scatterometer using buoy measurements, numerical weather prediction model analyses, and spectral decomposition reveals significant statistical differences between the two data sets. While QS wind speeds agree better with buoy wind speeds than ASCAT above 15 m s-1, ASCAT wind directions agree better with buoy directions overall than QS. In contrast, it is shown that sea-level pressure (SLP) fields derived from ASCAT and QS measurements compare better with each other than the winds in a statistical sense, even though ASCAT bulk pressure gradients (BPGs) are slightly weaker than buoy pressure gradients and have slightly lower spectral energy than QS. Weaker BPGs in ASCAT are consistent with the low bias in ASCAT wind speeds. Thus, it is proposed that scatterometer-derived SLP fields can be used as a filter to improve the wind directions. This improves the QS wind directions but has less effect on the more accurate ASCAT wind directions. The unfiltered ASCAT wind vector statistics compare well with the statistics of the direction-filtered QS winds. It is suggested that this methodology might provide a basis for minimizing the discrepancies between various satellite wind measurement data sets in view of producing a long-term record of satellite-derived SLP fields and ocean surface wind vectors.
Keywords: Advaned Scatterometer (ASCAT); ocean surface winds; planetary boundary layer modeling; QuikSCAT; scatterometer; sea-level pressure; spaceborne radar; wind validation
Mission: |ASCAT|
URL: https://doi.org/10.1109/TGRS.2011.2172620
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Plagge, A.M., Vandemark, D., and Chapron, B. (2012). Examining the Impact of Surface Currents on Satellite Scatterometer and Altimeter Ocean Winds, Journal of Atmospheric and Oceanic Technology, 29(12), 1776-1793, 10.1175/JTECH-D-12-00017.1. Journal Article »
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Title: Examining the Impact of Surface Currents on Satellite Scatterometer and Altimeter Ocean Winds
Type: Journal Article
Publication: Journal of Atmospheric and Oceanic Technology
Author(s): Plagge, A.M., Vandemark, D., and Chapron, B.
Year: 2012
Formatted Citation: Plagge, A.M., Vandemark, D., and Chapron, B., 2012: Examining the Impact of Surface Currents on Satellite Scatterometer and Altimeter Ocean Winds, Journal of Atmospheric and Oceanic Technology, 29(12), 1776-1793, 10.1175/JTECH-D-12-00017.1.
Abstract: A 5-yr dataset collected over two surface current and meteorological moorings allows rigorous evaluation of questions surrounding wave current interaction and the scatterometer. Results demonstrate that scatterometer winds represent winds relative to the moving sea surface, affirming previous observational efforts that inferred the phenomenon using climatological approaches over larger time and space scales in equatorial and western boundary currents. Comparisons of wind residuals between Ku-band Quick Scatterometer (QuikSCAT) and buoy measurements show nearly one-to-one correlations with ocean surface velocity for 5-, 12.5-, and 25-km resolution wind speed products, especially under conditions of moderate wind speed and near-neutral atmospheric stability. Scatterometer and buoy wind direction differences due to currents were observed to be negligible for the range of surface velocities encountered and the length scales observed by QuikSCAT. Similar analyses are applied to C-band Advanced Scatterometer (ASCAT) satellite wind measurements at the same sites, as well as to satellite altimeter winds, and overall confirm the results seen with QuikSCAT; differences are likely the combined result of sampling, satellite wind algorithms, and geophysical wind wave coupling in the presence of currents. On the whole, this study affirms that at length scales of 10 km and longer the scatterometer wind can be considered to be current relative. Observed differences between earth-relative and current-relative winds of order 10%-20% of the wind velocity are not uncommon in this and other ocean regions and this study more fully validates that microwave remote sensing winds appear to respond to wind stress even in the presence of larger-scale currents.
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Mission: |NSCAT|ASCAT|
URL: https://doi.org/10.1175/JTECH-D-12-00017.1
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Reeves, S. (2012). Sea Ice Mapping Using Enhanced Resolution Advanced Scatterometer Images, Thesis »
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Title: Sea Ice Mapping Using Enhanced Resolution Advanced Scatterometer Images
Type: Thesis
Publication:
Author(s): Reeves, S.
Year: 2012
Formatted Citation: Reeves, S., 2012: Sea Ice Mapping Using Enhanced Resolution Advanced Scatterometer Images,
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URL: http://hdl.lib.byu.edu/1877/etd5198
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Scambos, T.A., Frezzotti, M., Haran, T., Bohlander, J., Lenaerts, J.T.M., Van Den Broeke, M.R., Jezek, K., Long, D., Urbini, S., Farness, K., Neumann, T., Albert, M., and Winther, J.-G. (2012). Extent of Low-Accumulation 'Wind Glaze' Areas on the East Antarctic Plateau: Implications for Continental Ice Mass Balance, Journal of Glaciology, 58(210), 633-647, 10.3189/2012JoG11J232. Journal Article »
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Title: Extent of Low-Accumulation 'Wind Glaze' Areas on the East Antarctic Plateau: Implications for Continental Ice Mass Balance
Type: Journal Article
Publication: Journal of Glaciology
Author(s): Scambos, T.A., Frezzotti, M., Haran, T., Bohlander, J., Lenaerts, J.T.M., Van Den Broeke, M.R., Jezek, K., Long, D., Urbini, S., Farness, K., Neumann, T., Albert, M., and Winther, J.-G.
Year: 2012
Formatted Citation: Scambos, T.A., Frezzotti, M., Haran, T., Bohlander, J., Lenaerts, J.T.M., Van Den Broeke, M.R., Jezek, K., Long, D., Urbini, S., Farness, K., Neumann, T., Albert, M., and Winther, J.-G., 2012: Extent of Low-Accumulation 'Wind Glaze' Areas on the East Antarctic Plateau: Implications for Continental Ice Mass Balance, Journal of Glaciology, 58(210), 633-647, 10.3189/2012JoG11J232.
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URL: https://doi.org/10.3189/2012JoG11J232
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Swan, A.M. and Long, D.G. (2012). Multiyear Arctic Sea Ice Classification Using QuikSCAT, IEEE Transactions on Geoscience and Remote Sensing, 50(9), 3317-3326, 10.1109/TGRS.2012.2184123. Journal Article »
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Title: Multiyear Arctic Sea Ice Classification Using QuikSCAT
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Swan, A.M. and Long, D.G.
Year: 2012
Formatted Citation: Swan, A.M. and Long, D.G., 2012: Multiyear Arctic Sea Ice Classification Using QuikSCAT, IEEE Transactions on Geoscience and Remote Sensing, 50(9), 3317-3326, 10.1109/TGRS.2012.2184123.
Abstract: Long-term trends in Arctic sea ice are of particular interest in studies of global temperature, climate change, and industrial application. This paper analyzes intra-annual and interannual trends in Ku-band backscatter over first-year (FY) and multiyear (MY) sea ice to develop a new sea-ice-type classification method. Histograms of backscatter are derived from high-resolution backscatter images created using the scatterometer image reconstruction (SIR) algorithm applied to measurements obtained by the SeaWinds instrument aboard QuikSCAT. The backscatter of FY and MY sea ice are clearly identifiable and are observed to vary seasonally. Using an average of the annual backscatter trends obtained from QuikSCAT, a classification of MY ice is obtained, which uses a time-dependent threshold value. Validation of the classification method is done using regional ice charts from the Canadian Ice Service. Differences in ice classification are found to be less than 6$%$ for the winters of 2006�2007 and 2007�2008, and the end of 2008. Anomalies in the distribution of sea ice backscatter from year to year suggest a reduction in MY ice cover between 2003 and 2009 and an approximately equivalent increase in FY ice cover.
Keywords: Ice classification , QuikSCAT , microwave remote sensing , sea ice
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URL: https://doi.org/10.1109/TGRS.2012.2184123
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Tokinaga, H., Xie, S.-P., Deser, C., Kosaka, Y., and Okumura, Y.M. (2012). Slowdown of the Walker Circulation Driven by Tropical Indo-Pacific Warming, Nature, 491, 439-443, 10.1038/nature11576. Journal Article »
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Title: Slowdown of the Walker Circulation Driven by Tropical Indo-Pacific Warming
Type: Journal Article
Publication: Nature
Author(s): Tokinaga, H., Xie, S.-P., Deser, C., Kosaka, Y., and Okumura, Y.M.
Year: 2012
Formatted Citation: Tokinaga, H., Xie, S.-P., Deser, C., Kosaka, Y., and Okumura, Y.M., 2012: Slowdown of the Walker Circulation Driven by Tropical Indo-Pacific Warming, Nature, 491, 439-443, 10.1038/nature11576.
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URL: https://doi.org/10.1038/nature11576
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Tokinaga, H., Xie, S.-P., Timmermann, A., McGregor, S., Ogata, T., Kubota, H., and Okumura, Y.M. (2012). Regional Patterns of Tropical Indo-Pacific Climate Change: Evidence of the Walker Circulation Weakening, Journal of Climate, 25(5), 1689-1710, 10.1175/JCLI-D-11-00263.1. Journal Article »
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Title: Regional Patterns of Tropical Indo-Pacific Climate Change: Evidence of the Walker Circulation Weakening
Type: Journal Article
Publication: Journal of Climate
Author(s): Tokinaga, H., Xie, S.-P., Timmermann, A., McGregor, S., Ogata, T., Kubota, H., and Okumura, Y.M.
Year: 2012
Formatted Citation: Tokinaga, H., Xie, S.-P., Timmermann, A., McGregor, S., Ogata, T., Kubota, H., and Okumura, Y.M., 2012: Regional Patterns of Tropical Indo-Pacific Climate Change: Evidence of the Walker Circulation Weakening, Journal of Climate, 25(5), 1689-1710, 10.1175/JCLI-D-11-00263.1.
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URL: https://doi.org/10.1175/JCLI-D-11-00263.1
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Trusel, L.D., Frey, K.E., and Das, S.B. (2012). Antarctic Surface Melting Dynamics: Enhanced Perspectives from Radar Scatterometer Data, Journal of Geophysical Research, 117, F02023, 10.1029/2011JF002126. Journal Article »
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Title: Antarctic Surface Melting Dynamics: Enhanced Perspectives from Radar Scatterometer Data
Type: Journal Article
Publication: Journal of Geophysical Research
Author(s): Trusel, L.D., Frey, K.E., and Das, S.B.
Year: 2012
Formatted Citation: Trusel, L.D., Frey, K.E., and Das, S.B., 2012: Antarctic Surface Melting Dynamics: Enhanced Perspectives from Radar Scatterometer Data, Journal of Geophysical Research, 117, F02023, 10.1029/2011JF002126.
Abstract: Antarctic ice sheet surface melting can regionally influence ice shelf stability, mass balance, and glacier dynamics, in addition to modulating near-surface physical and chemical properties over wide areas. Here, we investigate variability in surface melting from 1999 to 2009 using radar backscatter time series from the SeaWinds scatterometer aboard the QuikSCAT satellite. These daily, continent-wide observations are explored in concert with in situ meteorological records to validate a threshold-based melt detection method. Radar backscatter decreases during melting are significantly correlated with in situ positive degree-days as well as meltwater production determined from energy balance modeling at Neumayer Station, East Antarctica. These results support the use of scatterometer data as a diagnostic indicator of melt intensity (i.e., the relative liquid water production during melting). Greater spatial and temporal melting detected relative to previous passive microwave-based studies is attributed to a higher sensitivity of the scatterometer instrument. Continental melt intensity variability can be explained in part by the dynamics of the Southern Annular Mode and the Southern Oscillation Index, and extreme melting events across the Ross Ice Shelf region may be associated with El Nino conditions. Furthermore, we find that the Antarctic Peninsula accounts for only 20% of Antarctic melt extent but greater than 50% of the total Antarctic melt intensity. Over most areas, annual melt duration and intensity are proportional. However, regional and localized distinctions exist where the melt intensity metric provides greater insight into melting dynamics than previously obtainable with other remote sensing techniques.
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Mission: |SeaWinds|
URL: https://doi.org/10.1029/2011JF002126
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van Loon, H., Brown, J., and Milliff, R.F. (2012). Trends in Sunspots and North Atlantic Sea Level Pressure, Journal of Geophysical Research: Atmospheres, 117, D07106, 10.1029/2012JD017502. Journal Article »
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Title: Trends in Sunspots and North Atlantic Sea Level Pressure
Type: Journal Article
Publication: Journal of Geophysical Research: Atmospheres
Author(s): van Loon, H., Brown, J., and Milliff, R.F.
Year: 2012
Formatted Citation: van Loon, H., Brown, J., and Milliff, R.F., 2012: Trends in Sunspots and North Atlantic Sea Level Pressure, Journal of Geophysical Research: Atmospheres, 117, D07106, 10.1029/2012JD017502.
Abstract: We analyze the periods 1878-1944 and 1944-2008. The quasi-stationary wave in the North Atlantic region was stronger and the baroclinity steeper in 1878-1944 than in 1944-2008. The North Atlantic Oscillation Index-as defined by the Climate Research Unit, University of East Anglia-was higher in the former period too. We illustrate these statements by maps of sea level pressure and air temperature at the surface. The long-term trends in the North Atlantic Oscillation Index are linked to the trend in sunspot number such that when, in the mean, the sunspot numbers were high (Gleissberg maxima) the trends in the two quantities were parallel; and when the mean sunspot numbers were low (Gleissberg minima) the trends in the North Atlantic Oscillation Index and sunspots were opposite. We find the connections between the trends statistically significant, and we infer that the level of solar activity played a role in the trends of the past two centuries in the North Atlantic region. However, we cannot as yet provide a mechanism linking the solar trends to those in the atmosphere and ocean, but as a step toward an explanation, the equator to pole temperature gradient is steeper in a Gleissberg minimum than in a maximum.
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URL: https://doi.org/10.1029/2012JD017502
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Vernet, M., Smith, K., Cefarelli, A., Helly, J., Kaufmann, R., Lin, H., Long, D., Murray, A., Robison, B., Ruhl, H., Shaw, T., Sherman, A., and Sprintall, J. (2012). Islands of Ice: Influence of Free-Drifting Antarctic Icebergs on Pelagic Marine Ecosystems, Oceanography, 25(3), 38-39, 10.5670/oceanog.2012.72. Journal Article »
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Title: Islands of Ice: Influence of Free-Drifting Antarctic Icebergs on Pelagic Marine Ecosystems
Type: Journal Article
Publication: Oceanography
Author(s): Vernet, M., Smith, K., Cefarelli, A., Helly, J., Kaufmann, R., Lin, H., Long, D., Murray, A., Robison, B., Ruhl, H., Shaw, T., Sherman, A., and Sprintall, J.
Year: 2012
Formatted Citation: Vernet, M., Smith, K., Cefarelli, A., Helly, J., Kaufmann, R., Lin, H., Long, D., Murray, A., Robison, B., Ruhl, H., Shaw, T., Sherman, A., and Sprintall, J., 2012: Islands of Ice: Influence of Free-Drifting Antarctic Icebergs on Pelagic Marine Ecosystems, Oceanography, 25(3), 38-39, 10.5670/oceanog.2012.72.
Abstract: Regional warming around West Antarctica, including the Antarctic Peninsula, is related to the retreat of glaciers that has resulted in significant ice mass loss in recent decades (De Angelis and Skvarca, 2003). Large icebergs (> 18.5 km long) originating from ice shelves in the Ross and Weddell Seas (Scambos et al., 2000) are attributed primarily to major loss events in these regions. Once free, icebergs become entrained in the counterclockwise Antarctic Coastal Current (Figure 1), eventually entering a strong northward flow in the Northwest Weddell Sea. We examined free-drifting icebergs in the Atlantic sector of the Southern Ocean in December 2005, aboard ARSV Laurence M. Gould, and in June 2008 and March/April 2009, aboard RVIB Nathaniel B. Palmer. Prior to these studies, little information was available about the effects of icebergs on the pelagic realm. On these cruises, we investigated the "iceberg ecosystem" (Smith et al., 2007; Smith, 2011) to assess the degree to which icebergs are (1) hotspots of biological activity across multiple trophic levels, and (2) focal points for enhanced export of organic carbon to the deep sea. An important focus of this work was to examine the fundamental mechanisms by which icebergs affect the pelagic ecosystem, including physical disruption and effects on the availability of critical nutrients (e.g., iron, nitrate).
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URL: https://doi.org/10.5670/oceanog.2012.72
Other URLs:
Weissman, D.E., Stiles, B.W., Hristova-Veleva, S.M., Long, D.G., Smith, D.K., Hilburn, K.A., and Jones, W.L. (2012). Challenges to Satellite Sensors of Ocean Winds: Addressing Precipitation Effects, Journal of Atmospheric and Oceanic Technology, 29(3), 356-374, 10.1175/JTECH-D-11-00054.1. Journal Article »
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Title: Challenges to Satellite Sensors of Ocean Winds: Addressing Precipitation Effects
Type: Journal Article
Publication: Journal of Atmospheric and Oceanic Technology
Author(s): Weissman, D.E., Stiles, B.W., Hristova-Veleva, S.M., Long, D.G., Smith, D.K., Hilburn, K.A., and Jones, W.L.
Year: 2012
Formatted Citation: Weissman, D.E., Stiles, B.W., Hristova-Veleva, S.M., Long, D.G., Smith, D.K., Hilburn, K.A., and Jones, W.L., 2012: Challenges to Satellite Sensors of Ocean Winds: Addressing Precipitation Effects, Journal of Atmospheric and Oceanic Technology, 29(3), 356-374, 10.1175/JTECH-D-11-00054.1.
Abstract: Measurements of global ocean surface winds made by orbiting satellite radars have provided valuable information to the oceanographic and meteorological communities since the launch of the Seasat in 1978, by the National Aeronautics and Space Administration (NASA). When Quick Scatterometer (QuikSCAT) was launched in 1999, it ushered in a new era of dual-polarized, pencil-beam, higher-resolution scatterometers for measuring the global ocean surface winds from space. A constant limitation on the full utilization of scatterometer-derived winds is the presence of isolated rain events, which affect about 7% of the observations. The vector wind sensors, the Ku-band scatterometers [NASA's SeaWinds on the QuikSCAT and Midori-II platforms and Indian Space Research Organisation's (ISRO's) Ocean Satellite (Oceansat)-2], and the current C-band scatterometer [Advanced Wind Scatterometer (ASCAT), on the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT)'s Meteorological Operation (MetOp) platform] all experience rain interference, but with different characteristics. Over this past decade, broad-based research studies have sought to better understand the physics of the rain interference problem, to search for methods to bypass the problem (using rain detection, flagging, and avoidance of affected areas), and to develop techniques to improve the quality of the derived wind vectors that are adversely affected by rain. This paper reviews the state of the art in rain flagging and rain correction and describes many of these approaches, methodologies, and summarizes the results.
Keywords: Radars/Radar observations, Satellite observations
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URL: https://doi.org/10.1175/JTECH-D-11-00054.1
Other URLs:
Yu, L. and Jin, X. (2012). Buoy Perspective of a High-Resolution Global Ocean Vector Wind Analysis Constructed from Passive Radiometers and Active Scatterometers (1987-Present), Journal of Geophysical Research, 117(C11), 10.1029/2012JC008069. Journal Article »
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Title: Buoy Perspective of a High-Resolution Global Ocean Vector Wind Analysis Constructed from Passive Radiometers and Active Scatterometers (1987-Present)
Type: Journal Article
Publication: Journal of Geophysical Research
Author(s): Yu, L. and Jin, X.
Year: 2012
Formatted Citation: Yu, L. and Jin, X., 2012: Buoy Perspective of a High-Resolution Global Ocean Vector Wind Analysis Constructed from Passive Radiometers and Active Scatterometers (1987-Present), Journal of Geophysical Research, 117(C11), 10.1029/2012JC008069.
Abstract: The study used 126 buoy time series as a benchmark to evaluate a satellite-based daily, 0.25-degree gridded global ocean surface vector wind analysis developed by the Objectively Analyzed airs-sea Fluxes (OAFlux) project. The OAFlux winds were produced from synthesizing wind speed and direction retrievals from 12 sensors acquired during the satellite era from July 1987 onward. The 12 sensors included scatterometers (QuikSCAT and ASCAT), passive microwave radiometers (AMSRE, SSMI and SSMIS series), and the passive polarimetric microwave radiometer from WindSat. Accuracy and consistency of the OAFlux time series are the key issues examined here. A total of 168,836 daily buoy measurements were assembled from 126 buoys, including both active and archive sites deployed during 1988–2010. With 106 buoys from the tropical array network, the buoy winds are a good reference for wind speeds in low and mid-range. The buoy comparison shows that OAFlux wind speed has a mean difference of −0.13 ms−1 and an RMS difference of 0.71 ms−1, and wind direction has a mean difference of −0.55 degree and an RMS difference of 17 degrees. Vector correlation of OAFlux and buoy winds is of 0.9 and higher over almost all the sites. Influence of surface currents on the OAFlux/buoy mean difference pattern is displayed in the tropical Pacific, with higher (lower) OAFlux wind speed in regions where wind and current have the opposite (same) sign. Improved representation of daily wind variability by the OAFlux synthesis is suggested, and a decadal signal in global wind speed is evident.
Keywords: OAFlux; ocean vector; satellite-based; wind analysis
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URL: https://doi.org/10.1029/2012JC008069
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Yu, W., Han, W., and Gochis, D. (2012). Influence of the Madden-Julian Oscillation and Intraseasonal Waves on Surface Wind and Convection of the Tropical Atlantic Ocean, Journal of Climate, 25(23), 8057-8074, 10.1175/JCLI-D-11-00528.1. Journal Article »
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Title: Influence of the Madden-Julian Oscillation and Intraseasonal Waves on Surface Wind and Convection of the Tropical Atlantic Ocean
Type: Journal Article
Publication: Journal of Climate
Author(s): Yu, W., Han, W., and Gochis, D.
Year: 2012
Formatted Citation: Yu, W., Han, W., and Gochis, D., 2012: Influence of the Madden-Julian Oscillation and Intraseasonal Waves on Surface Wind and Convection of the Tropical Atlantic Ocean, Journal of Climate, 25(23), 8057-8074, 10.1175/JCLI-D-11-00528.1.
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URL: https://doi.org/10.1175/JCLI-D-11-00528.1
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Alsweiss, S.O., Laupattarakasem, P., and Jones, W.L. (2011). A Novel Ku-Band Radiometer/Scatterometer Approach for Improved Ocean Wind Vector Measurements, IEEE Transactions on Geoscience and Remote Sensing, 49(9), 3189-3197, 10.1109/TGRS.2010.2093903. Journal Article »
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Title: A Novel Ku-Band Radiometer/Scatterometer Approach for Improved Ocean Wind Vector Measurements
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Alsweiss, S.O., Laupattarakasem, P., and Jones, W.L.
Year: 2011
Formatted Citation: Alsweiss, S.O., Laupattarakasem, P., and Jones, W.L., 2011: A Novel Ku-Band Radiometer/Scatterometer Approach for Improved Ocean Wind Vector Measurements, IEEE Transactions on Geoscience and Remote Sensing, 49(9), 3189-3197, 10.1109/TGRS.2010.2093903.
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URL: https://doi.org/10.1109/TGRS.2010.2093903
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Boening, C., Lee, T., and Zlotnicki, V. (2011). A Record-High Ocean Bottom Pressure in the South Pacific Observed by GRACE, Geophysical Research Letters, 38(4), L04602, 10.1029/2010GL046013. Journal Article »
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Title: A Record-High Ocean Bottom Pressure in the South Pacific Observed by GRACE
Type: Journal Article
Publication: Geophysical Research Letters
Author(s): Boening, C., Lee, T., and Zlotnicki, V.
Year: 2011
Formatted Citation: Boening, C., Lee, T., and Zlotnicki, V., 2011: A Record-High Ocean Bottom Pressure in the South Pacific Observed by GRACE, Geophysical Research Letters, 38(4), L04602, 10.1029/2010GL046013.
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URL: https://doi.org/10.1029/2010GL046013
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Cheng, X., Xie, S.-P., Tokinaga, H., and Du, Y. (2011). Interannual Variability of High-Wind Occurrence Over the North Atlantic, Journal of Climate, 24(24), 6515-6527, 10.1175/2011JCLI4147.1. Journal Article »
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Title: Interannual Variability of High-Wind Occurrence Over the North Atlantic
Type: Journal Article
Publication: Journal of Climate
Author(s): Cheng, X., Xie, S.-P., Tokinaga, H., and Du, Y.
Year: 2011
Formatted Citation: Cheng, X., Xie, S.-P., Tokinaga, H., and Du, Y., 2011: Interannual Variability of High-Wind Occurrence Over the North Atlantic, Journal of Climate, 24(24), 6515-6527, 10.1175/2011JCLI4147.1.
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URL: https://doi.org/10.1175/2011JCLI4147.1
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Halkides, D. and Lee, T. (2011). Mechanisms Controlling Seasonal Mixed Layer Temperature and Salinity in the Southwestern Tropical Indian Ocean, Dynamics of Atmospheres and Oceans, 51(3), 77-93, 10.1016/j.dynatmoce.2011.03.002. Journal Article »
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Title: Mechanisms Controlling Seasonal Mixed Layer Temperature and Salinity in the Southwestern Tropical Indian Ocean
Type: Journal Article
Publication: Dynamics of Atmospheres and Oceans
Author(s): Halkides, D. and Lee, T.
Year: 2011
Formatted Citation: Halkides, D. and Lee, T., 2011: Mechanisms Controlling Seasonal Mixed Layer Temperature and Salinity in the Southwestern Tropical Indian Ocean, Dynamics of Atmospheres and Oceans, 51(3), 77-93, 10.1016/j.dynatmoce.2011.03.002.
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URL: https://doi.org/10.1016/j.dynatmoce.2011.03.002
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Halkides, D., Lee, T., and Kida, S. (2011). Mechanisms Controlling Seasonal Mixed Layer Temperature and Salinity of the Indonesian Seas, Ocean Dynamics, 61, 481–495, 10.1007/s10236-010-0374-3. Journal Article »
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Title: Mechanisms Controlling Seasonal Mixed Layer Temperature and Salinity of the Indonesian Seas
Type: Journal Article
Publication: Ocean Dynamics
Author(s): Halkides, D., Lee, T., and Kida, S.
Year: 2011
Formatted Citation: Halkides, D., Lee, T., and Kida, S., 2011: Mechanisms Controlling Seasonal Mixed Layer Temperature and Salinity of the Indonesian Seas, Ocean Dynamics, 61, 481–495, 10.1007/s10236-010-0374-3.
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URL: https://doi.org/10.1007/s10236-010-0374-3
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Han W., McCreary, J.P., Masumoto, Y., Vialard, J., and Duncan, B. (2011). Basin Resonances in the Equatorial Indian Ocean, Journal of Physical Oceanography, 41(6), 1252-1270, 10.1175/2011JPO4591.1. Journal Article »
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Title: Basin Resonances in the Equatorial Indian Ocean
Type: Journal Article
Publication: Journal of Physical Oceanography
Author(s): Han W., McCreary, J.P., Masumoto, Y., Vialard, J., and Duncan, B.
Year: 2011
Formatted Citation: Han W., McCreary, J.P., Masumoto, Y., Vialard, J., and Duncan, B., 2011: Basin Resonances in the Equatorial Indian Ocean, Journal of Physical Oceanography, 41(6), 1252-1270, 10.1175/2011JPO4591.1.
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URL: https://doi.org/10.1175/2011JPO4591.1
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Hattori, M., Mori, S., and Matsumoto, J. (2011). The Cross-Equatorial Northerly Surge over the Maritime Continent and Its Relationship to Precipitation Patterns, Journal of the Meteorological Society of Japan, 89a, 27-47, 10.2151/jmsj.2011-A02. Journal Article »
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Title: The Cross-Equatorial Northerly Surge over the Maritime Continent and Its Relationship to Precipitation Patterns
Type: Journal Article
Publication: Journal of the Meteorological Society of Japan
Author(s): Hattori, M., Mori, S., and Matsumoto, J.
Year: 2011
Formatted Citation: Hattori, M., Mori, S., and Matsumoto, J., 2011: The Cross-Equatorial Northerly Surge over the Maritime Continent and Its Relationship to Precipitation Patterns, Journal of the Meteorological Society of Japan, 89a, 27-47, 10.2151/jmsj.2011-A02.
Abstract: This study describes the characteristics of the cross-equatorial northerly surge (CENS), a northerly flow that appears intermittently over the equatorial region between October and April, and its relationship to the precipitation patterns over the Maritime Continent. The CENS in this study was defined as the area-averaged northerly wind exceeding 5 m s(-1) over 105 degrees E-115 degrees E, 5 degrees S-EQ based on the QuikSCAT sea surface wind data. During the 10 winters from December 2000 to March 2009, 62 CENS events were extracted and classified into the following patterns: 11 events were associated with cold surges and termed the CS pattern; 20 events were associated with tropical intra-seasonal variations and termed the MJO pattern; 16 events were associated with both cold surges and tropical intra-seasonal variations and termed the CS MJO pattern; and other 15 events were not associated with these patterns. In the CS pattern, the development and dissipation processes of the cold surge appeared, and the increased precipitation to the north of the island of Java was significant. In the MJO pattern, a wide area of northerly winds in the vicinity of the depression around 10 degrees S continued for a longer period than in the CS pattern, and the increased precipitation west of Sumatra and south of Java was significant. The CS MJO pattern showed features of the northerly wind fields of both the CS and MJO patterns and was associated with the greatest increase in precipitation of the three patterns in the Maritime Continent, in particular, in northwestern Java and both north and south of Java. The generation of CENS was an important environmental factor for inducing the wide positive precipitation anomaly compared to the climatological mean over the Maritime Continent.
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Mission: |SeaWinds|
URL: https://doi.org/10.2151/jmsj.2011-A02
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Hicks, B.R. and Long, D.G. (2011). Inferring Greenland Melt and Refreeze Severity from SeaWinds Scatterometer Data, International Journal of Remote Sensing, 32(23), 8053-8080, 10.1080/01431161.2010.532174. Journal Article »
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Title: Inferring Greenland Melt and Refreeze Severity from SeaWinds Scatterometer Data
Type: Journal Article
Publication: International Journal of Remote Sensing
Author(s): Hicks, B.R. and Long, D.G.
Year: 2011
Formatted Citation: Hicks, B.R. and Long, D.G., 2011: Inferring Greenland Melt and Refreeze Severity from SeaWinds Scatterometer Data, International Journal of Remote Sensing, 32(23), 8053-8080, 10.1080/01431161.2010.532174.
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Mission: |SeaWinds|
URL: https://doi.org/10.1080/01431161.2010.532174
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Hong, X., Bishop, C.H., Holt, T., and O'Neill, L. (2011). Impacts of Sea Surface Temperature Uncertainty on the Western North Pacific Subtropical High (WNPSH) and Rainfall, Weather and Forecasting, 26(3), 371-387.
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Title: Impacts of Sea Surface Temperature Uncertainty on the Western North Pacific Subtropical High (WNPSH) and Rainfall
Type: Journal Article
Publication: Weather and Forecasting
Author(s): Hong, X., Bishop, C.H., Holt, T., and O'Neill, L.
Year: 2011
Formatted Citation: Hong, X., Bishop, C.H., Holt, T., and O'Neill, L., 2011: Impacts of Sea Surface Temperature Uncertainty on the Western North Pacific Subtropical High (WNPSH) and Rainfall, Weather and Forecasting, 26(3), 371-387.
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Katsaros, K.B., Bentamy, A., Bourassa, M., Ebuchi, N., Gower, J., Liu, W.T., and Vignudelli, S. (2011). Climate Data Issues from an Oceanographic Remote Sensing Perspective, Remote Sensing of the Changing Oceans, 7-32, 10.1007/978-3-642-16541-2_2. Chapter »
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Title: Climate Data Issues from an Oceanographic Remote Sensing Perspective
Type: Chapter
Publication: Remote Sensing of the Changing Oceans
Author(s): Katsaros, K.B., Bentamy, A., Bourassa, M., Ebuchi, N., Gower, J., Liu, W.T., and Vignudelli, S.
Year: 2011
Formatted Citation: Katsaros, K.B., Bentamy, A., Bourassa, M., Ebuchi, N., Gower, J., Liu, W.T., and Vignudelli, S., 2011: Climate Data Issues from an Oceanographic Remote Sensing Perspective, Remote Sensing of the Changing Oceans, 7-32, 10.1007/978-3-642-16541-2_2.
Abstract: In this chapter we review several climatologically important variables with a history of observation from spaceborne platforms. These include sea surface temperature and wind vectors, altimetric estimates of sea surface height, energy and water vapor fluxes at the sea surface, precipitation over the ocean, and ocean color. We then discuss possible improvements in sampling for climate and climate change definition. Issues of consistency of different data sources, archiving and distribution of these types of data are discussed. The practical prospect of immediate international coordination through the concept of virtual constellations is discussed and applauded.
Keywords: Oceanographic satellite sensors ; Scatterometers ; Altimeters ; microwave radiometers ; infrared and ocean color sensors ; winds ; sea surface temperature ; air-sea fluxes ; international cooperation for climate quality data ; sampling ; consistency ; archiving and distribution
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URL: https://doi.org/10.1007/978-3-642-16541-2_2
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Knapp K.R., Ansari, S., Bain, C.L., Bourassa, M.A., Dickinson, M.J., Funk, C., Helms, C.N., Hennon, C.C., Holmes, C.D., Huffman, G.J., Kossin, J.P., Lee, H.-T., Loew, A., and Magnusdottir, G. (2011). Globally Gridded Satellite (GridSat) Observations for Climate Studies, Bulletin of the American Meteorological Society, 92(7), 893-907, 10.1175/2011BAMS3039.1. Journal Article »
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Title: Globally Gridded Satellite (GridSat) Observations for Climate Studies
Type: Journal Article
Publication: Bulletin of the American Meteorological Society
Author(s): Knapp K.R., Ansari, S., Bain, C.L., Bourassa, M.A., Dickinson, M.J., Funk, C., Helms, C.N., Hennon, C.C., Holmes, C.D., Huffman, G.J., Kossin, J.P., Lee, H.-T., Loew, A., and Magnusdottir, G.
Year: 2011
Formatted Citation: Knapp K.R., Ansari, S., Bain, C.L., Bourassa, M.A., Dickinson, M.J., Funk, C., Helms, C.N., Hennon, C.C., Holmes, C.D., Huffman, G.J., Kossin, J.P., Lee, H.-T., Loew, A., and Magnusdottir, G., 2011: Globally Gridded Satellite (GridSat) Observations for Climate Studies, Bulletin of the American Meteorological Society, 92(7), 893-907, 10.1175/2011BAMS3039.1.
Abstract: Geostationary satellites have provided routine, high temporal resolution Earth observations since the 1970s. Despite the long period of record, use of these data in climate studies has been limited for numerous reasons, among them that no central archive of geostationary data for all international satellites exists, full temporal and spatial resolution data are voluminous, and diverse calibration and navigation formats encumber the uniform processing needed for multisatellite climate studies. The International Satellite Cloud Climatology Project (ISCCP) set the stage for overcoming these issues by archiving a subset of the full-resolution geostationary data at ~10-km resolution at 3-hourly intervals since 1983. Recent efforts at NOAA's National Climatic Data Center to provide convenient access to these data include remapping the data to a standard map projection, recalibrating the data to optimize temporal homogeneity, extending the record of observations back to 1980, and reformatting the data for broad public distribution. The Gridded Satellite (GridSat) dataset includes observations from the visible, infrared window, and infrared water vapor channels. Data are stored in Network Common Data Format (netCDF) using standards that permit a wide variety of tools and libraries to process the data quickly and easily. A novel data layering approach, together with appropriate satellite and file metadata, allows users to access GridSat data at varying levels of complexity based on their needs. The result is a climate data record already in use by the meteorological community. Examples include reanalysis of tropical cyclones, studies of global precipitation, and detection and tracking of the intertropical convergence zone.
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URL: https://doi.org/10.1175/2011BAMS3039.1
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Lindsley, R. and Long, D.G. (2011). Estimating Surface Oil Extent from the Deepwater Horizon Oil Spill using ASCAT Backscatter, 2011 IEEE RadarCon (RADAR), 559-563, 10.1109/RADAR.2011.5960599. Conference Paper »
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Title: Estimating Surface Oil Extent from the Deepwater Horizon Oil Spill using ASCAT Backscatter
Type: Conference Paper
Publication: 2011 IEEE RadarCon (RADAR)
Author(s): Lindsley, R. and Long, D.G.
Year: 2011
Formatted Citation: Lindsley, R. and Long, D.G., 2011: Estimating Surface Oil Extent from the Deepwater Horizon Oil Spill using ASCAT Backscatter, 2011 IEEE RadarCon (RADAR), 559-563, 10.1109/RADAR.2011.5960599.
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Mission: |ASCAT|
URL: https://doi.org/10.1109/RADAR.2011.5960599
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Matthews, D., Powell, B., and Milliff, R. (2011). Dominant Spatial Variability Scales from Observations Around the Hawaiian Islands, Deep Sea Research Part I: Oceanographic Research Papers, 58(10), 979-987, 10.1016/j.dsr.2011.07.004. Journal Article »
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Title: Dominant Spatial Variability Scales from Observations Around the Hawaiian Islands
Type: Journal Article
Publication: Deep Sea Research Part I: Oceanographic Research Papers
Author(s): Matthews, D., Powell, B., and Milliff, R.
Year: 2011
Formatted Citation: Matthews, D., Powell, B., and Milliff, R., 2011: Dominant Spatial Variability Scales from Observations Around the Hawaiian Islands, Deep Sea Research Part I: Oceanographic Research Papers, 58(10), 979-987, 10.1016/j.dsr.2011.07.004.
Abstract: We utilize a variety of available observations with a semivariogram technique to quantify the oceanic variability around the Hawaiian Islands. The Hawaiian Islands have a significant impact on the North Pacific circulation, and quantifying the characteristics of the variability is important for understanding the eddy energy, as well as required for statistical techniques to work with the data, such as optimal interpolation, data assimilation, etc. Both satellite sea surface height and temperature data are used to determine horizontal scales of variability, while Argo profiles, ship-borne profiles, and autonomous Seagliders provide estimates of the vertical scales. In the lee of the islands, satellite data reveal an increase in horizontal variability attributed to enhanced eddy activity that persists for over 1000 km westward; however, only within 400 km of the immediate lee the horizontal length scales are greatly reduced. Further west, length scales increase significantly indicating a change in the generation mechanism for eddy variability and where eddies merge and coalesce. The meridional length scale gradient is found to be larger than previous results and more representative of the gradient of the first baroclinic mode of the internal Rossby radius. Vertical length scales are shown to increase in the lee, with vertical temperature variability doubled from the windward side.
Keywords: Length scales; Mesoscale variability; Hawaiian Islands
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URL: https://doi.org/10.1016/j.dsr.2011.07.004
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Meissner, T., Ricciardulli, L., and Wentz, F. (2011). All-Weather Wind Vector Measurements from Intercalibrated Active and Passive Microwave Satellite Sensors, 2011 IEEE International Geoscience and Remote Sensing Symposium, 1509-1511, 10.1109/IGARSS.2011.6049354. Conference Paper »
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Title: All-Weather Wind Vector Measurements from Intercalibrated Active and Passive Microwave Satellite Sensors
Type: Conference Paper
Publication: 2011 IEEE International Geoscience and Remote Sensing Symposium
Author(s): Meissner, T., Ricciardulli, L., and Wentz, F.
Year: 2011
Formatted Citation: Meissner, T., Ricciardulli, L., and Wentz, F., 2011: All-Weather Wind Vector Measurements from Intercalibrated Active and Passive Microwave Satellite Sensors, 2011 IEEE International Geoscience and Remote Sensing Symposium, 1509-1511, 10.1109/IGARSS.2011.6049354.
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URL: https://doi.org/10.1109/IGARSS.2011.6049354
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Milliff, R.F., Bonazzi, A., Wikle, C.K., Pinardi, N., and Berliner, L.M. (2011). Ocean Ensemble Forecasting. Part I: Ensemble Mediterranean Winds from a Bayesian Hierarchical Model, Quarterly Journal of the Royal Meteorological Society, 137(Part B), 858-878, 10.1002/qj.767. Journal Article »
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Title: Ocean Ensemble Forecasting. Part I: Ensemble Mediterranean Winds from a Bayesian Hierarchical Model
Type: Journal Article
Publication: Quarterly Journal of the Royal Meteorological Society
Author(s): Milliff, R.F., Bonazzi, A., Wikle, C.K., Pinardi, N., and Berliner, L.M.
Year: 2011
Formatted Citation: Milliff, R.F., Bonazzi, A., Wikle, C.K., Pinardi, N., and Berliner, L.M., 2011: Ocean Ensemble Forecasting. Part I: Ensemble Mediterranean Winds from a Bayesian Hierarchical Model, Quarterly Journal of the Royal Meteorological Society, 137(Part B), 858-878, 10.1002/qj.767.
Abstract: A Bayesian hierarchical model (BHM) is developed to estimate surface vector wind (SVW) fields and associated uncertainties over the Mediterranean Sea. The BHM�SVW incorporates data-stage inputs from analyses and forecasts of the European Centre for Medium-Range Weather Forecasts (ECMWF) and SVW retrievals from the QuikSCAT data record. The process-model stage of the BHM�SVW is based on a Rayleigh friction equation model for surface winds. Dynamical interpretations of posterior distributions of the BHM�SVW parameters are discussed. Ten realizations from the posterior distribution of the BHM�SVW are used to force the data-assimilation step of an experimental ensemble ocean forecast system for the Mediterranean Sea in order to create a set of ensemble initial conditions. The sequential data-assimilation method of the Mediterranean forecast system (MFS) is adapted to the ensemble implementation. Analyses of sample ensemble initial conditions for a single data-assimilation period in MFS are presented to demonstrate the multivariate impact of the BHM�SVW ensemble generation methodology. Ensemble initial-condition spread is quantified by computing standard deviations of ocean state variable fields over the ten ensemble members. The methodological findings in this article are of two kinds. From the perspective of statistical modelling, the process-model development is more closely related to physical balances than in previous work with models for the SVW. From the ocean forecast perspective, the generation of ocean ensemble initial conditions via BHM is shown to be practical for operational implementation in an ensemble ocean forecast system. Phenomenologically, ensemble spread generated via BHM�SVW occurs on ocean mesoscale time- and space-scales, in close association with strong synoptic-scale wind-forcing events. A companion article describes the impacts of the BHM�SVW ensemble method on the ocean forecast in comparisons with more traditional ensemble methods.
Keywords: QuikSCAT surface winds; ECMWF analysis winds; physics-based priors
Mission: |SeaWinds|
URL: https://doi.org/10.1002/qj.767
Other URLs:
Owen, M.P. and Long, D.G. (2011). Simultaneous Wind and Rain Estimation for QuikSCAT at Ultra-High Resolution, IEEE Transactions on Geoscience and Remote Sensing, 49(6), 1865-1878, 10.1109/TGRS.2010.2102361. Journal Article »
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Title: Simultaneous Wind and Rain Estimation for QuikSCAT at Ultra-High Resolution
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Owen, M.P. and Long, D.G.
Year: 2011
Formatted Citation: Owen, M.P. and Long, D.G., 2011: Simultaneous Wind and Rain Estimation for QuikSCAT at Ultra-High Resolution, IEEE Transactions on Geoscience and Remote Sensing, 49(6), 1865-1878, 10.1109/TGRS.2010.2102361.
Abstract: Although originally designed solely for wind retrieval, the QuikSCAT scatterometer has proved to be a useful tool for rain estimation as well. Resolution enhancement algorithms designed for QuikSCAT allow for ultra-high-resolution (UHR) (2.5 km) simultaneous wind and rain (SWR) retrieval. The principle advantage of UHR SWR estimation is that compared to conventional resolution, the higher resolution allows for identification of much smaller rain events and their effects on the wind field. To enable SWR retrieval, we adjust the geophysical model function to account for rain effects such as attenuation and increased backscatter due to increased surface roughness. Two possible rain models are proposed, a phenomenological rain model and an effective rain model. Both models are compared by evaluating data fit and rain estimation performance. Comparisons of a co-located data set show that QuikSCAT UHR SWR integrated rain rates are comparable to those from tropical rain measuring mission precipitation radar (TRMM PR) but have higher variance. Buoy comparisons reveal improved wind estimates in the presence of rain. The theoretic estimator bounds are compared to both the simulated estimator variance and the actual estimator variance. The estimator bounds indicate that despite high-noise levels, wind and rain information is still retrievable at UHR, although certain directions have degraded estimator bounds. Both rain models are compared to truth data and are shown to have comparable performance for most rain rates. Comparison with buoy measurements shows that in the presence of rain, QuikSCAT UHR SWR wind estimates have less bias and variability than wind-only estimates. Although QuikSCAT UHR SWR rain estimates are noisier than TRMM PR rain rates, they provide a useful rain flag for QuikSCAT winds.
Keywords: QuikSCAT , resolution enhancement , scatterometry , simultaneous wind/rain retrieval , wind retrieval
Mission: |SeaWinds|
URL: https://doi.org/10.1109/TGRS.2010.2102361
Other URLs:
Pinardi, N., Bonazzi, A., Dobricic, S., Milliff, R.F., Wikle, C.K., and Berliner, L.M. (2011). Ocean Ensemble Forecasting. Part II: Mediterranean Forecast System Response, Quarterly Journal of the Royal Meteorological Society, 137(657), 879-893, 10.1002/qj.816. Journal Article »
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Title: Ocean Ensemble Forecasting. Part II: Mediterranean Forecast System Response
Type: Journal Article
Publication: Quarterly Journal of the Royal Meteorological Society
Author(s): Pinardi, N., Bonazzi, A., Dobricic, S., Milliff, R.F., Wikle, C.K., and Berliner, L.M.
Year: 2011
Formatted Citation: Pinardi, N., Bonazzi, A., Dobricic, S., Milliff, R.F., Wikle, C.K., and Berliner, L.M., 2011: Ocean Ensemble Forecasting. Part II: Mediterranean Forecast System Response, Quarterly Journal of the Royal Meteorological Society, 137(657), 879-893, 10.1002/qj.816.
Abstract: This article analyzes the ocean forecast response to surface vector wind (SVW) distributions generated by a Bayesian hierarchical model (BHM) developed in Part I of this series. A new method for ocean ensemble forecasting (OEF), the so-called BHM-SVW-OEF, is described. BHM-SVW realizations are used to produce and force perturbations in the ocean state during 14 day analysis and 10 day forecast cycles of the Mediterranean Forecast System (MFS). The BHM-SVW-OEF ocean response spread is amplified at the mesoscales and in the pycnocline of the eddy field. The new method is compared with an ensemble response forced by European Centre for Medium-Range Weather Forecasts (ECMWF) ensemble prediction system (EEPS) surface winds, and with an ensemble forecast started from perturbed initial conditions derived from an ad hoc thermocline intensified random perturbation (TIRP) method. The EEPS-OEF shows spread on basin scales while the TIRP-OEF response is mesoscale-intensified as in the BHM-SVW-OEF response. TIRP-OEF perturbations fill more of the MFS domain, while the BHM-SVW-OEF perturbations are more location-specific, concentrating ensemble spread at the sites where the ocean-model response to uncertainty in the surface wind forcing is largest.
Keywords: forecast uncertainty; wind perturbations; model error structure; mesoscales; upper ocean variability; Bayesian hierarchical methods
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URL: https://doi.org/10.1002/qj.816
Other URLs:
Quilfen, Y., Vandemark, D., Chapron, B., Feng, H., and Sienkiewicz, J. (2011). Estimating Gale to Hurricane Force Winds Using the Satellite Altimeter, Journal of Atmospheric and Oceanic Technology, 28(4), 453-458, 10.1175/JTECH-D-10-05000.1. Journal Article »
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Title: Estimating Gale to Hurricane Force Winds Using the Satellite Altimeter
Type: Journal Article
Publication: Journal of Atmospheric and Oceanic Technology
Author(s): Quilfen, Y., Vandemark, D., Chapron, B., Feng, H., and Sienkiewicz, J.
Year: 2011
Formatted Citation: Quilfen, Y., Vandemark, D., Chapron, B., Feng, H., and Sienkiewicz, J., 2011: Estimating Gale to Hurricane Force Winds Using the Satellite Altimeter, Journal of Atmospheric and Oceanic Technology, 28(4), 453-458, 10.1175/JTECH-D-10-05000.1.
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URL: https://doi.org/10.1175/JTECH-D-10-05000.1
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Ren, D., Fu, R., Leslie, L.M., Chen, J., Wilson, C.R., and Karoly, D.J. (2011). The Greenland Ice Sheet Response to Transient Climate Change, Journal of Climate, 24(13), 3469-3483, 10.1175/2011JCLI3708.1. Journal Article »
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Title: The Greenland Ice Sheet Response to Transient Climate Change
Type: Journal Article
Publication: Journal of Climate
Author(s): Ren, D., Fu, R., Leslie, L.M., Chen, J., Wilson, C.R., and Karoly, D.J.
Year: 2011
Formatted Citation: Ren, D., Fu, R., Leslie, L.M., Chen, J., Wilson, C.R., and Karoly, D.J., 2011: The Greenland Ice Sheet Response to Transient Climate Change, Journal of Climate, 24(13), 3469-3483, 10.1175/2011JCLI3708.1.
Abstract: This study applies a multiphase, multiple-rheology, scalable, and extensible geofluid model to the Greenland Ice Sheet (GrIS). The model is driven by monthly atmospheric forcing from global climate model simulations. Novel features of the model, referred to as the scalable and extensible geofluid modeling system (SEGMENT-Ice), include using the full Navier-Stokes equations to account for nonlocal dynamic balance and its influence on ice flow, and a granular sliding layer between the bottom ice layer and the lithosphere layer to provide a mechanism for possible large-scale surges in a warmer future climate (granular basal layer is for certain specific regions, though). Monthly climate of SEGMENT-Ice allows an investigation of detailed features such as seasonal melt area extent (SME) over Greenland. The model reproduced reasonably well the annual maximum SME and total ice mass lost rate when compared observations from the Special Sensing Microwave Imager (SSM/I) and Gravity Recovery and Climate Experiment (GRACE) over the past few decades. The SEGMENT-Ice simulations are driven by projections from two relatively high-resolution climate models, the NCAR Community Climate System Model, version 3 (CCSM3) and the Model for Interdisciplinary Research on Climate 3.2, high-resolution version [MIROC3.2(hires)], under a realistic twenty-first-century greenhouse gas emission scenario. They suggest that the surface flow would be enhanced over the entire GrIS owing to a reduction of ice viscosity as the temperature increases, despite the small change in the ice surface topography over the interior of Greenland. With increased surface flow speed, strain heating induces more rapid heating in the ice at levels deeper than due to diffusion alone. Basal sliding, especially for granular sediments, provides an efficient mechanism for fast-glacier acceleration and enhanced mass loss. This mechanism, absent from other models, provides a rapid dynamic response to climate change. Net mass loss estimates from the new model should reach similar to 220 km(3) yr(-1) by 2100, significantly higher than estimates by the Intergovernmental Panel on Climate Change (IPCC) Assessment Report 4 (AR4) of similar to 50-100 km(3) yr(-1). By 2100, the perennial frozen surface area decreases up to similar to 60%, to similar to 7 x 10(5) km(2), indicating a massive expansion of the ablation zone. Ice mass change patterns, particularly along the periphery, are very similar between the two climate models.
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URL: https://doi.org/10.1175/2011JCLI3708.1
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Small, R.J., Xie, S.-P., Maloney, E.D., deSzoeke, S.P., and Miyama, T. (2011). Intraseasonal Variability in the Far-East Pacific: Investigation of the Role of Air-Sea Coupling in a Regional Coupled Model, Climate Dynamics, 36, 867-890, 10.1007/s00382-010-0786-2. Journal Article »
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Title: Intraseasonal Variability in the Far-East Pacific: Investigation of the Role of Air-Sea Coupling in a Regional Coupled Model
Type: Journal Article
Publication: Climate Dynamics
Author(s): Small, R.J., Xie, S.-P., Maloney, E.D., deSzoeke, S.P., and Miyama, T.
Year: 2011
Formatted Citation: Small, R.J., Xie, S.-P., Maloney, E.D., deSzoeke, S.P., and Miyama, T., 2011: Intraseasonal Variability in the Far-East Pacific: Investigation of the Role of Air-Sea Coupling in a Regional Coupled Model, Climate Dynamics, 36, 867-890, 10.1007/s00382-010-0786-2.
Abstract: Intraseasonal variability in the eastern Pacific warm pool in summer is studied, using a regional ocean-atmosphere model, a linear baroclinic model (LBM), and satellite observations. The atmospheric component of the model is forced by lateral boundary conditions from reanalysis data. The aim is to quantify the importance to atmospheric deep convection of local air-sea coupling. In particular, the effect of sea surface temperature (SST) anomalies on surface heat fluxes is examined. Intraseasonal (20-90 day) east Pacific warm-pool zonal wind and outgoing longwave radiation (OLR) variability in the regional coupled model are correlated at 0.8 and 0.6 with observations, respectively, significant at the 99% confidence level. The strength of the intraseasonal variability in the coupled model, as measured by the variance of outgoing longwave radiation, is close in magnitude to that observed, but with a maximum located about 10° further west. East Pacific warm pool intraseasonal convection and winds agree in phase with those from observations, suggesting that remote forcing at the boundaries associated with the Madden-Julian oscillation determines the phase of intraseasonal convection in the east Pacific warm pool. When the ocean model component is replaced by weekly reanalysis SST in an atmosphere-only experiment, there is a slight improvement in the location of the highest OLR variance. Further sensitivity experiments with the regional atmosphere-only model in which intraseasonal SST variability is removed indicate that convective variability has only a weak dependence on the SST variability, but a stronger dependence on the climatological mean SST distribution. A scaling analysis confirms that wind speed anomalies give a much larger contribution to the intraseasonal evaporation signal than SST anomalies, in both model and observations. A LBM is used to show that local feedbacks would serve to amplify intraseasonal convection and the large-scale circulation. Further, Hovmöller diagrams reveal that whereas a significant dynamic intraseasonal signal enters the model domain from the west, the strong deep convection mostly arises within the domain. Taken together, the regional and linear model results suggest that in this region remote forcing and local convection-circulation feedbacks are both important to the intraseasonal variability, but ocean-atmosphere coupling has only a small effect. Possible mechanisms of remote forcing are discussed.
Keywords: Intraseasonal variability - Maddenâ-Julian oscillation - East Pacific - Climate - Tropical meteorology - Air-sea interaction - Coupled models - Regional models
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URL: https://doi.org/10.1007/s00382-010-0786-2
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Smith, S.R., Bourassa, M.A., and Long, M. (2011). Pirate Attacks Affect Indian Ocean Climate Research, Eos, Transactions American Geophysical Union, 92(27), 225-226, 10.1029/2011EO270001. Journal Article »
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Title: Pirate Attacks Affect Indian Ocean Climate Research
Type: Journal Article
Publication: Eos, Transactions American Geophysical Union
Author(s): Smith, S.R., Bourassa, M.A., and Long, M.
Year: 2011
Formatted Citation: Smith, S.R., Bourassa, M.A., and Long, M., 2011: Pirate Attacks Affect Indian Ocean Climate Research, Eos, Transactions American Geophysical Union, 92(27), 225-226, 10.1029/2011EO270001.
Abstract: Pirate attacks in the Gulf of Aden and the Indian Ocean off the coast of Somalia nearly doubled from 111 in 2008 to 217 in 2009 [International Maritime Bureau, 2009, International Maritime Bureau, 2010]. Consequently, merchant vessel traffic in the area around Somalia significantly decreased. Many of these merchant vessels carry instruments that record wind and other weather conditions near the ocean surface, and alterations in ship tracks have resulted in a hole sized at about 2.5 million square kilometers in the marine weather-observing network off the coast of Somalia. The data void exists in the formation region of the Somali low-level jet, a wind pattern that is one of the main drivers of the Indian summer monsoon. Further, a stable, multidecadal record has been interrupted, and consequently, long-term analyses of the jet derived from surface wind data are now showing artificial anomalies that will affect efforts by scientists to identify interannual to decadal variations in the climate of the northwestern Indian Ocean.
Keywords: winds ; climate ; Indian Ocean
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URL: https://doi.org/10.1029/2011EO270001
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Stuart, K.M. and Long, D.G. (2011). Iceberg Size and Orientation Estimation Using SeaWinds, Cold Regions Science and Technology, 69(1), 39-51, 10.1016/j.coldregions.2011.07.006. Journal Article »
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Title: Iceberg Size and Orientation Estimation Using SeaWinds
Type: Journal Article
Publication: Cold Regions Science and Technology
Author(s): Stuart, K.M. and Long, D.G.
Year: 2011
Formatted Citation: Stuart, K.M. and Long, D.G., 2011: Iceberg Size and Orientation Estimation Using SeaWinds, Cold Regions Science and Technology, 69(1), 39-51, 10.1016/j.coldregions.2011.07.006.
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URL: https://doi.org/10.1016/j.coldregions.2011.07.006
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Stuart, K.M., and Long, D.G. (2011). Tracking Large Tabular Icebergs Using the SeaWinds Ku-band Microwave Scatterometer, Deep Sea Research II, 58(11-12), 1285-1300, 10.1016/j.dsr2.2010.11.004. Journal Article »
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Title: Tracking Large Tabular Icebergs Using the SeaWinds Ku-band Microwave Scatterometer
Type: Journal Article
Publication: Deep Sea Research II
Author(s): Stuart, K.M., and Long, D.G.
Year: 2011
Formatted Citation: Stuart, K.M., and Long, D.G., 2011: Tracking Large Tabular Icebergs Using the SeaWinds Ku-band Microwave Scatterometer, Deep Sea Research II, 58(11-12), 1285-1300, 10.1016/j.dsr2.2010.11.004.
Abstract: Knowledge of iceberg locations is important for safety reasons as well as for understanding many geophysical and biological processes. Originally designed to measure wind speed and direction over the ocean, SeaWinds is a microwave scatterometer that operates at 13.4 GHz (Ku-band) on the QuikSCAT satellite. Radar measurements from SeaWinds are collected and processed on a daily basis using resolution-enhancement techniques to produce daily radar images. Because icebergs scatter microwave energy more than sea ice and sea water, icebergs are detected as high-backscatter targets surrounded by lower-backscatter regions in daily SeaWinds images. As a result, iceberg positions are determined in real-time and a time-series of iceberg positions is maintained in an Antarctic iceberg database by Brigham Young University`s Microwave Earth Remote Sensing (MERS) laboratory. Since SeaWinds operates independent of both solar illumination and cloud cover and has a large daily spatial coverage, this paper demonstrates that SeaWinds is an excellent platform to detect and track large tabular icebergs. These icebergs are generally larger than 5 km and are typically characterized as a rough ice plateau above the surrounding sea water or sea ice. The number of icebergs tracked in the MERS Antarctic iceberg database is found to be generally greater than the number of icebergs tracked by the National Ice Center. The movement patterns of all icebergs detected by SeaWinds are also analyzed and 90% of icebergs are found to travel a counter-clockwise path around Antarctica and accumulate in the Weddell and Scotia Seas. Iceberg detection and tracking is demonstrated via multiple case studies that highlight icebergs C-19a and A-22a using the MERS database and through real-time operational support of the 2005, 2008, and 2009 NSF Antarctic cruises. Iceberg positions are validated by using collocated high-resolution satellite imagery and by navigating the NSF ships to physically intercept several large tabular icebergs in the Weddell and Scotia Seas.
Keywords: SeaWinds, Scatterometer, Resolution enhancement, Icebergs, Sea ice, NSF Antarctic cruise
Mission: |SeaWinds|
URL: https://doi.org/10.1016/j.dsr2.2010.11.004
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Tokinaga, H. and Xie, S.-P. (2011). Wave and Anemometer-Based Sea-Surface Wind (WASWind) for Climate Change Analysis, Journal of Climate, 24(1), 267-285, 10.1175/2010JCLI3789.1. Journal Article »
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Title: Wave and Anemometer-Based Sea-Surface Wind (WASWind) for Climate Change Analysis
Type: Journal Article
Publication: Journal of Climate
Author(s): Tokinaga, H. and Xie, S.-P.
Year: 2011
Formatted Citation: Tokinaga, H. and Xie, S.-P., 2011: Wave and Anemometer-Based Sea-Surface Wind (WASWind) for Climate Change Analysis, Journal of Climate, 24(1), 267-285, 10.1175/2010JCLI3789.1.
Abstract: Ship-based measurements of sea surface wind speed displays a spurious upward trend due to increases in anemometer height. To correct this bias, we construct a new sea surface wind dataset from ship observations of wind speed and wind wave height archived in the International Comprehensive Ocean-Atmosphere Data Set (ICOADS). The Wave and Anemometer-based Sea-surface Wind (WASWind) dataset is available for wind velocity and scalar speed at monthly resolution on a 4º x 4º longitude-latitude grid from 1950 to 2008. It substantially reduces the upward trend in wind speed through height-correction for anemometer-measured winds, rejection of spurious Beaufort winds, and use of estimated winds from wind wave height. The reduced global upward trend is smallest among the existing global datasets of in-situ observations and comparable with those of reanalysis products. Despite the significant reduction of globally-averaged wind speed trend, WASWind features rich spatial structures in trend pattern, making it a valuable dataset for studies of climate changes on regional scales. Not only does the combination of ship winds and wind wave height successfully reproduce major modes of seasonal-to-decadal variability, but its trend patterns are also physically consistent with sea level pressure (SLP) measurements. WASWind is in close agreement with wind changes in satellite measurements by the Special Sensor Microwave Imagers (SSM/Is) for the recent two decades. The agreement in trend pattern with such independent observations illustrates the utility of WASWind for climate trend analysis. An application to the South Asian summer monsoon is presented.
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URL: https://doi.org/10.1175/2010JCLI3789.1
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Tokinaga, H., and Xie, S.-P. (2011). Weakening of the Equatorial Atlantic Cold Tongue Over the Past Six Decades, Journal Article »
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Title: Weakening of the Equatorial Atlantic Cold Tongue Over the Past Six Decades
Type: Journal Article
Publication:
Author(s): Tokinaga, H., and Xie, S.-P.
Year: 2011
Formatted Citation: Tokinaga, H., and Xie, S.-P., 2011: Weakening of the Equatorial Atlantic Cold Tongue Over the Past Six Decades,
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URL: https://doi.org/10.1038/ngeo1078
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Wang, S., O'Neill, L., Jiang, Q., Hong, X., Jin, H., de Szoeke, S., Thompson, W., and Zheng, X. (2011). A Regional Real-Time Forecast of Marine Boundary Layers During VOCALS-REx, Atmospheric Chemistry and Physics, 11(2), 465-477, 10.5194/acp-11-421-2011. Journal Article »
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Title: A Regional Real-Time Forecast of Marine Boundary Layers During VOCALS-REx
Type: Journal Article
Publication: Atmospheric Chemistry and Physics
Author(s): Wang, S., O'Neill, L., Jiang, Q., Hong, X., Jin, H., de Szoeke, S., Thompson, W., and Zheng, X.
Year: 2011
Formatted Citation: Wang, S., O'Neill, L., Jiang, Q., Hong, X., Jin, H., de Szoeke, S., Thompson, W., and Zheng, X., 2011: A Regional Real-Time Forecast of Marine Boundary Layers During VOCALS-REx, Atmospheric Chemistry and Physics, 11(2), 465-477, 10.5194/acp-11-421-2011.
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URL: https://doi.org/10.5194/acp-11-421-2011
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Wanninkhof, R., Park, G.-H., Chelton, D.B., and Risien, C.M. (2011). Impact of Small-Scale Variability on Air-Sea CO2 Fluxes, Gas Transfer At Water Surfaces, 431-444. Book Chapter »
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Title: Impact of Small-Scale Variability on Air-Sea CO2 Fluxes
Type: Book Chapter
Publication: Gas Transfer At Water Surfaces
Author(s): Wanninkhof, R., Park, G.-H., Chelton, D.B., and Risien, C.M.
Year: 2011
Formatted Citation: Wanninkhof, R., Park, G.-H., Chelton, D.B., and Risien, C.M., 2011: Impact of Small-Scale Variability on Air-Sea CO2 Fluxes, Gas Transfer At Water Surfaces, 431-444.
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URL: https://www.researchgate.net/publication/268382920_Impact_of_small-scale_variability_on_air-sea_CO2_fluxes
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Weissman, D.E., and Bourassa, M.A. (2011). The Influence of Rainfall Upon Scatterometer Estimates for Sea Surface Stress and Boundary Layer Parameterization Models Within Tropical Cyclone Environments, IEEE Trans. Geosci. Remote Sens., 49(12), 4805-4814, 10.1109/TGRS.2011.2170842. Journal Article »
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Title: The Influence of Rainfall Upon Scatterometer Estimates for Sea Surface Stress and Boundary Layer Parameterization Models Within Tropical Cyclone Environments
Type: Journal Article
Publication: IEEE Trans. Geosci. Remote Sens.
Author(s): Weissman, D.E., and Bourassa, M.A.
Year: 2011
Formatted Citation: Weissman, D.E., and Bourassa, M.A., 2011: The Influence of Rainfall Upon Scatterometer Estimates for Sea Surface Stress and Boundary Layer Parameterization Models Within Tropical Cyclone Environments, IEEE Trans. Geosci. Remote Sens., 49(12), 4805-4814, 10.1109/TGRS.2011.2170842.
Abstract: The use of satellite scatterometers to probe the winds in and near strong tropical cyclones (TCs) is a valuable tool for both numerical weather prediction and weather forecasters. The presence of widespread rain in these storms impedes the estimation of surface winds from the radar cross section measurements, when using a Ku-band radar. This paper seeks improvements in the methodology to infer surface winds and stresses from the satellite radar cross section data, by removing the effects of rain contamination at the ocean surface. The findings provide insights into improvements in the modeling efforts of TC intensity. This study demonstrates the use of high-resolution rain measurements obtained from a Next-Generation Radar collocated and simultaneous with the National Aeronautics and Space Ad ministration Quick Scatterometer. Through the application of the National Oceanic and Atmospheric Administration/Atlantic Oceanographic and Meteorological Laboratory/Hurricane Re search Division TC wind analysis (H* WIND), we are studying the dependence of a surface normalized radar cross section (NRCS), which is related to surface stress, on the TC wind speed and rain rate. One of our findings is that, in the three TCs we have studied, the highest winds are accompanied by significant rain. Another is that the wind-driven rain can act as a roughening effect as measured by the H-pol NRCS. We also offer reasons why this can be interpreted as an additional stress on the surface. This roughening affects both the estimation of surface winds by scatterometers and the air-sea energy exchanges. This information could lead to an improved understanding of the dependence of the drag coefficient on both wind and rain.
Keywords: Meteorological radar , radar cross section , radar remote sensing , scatterometry
Mission: |SeaWinds|
URL: https://doi.org/10.1109/TGRS.2011.2170842
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Williams, B.A., and Long, D.G. (2011). A Reconstruction Approach to Scatterometer Wind Vector Field Retrieval, IEEE Trans. Geosci. Remote Sens., 49(6), 1850-1864, 10.1109/TGRS.2010.2100402. Journal Article »
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Title: A Reconstruction Approach to Scatterometer Wind Vector Field Retrieval
Type: Journal Article
Publication: IEEE Trans. Geosci. Remote Sens.
Author(s): Williams, B.A., and Long, D.G.
Year: 2011
Formatted Citation: Williams, B.A., and Long, D.G., 2011: A Reconstruction Approach to Scatterometer Wind Vector Field Retrieval, IEEE Trans. Geosci. Remote Sens., 49(6), 1850-1864, 10.1109/TGRS.2010.2100402.
Abstract: This paper approaches wind field estimation from scatterometer measurements as the inversion of a noisy nonlinear sampling operation. The forward sampling model is presented and made discrete for practical purposes. Generally, the wind estimation problem is ill-posed at high resolution, which means that there are more parameters to estimate than measurements. A Bayesian approach based on maximum a posteriori (MAP) estimation is proposed to regularize the problem. This allows the simultaneous estimation of the regular samples of the high-resolution wind vector field directly from the noisy aperture-filtered backscatter ?° measurements. The MAP reconstruction approach is applied to the SeaWinds scatterometer, the examples are presented, and the results are compared to standard products. The MAP reconstruction method produces results that are consistent with standard products while preserving the higher spatial resolution information. The MAP estimates result in a similar resolution to the standard ultrahigh-resolution processing method but with a lower bias and a lower variability in the estimates.
Keywords: Irregular sampling , maximum a posteriori (MAP) estimation , reconstruction , scatterometry , wind estimation
Mission: |SeaWinds|
URL: https://doi.org/10.1109/TGRS.2010.2100402
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Yu W., Han, W., Maloney, E.D., Gochis, D., and Xie, S.-P. (2011). Observations of Eastward Propagation of Atmospheric Intraseasonal Oscillations from the Pacific to the Atlantic Ocean, Journal of Geophysical Research: Atmospheres, 16(D2), 10.1029/2010JD014336. Journal Article »
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Title: Observations of Eastward Propagation of Atmospheric Intraseasonal Oscillations from the Pacific to the Atlantic Ocean
Type: Journal Article
Publication: Journal of Geophysical Research: Atmospheres
Author(s): Yu W., Han, W., Maloney, E.D., Gochis, D., and Xie, S.-P.
Year: 2011
Formatted Citation: Yu W., Han, W., Maloney, E.D., Gochis, D., and Xie, S.-P., 2011: Observations of Eastward Propagation of Atmospheric Intraseasonal Oscillations from the Pacific to the Atlantic Ocean, Journal of Geophysical Research: Atmospheres, 16(D2), 10.1029/2010JD014336.
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URL: https://doi.org/10.1029/2010JD014336
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Zhang, S., Liu, J.W., Xie, S.-P., and Meng, X. (2011). The Formation of a Surface Anticyclone in the Spring Yellow and East China Seas, Journal of the Meteorological Society of Japan, 89, 119-131, 10.2151/jmsj.2011-202. Journal Article »
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Title: The Formation of a Surface Anticyclone in the Spring Yellow and East China Seas
Type: Journal Article
Publication: Journal of the Meteorological Society of Japan
Author(s): Zhang, S., Liu, J.W., Xie, S.-P., and Meng, X.
Year: 2011
Formatted Citation: Zhang, S., Liu, J.W., Xie, S.-P., and Meng, X., 2011: The Formation of a Surface Anticyclone in the Spring Yellow and East China Seas, Journal of the Meteorological Society of Japan, 89, 119-131, 10.2151/jmsj.2011-202.
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URL: https://doi.org/10.2151/jmsj.2011-202
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Bourassa, A.M., Bonekamp, H., Chang, P., Chelton, D., Courtney, J., Edson, R., Figa, J., He, Y., Hersbach, H., Hilburn, K., Lee, T., Liu, W.T., Long, D., Kelly, A., Knabb, R., Lindstorm, E., Perrie, W., Portabella, M., Powell, M., Rodriguez, E., Smith, D., Stoffelen, A., Swail, V., and Wentz, F. (2010). Remotely Sensed Winds and Wind Stresses for Marine Forecasting and Ocean Modeling, OceanObs '09: Sustained Ocean Observations and Information for Society Conference (Vol. 2), ESA Publication WPP-306, 10.5270/OceanObs09.cwp.08. Conference Paper »
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Title: Remotely Sensed Winds and Wind Stresses for Marine Forecasting and Ocean Modeling
Type: Conference Paper
Publication: OceanObs '09: Sustained Ocean Observations and Information for Society Conference (Vol. 2)
Author(s): Bourassa, A.M., Bonekamp, H., Chang, P., Chelton, D., Courtney, J., Edson, R., Figa, J., He, Y., Hersbach, H., Hilburn, K., Lee, T., Liu, W.T., Long, D., Kelly, A., Knabb, R., Lindstorm, E., Perrie, W., Portabella, M., Powell, M., Rodriguez, E., Smith, D., Stoffelen, A., Swail, V., and Wentz, F.
Year: 2010
Formatted Citation: Bourassa, A.M., Bonekamp, H., Chang, P., Chelton, D., Courtney, J., Edson, R., Figa, J., He, Y., Hersbach, H., Hilburn, K., Lee, T., Liu, W.T., Long, D., Kelly, A., Knabb, R., Lindstorm, E., Perrie, W., Portabella, M., Powell, M., Rodriguez, E., Smith, D., Stoffelen, A., Swail, V., and Wentz, F., 2010: Remotely Sensed Winds and Wind Stresses for Marine Forecasting and Ocean Modeling, OceanObs '09: Sustained Ocean Observations and Information for Society Conference (Vol. 2), ESA Publication WPP-306, 10.5270/OceanObs09.cwp.08.
Abstract: Ocean surface vector winds (OSVW) are used to estimate momentum transfer (surface stress) between the atmosphere and ocean, and are critically important for determining the large scale ocean circulation and transport. Vector winds are needed to estimate the ageostrophic (Ekman) component of ocean currents, and consequently are linked to atmospheric and oceanographic upwelling and downwelling, coastal upwelling, primary productivity, cross shelf transport, ice transport, mixed layer evolution, and deep water formation. Accurate wind speeds are also essential for reliable computations of air/sea heat fluxes (e.g., sensible and latent heat fluxes) as well as mass fluxes (e.g., CO₂ and H₂O), making surface winds critically important for budgeting energy, moisture and Carbon, and for studies of ocean acidification. Wind and wave information are essential for marine safety. The advection and offshore transport of nutrients and fresh water can be linked to the life cycle and annual variability in fish stocks. Both scalar and vector winds can be linked to upper ocean mixing, which is easily linked to ocean, atmospheric, cryospheric, and terrestrial climate change. For shorter time scale applications, surface wind vectors are also used for forecasts of storm surge and waves. Ocean surface winds change rapidly in both time and space. Satellite-based sampling density and relatively good accuracy make satellite winds desirable data (particularly for regions with sparse in situ observations) for many related applications such as coastal upwelling, oceanic/atmospheric coupling associated with both tropical instability wave and ocean fronts [Chelton et al. 2004], ocean currents [Lagerloef et al. 2003], detection of tropical disturbances [Gierach et al. 2007], wave forecasting, weather forecasting [Isaksen and Stoffelen, 2000], and storm surge [Morey et al. 2006], to list a small sample of applications. Portions of the same observing systems are also used to provide observations of sea ice extent and rainfall (fresh water flux). There were several reviews of spacebased wind measurements and applications [e.g., Liu 2002, Liu and Xie 2006]. The keys to improving the ocean wind observing system are improved bias removal and calibration for very high and low wind speeds, better temporal sampling (via a constellation), finer spatial resolution, e.g., on the ocean eddy scale and for near-coastal winds, intercalibration of observations, and improved methods of blending observations (scalar winds and vector winds) from multiple platforms.
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URL: https://www.coaps.fsu.edu/scatterometry/reports/docs/OceanObs09_Winds_White_Paper.pdf
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Bourassa, M., Gille, S., Jackson, D.L., Roberts, B.J., and Wick, G.A. (2010). Ocean Winds and Turbulent Air-Sea Fluxes Inferred From Remote Sensing, Oceanography, 23(4), 36-51, 10.5670/oceanog.2010.04. Journal Article »
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Title: Ocean Winds and Turbulent Air-Sea Fluxes Inferred From Remote Sensing
Type: Journal Article
Publication: Oceanography
Author(s): Bourassa, M., Gille, S., Jackson, D.L., Roberts, B.J., and Wick, G.A.
Year: 2010
Formatted Citation: Bourassa, M., Gille, S., Jackson, D.L., Roberts, B.J., and Wick, G.A., 2010: Ocean Winds and Turbulent Air-Sea Fluxes Inferred From Remote Sensing, Oceanography, 23(4), 36-51, 10.5670/oceanog.2010.04.
Abstract: Surface turbulent fluxes are key pathways through which the atmosphere is coupled with the ocean. They provide mechanisms through which momentum, energy, moisture, and materials such as CO₂ are transferred between the ocean and atmosphere. Surface fluxes are also important players in vertical and horizontal transport in the atmosphere and the ocean. There have been attempts to estimate surface fluxes directly from satellite observations, however, they are typically calculated from observations of surface and near-surface variables. Recent improvements in the measurement of vector winds, air temperatures, and atmospheric humidities have all contributed to better estimation of surface fluxes from satellite observations. These advances are discussed in the context of applications, with examples from a tropical cyclone and a very strong mid-latitude storm. Proposed future systems that use improved instrumentation and collocate observations of winds, temperatures, and humidities will increase the accuracy beyond current capabilities. Targets for a variety of important climate-related processes are provided.
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URL: https://doi.org/10.5670/oceanog.2010.04
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Bourassa, M.A., Gille, S.T., and Clayson, C.A. (2010). Surface Fluxes: Challenges for High Latitudes: Workshop report from the U.S. CLIVAR High Latitudes Surface Flux Working Group, U.S. CLIVAR Variations, 8(1), 7,14. Journal Article »
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Title: Surface Fluxes: Challenges for High Latitudes: Workshop report from the U.S. CLIVAR High Latitudes Surface Flux Working Group
Type: Journal Article
Publication: U.S. CLIVAR Variations
Author(s): Bourassa, M.A., Gille, S.T., and Clayson, C.A.
Year: 2010
Formatted Citation: Bourassa, M.A., Gille, S.T., and Clayson, C.A., 2010: Surface Fluxes: Challenges for High Latitudes: Workshop report from the U.S. CLIVAR High Latitudes Surface Flux Working Group, U.S. CLIVAR Variations, 8(1), 7,14.
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URL: https://usclivar.org/sites/default/files/newsletter/Variations-V8N1-1.pdf
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Bourassa, M.A., Rodriguez, E., and Gaston, R. (2010). NASA's Ocean Vector Winds Science Team Workshops, Bulletin of the American Meteorological Society, 91(7), 925-928, 10.1175/2010BAMS2880.1. Journal Article »
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Title: NASA's Ocean Vector Winds Science Team Workshops
Type: Journal Article
Publication: Bulletin of the American Meteorological Society
Author(s): Bourassa, M.A., Rodriguez, E., and Gaston, R.
Year: 2010
Formatted Citation: Bourassa, M.A., Rodriguez, E., and Gaston, R., 2010: NASA's Ocean Vector Winds Science Team Workshops, Bulletin of the American Meteorological Society, 91(7), 925-928, 10.1175/2010BAMS2880.1.
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URL: https://doi.org/10.1175/2010BAMS2880.1
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Bryan, F., Thomas, R., Dennis, J., Chelton, D.B., Loeb, N.G., and McClean, J.L. (2010). Frontal Scale Air-Sea Interaction in High-Resolution Coupled Climate Models, Journal of Climate, 23(23), 6277-6291, 10.1175/2010JCLI3665.1. Journal Article »
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Title: Frontal Scale Air-Sea Interaction in High-Resolution Coupled Climate Models
Type: Journal Article
Publication: Journal of Climate
Author(s): Bryan, F., Thomas, R., Dennis, J., Chelton, D.B., Loeb, N.G., and McClean, J.L.
Year: 2010
Formatted Citation: Bryan, F., Thomas, R., Dennis, J., Chelton, D.B., Loeb, N.G., and McClean, J.L., 2010: Frontal Scale Air-Sea Interaction in High-Resolution Coupled Climate Models, Journal of Climate, 23(23), 6277-6291, 10.1175/2010JCLI3665.1.
Abstract: The emerging picture of frontal scale air-sea interaction derived from high-resolution satellite observations of surface winds and sea surface temperature (SST) provides a unique opportunity to test the fidelity of high-resolution coupled climate simulations. Initial analysis of the output of a suite of Community Climate System Model (CCSM) experiments indicates that characteristics of frontal scale ocean-atmosphere interaction, such as the positive correlation between SST and surface wind stress, are realistically captured only when the ocean component is eddy resolving. The strength of the coupling between SST and surface stress is weaker than observed, however, as has been found previously for numerical weather prediction models and other coupled climate models. The results are similar when the atmospheric component model grid resolution is doubled from 0.5° to 0.25°, an indication that shortcomings in the representation of subgrid scale atmospheric planetary boundary layer processes, rather than resolved scale processes, are responsible for the weakness of the coupling. In the coupled model solutions the response to mesoscale SST features is strongest in the atmospheric boundary layer, but there is a deeper reaching response of the atmospheric circulation apparent in free tropospheric clouds. This simulated response is shown to be consistent with satellite estimates of the relationship between mesoscale SST and all-sky albedo.
Keywords: Airndashsea interaction, Coupled models, Sea surface temperature, Albedo, Wind stress, Mesoscale systems
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URL: https://doi.org/10.1175/2010JCLI3665.1
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Chelton, D.B. and Xie, S.-P. (2010). Coupled Ocean-Atmospheric Interaction at Oceanic Mesoscales, Oceanography, 23(4), 52-69, 10.5670/oceanog.2010.05. Journal Article »
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Title: Coupled Ocean-Atmospheric Interaction at Oceanic Mesoscales
Type: Journal Article
Publication: Oceanography
Author(s): Chelton, D.B. and Xie, S.-P.
Year: 2010
Formatted Citation: Chelton, D.B. and Xie, S.-P., 2010: Coupled Ocean-Atmospheric Interaction at Oceanic Mesoscales, Oceanography, 23(4), 52-69, 10.5670/oceanog.2010.05.
Abstract: Satellite observations have revealed a remarkably strong positive correlation between sea surface temperature (SST) and surface winds on oceanic mesoscales of 10-1000 km. Although SST influence on the atmosphere had previously been identified from several in situ observational studies, its widespread existence in regions of strong SST gradients throughout the world's ocean and the detailed structure of the surface wind response to SST have only become evident over the past decade from simultaneous satellite measurements of SST and surface winds. This has stimulated considerable scientific interest in the implications of this air-sea interaction to large-scale and mesoscale circulation of the atmosphere and ocean. Convergence and divergence of surface winds in regions of spatially varying SST generate vertical motion that can penetrate deep into the atmosphere. Spatial variability of the SST field also results in a curl of the wind stress and associated upwelling and downwelling that feeds back on the ocean and alters SST itself. Significant progress has been made toward understanding the two-way coupling between the ocean and atmosphere but many exciting research opportunities remain. In addition to regional and global modeling, future research on coupled ocean-atmosphere interaction will continue to be guided by satellite observations. In particular, high-resolution measurements in the vicinity of narrow, intense SST fronts and immediately adjacent to land provided by the next-generation scatterometer will open up new areas of research that cannot be addressed from presently available data sets.
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URL: https://doi.org/10.5670/oceanog.2010.05
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Chien, C.-Y., Speer, K., and Bourassa, M. (2010). Comparison of Wind Products in the Southern Ocean, U.S. CLIVAR Variations, 8(1), 8-10. Journal Article »
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Title: Comparison of Wind Products in the Southern Ocean
Type: Journal Article
Publication: U.S. CLIVAR Variations
Author(s): Chien, C.-Y., Speer, K., and Bourassa, M.
Year: 2010
Formatted Citation: Chien, C.-Y., Speer, K., and Bourassa, M., 2010: Comparison of Wind Products in the Southern Ocean, U.S. CLIVAR Variations, 8(1), 8-10.
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URL: http://www.usclivar.org/Newsletter/VariationsV8N1.pdf
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Cronin, M.F., Bond, N., Booth, J., Ichikawa, H., Joyce, T.M., Kelly, K., Kubota, M., Qiu, B., Reason, C., Rouault, M., Sabine, C., Saino, T., Small, J., Suga, T., Talley, L.D., Thompson, L., and Weller, R.A. (2010). Monitoring Ocean-Atmosphere Interactions in Western Boundary Current Extensions, OceanObs`09: Sustained Ocean Observations and Information for Society Conference (Vol. 2), ESA Publication WPP-306, 10.5270/OceanObs09.cwp.20. Conference Paper »
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Title: Monitoring Ocean-Atmosphere Interactions in Western Boundary Current Extensions
Type: Conference Paper
Publication: OceanObs`09: Sustained Ocean Observations and Information for Society Conference (Vol. 2)
Author(s): Cronin, M.F., Bond, N., Booth, J., Ichikawa, H., Joyce, T.M., Kelly, K., Kubota, M., Qiu, B., Reason, C., Rouault, M., Sabine, C., Saino, T., Small, J., Suga, T., Talley, L.D., Thompson, L., and Weller, R.A.
Year: 2010
Formatted Citation: Cronin, M.F., Bond, N., Booth, J., Ichikawa, H., Joyce, T.M., Kelly, K., Kubota, M., Qiu, B., Reason, C., Rouault, M., Sabine, C., Saino, T., Small, J., Suga, T., Talley, L.D., Thompson, L., and Weller, R.A., 2010: Monitoring Ocean-Atmosphere Interactions in Western Boundary Current Extensions, OceanObs`09: Sustained Ocean Observations and Information for Society Conference (Vol. 2), ESA Publication WPP-306, 10.5270/OceanObs09.cwp.20.
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URL: https://www.researchgate.net/publication/228778570_Monitoring_ocean-atmosphere_interactions_in_western_boundary_current_extensions
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Fairall, C., Barnier, B., Berry, D.I., Bourassa, M.A., Bradley, F., Clayson, C.A., de Leeuw, G., Drennan, W.M., Gille, S.T., Gulev, S.K., Kent, E.C., McGillis, W.R., Quartly, G.D., Ryabinin, V., Smith, S.R., Weller, R.A., Yelland, M.J., and Zhang, H.M. (2010). Observations to Quantify Air-Sea Fluxes and Their Role in Climate Variability, OceanObs'09: Sustained Ocean Observations and Information for Society Conference (Vol. 2), ESA Publication WPP-306, 10.5270/OceanObs09.cwp.27. Conference Paper »
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Title: Observations to Quantify Air-Sea Fluxes and Their Role in Climate Variability
Type: Conference Paper
Publication: OceanObs'09: Sustained Ocean Observations and Information for Society Conference (Vol. 2)
Author(s): Fairall, C., Barnier, B., Berry, D.I., Bourassa, M.A., Bradley, F., Clayson, C.A., de Leeuw, G., Drennan, W.M., Gille, S.T., Gulev, S.K., Kent, E.C., McGillis, W.R., Quartly, G.D., Ryabinin, V., Smith, S.R., Weller, R.A., Yelland, M.J., and Zhang, H.M.
Year: 2010
Formatted Citation: Fairall, C., Barnier, B., Berry, D.I., Bourassa, M.A., Bradley, F., Clayson, C.A., de Leeuw, G., Drennan, W.M., Gille, S.T., Gulev, S.K., Kent, E.C., McGillis, W.R., Quartly, G.D., Ryabinin, V., Smith, S.R., Weller, R.A., Yelland, M.J., and Zhang, H.M., 2010: Observations to Quantify Air-Sea Fluxes and Their Role in Climate Variability, OceanObs'09: Sustained Ocean Observations and Information for Society Conference (Vol. 2), ESA Publication WPP-306, 10.5270/OceanObs09.cwp.27.
Abstract: Flux products quantifying exchanges between ocean and atmosphere are needed for forcing models, understanding ocean dynamics, investigating the ocean's role in climate, and assessing coupled models. Research experiments are essential to improve flux parameterizations, and longer research deployments are required to sample rare events. Urgently needed technological improvements include longer battery life, more robust sensors and improvement of sensors for humidity, precipitation and direct gas and particle fluxes. A range of different flux products are needed, incorporating data from ships, satellites and models in different combinations and using different methods. All products must be characterized with uncertainty estimates. Dataset validation requires high quality observations from ocean flux reference sites and from ships. The continued development of flux products from satellites provides much-needed sampling. Continual intercomparisons among products and with high quality observations will lead to improved flux datasets, while improvements to the flux data management system would facilitate these intercomparisons.
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URL: https://downloads.psl.noaa.gov/BLO/Air-Sea/oceanobs/pubs/fy09/fairall_etal_CWP_cwp2b03.pdf
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Gille, S., Bourassa, M., Bitz, C., Carlson, D., Cerovecki, I., Cronin, M., Drennan, W., Fairall, C., Hoffman, R., Magnusdottir, G., Pinker, R., Renfrew, I., Serreze, M., Speer, K., Talley, L., and Wick, G. (2010). Surface Fluxes in High Latitude Regions, OceanObs`09: Sustained Ocean Observations and Information for Society Conference (Vol. 2), ESA Publication WPP-306. Conference Paper »
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Title: Surface Fluxes in High Latitude Regions
Type: Conference Paper
Publication: OceanObs`09: Sustained Ocean Observations and Information for Society Conference (Vol. 2)
Author(s): Gille, S., Bourassa, M., Bitz, C., Carlson, D., Cerovecki, I., Cronin, M., Drennan, W., Fairall, C., Hoffman, R., Magnusdottir, G., Pinker, R., Renfrew, I., Serreze, M., Speer, K., Talley, L., and Wick, G.
Year: 2010
Formatted Citation: Gille, S., Bourassa, M., Bitz, C., Carlson, D., Cerovecki, I., Cronin, M., Drennan, W., Fairall, C., Hoffman, R., Magnusdottir, G., Pinker, R., Renfrew, I., Serreze, M., Speer, K., Talley, L., and Wick, G., 2010: Surface Fluxes in High Latitude Regions, OceanObs`09: Sustained Ocean Observations and Information for Society Conference (Vol. 2), ESA Publication WPP-306.
Abstract: Improving knowledge of air-sea exchanges of heat, momentum, fresh water, and gas is critical to understanding climate, and this is particularly true in high latitude regions, where anthropogenic climate change is predicted to be exceptionally rapid. Existing gridded flux products can differ substantially, and in many cases there is no clear consensus about which flux products are most reliable. Progress on air-sea fluxes will require a combination of efforts, including a concerted plan to make better use of ships of opportunity to collect meteorological data, targeted efforts to deploy a few flux moorings in high wind regions, and improved satellite retrievals of flux related variables.
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URL: http://www.oceanobs09.net/proceedings/ac/FCXNL-09A02-1659859-1-ac2b10.pdf
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Guimond, S.R., Heymsfield, G.M., and Turk, F.J. (2010). Multiscale Observations of Hurricane Dennis (2005): The Effects of Hot Towers on Rapid Intensification, Journal of the Atmospheric Sciences, 67(3), 633-654, 10.1175/2009JAS3119.1. Journal Article »
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Title: Multiscale Observations of Hurricane Dennis (2005): The Effects of Hot Towers on Rapid Intensification
Type: Journal Article
Publication: Journal of the Atmospheric Sciences
Author(s): Guimond, S.R., Heymsfield, G.M., and Turk, F.J.
Year: 2010
Formatted Citation: Guimond, S.R., Heymsfield, G.M., and Turk, F.J., 2010: Multiscale Observations of Hurricane Dennis (2005): The Effects of Hot Towers on Rapid Intensification, Journal of the Atmospheric Sciences, 67(3), 633-654, 10.1175/2009JAS3119.1.
Abstract: A synthesis of remote sensing and in situ observations throughout the life cycle of Hurricane Dennis (2005) during the NASA Tropical Cloud Systems and Processes (TCSP) experiment is presented. Measurements from the ER-2 Doppler radar (EDOP), the Advanced Microwave Sounding Unit (AMSU), airborne radiometer, and flight-level instruments are used to provide a multiscale examination of the storm. The main focus is an episode of deep convective bursts ("hot towers") occurring during a mature stage of the storm and preceding a period of rapid intensification (11-hPa pressure drop in 1 h 35 min). The vigorous hot towers penetrated to 16-km height, had maximum updrafts of 20 m s(-1) 12-14-km height, and possessed a strong transverse circulation through the core of the convection. Significant downdrafts (maximum of 10-12 in s(-1)) on the flanks of the updrafts were observed, with their cumulative effects hypothesized to result in the observed increases in the warm core. In one ER-2 overpass, subsidence was transported toward the eye by 15-20 m s(-1) inflow occurring over a deep layer (0.5-10 km) coincident with a hot tower. Fourier analysis of the AMSU satellite measurements revealed a large shift in the storm's warm core structure, from asymmetric to axisymmetric, similar to 12 h after the convective bursts began. In addition, flight-level wind calculations of the axisymmetric tangential velocity and inertial stability showed a contraction of the maximum winds and an increase in the stiffness of the vortex, respectively, after the EDOP observations. The multiscale observations presented here reveal unique, ultra-high-resolution details of hot towers and their coupling to the parent vortex, the balanced dynamics of which can be generally explained by the axisymmetrization and efficiency theories.
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URL: https://doi.org/10.1175/2009JAS3119.1
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Gulev, S.K., Josey, S.A., Bourassa, M., Breivik, L.-A., Cronin,M. F., Fairall, C., Gille, S., Kent, E.C., Lee, C.M., McPhaden, M.J., Monteiro, P.M.S., Schuster, U., Smith, S.R., Trenberth, K.E., Wallace, D., and Woodruff, S.D. (2010). Surface Energy, CO₂ Fluxes and Sea Ice, OceanObs'09: Sustained Ocean Observations and Information for Society Conference (Vol. 1), ESA Publication WPP-306, 10.5270/OceanObs09.pp.19. Conference Paper »
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Title: Surface Energy, CO₂ Fluxes and Sea Ice
Type: Conference Paper
Publication: OceanObs'09: Sustained Ocean Observations and Information for Society Conference (Vol. 1)
Author(s): Gulev, S.K., Josey, S.A., Bourassa, M., Breivik, L.-A., Cronin,M. F., Fairall, C., Gille, S., Kent, E.C., Lee, C.M., McPhaden, M.J., Monteiro, P.M.S., Schuster, U., Smith, S.R., Trenberth, K.E., Wallace, D., and Woodruff, S.D.
Year: 2010
Formatted Citation: Gulev, S.K., Josey, S.A., Bourassa, M., Breivik, L.-A., Cronin,M. F., Fairall, C., Gille, S., Kent, E.C., Lee, C.M., McPhaden, M.J., Monteiro, P.M.S., Schuster, U., Smith, S.R., Trenberth, K.E., Wallace, D., and Woodruff, S.D., 2010: Surface Energy, CO₂ Fluxes and Sea Ice, OceanObs'09: Sustained Ocean Observations and Information for Society Conference (Vol. 1), ESA Publication WPP-306, 10.5270/OceanObs09.pp.19.
Abstract: This paper reviews the current state of observation, parameterization and evaluation of surface air-sea energy and gas fluxes, and sea ice, for the purposes of monitoring and predicting the state of the global ocean. The last 10 years have been marked by the development of more accurate parameterizations of turbulent fluxes, in particular COARE-3. A seamless approach to surface flux observing systems is also being developed ranging from highly accurate observations on buoys and research ship campaigns to the longstanding Voluntary Observing Ship (VOS) scheme. In addition to flux products based on in situ data, satellite measurements and numerical weather prediction, several hybrid products have been developed which combine data from these different sources. Satellite monitoring of sea ice has been extended to more accurate and higher resolution estimation of ice extent and quantification of ice thickness. Global air-sea CO2 flux products are now based on significantly better-sampled datasets reducing the uncertainty in the ocean carbon budget. Despite these advances, considerable gaps remain in our understanding of air-sea fluxes, for example, at both high and low wind speeds, for gas and aerosol exchange and in marginal ice zones. Furthermore, there are serious concerns about the recent decline in the number of VOS observations. Closure of global and regional energy balances still cannot be achieved without adjustments to the flux fields and/or the underlying surface meteorological variables. The impact of sampling on interannual variability of fluxes makes estimates of climate tendencies in air-sea exchanges highly uncertain. In order to meet these challenges we formulate a future vision of a surface flux observing system, which provides a synergy of in situ measurements (buoys, research vessels and merchant ships), remote sensing and models.
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URL: https://www.researchgate.net/publication/228418613_Surface_Energy_CO2_Fluxes_and_Sea_Ice
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Han W., Meehl, G.A., Rajagopalan, B., Fasullo, J.T., Hu, A., Lin, J., Large, W.G., Wang, J.-w., Quan, X.-W., Trenary, L.L., Wallcraft, A., Shinoda, T., and Yeager, S. (2010). Patterns of Indian Ocean Sea-Level Change in a Warming Climate, Nature Geoscience, 3, 546-550, 10.1038/ngeo901. Journal Article »
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Title: Patterns of Indian Ocean Sea-Level Change in a Warming Climate
Type: Journal Article
Publication: Nature Geoscience
Author(s): Han W., Meehl, G.A., Rajagopalan, B., Fasullo, J.T., Hu, A., Lin, J., Large, W.G., Wang, J.-w., Quan, X.-W., Trenary, L.L., Wallcraft, A., Shinoda, T., and Yeager, S.
Year: 2010
Formatted Citation: Han W., Meehl, G.A., Rajagopalan, B., Fasullo, J.T., Hu, A., Lin, J., Large, W.G., Wang, J.-w., Quan, X.-W., Trenary, L.L., Wallcraft, A., Shinoda, T., and Yeager, S., 2010: Patterns of Indian Ocean Sea-Level Change in a Warming Climate, Nature Geoscience, 3, 546-550, 10.1038/ngeo901.
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URL: https://doi.org/10.1038/ngeo901
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Jiang, Q., Wang, S., and O'Neill, L.W. (2010). Some Insights into the Characteristics and Dynamics of the Chilean Low-Level Coastal Jet, Monthly Weather Review, 138(8), 3185-3206, 10.1175/2010MWR3368.1. Journal Article »
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Title: Some Insights into the Characteristics and Dynamics of the Chilean Low-Level Coastal Jet
Type: Journal Article
Publication: Monthly Weather Review
Author(s): Jiang, Q., Wang, S., and O'Neill, L.W.
Year: 2010
Formatted Citation: Jiang, Q., Wang, S., and O'Neill, L.W. , 2010: Some Insights into the Characteristics and Dynamics of the Chilean Low-Level Coastal Jet, Monthly Weather Review, 138(8), 3185-3206, 10.1175/2010MWR3368.1.
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URL: https://doi.org/10.1175/2010MWR3368.1
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Kelly, K.A., Small, R.J., Samelson, R. M., Qiu, B., Joyce, T., Cronin, M., and Kwon, Y.-O. (2010). Western Boundary Currents and Frontal Air-Sea Interaction: Gulf Stream and Kuroshio Extension, Journal of Climate, 23(21), 5644-5667, 10.1175/2010JCLI3346.1. Journal Article »
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Title: Western Boundary Currents and Frontal Air-Sea Interaction: Gulf Stream and Kuroshio Extension
Type: Journal Article
Publication: Journal of Climate
Author(s): Kelly, K.A., Small, R.J., Samelson, R. M., Qiu, B., Joyce, T., Cronin, M., and Kwon, Y.-O.
Year: 2010
Formatted Citation: Kelly, K.A., Small, R.J., Samelson, R. M., Qiu, B., Joyce, T., Cronin, M., and Kwon, Y.-O., 2010: Western Boundary Currents and Frontal Air-Sea Interaction: Gulf Stream and Kuroshio Extension, Journal of Climate, 23(21), 5644-5667, 10.1175/2010JCLI3346.1.
Abstract: In the northern hemisphere mid-latitude western boundary current (WBC) systems there is a complex interaction between dynamics and thermodynamics and between atmosphere and ocean. Their potential contribution to the climate system motivated major parallel field programs in both the North Pacific (KESS) and the North Atlantic (CLIMODE) and preliminary observations and analyses from these programs highlight that complexity. The Gulf Stream (GS) in the North Atlantic and the Kuroshio Extension (KE) in the North Pacific have broad similarities, as subtropical gyre WBCs, but also significant differences, which affect the regional air-sea exchange processes and their larger-scale interactions. The 15-yr satellite altimeter data record, which provides a rich source of information, is combined here with the longer historical record from in situ data to describe and compare the current systems. While many important similarities have been noted on the dynamic and thermodynamic aspects of the time-varying GS and KE, some not-so-subtle differences exist in current variability, mode water properties, and recirculation gyre structure. This paper provides a comprehensive comparison of these two current systems from both dynamical and thermodynamical perspectives with the goal of developing and evaluating hypotheses about the physics underlying the observed differences, and exploring the WBC`s potential to influence midlatitude sea-air interaction. Differences between the GS and KE systems offer opportunities to compare the dominant processes and thereby to advance understanding of their role in the climate system.
Keywords: Boundary currents, Air-sea interaction, Climate variability, Satellite observations, North Pacific Ocean
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URL: https://doi.org/10.1175/2010JCLI3346.1
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Kwon, Y.-O., Alexander, M.A., Bond, N.A., Frankignoul, C., Nakamura, H., Qiu, B., and Thompson, L. (2010). Role of Gulf Stream and Kuroshio-Oyashio Systems in Large-Scale Atmosphere-Ocean Interaction: A Review, Journal of Climate, 23(12), 3249-3281, 10.1175/2010JCLI3343.1. Journal Article »
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Title: Role of Gulf Stream and Kuroshio-Oyashio Systems in Large-Scale Atmosphere-Ocean Interaction: A Review
Type: Journal Article
Publication: Journal of Climate
Author(s): Kwon, Y.-O., Alexander, M.A., Bond, N.A., Frankignoul, C., Nakamura, H., Qiu, B., and Thompson, L.
Year: 2010
Formatted Citation: Kwon, Y.-O., Alexander, M.A., Bond, N.A., Frankignoul, C., Nakamura, H., Qiu, B., and Thompson, L., 2010: Role of Gulf Stream and Kuroshio-Oyashio Systems in Large-Scale Atmosphere-Ocean Interaction: A Review, Journal of Climate, 23(12), 3249-3281, 10.1175/2010JCLI3343.1.
Abstract: Ocean-atmosphere interaction over the Northern Hemisphere western boundary current (WBC) regions, i.e. the Gulf Stream, Kuroshio, Oyashio, and their extensions, is reviewed with an emphasis on their role in basin-scale climate variability. SST anomalies exhibit considerable variance on interannual to decadal time scales in these regions. Low-frequency SST variability is primarily driven by basin-scale wind stress curl variability via oceanic Rossby wave adjustment of the gyre scale circulation that modulates the latitude and strength of the WBC-related oceanic fronts. Rectification of the variability by meso-scale eddies, reemergence of the anomalies from the preceding winter, and tropical remote forcing also play important roles in driving and maintaining the low-frequency variability in these regions. In the Gulf Stream region, interaction with the deep western boundary current also likely influences the low-frequency variability. Surface heat fluxes damp the low-frequency SST anomalies over the WBC regions, thus heat fluxes originate with heat anomalies in the ocean and have the potential to drive the overlying atmospheric circulation. While recent observational studies demonstrate a local atmospheric boundary layer response to WBC changes, the latter`s influence on the large-scale atmospheric circulation is still unclear. Nevertheless, heat and moisture fluxes from the WBCs into the atmosphere influence the mean state of the atmospheric circulation, including anchoring of the latitude of the storm tracks to the WBCs. Furthermore, many climate models suggest that the large-scale atmospheric response to SST anomalies driven by ocean dynamics in WBC regions can be important in generating decadal climate variability. As a step towards bridging climate model results and observations, the degree of realism of the WBC in current climate model simulations is assessed. Finally, outstanding issues concerning ocean-atmosphere interaction in WBC regions and its impact on climate variability are discussed.
Keywords: Currents, Sea surface temperature, Anomalies, Large-scale motions, Oceanic mixed layer, Northern Hemisphere
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URL: https://doi.org/10.1175/2010JCLI3343.1
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Laupattarakasem, P., Jones, W.L., Hennon, C.C., Allard, J.R., Harless, A.R., and Black, P.G. (2010). Improved Hurricane Ocean Vector Winds using SeaWinds Active/Passive Retrievals, IEEE Transactions on Geoscience and Remote Sensing, 48(7), 2909-2923, 10.1109/TGRS.2010.2043110. Journal Article »
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Title: Improved Hurricane Ocean Vector Winds using SeaWinds Active/Passive Retrievals
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Laupattarakasem, P., Jones, W.L., Hennon, C.C., Allard, J.R., Harless, A.R., and Black, P.G.
Year: 2010
Formatted Citation: Laupattarakasem, P., Jones, W.L., Hennon, C.C., Allard, J.R., Harless, A.R., and Black, P.G., 2010: Improved Hurricane Ocean Vector Winds using SeaWinds Active/Passive Retrievals, IEEE Transactions on Geoscience and Remote Sensing, 48(7), 2909-2923, 10.1109/TGRS.2010.2043110.
Abstract: The SeaWinds scatterometer, onboard the QuikSCAT satellite, infers global ocean vector winds (OVWs), however, for a number of reasons, these measurements in hurricanes are significantly degraded. This paper presents an improved hurricane OVW retrieval approach, known as Q-Winds, which is derived from combined SeaWinds active and passive measurements. In this technique, the effects of rain are implicitly included in a new geophysical model function, which relates oceanic brightness temperature and radar backscatter measurements (at the top of the atmosphere) to the surface wind vector under both clear sky and in the presence of light to moderate rain. This approach extends the useful wind speed measurement range for tropical cyclones beyond that exhibited by the standard SeaWinds Project Level-2B (L2B) 12.5-km wind vector algorithm. A description of the Q-Winds algorithm is given, and examples of OVW retrievals are presented for the Q-Winds and L2B 12.5-km algorithms for ten hurricane overpasses in 2003-2008. These data are also compared to independent surface wind vector estimates from the National Oceanic and Atmospheric Administration Hurricane Research Division`s objective hurricane surface wind analysis technique known as H*Wind. These comparisons suggest that the Q-Winds OVW product agrees better with independently derived H^ Wind analysis winds than does the conventional L2B OVW product.
Keywords: ocean temperature , oceanographic techniques , rain , remote sensing by radar , storms , wind, AD 2003 to 2008 , Q-Winds algorithm , QuikSCAT satellite , SeaWinds Project Level-2B wind vector algorithm , SeaWinds active-passive retrievals , SeaWinds scatt
Mission: |SeaWinds|
URL: https://doi.org/10.1109/TGRS.2010.2043110
Other URLs:
Lee, T. and McPhaden, M. (2010). Increasing Intensity of El Niño in the Central-Equatorial Pacific, Geophysical Research Letters, 37(14), L14603, 10.1029/2010GL044007. Journal Article »
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Title: Increasing Intensity of El Niño in the Central-Equatorial Pacific
Type: Journal Article
Publication: Geophysical Research Letters
Author(s): Lee, T. and McPhaden, M.
Year: 2010
Formatted Citation: Lee, T. and McPhaden, M., 2010: Increasing Intensity of El Niño in the Central-Equatorial Pacific, Geophysical Research Letters, 37(14), L14603, 10.1029/2010GL044007.
Abstract: Satellite observations suggest that the intensity of El Niño events in the central equatorial Pacific (CP) has almost doubled in the past three decades, with the strongest warming occurring in 2009-10. This is related to the increasing intensity as well as occurrence frequency of the so-called CP El Niño events since the 1990s. While sea surface temperature (SST) in the CP region during El Niño years has been increasing, those during neutral and La Niña years have not. Therefore, the well-documented warming trend of the warm pool in the CP region is primarily a result of more intense El Niño events rather than a general rise of background SST.
Keywords: El Niño * Oceanography: Physical: ENSO * Oceanography: General: Equatorial oceanography * Global Change: Climate variability
Mission:
URL: https://doi.org/10.1029/2010GL044007
Other URLs:
Lee, T., Awaji, T., Balmaseda, M., Ferry, N.,Fujii, Y., Fukumori, I., Giese, B., Heimbach, P., Köhl, A., Masina, S., Remy, E., Rosati, A., Schodlok, M., Stammer, D., and Weaver, A. (2010). Consistency and Fidelity of Indonesian-Throughflow Total Volume Transport Estimated by 14 Ocean Data Assimilation Products, Dynamics of Atmospheres and Oceans, 50(2), 201-223, 10.1016/j.dynatmoce.2009.12.004. Journal Article »
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Title: Consistency and Fidelity of Indonesian-Throughflow Total Volume Transport Estimated by 14 Ocean Data Assimilation Products
Type: Journal Article
Publication: Dynamics of Atmospheres and Oceans
Author(s): Lee, T., Awaji, T., Balmaseda, M., Ferry, N.,Fujii, Y., Fukumori, I., Giese, B., Heimbach, P., Köhl, A., Masina, S., Remy, E., Rosati, A., Schodlok, M., Stammer, D., and Weaver, A.
Year: 2010
Formatted Citation: Lee, T., Awaji, T., Balmaseda, M., Ferry, N.,Fujii, Y., Fukumori, I., Giese, B., Heimbach, P., Köhl, A., Masina, S., Remy, E., Rosati, A., Schodlok, M., Stammer, D., and Weaver, A., 2010: Consistency and Fidelity of Indonesian-Throughflow Total Volume Transport Estimated by 14 Ocean Data Assimilation Products, Dynamics of Atmospheres and Oceans, 50(2), 201-223, 10.1016/j.dynatmoce.2009.12.004.
Abstract: Monthly averaged total volume transport of the Indonesian throughflow (ITF) estimated by 14 global ocean data assimilation (ODA) products that are decade to multi-decade long are compared among themselves and with observations from the INSTANT Program (2004-2006). The main goals of the comparisons are to examine the consistency and evaluate the skill of different ODA products in simulating ITF transport. The ensemble averaged, time-mean value of ODA estimates is 13.6 Sv (1 Sv = 10⁶m³/s) for the common 1993-2001 period and 13.9 Sv for the 2004-2006 INSTANT Program period. These values are close to the 15-Sv estimate derived from INSTANT observations. All but one ODA time-mean estimate fall within the range of uncertainty of the INSTANT estimate. In terms of temporal variability, the scatter among different ODA estimates averaged over time is 1.7 Sv, which is substantially smaller than the magnitude of the temporal variability simulated by the ODA systems. Therefore, the overall "signal-to-noise" ratio for the ensemble estimates is larger than one. The best consistency among the products occurs on seasonal-to-interannual time scales, with generally stronger (weaker) ITF during boreal summer (winter) and during La Nina (El Nino) events. The scatter among different products for seasonal-to-interannual time scales is approximately 1 Sv. Despite the good consistency, systematic difference is found between most ODA products and the INSTANT observations. All but the highest-resolution (18 km) ODA product show a dominant annual cycle while the INSTANT estimate and the 18-km product exhibit a strong semi-annual signal. The coarse resolution is an important factor that limits the level of agreement between ODA and INSTANT estimates. Decadal signals with periods of 10-15 years are seen. The most conspicuous and consistent decadal change is a relatively sharp increase in ITF transport during 1993-2000 associated with the strengthening tropical Pacific trade wind. Most products do not show a weakening ITF after the mid-1970s' associated with the weakened Pacific trade wind. The scatter of ODA estimates is smaller after than before 1980, reflecting the impact of the enhanced observations after the 1980s. To assess the representativeness of using the average over a three-year period (e.g., the span of the INSTANT Program) to describe longer-term mean, we investigate the temporal variations of the three-year low-pass ODA estimates. The average variation is about 3.6 Sv, which is largely due to the increase of ITF transport from 1993 to 2000. However, the three-year average during the 2004-2006 INSTANT Program period is within 0.5 Sv of the long-term mean for the past few decades.
Keywords: Indonesian throughflow, Ocean data assimilation
Mission:
URL: https://doi.org/10.1016/j.dynatmoce.2009.12.004
Other URLs:
Lee, T., Hobbs, W., Willis, J., Halkides, D., Fukumori, I., Armstrong, E.M., Hayashi, A.K., Liu, W.T., Patzert, W., and Want, O. (2010). Record Warming in the South Pacific and Western Antarctica Associated with the Strong Central-Pacific El Niño in 2009-10, Geophysical Research Letters, 37, L19704, 10.1029/2010GL044865. Journal Article »
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Title: Record Warming in the South Pacific and Western Antarctica Associated with the Strong Central-Pacific El Niño in 2009-10
Type: Journal Article
Publication: Geophysical Research Letters
Author(s): Lee, T., Hobbs, W., Willis, J., Halkides, D., Fukumori, I., Armstrong, E.M., Hayashi, A.K., Liu, W.T., Patzert, W., and Want, O.
Year: 2010
Formatted Citation: Lee, T., Hobbs, W., Willis, J., Halkides, D., Fukumori, I., Armstrong, E.M., Hayashi, A.K., Liu, W.T., Patzert, W., and Want, O., 2010: Record Warming in the South Pacific and Western Antarctica Associated with the Strong Central-Pacific El Niño in 2009-10, Geophysical Research Letters, 37, L19704, 10.1029/2010GL044865.
Abstract: Satellite data for the past three decades reveal a record-high sea surface temperature (SST) anomaly within a large mid-latitude region of the south-central Pacific (SCP) during the mature phase of the 2009-10 El Niño, with a peak magnitude that is 5 times the standard deviation of local SST anomaly and is warmer than the concurrent tropical-Pacific SST anomaly. The SCP oceanic warming was confined to the upper 50 meters and is associated with an extreme and persistent anticyclone. Wind changes associated with the anticyclone caused the oceanic warming with surface heat flux and ocean processes playing equally important roles. The anticyclone diverted circumpolar westerlies and warm air towards Antarctica. Austral-summer SST in the Bellingshausen Sea also reached a three-decade high. The extreme atmospheric and oceanic anomalies in the South Pacific may have been fueled by the 2009-10 El Niño because of its record-high SST anomaly in the central-equatorial Pacific.
Keywords: * South Pacific * Antarctica * El Nino * Global Change: Climate variability * Oceanography: Physical: ENSO
Mission:
URL: https://doi.org/10.1029/2010GL044865
Other URLs:
Lee, T., Qiu, B., Hakkinen, S., Kelly, K., Qiu, B., Bonekamp, H., and Lindstrom, E.J. (2010). Satellite Observations of Ocean Circulation Changes Associated with Climate Variability, Oceanography, 23(4), 70-81, 10.5670/oceanog.2010.06. Journal Article »
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Title: Satellite Observations of Ocean Circulation Changes Associated with Climate Variability
Type: Journal Article
Publication: Oceanography
Author(s): Lee, T., Qiu, B., Hakkinen, S., Kelly, K., Qiu, B., Bonekamp, H., and Lindstrom, E.J.
Year: 2010
Formatted Citation: Lee, T., Qiu, B., Hakkinen, S., Kelly, K., Qiu, B., Bonekamp, H., and Lindstrom, E.J., 2010: Satellite Observations of Ocean Circulation Changes Associated with Climate Variability, Oceanography, 23(4), 70-81, 10.5670/oceanog.2010.06.
Abstract: Decades of satellite observations have greatly improved our understanding of large-scale ocean circulation changes associated with climate variability, related air-sea interaction, and interbasin linkages. The continuation and enhancement (e.g., increased spatial resolution and frequency) of these satellite measurements and observations of additional parameters (e.g., sea surface salinity) in the coming decades are critical to further advancing our ability to monitor and understand decadal and longer variations in ocean circulation and determining the extent to which these changes result from natural climate variability or anthropogenic inputs.
Keywords: ocean circulation , climate variability , satellite oceanography
Mission:
URL: https://doi.org/10.5670/oceanog.2010.06
Other URLs:
Levy, G. and Patoux, J. (2010). Indian Ocean Near-Equatorial Symmetric Stability from Satellite Observations: An Illusive Connection to Atmospheric Convection, International Journal of Remote Sensing, 31(17-18), 4665-4681, 10.1080/01431161.2010.485153. Journal Article »
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Title: Indian Ocean Near-Equatorial Symmetric Stability from Satellite Observations: An Illusive Connection to Atmospheric Convection
Type: Journal Article
Publication: International Journal of Remote Sensing
Author(s): Levy, G. and Patoux, J.
Year: 2010
Formatted Citation: Levy, G. and Patoux, J., 2010: Indian Ocean Near-Equatorial Symmetric Stability from Satellite Observations: An Illusive Connection to Atmospheric Convection, International Journal of Remote Sensing, 31(17-18), 4665-4681, 10.1080/01431161.2010.485153.
Abstract: The north-south symmetry of the low level near-equatorial atmospheric flow is examined in relation to the position of the Intertropical Convergence Zone (ITCZ) over the Indian Ocean with the aid of satellite and reanalysis data. Absolute vorticity (AV) and convergence fields on temporal scales of 10 days are derived from 7 years of Quick Scatterometer (QuikSCAT) observations and related statistically to organized convection deduced from outgoing longwave radiation (OLR) measured by the National Oceanic and Atmospheric Administration (NOAA) polar-orbiting satellites. The AV observations reveal a belt of symmetric instability on the summer side of the equator. The evolution of this symmetric instability with respect to the cross-equatorial flow (CEF), the location of the ITCZ, and monsoonal forcing is investigated. We identify three distinct dominant convective regimes. We show that during the active Indian monsoon season, symmetric instability and the displacement of the zero-AV line off the equator are directly linked to organized convection and the off-equatorial location of the ITCZ. The advective (inertial) regime interacts with and is controlled by monsoon and CEF. In periods of transition between summer and winter monsoon, the lower atmosphere is symmetrically stable and two other convective regimes can be identified: a double ITCZ, and localized convection near the equator.
Keywords:
Mission: |SeaWinds|
URL: https://doi.org/10.1080/01431161.2010.485153
Other URLs:
Lindsley, R.D. and Long, D.G. (2010). Adapting the SIR Algorithm to ASCAT, 2010 IEEE International Geoscience and Remote Sensing Symposium, 3402-3405, 10.1109/IGARSS.2010.5650207. Conference Paper »
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Title: Adapting the SIR Algorithm to ASCAT
Type: Conference Paper
Publication: 2010 IEEE International Geoscience and Remote Sensing Symposium
Author(s): Lindsley, R.D. and Long, D.G.
Year: 2010
Formatted Citation: Lindsley, R.D. and Long, D.G., 2010: Adapting the SIR Algorithm to ASCAT, 2010 IEEE International Geoscience and Remote Sensing Symposium, 3402-3405, 10.1109/IGARSS.2010.5650207.
Abstract:
Keywords:
Mission: |ASCAT|
URL: https://doi.org/10.1109/IGARSS.2010.5650207
Other URLs:
Lindstrom, E.J., Bourassa, M.A., Breivik, L.-A., Donlon, C.J., Fu, L.-L., Hacker, P., Lagerloef, G., Lee, T., Le Quere, C., Swail, V., Wilson, W.S., and Zlotnicki, V. (2010). Research Satellite Missions, OceanObs`09: Sustained Ocean Observations and Information for Society Conference (Vol. 1), ESA Publication WPP-306, 10.5270/OceanObs09.pp.19. Conference Paper »
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Title: Research Satellite Missions
Type: Conference Paper
Publication: OceanObs`09: Sustained Ocean Observations and Information for Society Conference (Vol. 1)
Author(s): Lindstrom, E.J., Bourassa, M.A., Breivik, L.-A., Donlon, C.J., Fu, L.-L., Hacker, P., Lagerloef, G., Lee, T., Le Quere, C., Swail, V., Wilson, W.S., and Zlotnicki, V.
Year: 2010
Formatted Citation: Lindstrom, E.J., Bourassa, M.A., Breivik, L.-A., Donlon, C.J., Fu, L.-L., Hacker, P., Lagerloef, G., Lee, T., Le Quere, C., Swail, V., Wilson, W.S., and Zlotnicki, V., 2010: Research Satellite Missions, OceanObs`09: Sustained Ocean Observations and Information for Society Conference (Vol. 1), ESA Publication WPP-306, 10.5270/OceanObs09.pp.19.
Abstract: Satellites view the surface of the world oceans in days to weeks, and can repeat such measurements for many years. Among the Essential Climate Variables (ECVs), those that can be measured from space are sea surface temperature, height, vector winds, colour, as well as sea state and sea ice. In addition, there are emerging ECVs: ocean mass and sea surface salinity. Our recommendations can be summarized as follows ? Sea Surface Temperature. Continue the high resolution infrared record, and the all-weather microwave record. Research: obtain better blended products with improved, well characterized accuracy. ? Sea Surface Height. Continue the climate record of the Jason-series, and the operational use of the high inclination altimeters. Make these sustained, systematic observations useful for both applications and research. Use CryoSat for improved resolution, and approve the Surface Water Ocean Topography (SWOT) mission for launch no later than 2016. Research: improve the accuracy for climate record. ? Ocean Vector Winds. Continue the observations obtained by the European Space Agency`s Advanced Scatterometer (ASCAT). Replace QuikSCAT as soon as possible. Develop sustained, systematic observations to follow on QuikSCAT. Research: a constellation, with improved spatial resolution and sensitivity, and creation of a true climate record from the set of diverse scatterometers.. ? Ocean Colour. Continue the data record, fly climatequality, well calibrated instruments. Research: improved analyses enabled by sensitive, wellcharacterized instruments. Derive new parameters, for example distinguish between plankton species, using existing and planned instruments with increased spectral band coverage, such the European Medium Resolution Imaging Spectrometer (MERIS) and the planned US Hyperspectral Infrared Imager (HyspIRI). ? Sea State. Improve coverage. Derive new quantities. Continue the data record for both altimeter and SAR derived sea state quantities. Create a real climate record for wave products. ? Sea Ice. Continue the climate record of sea ice coverage. Research: improved resolution. Add sea ice thickness and dynamics. For all of the above, the concept of constellations must be followed: voluntary coordination of the observing systems from different countries to improve accuracy, resolution and overall coverage for any one parameter. Inherent in this concept is the need to cross-calibrate the various observing systems and remove any systematic differences in order to yield true climate records. ? Sea Surface Salinity. An emerging ECV. Research: use the Soil Moisture and Ocean Salinity (SMOS) mission, launched in November 2009, and the future Aquarius/SAC-D mission to begin a climate record. ? Ocean Mass and Geoid. An emerging ECV. Continue to improve the accuracy of the first 7 years of this climate record of total ocean mass, and time changes of ocean bottom pressure from the Gravity Recovery and Climate Experiment (GRACE) mission. Ensure continuity of this new measurement. Improve the time-averaged geoid using GOCE, aided by GRACE, CHAMP, and historical laser-tracked geodetic satellites. The previous decade saw these ECVs be used primarily on their own. We fully expect interdisciplinary use of two or more ECVs to become the norm in the next decade.
Keywords:
Mission: |SeaWinds|ASCAT|
URL: https://abstracts.congrex.com/scripts/jmevent/abstracts/FCXNL-09A02b-1927837-1-LINDSTROM-Oceanobs09-Research_Satellites-CAMERA-READY-o.pdf
Other URLs:
Liu, W.T., Tang, W., and Xie, X. (2010). Wind Power at Sea as Observed from Space, Wind Power, Chapter 14, 341-352, 10.5772/8344. Journal Article »
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Title: Wind Power at Sea as Observed from Space
Type: Journal Article
Publication: Wind Power
Author(s): Liu, W.T., Tang, W., and Xie, X.
Year: 2010
Formatted Citation: Liu, W.T., Tang, W., and Xie, X., 2010: Wind Power at Sea as Observed from Space, Wind Power, Chapter 14, 341-352, 10.5772/8344.
Abstract:
Keywords:
Mission:
URL: https://doi.org/10.5772/8344
Other URLs:
Liu, W.T., Xie, X., and Tang, W. (2010). Scatterometer's Unique Capability in Measuring Ocean Surface Stress, Oceanography from Space, Barale, Gower, and Alberotanza (eds), Chapter 6, Springer, 93-111, 10.1007/978-90-481-8681-5_6. Book Chapter »
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Title: Scatterometer's Unique Capability in Measuring Ocean Surface Stress
Type: Book Chapter
Publication: Oceanography from Space, Barale, Gower, and Alberotanza (eds)
Author(s): Liu, W.T., Xie, X., and Tang, W.
Year: 2010
Formatted Citation: Liu, W.T., Xie, X., and Tang, W., 2010: Scatterometer's Unique Capability in Measuring Ocean Surface Stress, Oceanography from Space, Barale, Gower, and Alberotanza (eds), Chapter 6, Springer, 93-111, 10.1007/978-90-481-8681-5_6.
Abstract:
Keywords:
Mission:
URL: https://doi.org/10.1007/978-90-481-8681-5_6
Other URLs:
Minobe, S., Kuwano-Yoshida, A., Miyashita, M., Tokinaga, H., and Xie, S.-P. (2010). Atmospheric Response to the Gulf Stream: Seasonal Variations, Journal of Climate, 23(13), 3699-3719, 10.1175/2010JCLI3359.1. Journal Article »
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Title: Atmospheric Response to the Gulf Stream: Seasonal Variations
Type: Journal Article
Publication: Journal of Climate
Author(s): Minobe, S., Kuwano-Yoshida, A., Miyashita, M., Tokinaga, H., and Xie, S.-P.
Year: 2010
Formatted Citation: Minobe, S., Kuwano-Yoshida, A., Miyashita, M., Tokinaga, H., and Xie, S.-P., 2010: Atmospheric Response to the Gulf Stream: Seasonal Variations, Journal of Climate, 23(13), 3699-3719, 10.1175/2010JCLI3359.1.
Abstract: The atmospheric response to the Gulf Stream front in sea surface temperature is investigated using high-resolution data from satellite observations and operational analysis and forecast. Two types of atmospheric response are observed with different seasonality and spatial distribution. In winter, surface wind convergence is strong over the Gulf Stream proper between Cape Hatteras and the Great Banks, consistent with atmospheric pressure adjustments to sea surface temperature gradients. The surface convergence is accompanied by enhanced precipitation and the frequent occurrence of midlevel clouds. Local evaporation and precipitation are roughly in balance over the Florida Current and the western Gulf Stream proper. In summer, strong precipitation, enhanced high clouds, and increased lightning flash rate are observed over the Florida Current and the western Gulf Stream proper, without seasonal surface convergence enhancement. For the precipitation maximum over the Florida Current, local evaporation supplies about half of the water vapor, and additional moisture is transported from the south on the west flank of the North Atlantic subtropical high. Atmospheric heating estimated by a Japanese reanalysis reveals distinct seasonal variations. In winter, a shallow-heating mode dominates the Gulf Stream proper, with strong sensible heating in the marine atmospheric boundary layer and latent heating in the lower troposphere. In summer, a deep-heating mode is pronounced over the Florida Current and the western Gulf Stream proper, characterized by latent heating in the middle and upper troposphere due to deep convection. Possible occurrences of these heating modes in other regions are discussed.
Keywords: Atlantic Ocean, Boundary currents, Currents, Seasonal variability, Atmosphere-ocean interaction, Heating
Mission:
URL: https://doi.org/10.1175/2010JCLI3359.1
Other URLs:
O'Neill, L.W., Esbensen, S.K., Thum, N., Samelson, R.M., and Chelton, D.B. (2010). Dynamical Analysis of the Boundary Layer and Surface Wind Responses to Mesoscale SST Perturbations, Journal of Climate, 23(3), 559-581, 10.1175/2009JCLI2662.1. Journal Article »
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Title: Dynamical Analysis of the Boundary Layer and Surface Wind Responses to Mesoscale SST Perturbations
Type: Journal Article
Publication: Journal of Climate
Author(s): O'Neill, L.W., Esbensen, S.K., Thum, N., Samelson, R.M., and Chelton, D.B.
Year: 2010
Formatted Citation: O'Neill, L.W., Esbensen, S.K., Thum, N., Samelson, R.M., and Chelton, D.B., 2010: Dynamical Analysis of the Boundary Layer and Surface Wind Responses to Mesoscale SST Perturbations, Journal of Climate, 23(3), 559-581, 10.1175/2009JCLI2662.1.
Abstract: The dynamical response of the marine atmospheric boundary layer (MABL) to mesoscale sea surface temperature (SST) perturbations is investigated over the Agulhas Return Current during winter from a 1-month, high-resolution, three-dimensional simulation using the Weather Research and Forecasting (WRF) mesoscale model. A steady lower boundary condition for July 2002 is obtained using SST measurements from the Advanced Microwave Scanning Radiometer on the Earth Observing System (EOS)–Aqua satellite (AMSR-E). The WRF models’ ability to accurately simulate the SST-induced surface wind response is demonstrated from a comparison with satellite surface wind observations from the SeaWinds scatterometer on the Quick Scatterometer (QuikSCAT) satellite. Relevant features of this simulation include a quasi-periodic distribution of mesoscale SST perturbations with spatial scales 200 km and strong winds that lead to a large surface sensible heat flux response, whose broad range of 80–100 W m?2 between warm and cool SST perturbations is much larger than seen in most previous simulations of mesoscale wind–SST coupling. This simulation provides the first realistic example of vertical turbulent redistribution of momentum driven by the SST-induced surface heating perturbations acting in concert with the SST-induced pressure gradients to accelerate near-surface flow toward warm water and decelerate near-surface flow toward cool water. This simulation is also the first example of a near-surface wind speed response to mesoscale SST perturbations that differs qualitatively and substantially from the vertically averaged MABL wind response. In the vertically averaged MABL momentum budget, the surface wind stress acts as a drag on the SST-induced perturbation flow as it is being accelerated by SST-induced pressure gradients. However, only in the middle and upper reaches of the MABL does the turbulent stress divergence act as a drag on the SST-induced winds perturbations in this simulation. These mesoscale SST perturbations are also shown to modify the wind direction within the MABL. Dynamically, this is accomplished through SST-induced perturbations to the crosswind components of the pressure gradient, turbulent stress divergence, and the Coriolis force.
Keywords: Boundary layer, Wind, Sea surface temperature, Mesoscale models, Marine boundary layer
Mission: |SeaWinds|
URL: https://doi.org/10.1175/2009JCLI2662.1
Other URLs:
Owen, M. and Long, D.G. (2010). Towards Baysian Estimator Selection for QuikSCAT Wind and Rain Estimation, 2010 IEEE International Geoscience and Remote Sensing Symposium, 1331-1334, 10.1109/IGARSS.2010.5650889. Conference Paper »
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Title: Towards Baysian Estimator Selection for QuikSCAT Wind and Rain Estimation
Type: Conference Paper
Publication: 2010 IEEE International Geoscience and Remote Sensing Symposium
Author(s): Owen, M. and Long, D.G.
Year: 2010
Formatted Citation: Owen, M. and Long, D.G., 2010: Towards Baysian Estimator Selection for QuikSCAT Wind and Rain Estimation, 2010 IEEE International Geoscience and Remote Sensing Symposium, 1331-1334, 10.1109/IGARSS.2010.5650889.
Abstract:
Keywords:
Mission:
URL: https://doi.org/10.1109/IGARSS.2010.5650889
Other URLs:
Owen, M. and Long, D.G. (2010). Towards an Improved Wind and Rain Backscatter Model for ASCAT, 2010 IEEE International Geoscience and Remote Sensing Symposium, 2531-2534, 10.1109/IGARSS.2010.5651896. Conference Paper »
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Title: Towards an Improved Wind and Rain Backscatter Model for ASCAT
Type: Conference Paper
Publication: 2010 IEEE International Geoscience and Remote Sensing Symposium
Author(s): Owen, M. and Long, D.G.
Year: 2010
Formatted Citation: Owen, M. and Long, D.G., 2010: Towards an Improved Wind and Rain Backscatter Model for ASCAT, 2010 IEEE International Geoscience and Remote Sensing Symposium, 2531-2534, 10.1109/IGARSS.2010.5651896.
Abstract: The ASCAT scatterometer measures the backscatter from the ocean surface with which it infers the near-surface wind vector. When rain is present in the observation area the windinduced backscatter is modified by the rain. This paper uses co-located observations from TRMM PR to model the effects of rain on the ASCAT observed backscatter. Two model types are considered, a phenomenological rain model and a lumped effect rain model which are comparable for most rain rates. For low rain events the ASCAT observed backscatter due to rain is not substantial, however for moderate to high rains the rain-induced backscatter from the ocean surface can be significant, and for extreme rain rates the atmospheric scattering and attenuation are dominant.
Keywords:
Mission:
URL: https://doi.org/10.1109/IGARSS.2010.5651896
Other URLs:
O`Neill, L.W., Chelton, D.B., and Esbensen, S.K. (2010). The Effects of SST-Induced Surface Wind Speed and Direction Gradients on Midlatitude Surface Vorticity and Divergence, Journal of Climate, 23(2), 255-281, 10.1175/2009JCLI2613.1. Journal Article »
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Title: The Effects of SST-Induced Surface Wind Speed and Direction Gradients on Midlatitude Surface Vorticity and Divergence
Type: Journal Article
Publication: Journal of Climate
Author(s): O`Neill, L.W., Chelton, D.B., and Esbensen, S.K.
Year: 2010
Formatted Citation: O`Neill, L.W., Chelton, D.B., and Esbensen, S.K., 2010: The Effects of SST-Induced Surface Wind Speed and Direction Gradients on Midlatitude Surface Vorticity and Divergence, Journal of Climate, 23(2), 255-281, 10.1175/2009JCLI2613.1.
Abstract: The effects of surface wind speed and direction gradients on midlatitude surface vorticity and divergence fields associated with mesoscale sea surface temperature (SST) variability having spatial scales of 100-1000 km are investigated using vector wind observations from the SeaWinds scatterometer on the Quick Scatterometer (QuikSCAT) satellite and SST from the Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E) Aqua satellite. The wind-SST coupling is analyzed over the period June 2002-August 2008, corresponding to the first 6+ years of the AMSR-E mission. Previous studies have shown that strong wind speed gradients develop in response to persistent mesoscale SST features associated with the Kuroshio Extension, Gulf Stream, South Atlantic, and Agulhas Return Current regions. Midlatitude SST fronts also significantly modify surface wind direction, the surface wind speed and direction responses to typical SST differences of about 2°-4°C are, on average, about 1-2 m s?1 and 4°-8°, respectively, over all four regions. Wind speed perturbations are positively correlated and very nearly collocated spatially with the SST perturbations. Wind direction perturbations, however, are displaced meridionally from the SST perturbations, with cyclonic flow poleward of warm SST and anticyclonic flow poleward of cool SST. Previous observational analyses have shown that small-scale perturbations in the surface vorticity and divergence fields are related linearly to the crosswind and downwind components of the SST gradient, respectively. When the vorticity and divergence fields are analyzed in curvilinear natural coordinates, the wind speed contributions to the SST-induced vorticity and divergence depend equally on the crosswind and downwind SST gradients, respectively. SST-induced wind direction gradients also significantly modify the vorticity and divergence fields, weakening the vorticity response to crosswind SST gradients while enhancing the divergence response to downwind SST gradients.
Keywords: Sea surface temperature, Surface observations, Wind stress, Vorticity, Convergence/divergence
Mission: |SeaWinds|
URL: https://doi.org/10.1175/2009JCLI2613.1
Other URLs:
Patoux, J., Foster, R.C., and Brown, R.A. (2010). A Method for Including Mesoscale and Synoptic-Scale Information in Scatterometer Wind Retrievals, Journal of Geophysical Research: Atmospheres, 115(D11), D11105, 10.1029/2009JD013193. Journal Article »
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Title: A Method for Including Mesoscale and Synoptic-Scale Information in Scatterometer Wind Retrievals
Type: Journal Article
Publication: Journal of Geophysical Research: Atmospheres
Author(s): Patoux, J., Foster, R.C., and Brown, R.A.
Year: 2010
Formatted Citation: Patoux, J., Foster, R.C., and Brown, R.A., 2010: A Method for Including Mesoscale and Synoptic-Scale Information in Scatterometer Wind Retrievals, Journal of Geophysical Research: Atmospheres, 115(D11), D11105, 10.1029/2009JD013193.
Abstract: A method for improving scatterometer wind retrievals based on the mesoscale and synoptic-scale structure of the flow field is presented and evaluated. The large-scale structure of the flow is inferred from the sea-level pressure (SLP) field derived from the scatterometer winds using a planetary boundary layer model. The wind vectors derived from this SLP field can be used to either (1) inform the ambiguity selection, (2) correct the direction of the scatterometer wind vectors, in all cases or above a certain threshold, or (3) replace the scatterometer winds. The methodology is demonstrated with QuikSCAT (QS) scatterometer wind vectors. The new wind vector set is evaluated statistically by comparison with buoy measurements, with numerical weather prediction model analyses, and by spectral analysis. It is found that the new wind vectors are particularly valuable at nadir and in rain-contaminated areas, and that their spectral behavior is closer to a power law than are the uncorrected QS winds.
Keywords: * scatterometer wind retrieval * sea-level pressure * planetary boundary layer * Atmospheric Processes: Remote sensing * Atmospheric Processes: Boundary layer processes * Atmospheric Processes: Ocean/atmosphere interactions * A
Mission: |SeaWinds|
URL: https://doi.org/10.1029/2009JD013193
Other URLs:
Rienecker, M.M., Awaji, T., Balmaseda, M., Barnier, B., Behringer, D., Bell, M., Bourassa, M., Brasseur, P., Carton, J., Cummings, J., Breivik, L.-A., Dombrowsky, E., Fairall, C., Ferry, N., Forget, G., Freeland, H., Griffies, S.M., Haines, K., Harrison, E.E., Heimbach, P., Kamachi, M., Kent, E., Lee, T., Le Traon, P.-Y., McPhaden, M., Martin, M.J., Oke, P., Palmer, M.D., Remy, E., Rosati, T., Schiller, A., Smith, D.M., Snowden, D., Stammer, D., Trenberth, K.E., and Xue, Y. (2010). Synthesis and Assimilation Systems - Essential Adjuncts to the Global Ocean Observing System, OceanObs`09: Sustained Ocean Observations and Information for Society Conference (Vol. 1), ESA Publication WPP-306, 10.5270/OceanObs09.pp.31. Conference Paper »
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Title: Synthesis and Assimilation Systems - Essential Adjuncts to the Global Ocean Observing System
Type: Conference Paper
Publication: OceanObs`09: Sustained Ocean Observations and Information for Society Conference (Vol. 1)
Author(s): Rienecker, M.M., Awaji, T., Balmaseda, M., Barnier, B., Behringer, D., Bell, M., Bourassa, M., Brasseur, P., Carton, J., Cummings, J., Breivik, L.-A., Dombrowsky, E., Fairall, C., Ferry, N., Forget, G., Freeland, H., Griffies, S.M., Haines, K., Harrison, E.E., Heimbach, P., Kamachi, M., Kent, E., Lee, T., Le Traon, P.-Y., McPhaden, M., Martin, M.J., Oke, P., Palmer, M.D., Remy, E., Rosati, T., Schiller, A., Smith, D.M., Snowden, D., Stammer, D., Trenberth, K.E., and Xue, Y.
Year: 2010
Formatted Citation: Rienecker, M.M., Awaji, T., Balmaseda, M., Barnier, B., Behringer, D., Bell, M., Bourassa, M., Brasseur, P., Carton, J., Cummings, J., Breivik, L.-A., Dombrowsky, E., Fairall, C., Ferry, N., Forget, G., Freeland, H., Griffies, S.M., Haines, K., Harrison, E.E., Heimbach, P., Kamachi, M., Kent, E., Lee, T., Le Traon, P.-Y., McPhaden, M., Martin, M.J., Oke, P., Palmer, M.D., Remy, E., Rosati, T., Schiller, A., Smith, D.M., Snowden, D., Stammer, D., Trenberth, K.E., and Xue, Y., 2010: Synthesis and Assimilation Systems - Essential Adjuncts to the Global Ocean Observing System, OceanObs`09: Sustained Ocean Observations and Information for Society Conference (Vol. 1), ESA Publication WPP-306, 10.5270/OceanObs09.pp.31.
Abstract: Ocean assimilation systems synthesize diverse in situ and satellite data streams into four-dimensional state estimates by combining the various observations with the model. Assimilation is particularly important for the ocean where subsurface observations, even today, are sparse and intermittent compared with the scales needed to represent ocean variability and where satellites only sense the surface. Developments in assimilation and in the observing system have advanced our understanding and prediction of ocean variations at mesoscale and climate scales. Use of these systems for assessing the observing system helps identify the strengths of each observation type. Results indicate that the ocean remains under-sampled and that further improvements in the observing system are needed. Prospects for future advances lie in improved models and better estimates of error statistics for both models and observations. Future developments will be increasingly towards consistent analyses across components of the Earth system. However, even today ocean synthesis and assimilation systems are providing products that are useful for many applications and should be considered an integral part of the global ocean observing and information system.
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URL: https://ntrs.nasa.gov/api/citations/20100033200/downloads/20100033200.pdf
Other URLs:
Sasaki, H., Xie, S.-P., Taguchi, B., Nonaka, M., and Masumoto, Y. (2010). Seasonal Variations of the Hawaiian Lee Countercurrent Induced by the Meridional Migration of the Trade Winds, Ocean Dynamics, 60(3), 705-715, 10.1007/s10236-009-0258-6. Journal Article »
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Title: Seasonal Variations of the Hawaiian Lee Countercurrent Induced by the Meridional Migration of the Trade Winds
Type: Journal Article
Publication: Ocean Dynamics
Author(s): Sasaki, H., Xie, S.-P., Taguchi, B., Nonaka, M., and Masumoto, Y.
Year: 2010
Formatted Citation: Sasaki, H., Xie, S.-P., Taguchi, B., Nonaka, M., and Masumoto, Y., 2010: Seasonal Variations of the Hawaiian Lee Countercurrent Induced by the Meridional Migration of the Trade Winds, Ocean Dynamics, 60(3), 705-715, 10.1007/s10236-009-0258-6.
Abstract: Seasonal variations of the Hawaiian Lee Countercurrent (HLCC) are investigated using satellite observations of sea surface height and wind stress as well as eddy-resolving ocean model simulations. The HLCC is strong from summer to winter and weak in spring between the dateline and the Hawaiian Islands. In response to the seasonal migration of the northeast trade winds in the meridional direction, the wind curl dipole lee of Hawaii varies in strength, exciting westward-propagating Rossby waves. The analyses of both observations and simulations show that the propagation of Rossby waves south of the HLCC, driven by the southern pole of the wind curl dipole in the lee of the islands, contributes the most to the seasonal variations of the HLCC. Unlike the wind-driven seasonal variations, our analysis suggests that other mechanisms such as mode water intrusion or air-sea interaction may cause the interannual variations of the HLCC.
Keywords: Hawaiian Lee Countercurrent - Seasonal variations - Rossby waves - High-resolution ocean model
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URL: https://doi.org/10.1007/s10236-009-0258-6
Other URLs:
Scott, R., Bourassa, M.A., Chelton, D., Cipollini, P., Ferrari, R., Fu, L., Galperin, B., Gille, S., Huang, H., Klein, P., Maximenko, N., Morrow, R., Qiu, B., Rodriguez, E., Scott, R., Tailleux, R., and Wunsch, C. (2010). Integrating Satellite Altimetry and Key Observations: What We've Learned, and What's Possible with New Technologies, OceanObs`09: Sustained Ocean Observations and Information for Society, ESA Publication WPP-306, 10.5270/OceanObs09.cwp.76. Conference Paper »
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Title: Integrating Satellite Altimetry and Key Observations: What We've Learned, and What's Possible with New Technologies
Type: Conference Paper
Publication: OceanObs`09: Sustained Ocean Observations and Information for Society
Author(s): Scott, R., Bourassa, M.A., Chelton, D., Cipollini, P., Ferrari, R., Fu, L., Galperin, B., Gille, S., Huang, H., Klein, P., Maximenko, N., Morrow, R., Qiu, B., Rodriguez, E., Scott, R., Tailleux, R., and Wunsch, C.
Year: 2010
Formatted Citation: Scott, R., Bourassa, M.A., Chelton, D., Cipollini, P., Ferrari, R., Fu, L., Galperin, B., Gille, S., Huang, H., Klein, P., Maximenko, N., Morrow, R., Qiu, B., Rodriguez, E., Scott, R., Tailleux, R., and Wunsch, C., 2010: Integrating Satellite Altimetry and Key Observations: What We've Learned, and What's Possible with New Technologies, OceanObs`09: Sustained Ocean Observations and Information for Society, ESA Publication WPP-306, 10.5270/OceanObs09.cwp.76.
Abstract: The advent of high accuracy satellite altimetry in the 1990`s brought the first global view of ocean dynamics, which together with a global network of supporting observations brought a revolution in understanding of how the ocean works (Fu and Cazenave, 2001). At present a constellation of flying satellite missions routinely provides sea level anomaly, sea winds, sea surface temperature (SST), ocean colour, etc. with mesoscale resolution (50km to 100km, 20 to 150 days) on a near global scale. Concurrently, in situ monitoring is carried out by surface drifters, Argo floats, moorings, sea gliders as well as ship-borne CTD and XBT (to measure profiles of temperature and salinity), and ADCP (to measure current velocity profiles). This global observational system allowed observational oceanography to develop into an essentially quantitative science. This became possible because 1) the accuracy and volume of observations exceeded critical values, 2) numerous studies demonstrated good agreement between independent datasets, and critically 3) the data resolution crossed the threshold of revealing much of the mesoscale in two-dimensions, when previously it was only revealed in one-dimension along satellite ground tracks (Stammer, 1997) with wide gaps in between. Fortuitously computing power kept pace allowing basin scale numerical ocean models to cross the threshold of revealing the mesoscale around the turn of the century (Smith et al., 2000). The mesoscale is characterized by the most energetic motions and strong nonlinear interactions, issuing in a more complex range of phenomena. Below in Part I we present some highlights of this development. In Part II we describe future prospects, and Part III provides a reminder of the importance of maintaining continuity of high-quality observations. This white paper comes at a critical juncture in ocean observing. While the utility of the observing network is firmly grounded in the success of the past, and technological advances promise the possibility of substantial gains, we still lack the commitment for sustained funding of even the existing observing network. We wish to express herein our sincere concern for the future of ocean observing, and in particular the satellite altimeter and supporting observations (especially scatterometer and drifter data).
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URL: https://www.researchgate.net/publication/265179580
Other URLs:
Thompson, L. and Kwon, Y.-O. (2010). An Enhancement of a Coupled Mode of Variability in CCSM3 in the North Pacific Owing to Ocean Model Biases, Journal of Climate, 23(23), 6221–6233, 10.1175/2010JCLI3402.1. Journal Article »
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Title: An Enhancement of a Coupled Mode of Variability in CCSM3 in the North Pacific Owing to Ocean Model Biases
Type: Journal Article
Publication: Journal of Climate
Author(s): Thompson, L. and Kwon, Y.-O.
Year: 2010
Formatted Citation: Thompson, L. and Kwon, Y.-O., 2010: An Enhancement of a Coupled Mode of Variability in CCSM3 in the North Pacific Owing to Ocean Model Biases, Journal of Climate, 23(23), 6221–6233, 10.1175/2010JCLI3402.1.
Abstract:
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URL: https://doi.org/10.1175/2010JCLI3402.1
Other URLs:
Weissman, D.E., Winterbottom, H., and Bourassa, M.A. (2010). The Influence of Rainfall Upon Scatterometer Estimates for Sea Surface Stress: Applications to Boundary Layer Parameterization and Drag Coefficient Models within Tropical Cyclone Environments, OCEANS 2010, 1-7, 10.1109/OCEANS.2010.5664534. Conference Paper »
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Title: The Influence of Rainfall Upon Scatterometer Estimates for Sea Surface Stress: Applications to Boundary Layer Parameterization and Drag Coefficient Models within Tropical Cyclone Environments
Type: Conference Paper
Publication: OCEANS 2010
Author(s): Weissman, D.E., Winterbottom, H., and Bourassa, M.A.
Year: 2010
Formatted Citation: Weissman, D.E., Winterbottom, H., and Bourassa, M.A., 2010: The Influence of Rainfall Upon Scatterometer Estimates for Sea Surface Stress: Applications to Boundary Layer Parameterization and Drag Coefficient Models within Tropical Cyclone Environments, OCEANS 2010, 1-7, 10.1109/OCEANS.2010.5664534.
Abstract: The use of satellite scatterometers to probe the winds in and near strong tropical cyclones (TCs) is a valuable tool for both numerical weather prediction (NWP) and weather forecasters. The presence of widespread rain in these storms complicates the estimation of surface winds from the satellite. Improvements in the techniques to infer surface winds from the satellite observations, which remove the effects of rain contamination at the ocean surface, will improve the modeling efforts as they pertain to the prediction of TC intensity. We demonstrate the use of collated and simultaneous high-resolution rain measurements obtained from nearby Next-Generation Radar (NEXRAD) and NASA Quick Scatterometer (QuikSCAT) measurements, respectively. Through the application of the National Oceanic and Atmospheric Administration (NOAA)/Atlantic Oceanographic and Meteorological Laboratories (AOML)/Hurricane Research Division (HRD) TC wind analysis (H*WIND, Powell and Houston [1996] ), we will study the dependence of a surface normalized radar cross-section (NRCS) on the TC wind-speed and rain-rate. The objective is to better observe and understand the dependence of the drag coefficient upon the surface stress across a wide range of conditions and spatial scales within these storms.
Keywords: Atlantic Oceanographic and Meteorological Laboratories , Hurricane Research Division , NASA Quick Scatterometer measurement , National Oceanic and Atmospheric Administration , Next-Generation Radar measurement , boundary layer parameterization
Mission: |SeaWinds|
URL: https://doi.org/10.1109/OCEANS.2010.5664534
Other URLs:
Weissman, D.E., Winterbottom, H., and Bourassa, M.A. (2010). Studies of the Influence of Rainfall Upon Scatterometer Estimates for Sea Surface Stress: Applications to Boundary Layer Parameterization and Drag Coefficient Models within Tropical Cyclone Environments, 2010 IEEE International Geoscience and Remote Sensing Symposium, 4154-4157, 10.1109/IGARSS.2010.5652373. Conference Paper »
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Title: Studies of the Influence of Rainfall Upon Scatterometer Estimates for Sea Surface Stress: Applications to Boundary Layer Parameterization and Drag Coefficient Models within Tropical Cyclone Environments
Type: Conference Paper
Publication: 2010 IEEE International Geoscience and Remote Sensing Symposium
Author(s): Weissman, D.E., Winterbottom, H., and Bourassa, M.A.
Year: 2010
Formatted Citation: Weissman, D.E., Winterbottom, H., and Bourassa, M.A., 2010: Studies of the Influence of Rainfall Upon Scatterometer Estimates for Sea Surface Stress: Applications to Boundary Layer Parameterization and Drag Coefficient Models within Tropical Cyclone Environments, 2010 IEEE International Geoscience and Remote Sensing Symposium, 4154-4157, 10.1109/IGARSS.2010.5652373.
Abstract: The use of satellite scatterometers to probe the winds in and near strong tropical cyclones (TCs) is a valuable tool for both numerical weather prediction (NWP) and weather forecasters. The presence of widespread rain in these storms complicates the estimation of surface winds from the satellite. Improvements in the techniques to infer surface winds from the satellite observations, which remove the effects of rain contamination at the ocean surface, will improve the modeling efforts as they pertain to the prediction of TC intensity. This study will demonstrate the use of collated and simultaneous high-resolution rain measurements obtained from nearby Next-Generation Radar (NEXRAD) and NASA Quick Scatterometer (QuikSCAT) measurements, respectively. Through the application of the National Oceanic and Atmospheric Administration (NOAA)/Atlantic Oceanographic and Meteorological Laboratories (AOML)/Hurricane Research Division (HRD) TC wind analysis (H*WIND, Powell and Houston [1996] ), we will study the dependence of a surface normalized radar cross-section (NRCS) on the TC wind-speed and rain-rate. The objective is to better observe and understand the dependence of the drag coefficient upon the surface stress across a wide range of conditions and spatial scales within these storms.
Keywords: atmospheric boundary layer , NASA Quick Scatterometer , NEXRAD measurement , Next-Generation Radar , QuikSCAT measurement , boundary layer parameterization , drag coefficient model , numerical weather prediction , rain contamination , rai
Mission: |SeaWinds|
URL: https://doi.org/10.1109/IGARSS.2010.5652373
Other URLs:
Williams, B.A. and Long, D.G. (2010). Scatterometer Image Reconstruction from Aperture-Filtered Samples, Proceedings of the International Geoscience and Remote Sensing Symposium, 1835-1838, 10.1109/IGARSS.2010.5654148. Conference Paper »
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Title: Scatterometer Image Reconstruction from Aperture-Filtered Samples
Type: Conference Paper
Publication: Proceedings of the International Geoscience and Remote Sensing Symposium
Author(s): Williams, B.A. and Long, D.G.
Year: 2010
Formatted Citation: Williams, B.A. and Long, D.G., 2010: Scatterometer Image Reconstruction from Aperture-Filtered Samples, Proceedings of the International Geoscience and Remote Sensing Symposium, 1835-1838, 10.1109/IGARSS.2010.5654148.
Abstract:
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URL: https://doi.org/10.1109/IGARSS.2010.5654148
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Xu, H., Tokinaga, H., and Xie, S.-P. (2010). Atmospheric Effects of the Kuroshio Large Meander During 2004-2005, Journal of Climate, 23(17), 4704-4715, 10.1175/2010JCLI3267.1. Journal Article »
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Title: Atmospheric Effects of the Kuroshio Large Meander During 2004-2005
Type: Journal Article
Publication: Journal of Climate
Author(s): Xu, H., Tokinaga, H., and Xie, S.-P.
Year: 2010
Formatted Citation: Xu, H., Tokinaga, H., and Xie, S.-P., 2010: Atmospheric Effects of the Kuroshio Large Meander During 2004-2005, Journal of Climate, 23(17), 4704-4715, 10.1175/2010JCLI3267.1.
Abstract: In the summer of 2004, the Kuroshio took a large meander path south of Japan for the first time since 1991, and this large meander event persisted until the next summer. Satellite observations and numerical model simulations are used to study the effect of this large meander event on the atmosphere. The large meander leaves a cool water pool between the Kuroshio and Japanese coast. Sea surface temperature (SST) in the cool water pool is about 2°-3°C colder than the surroundings during winter and spring, whereas the SST signature substantially weakens in summer. A local reduction of wind speed is found over the cool water pool, and the positive SST-wind speed correlation is indicative of ocean forcing of the atmosphere. Cloud liquid water (CLW) content and precipitation also decrease over the cool SST pool. A regional atmospheric model successfully simulates atmospheric response to the Kuroshio large meander. The model experiments suggest that the reduced surface wind speed and precipitation are due to the large meander-induced SST cooling. Analysis of the surface perturbation momentum budgets shows the importance of the pressure adjustment mechanism in surface wind response to the cold SST anomalies.
Keywords: Boundary currents, Pacific Ocean, Regional models, Sea surface temperature, Satellite observations, Atmosphere-Ocean interaction
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URL: https://doi.org/10.1175/2010JCLI3267.1
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Yan, X.-H., Jo, Y.-H., Liu, W.T., and Dai, M. (2010). Salinity Variations in Water Column Due to Outflows Estimated by Multi-Sensor Remote Sensing, Advances in Geosciences, 18, 109-133, 10.1142/9789812838148_0006. Journal Article »
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Title: Salinity Variations in Water Column Due to Outflows Estimated by Multi-Sensor Remote Sensing
Type: Journal Article
Publication: Advances in Geosciences
Author(s): Yan, X.-H., Jo, Y.-H., Liu, W.T., and Dai, M.
Year: 2010
Formatted Citation: Yan, X.-H., Jo, Y.-H., Liu, W.T., and Dai, M., 2010: Salinity Variations in Water Column Due to Outflows Estimated by Multi-Sensor Remote Sensing, Advances in Geosciences, 18, 109-133, 10.1142/9789812838148_0006.
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URL: http://dx.doi.org/10.1142/9789812838148_0006
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Zhuang, W., Du, Y., Wang, D., Xie, Q., and Xie, S.-P. (2010). Pathways of Mesoscale Variability in the South China Sea, Chinese J. Oceanology Limnology, 28(5), 1055-1067, 10.1007/s00343-010-0035-x. Journal Article »
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Title: Pathways of Mesoscale Variability in the South China Sea
Type: Journal Article
Publication: Chinese J. Oceanology Limnology
Author(s): Zhuang, W., Du, Y., Wang, D., Xie, Q., and Xie, S.-P.
Year: 2010
Formatted Citation: Zhuang, W., Du, Y., Wang, D., Xie, Q., and Xie, S.-P., 2010: Pathways of Mesoscale Variability in the South China Sea, Chinese J. Oceanology Limnology, 28(5), 1055-1067, 10.1007/s00343-010-0035-x.
Abstract: The propagation of oceanic mesoscale signals in the South China Sea (SCS) is mapped from satellite altimetric observations and an eddy-resolving global ocean model by using the maximum cross-correlation (MCC) method. Significant mesoscale signals propagate along two major bands of high variability. The northern band is located west of the Luzon Strait, characterized by southwestward eddy propagation. Although eddies are the most active in winter, their southwestward migrations, steered by bathymetry, occur throughout the year. Advection by the mean flow plays a secondary role in modulating the propagating speed. The southern eddy band lies in the southwest part of the SCS deep basin and is oriented in an approximately meridional direction. Mesoscale variability propagates southward along the band in autumn. This southward eddy pathway could not be explained by mean flow advection and is likely related to eddy detachments from the western boundary current due to nonlinear effects. Our mapping of eddy propagation velocities provides important information for further understanding eddy dynamics in the SCS.
Keywords: sea level - mesoscale variability - maximum cross-correlation - South China Sea (SCS)
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URL: https://doi.org/10.1007/s00343-010-0035-x
Other URLs:
Zhuang, W., S.-P. Xie, D. Wang, B. Taguchi, H. Aiki, and H. Sasaki (2010). Intraseasonal Variability in Sea Surface Height over the South China Sea, J. Geophys. Res., 115, C04010, 10.1029/2009JC005647. Journal Article »
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Title: Intraseasonal Variability in Sea Surface Height over the South China Sea
Type: Journal Article
Publication: J. Geophys. Res.
Author(s): Zhuang, W., S.-P. Xie, D. Wang, B. Taguchi, H. Aiki, and H. Sasaki
Year: 2010
Formatted Citation: Zhuang, W., S.-P. Xie, D. Wang, B. Taguchi, H. Aiki, and H. Sasaki, 2010: Intraseasonal Variability in Sea Surface Height over the South China Sea, J. Geophys. Res., 115, C04010, 10.1029/2009JC005647.
Abstract: Intraseasonal sea surface height (SSH) variability and associated eddy energy in the South China Sea is studied using satellite observations and an eddy-resolving, global ocean general circulation model. In both the model hindcast and satellite observations, a conspicuous minimum of intraseasonal SSH variance is found along the continental break between the shallow shelf and deep basin. Specifically strong intraseasonal variability (ISV) exists in the following regions: on the northern continental shelf, in the Gulf of Thailand, and along two bands in the deep basin with the northern band located west of Luzon Strait and the southern one southeast of Vietnam. SSH ISV exhibits clear seasonality. During active seasons, ISV in the deep water, high-variance bands displays robust propagations in the direction of mean flow. Low correlation between observations and model hindcast suggests the importance dynamical instabilities for ISV in the deep basin, in agreement with an energetics analysis. An exception is along the Vietnam offshore jet during summer, where ISV is forced by wind curls created by Annam Cordillera. In shallow waters, especially in the Gulf of Thailand, SSH ISV is dominated by barotropic response to intraseasonal wind stress forcing. The agreement between altimetry and the model simulation in the Gulf of Thailand demonstrates the ability of satellite altimeters to observe SSH variability in shallow shelves of weak tides.
Keywords: * sea surface height * intraseasonal variability * South China Sea * Oceanography: General: Descriptive and regional oceanography * Oceanography: General: Marine meteorology * Oceanography: Physical: Sea level: variations and mean
Mission:
URL: http://www.agu.org/journals/jc/jc1004/2009JC005647/2009JC005647.pdf
Other URLs:
Becker, J.J., Sandwell, D.T., Smith, W.H.F., Braud, J., Binder, B., Depner, J., Fabre, D., Factor, J., Ingalls, S., Kim, S.H., Ladner, R., Marks, K., Nelson, S., Pharaoh, A., Trimmer, R., Von Rosenberg, J., Wallace, G., and Weatherall, P. (2009). Global Bathymetry and Elevation Data at 30 Arc Seconds Resolution: SRTM30_PLUS, Marine Geodesy, 32(4), 355-371, 10.1080/01490410903297766. Journal Article »
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Title: Global Bathymetry and Elevation Data at 30 Arc Seconds Resolution: SRTM30_PLUS
Type: Journal Article
Publication: Marine Geodesy
Author(s): Becker, J.J., Sandwell, D.T., Smith, W.H.F., Braud, J., Binder, B., Depner, J., Fabre, D., Factor, J., Ingalls, S., Kim, S.H., Ladner, R., Marks, K., Nelson, S., Pharaoh, A., Trimmer, R., Von Rosenberg, J., Wallace, G., and Weatherall, P.
Year: 2009
Formatted Citation: Becker, J.J., Sandwell, D.T., Smith, W.H.F., Braud, J., Binder, B., Depner, J., Fabre, D., Factor, J., Ingalls, S., Kim, S.H., Ladner, R., Marks, K., Nelson, S., Pharaoh, A., Trimmer, R., Von Rosenberg, J., Wallace, G., and Weatherall, P., 2009: Global Bathymetry and Elevation Data at 30 Arc Seconds Resolution: SRTM30_PLUS, Marine Geodesy, 32(4), 355-371, 10.1080/01490410903297766.
Abstract: A new 30-arc second resolution global topography/bathymetry grid (SRTM30_PLUS) has been developed from a wide variety of data sources. Land and ice topography comes from the SRTM30 and ICESat topography, respectively. Ocean bathymetry is based on a new satellite-gravity model where the gravity-to-topography ratio is calibrated using 298 million edited soundings. The main contribution of this study is the compilation and editing of the raw soundings, which come from NOAA, individual scientists, SIO, NGA, JAMSTEC, IFREMER, GEBCO, and NAVOCEANO. The gridded bathymetry is available for ftp download in the same format as the 33 tiles of SRTM30 topography. There are 33 matching tiles of source identification number to convey the provenance of every grid cell. The raw sounding data, converted to a simple common format, are also available for ftp download.
Keywords: Global bathymetry, satellite altimetry
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URL: https://doi.org/10.1080/01490410903297766
Other URLs:
Becker, R.H. and Sultan, M. (2009). Land Subsidence in the Nile Delta: Inferences from Radar Interferometry, Holocene, 19(6), 949-954, 10.1177/0959683609336558. Journal Article »
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Title: Land Subsidence in the Nile Delta: Inferences from Radar Interferometry
Type: Journal Article
Publication: Holocene
Author(s): Becker, R.H. and Sultan, M.
Year: 2009
Formatted Citation: Becker, R.H. and Sultan, M., 2009: Land Subsidence in the Nile Delta: Inferences from Radar Interferometry, Holocene, 19(6), 949-954, 10.1177/0959683609336558.
Abstract: The Nile Delta formed by progression of a complex system of deltaic fans throughout the Pleistocene, with the Modern delta being formed from sediments supplied by at least ten distinct distributaries throughout the Holocene. With an average elevation of approximately 1 m above sea level within 30 km of the coast and a predicted rise in sea level of 1.8-5.9 mm/yr the subsidence of the northern delta has become a topic of major concern to the Egyptian population and government. The Nile Delta is home to more than 50 million people and the major agricultural production area for Egypt. We evaluated the modern rates of subsidence of sections of the northeastern Nile Delta (a total length of 110 km, up to 50 km from the coastline) using persistent scatterer radar interferometry techniques applied to 14 ERS-1 and ERS-2 scenes. The area covered includes the present active depocenter of the Damietta promontory, and the nearby Mendesian depocenter that was active up to recent times (to 2500 years ago). The highest subsidence rates (~8 mm/yr, twice average Holocene rates) do not correlate with the distribution of the thickest Holocene sediments, but rather with the distribution of the youngest depositional centers (major deposition occurred between ~3500 yr BP and present) at the terminus of the Damietta branch. The adjacent, slightly older (8000-2500 yr BP) Mendesian branch depositional center is subsiding at slower rates of 2-6 mm/yr. Results are interpreted to indicate that: (1) modern subsidence in the Delta is heavily influenced by compaction of the most recent sediments, and (2) highly threatened areas are at the terminus of the Damietta and possibly the Rosetta branches, where active deposition is occurring.
Keywords: INSAR subsidence Nile Delta Egypt Holocene radar
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URL: https://doi.org/10.1177/0959683609336558
Other URLs:
Bertotti, L. and Cavaleri, L. (2009). Large and Small Scale Wave Forecast in the Mediterranean Sea, Natural Hazards and Earth System Sciences, 9(3), 779-788, 10.5194/nhess-9-779-2009. Journal Article »
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Title: Large and Small Scale Wave Forecast in the Mediterranean Sea
Type: Journal Article
Publication: Natural Hazards and Earth System Sciences
Author(s): Bertotti, L. and Cavaleri, L.
Year: 2009
Formatted Citation: Bertotti, L. and Cavaleri, L., 2009: Large and Small Scale Wave Forecast in the Mediterranean Sea, Natural Hazards and Earth System Sciences, 9(3), 779-788, 10.5194/nhess-9-779-2009.
Abstract: We describe the implementation of an operational high resolution wind and wave forecasting system in the Mediterranean Sea, and then on a limited area centred on the south-east part of Italy, covering parts of the Adriatic and the Ionian seas. We analyse the performance at the two different resolutions during the first four months of operation, using the wind and wave data provided by the QuikSCAT scatterometer, and the Jason and Envisat altimeters. Useful accurate forecasts are found up to 72 h range, the maximum operational one. As expected, we find that the limited area models outperform both the wind and wave global or larger scale model results. However, we still find an appreciable underestimate by the models for surface wind speed and hence wave height, often concentrated on specific events.
Keywords: QuikSCAT
Mission: |SeaWinds|
URL: https://doi.org/10.5194/nhess-9-779-2009
Other URLs:
Bhattacharyya, R. and Majumdar, T.J. (2009). Bathymetry Prediction Over a Part of the Bombay High in the Western Offshore Using Very High Resolution Satellite Gravity Data, Current Science, 97(8), 1152-1161. Journal Article »
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Title: Bathymetry Prediction Over a Part of the Bombay High in the Western Offshore Using Very High Resolution Satellite Gravity Data
Type: Journal Article
Publication: Current Science
Author(s): Bhattacharyya, R. and Majumdar, T.J.
Year: 2009
Formatted Citation: Bhattacharyya, R. and Majumdar, T.J., 2009: Bathymetry Prediction Over a Part of the Bombay High in the Western Offshore Using Very High Resolution Satellite Gravity Data, Current Science, 97(8), 1152-1161.
Abstract:
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Mission:
URL: https://www.jstor.org/stable/24111957
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Booth, J.F., Thompson, L., Patoux, J., Kelly, K.A., and Dickinson, S. (2009). The Signature of the Midlatitude Tropospheric Storm Tracks in the Surface Winds, Journal of Climate, 23(5), 1160-1174, 10.1175/2009JCLI3064.1. Journal Article »
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Title: The Signature of the Midlatitude Tropospheric Storm Tracks in the Surface Winds
Type: Journal Article
Publication: Journal of Climate
Author(s): Booth, J.F., Thompson, L., Patoux, J., Kelly, K.A., and Dickinson, S.
Year: 2009
Formatted Citation: Booth, J.F., Thompson, L., Patoux, J., Kelly, K.A., and Dickinson, S., 2009: The Signature of the Midlatitude Tropospheric Storm Tracks in the Surface Winds, Journal of Climate, 23(5), 1160-1174, 10.1175/2009JCLI3064.1.
Abstract: Storm-track analysis is applied to the meridional winds at 10 m and 850 hPa for the winters of 1999-2006. The analysis is focused on the North Atlantic and North Pacific Ocean basins and the Southern Ocean spanning the region south of the Indian Ocean. The spatial patterns that emerge from the analysis of the 850-hPa winds are the typical free-tropospheric storm tracks. The spatial patterns that emerge from the analysis of the surface winds differ from the free-tropospheric storm tracks. The spatial differences between the surface and free-tropospheric storm tracks can be explained by the influence of the spatial variability in the instability of the atmospheric boundary layer. Strongly unstable boundary layers allow greater downward mixing of free-tropospheric momentum (momentum mixing), and this may be the cause of the stronger surface storm tracks in regions with greater instability in the time mean. Principal component analysis suggests that the basin-scale variability that is reflected in the storm-track signature is the same for the free-tropospheric and surface winds. Separating the data based on the boundary layer stability shows that the surface storm track has a local maximum in the region of maximum instability, even when there is no local maximum in the free-tropospheric storm track above the region. The spatial patterns of the surface storm tracks suggest a positive feedback for storm development as follows: 1) an existing storm generates strong free-tropospheric wind variability, 2) the momentum mixing of the unstable boundary layers acts to increase the ocean-atmosphere energy fluxes, and 3) the fluxes precondition the lower atmosphere for subsequent storm development.
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URL: https://doi.org/10.1175/2009JCLI3064.1
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Bourassa, M.A. (2009). The Future of Wind Measurements from Space, Space News, Nov. 23, 19-21. Journal Article »
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Title: The Future of Wind Measurements from Space
Type: Journal Article
Publication: Space News
Author(s): Bourassa, M.A.
Year: 2009
Formatted Citation: Bourassa, M.A., 2009: The Future of Wind Measurements from Space, Space News, Nov. 23, 19-21.
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URL: https://spacenews.com/future-wind-measurements-space/
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Bourassa, M.A. (2009). Uncertainty in Scatterometer Derived Vorticity, 2009 IEEE International Geoscience and Remote Sensing Symposium, III-805 - III-808, 10.1109/IGARSS.2009.5417889. Conference Paper »
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Title: Uncertainty in Scatterometer Derived Vorticity
Type: Conference Paper
Publication: 2009 IEEE International Geoscience and Remote Sensing Symposium
Author(s): Bourassa, M.A.
Year: 2009
Formatted Citation: Bourassa, M.A., 2009: Uncertainty in Scatterometer Derived Vorticity, 2009 IEEE International Geoscience and Remote Sensing Symposium, III-805 - III-808, 10.1109/IGARSS.2009.5417889.
Abstract: A more versatile and robust technique is developed for determining area averaged surface vorticity based on vector winds from swaths of remotely sensed wind vectors. This technique is discussed in detail and compared to two previous studies that focused on early development of tropical systems. The error characteristics of the technique are examined in detail. Specifically, three independent sources of error are explored: random observational error, truncation error and representation error. Observational errors are due to random errors in the wind observations, and determined as a worst-case estimate as a function of averaging spatial scale. The observational uncertainty in vorticity averaged for a roughly circular shape with a 100 km diameter, expressed as one standard deviation, is approximately 0.5 x 10^-5 s^-1 for the methodology described herein. Truncation error is associated with the assumption of linear changes between wind vectors. Uncertainty related to truncation has more organization in QuikSCAT data than observational uncertainty. On 25 km and 50 km scales, the truncation errors are very large. The third type of error, representation error, is due to the size of the area being averaged. This type of error is analogous to over-smoothing. Tropical and sub-tropical low pressure systems from three months of QuikSCAT observations are used to examine truncation and representation errors. Representation error results in a bias of approximately 1.5 x 10^-5 s^-1 for area averaged vorticity calculated on a 100 km scale compared to vorticity calculated on a 25 km scale. The discussion of these errors will benefit future projects of this nature as well as future satellite missions.
Keywords: atmospheric techniques , QuikSCAT data , area averaged surface vorticity , random observational error , remote sensing , representation error , scatterometer derived vorticity , QSCAT , error , scatterometry , vorticit , truncation error
Mission: |SeaWinds|
URL: https://doi.org/10.1109/IGARSS.2009.5417889
Other URLs:
Bourassa, M.A. and Hughes, P.J. (2009). Impacts of High Resolution SST Fields on Objective Analyses of Wind Fields, and Practical Constraints Related to Sampling, International GHRSST User Symposium, 2 pp..
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Title: Impacts of High Resolution SST Fields on Objective Analyses of Wind Fields, and Practical Constraints Related to Sampling
Type: Conference Paper
Publication: International GHRSST User Symposium
Author(s): Bourassa, M.A. and Hughes, P.J.
Year: 2009
Formatted Citation: Bourassa, M.A. and Hughes, P.J., 2009: Impacts of High Resolution SST Fields on Objective Analyses of Wind Fields, and Practical Constraints Related to Sampling, International GHRSST User Symposium, 2 pp..
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URL:
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Boutin, J., Quilfen, Y., Merlivat, L., and Piolle, J.F. (2009). Global Average of Air-Sea CO₂ Transfer Velocity from QuikSCAT Scatterometer Wind Speeds, Journal of Geophysical Research: Oceans, 114(C4), C04007, 10.1029/2007JC004168. Journal Article »
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Title: Global Average of Air-Sea CO₂ Transfer Velocity from QuikSCAT Scatterometer Wind Speeds
Type: Journal Article
Publication: Journal of Geophysical Research: Oceans
Author(s): Boutin, J., Quilfen, Y., Merlivat, L., and Piolle, J.F.
Year: 2009
Formatted Citation: Boutin, J., Quilfen, Y., Merlivat, L., and Piolle, J.F., 2009: Global Average of Air-Sea CO₂ Transfer Velocity from QuikSCAT Scatterometer Wind Speeds, Journal of Geophysical Research: Oceans, 114(C4), C04007, 10.1029/2007JC004168.
Abstract:
Keywords: QuikSCAT
Mission: |SeaWinds|
URL: https://doi.org/10.1029/2007JC004168
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Brennan, M.J., Hennon, C.C., and Knabb, R.D. (2009). The Operational Use of QuikSCAT Ocean Surface Vector Winds at the National Hurricane Center, Weather and Forecasting, 24(3), 621-645, 10.1175/2008WAF2222188.1. Journal Article »
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Title: The Operational Use of QuikSCAT Ocean Surface Vector Winds at the National Hurricane Center
Type: Journal Article
Publication: Weather and Forecasting
Author(s): Brennan, M.J., Hennon, C.C., and Knabb, R.D.
Year: 2009
Formatted Citation: Brennan, M.J., Hennon, C.C., and Knabb, R.D., 2009: The Operational Use of QuikSCAT Ocean Surface Vector Winds at the National Hurricane Center, Weather and Forecasting, 24(3), 621-645, 10.1175/2008WAF2222188.1.
Abstract: The utility and shortcomings of near-real-time ocean surface vector wind retrievals from the NASA Quick Scatterometer (QuikSCAT) in operational forecast and analysis activities at the National Hurricane Center (NHC) are described. The use of QuikSCAT data in tropical cyclone (TC) analysis and forecasting for center location/identification, intensity (maximum sustained wind) estimation, and analysis of outer wind radii is presented, along with shortcomings of the data due to the effects of rain contamination and wind direction uncertainties. Automated QuikSCAT solutions in TCs often fail to show a closed circulation, and those that do are often biased to the southwest of the NHC best-track position. QuikSCAT winds show the greatest skill in TC intensity estimation in moderate to strong tropical storms. In tropical depressions, a positive bias in QuikSCAT winds is seen due to enhanced backscatter by rain, while in major hurricanes rain attenuation, resolution, and signal saturation result in a large negative bias in QuikSCAT intensity estimates. QuikSCAT wind data help overcome the large surface data void in the analysis and forecast area of NHC's Tropical Analysis and Forecast Branch (TAFB). These data have resulted in improved analyses of surface features, better definition of high wind areas, and improved forecasts of high-wind events. The development of a climatology of gap wind events in the Gulf of Tehuantepec has been possible due to QuikSCAT wind data in a largely data-void region. The shortcomings of ocean surface vector winds from QuikSCAT in the operational environment at NHC are described, along with requirements for future ocean surface vector wind missions. These include improvements in the timeliness and quality of the data, increasing the wind speed range over which the data are reliable, and decreasing the impact of rain to allow for accurate retrievals in all-weather conditions.
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Mission: |SeaWinds|
URL: https://doi.org/10.1175/2008WAF2222188.1
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Candy, B., English, S.J., and Keogh, S.J. (2009). A Comparison of the Impact of QuikScat and Winds at Wind Vector Products on Met Office Analyses and Forecasts, IEEE Transactions on Geoscience and Remote Sensing, 47(6), 1632-1640, 10.1109/TGRS.2008.2009993. Journal Article »
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Title: A Comparison of the Impact of QuikScat and Winds at Wind Vector Products on Met Office Analyses and Forecasts
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Candy, B., English, S.J., and Keogh, S.J.
Year: 2009
Formatted Citation: Candy, B., English, S.J., and Keogh, S.J., 2009: A Comparison of the Impact of QuikScat and Winds at Wind Vector Products on Met Office Analyses and Forecasts, IEEE Transactions on Geoscience and Remote Sensing, 47(6), 1632-1640, 10.1109/TGRS.2008.2009993.
Abstract: Several studies have demonstrated that retrievals of wind vectors from the WindSat polarimetric radiometer are of sufficient quality to be considered for assimilation in operational numerical weather prediction models. In this paper, WindSat data are used in a state-of-the-art global meteorological analysis and forecasting system. Each wind vector contains a directional ambiguity and so is assimilated in a similar way to that of scatterometer data. The forecast impact of using analyses containing information from WindSat data was investigated for a period during August and September of 2005, when a large number of tropical cyclones were present. Forecast errors were reduced in the surface pressure fields, and the average improvement across the forecast range was found to be 1.0 %. This is comparable to the improvement of 1.1 % found in the same fields when winds were assimilated from the QuikScat scatterometer. The impact on tropical cyclone tracks in the forecasts was also studied. The scatterometer improved (reduced) the track errors markedly by 25% in the analyses. When impacts across the forecast range out to five days were also included, the improvement was found to be 8%. In contrast, the assimilation of WindSat data improved the analysis track errors by 7%, although this figure was found to be 10% across the complete forecast range. 2008 IEEE.
Keywords: QuikSCAT
Mission: |SeaWinds|WindSat|
URL: https://doi.org/10.1109/TGRS.2008.2009993
Other URLs:
Capps, S.B. and Zender, C.S. (2009). Global Ocean Wind Power Sensitivity to Surface Layer Stability, Geophysical Research Letters, 36(9), L09801, 10.1029/2008GL037063. Journal Article »
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Title: Global Ocean Wind Power Sensitivity to Surface Layer Stability
Type: Journal Article
Publication: Geophysical Research Letters
Author(s): Capps, S.B. and Zender, C.S.
Year: 2009
Formatted Citation: Capps, S.B. and Zender, C.S., 2009: Global Ocean Wind Power Sensitivity to Surface Layer Stability, Geophysical Research Letters, 36(9), L09801, 10.1029/2008GL037063.
Abstract: Global ocean wind power has recently been assessed (W. T. Liu et al., 2008) using scatterometry-based 10 m winds. We characterize, for the first time, wind power at 80 m (typical wind turbine hub height) above the global ocean surface, and account for the effects of surface layer stability. Accounting for realistic turbine height and atmospheric stability increases mean global ocean wind power by +58% and -4%, respectively. Our best estimate of mean global ocean wind power is 731 W m^-2, about 50% greater than the 487 W m^-2 based on previous methods. 80 m wind power is 1.2–1.5 times 10 m power equatorward of 30° latitude, between 1.4 and 1.7 times 10 m power in wintertime storm track regions and >6 times 10 m power in stable regimes east of continents. These results are relatively insensitive to methodology as wind power calculated using a fitted Weibull probability density function is within 10% of power calculated from discrete wind speed measurements over most of the global oceans.
Keywords: * wind power * surface layer * scatterometer
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URL: https://doi.org/10.1029/2008GL037063
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Chang, P.S., Jelenak, Z., Sienkiewicz, J.M., Knabb, R., Brennan, M.J., Long, D.G., and Freeberg, M. (2009). Operational Use and Impact of Satellite Remotely Sensed Ocean Surface Vector Winds in the Marine Warning and Forecasting Environment, Oceanography, 22(2), 194-207, 10.5670/oceanog.2009.49. Journal Article »
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Title: Operational Use and Impact of Satellite Remotely Sensed Ocean Surface Vector Winds in the Marine Warning and Forecasting Environment
Type: Journal Article
Publication: Oceanography
Author(s): Chang, P.S., Jelenak, Z., Sienkiewicz, J.M., Knabb, R., Brennan, M.J., Long, D.G., and Freeberg, M.
Year: 2009
Formatted Citation: Chang, P.S., Jelenak, Z., Sienkiewicz, J.M., Knabb, R., Brennan, M.J., Long, D.G., and Freeberg, M., 2009: Operational Use and Impact of Satellite Remotely Sensed Ocean Surface Vector Winds in the Marine Warning and Forecasting Environment, Oceanography, 22(2), 194-207, 10.5670/oceanog.2009.49.
Abstract: In 2002, a National Oceanographic Partnership Program project was initiated with the ambitious objective of maximizing the use of currently and soon-to-be-available satellite ocean surface vector wind (OSVW) data, such as NASAs QuikSCAT scatterometer, in the operational weather forecasting and warning environment. This effort brought together people from the operational forecasting and satellite remote-sensing communities, academia, and the private sector. This diverse gathering of skill and experience yielded documentation of the impacts of these data in the operational short-term warning and forecasting environment of the National Oceanic and Atmospheric Administration`s (NOAA`s) National Weather Service, improvement in the use of these data in the public and private sectors, and the transition of promising research results into the operational environment. This project helped create momentum that has continued to grow long after the formal effort ended, today, NOAA uses QuikSCAT operationally and is investigating how to best establish a sustained satellite OSVW observing capability.
Keywords: QuikSCAT
Mission: |SeaWinds|
URL: https://doi.org/10.5670/oceanog.2009.49
Other URLs:
Chen, G.X., Hou, Y.J., Chu, X.Q., Qi, P., and Hu, P. (2009). The Variability of Eddy Kinetic Energy in the South China Sea Deduced from Satellite Altimeter Data, Chinese Journal of Oceanology and Limnology, 27(4), 943-954, 10.1007/s00343-009-9297-6. Journal Article »
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Title: The Variability of Eddy Kinetic Energy in the South China Sea Deduced from Satellite Altimeter Data
Type: Journal Article
Publication: Chinese Journal of Oceanology and Limnology
Author(s): Chen, G.X., Hou, Y.J., Chu, X.Q., Qi, P., and Hu, P.
Year: 2009
Formatted Citation: Chen, G.X., Hou, Y.J., Chu, X.Q., Qi, P., and Hu, P., 2009: The Variability of Eddy Kinetic Energy in the South China Sea Deduced from Satellite Altimeter Data, Chinese Journal of Oceanology and Limnology, 27(4), 943-954, 10.1007/s00343-009-9297-6.
Abstract: We used fifteen years (1993-2007) of altimetric data, combined from different missions (ERS-1/2, TOPEX/Poseidon, Jason-1, and Envisat), to analyze the variability of the eddy kinetic energy (EKE) in the South China Sea (SCS). We found that the EKE ranged from 64 cm²/s² to 1 390 cm²/s² with a mean value of 314 cm²/s². The highest EKE center was observed to the east of Vietnam (with a mean value of 509 cm²/s²) and the second highest EKE region was located to the southwest of Taiwan Island (with a mean value of 319 cm²/s²). We also found that the EKE structure is the consequence of the superposition of different variability components. First, interannual variability is important in the SCS. Spectral analysis of the EKE interannual signal (IA-EKE) shows that the main periodicities of the IA-EKE to the east of Vietnam, to the southwest of Taiwan Island, and in the SCS are 3.75, 1.87, and 3.75 years, respectively. It is to the south of Taiwan Island that the IA-EKE signal has the most obvious impact on EKE variability. In addition, the IA-EKE exhibit different trends in different regions. An obvious positive trend is observed along the east coast of Vietnam, while a negative trend is found to the southwest of Taiwan Island and in the east basin of Vietnam. Correlation analysis shows that the IA-EKE has an obvious negative correlation with the SSTA in Niño3 (5°S-5°N, 90°W-150°W). El Niño-Southern Oscillation (ENSO) affects the IA-EKE variability in the SCS through an atmospheric bridge-wind stress curl over the SCS. Second, the seasonal cycle is the most obvious timescale affecting EKE variability. The locations of the most remarkable EKE seasonal variabilities in the SCS are to the east of Vietnam, to the southwest of Taiwan, and to the west of Philippines. To the east of Vietnam, the seasonal cycle is the dominant mechanism controlling EKE variability, which is attributed primarily to the annual cycle there of wind stress curl. In this area, the maximum EKE is observed in autumn. To the southwest of Taiwan Island, the EKE is enlarged by the stronger SCS circulation, which is caused by the intrusion branch from the Kuroshio in winter. Finally, intra-annual and mesoscale variability, although less important than the former, cannot be neglected. The most obvious intra-annual and mesoscale variability, which may be the result of baroclinic instability of the background flow, are observed to the southwest of Taiwan Island. Sporadic events can have an important effect on EKE variability.
Keywords: altimetry - eddy kinetic energy - annual and interannual variability - SCS
Mission:
URL: https://doi.org/10.1007/s00343-009-9297-6
Other URLs:
Chhak, K.C., Moore, A.M., and Milliff, R.F. (2009). Stochastic Forcing of Ocean Variability by the North Atlantic Oscillation, Journal of Physical Oceanography, 39(1), 162-184, 10.1175/2008JPO3972.1. Journal Article »
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Title: Stochastic Forcing of Ocean Variability by the North Atlantic Oscillation
Type: Journal Article
Publication: Journal of Physical Oceanography
Author(s): Chhak, K.C., Moore, A.M., and Milliff, R.F.
Year: 2009
Formatted Citation: Chhak, K.C., Moore, A.M., and Milliff, R.F., 2009: Stochastic Forcing of Ocean Variability by the North Atlantic Oscillation, Journal of Physical Oceanography, 39(1), 162-184, 10.1175/2008JPO3972.1.
Abstract: At middle and high latitudes, the magnitude of stochastic wind stress forcing of the ocean by atmospheric variability on synoptic timescales (i.e. "weather" related variability) is comparable to that of the seasonal cycle. Stochastic forcing may therefore have a significant influence on the ocean circulation, climate and ocean predictability. We explore here the influence of stochastic forcing associated with the North Atlantic Oscillation on the subtropical gyre circulation of the North Atlantic in an eddy permitting quasigeostrophic framework. For the North Atlantic winds used in this study, the root mean square of the annual average Ekman pumping velocity of the seasonal cycle between 35°N and 52°N is 1.3 × 10^-7 m s^-1, while the wintertime standard deviation of stochastic component of the North Atlantic Oscillation over the same latitude band is 2.2 × 10^-7 m s^-1. Significant stochastically-induced variability in the ocean circulation occurs near the western boundary region and along the western margins of the abyssal plains associated with vortex stretching, energy release from the mean flow, and the generation of topographic Rossby waves. Variability arises from a combination of two effects depending on the measure of variance used: growth of unstable modes of the underlying circulation, and modal interference resulting from their nonnormal nature which dominates during the first 10 days or so of perturbation growth. Near the surface, most of the variability is associated with large-scale changes in the barotropic circulation, although more than 20% of the energy and enstrophy variability is associated with small-scale baroclinic waves. In the deep ocean, much of the stochastically-induced variability is apparently due to topographic Rossby wave activity along the continental rise and ocean ridges. Previous studies have demonstrated that rectification of topographic Rossby wave-induced circulations in the western North Atlantic may contribute to the western boundary current recirculation zones. We suggest here that a source of topographic Rossby wave energy, significant enough to rectify the mean ocean circulation, may arise from stochastic forcing by large-scale atmospheric forcing, such as the North Atlantic Oscillation and other atmospheric teleconnection patterns.
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Mission:
URL: https://doi.org/10.1175/2008JPO3972.1
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da Silva, J.C.B., New, A.L., and Magalhaes, J.M. (2009). Internal Solitary Waves in the Mozambique Channel: Observations and Interpretation, Journal of Geophysical Research: Oceans, 114(C5), C05001, 10.1029/2008JC005125. Journal Article »
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Title: Internal Solitary Waves in the Mozambique Channel: Observations and Interpretation
Type: Journal Article
Publication: Journal of Geophysical Research: Oceans
Author(s): da Silva, J.C.B., New, A.L., and Magalhaes, J.M.
Year: 2009
Formatted Citation: da Silva, J.C.B., New, A.L., and Magalhaes, J.M., 2009: Internal Solitary Waves in the Mozambique Channel: Observations and Interpretation, Journal of Geophysical Research: Oceans, 114(C5), C05001, 10.1029/2008JC005125.
Abstract: This paper presents new results showing that the Sofala shelf in the Mozambique Channel (20°S, 36°E) is a previously unknown 'hot spot' for the generation of internal tides and internal waves. We investigate available Envisat advanced synthetic aperture radar imagery of the region, which is capable of showing the surface signatures of the internal waves. This is complemented by modeling of the ray pathways of internal tidal energy propagation, and of the P. G. Baines (1982) barotropic body force, which drives the generation of internal tides near the shelf break. The hot spot region is localized between 20° and 21°S because of the particular nature of the bathymetry there. Farther north and south, the forcing is reduced and insufficient to generate internal solitary waves in the synthetic aperture radar images. The analysis reveals two distinct types of internal wave trains that are observed traveling oceanward away from the shelf break, and we suggest that these result from direct generation at the shelf break and from 'local' generation at about 80 km from the shelf break, respectively, because of the surfacing of internal tidal rays at the thermocline. Finally, we have investigated seasonal differences in the wave patterns, which penetrate more extensively into the channel during the southern summer and appear slightly farther to the south during the southern winter. We also conclude that the local generation process is more likely to occur during the winter when the stratification is reduced.
Keywords: * internal solitary waves * local generation * SAR
Mission:
URL: https://doi.org/10.1029/2008JC005125
Other URLs:
Donelan, M.A. and Plant, W.J. (2009). A Threshold for Wind-Wave Growth, Journal of Geophysical Research: Oceans, 114(C7), C07012, 10.1029/2008JC005238. Journal Article »
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Title: A Threshold for Wind-Wave Growth
Type: Journal Article
Publication: Journal of Geophysical Research: Oceans
Author(s): Donelan, M.A. and Plant, W.J.
Year: 2009
Formatted Citation: Donelan, M.A. and Plant, W.J., 2009: A Threshold for Wind-Wave Growth, Journal of Geophysical Research: Oceans, 114(C7), C07012, 10.1029/2008JC005238.
Abstract: Measurements in a closed, recirculating wind-wave tank using variable wind speeds showed that wind waves in the gravity-capillary range exhibit a threshold in their growth. Surface wave height variance spectral densities in the wave number domain were measured for gravity-capillary waves using both radar backscatter and a wavelet transform technique applied to a laser probe. The measurements showed that when the wind speed was slowly ramped up, a threshold wind speed or friction velocity was required to produce waves. Turning the wind on suddenly showed that the wind stress did not grow as rapidly as the wind since the surface waves supporting the stress grew relatively slowly. Changing water temperature or current in the water caused a pronounced change in the wind speed threshold but not in the friction velocity threshold. Changes in fetch of as much as a factor of 2 had no discernible effect on the thresholds. The results imply that wind speed, being a condition imposed on the air-water interface, causes wave growth, while friction velocity, being a result of air-water interactions, is closely related to surface roughness, hence radar cross section, and changes during wave growth.
Keywords: * wind-wave generation * Bragg scattering * wavelet techniques * scatterometry
Mission:
URL: https://doi.org/10.1029/2008JC005238
Other URLs:
Elipot, S. and Gille, S.T. (2009). Ekman Layers in the Southern Ocean: Spectral Models and Observations, Vertical Viscosity and Boundary Layer Depth, Ocean Science, 5(2), 115-139, 10.5194/os-5-115-2009. Journal Article »
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Title: Ekman Layers in the Southern Ocean: Spectral Models and Observations, Vertical Viscosity and Boundary Layer Depth
Type: Journal Article
Publication: Ocean Science
Author(s): Elipot, S. and Gille, S.T.
Year: 2009
Formatted Citation: Elipot, S. and Gille, S.T., 2009: Ekman Layers in the Southern Ocean: Spectral Models and Observations, Vertical Viscosity and Boundary Layer Depth, Ocean Science, 5(2), 115-139, 10.5194/os-5-115-2009.
Abstract:
Keywords:
Mission:
URL: https://doi.org/10.5194/os-5-115-2009
Other URLs:
Freedman, A.H., Buermann, W., Lebreton, M., Chiro, L., and Smith, T.B. (2009). Modeling the Effects of Anthropogenic Habitat Change on Savanna Snake Invasions into African Rainforest, Conservation Biology, 23(1), 81-92, 10.1111/j.1523-1739.2008.01039.x. Journal Article »
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Title: Modeling the Effects of Anthropogenic Habitat Change on Savanna Snake Invasions into African Rainforest
Type: Journal Article
Publication: Conservation Biology
Author(s): Freedman, A.H., Buermann, W., Lebreton, M., Chiro, L., and Smith, T.B.
Year: 2009
Formatted Citation: Freedman, A.H., Buermann, W., Lebreton, M., Chiro, L., and Smith, T.B., 2009: Modeling the Effects of Anthropogenic Habitat Change on Savanna Snake Invasions into African Rainforest, Conservation Biology, 23(1), 81-92, 10.1111/j.1523-1739.2008.01039.x.
Abstract: We used a species-distribution modeling approach, ground-based climate data sets, and newly available remote-sensing data on vegetation from the MODIS and Quick Scatterometer sensors to investigate the combined effects of human-caused habitat alterations and climate on potential invasions of rainforest by 3 savanna snake species in Cameroon, Central Africa: the night adder (Causus maculatus), olympic lined snake (Dromophis lineatus), and African house snake (Lamprophis fuliginosus). Models with contemporary climate variables and localities from native savanna habitats showed that the current climate in undisturbed rainforest was unsuitable for any of the snake species due to high precipitation. Limited availability of thermally suitable nest sites and mismatches between important life-history events and prey availability are a likely explanation for the predicted exclusion from undisturbed rainforest. Models with only MODIS-derived vegetation variables and savanna localities predicted invasion in disturbed areas within the rainforest zone, which suggests that human removal of forest cover creates suitable microhabitats that facilitate invasions into rainforest. Models with a combination of contemporary climate, MODIS- and Quick Scatterometer-derived vegetation variables, and forest and savanna localities predicted extensive invasion into rainforest caused by rainforest loss. In contrast, a projection of the present-day species-climate envelope on future climate suggested a reduction in invasion potential within the rainforest zone as a consequence of predicted increases in precipitation. These results emphasize that the combined responses of deforestation and climate change will likely be complex in tropical rainforest systems.
Keywords: QuikSCAT
Mission: |SeaWinds|
URL: https://doi.org/10.1111/j.1523-1739.2008.01039.x
Other URLs:
Fukushima, H., Suzuki, K., Li, L., Suzuki, N., and Murakami, H. (2009). Improvement of the ADEOS-II/GLI Sun-Glint Algorithm Using Concomitant Microwave Scatterometer-Derived Wind Data, Advances in Space Research, 43(6), 941-947, 10.1016/j.asr.2008.07.013. Journal Article »
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Title: Improvement of the ADEOS-II/GLI Sun-Glint Algorithm Using Concomitant Microwave Scatterometer-Derived Wind Data
Type: Journal Article
Publication: Advances in Space Research
Author(s): Fukushima, H., Suzuki, K., Li, L., Suzuki, N., and Murakami, H.
Year: 2009
Formatted Citation: Fukushima, H., Suzuki, K., Li, L., Suzuki, N., and Murakami, H., 2009: Improvement of the ADEOS-II/GLI Sun-Glint Algorithm Using Concomitant Microwave Scatterometer-Derived Wind Data, Advances in Space Research, 43(6), 941-947, 10.1016/j.asr.2008.07.013.
Abstract: The tendency of over-estimation of sun-glint reflectance was found in GLI satellite ocean color data, after applying the traditional sun-glint model of Cox and Munk together with objective analysis wind data. ADEOS-II has provided a good opportunity to improve the glint model using data measured by GLI and SeaWinds, both onboard the satellite. With the help of simultaneous wind measurements achieved by SeaWinds, the Cox and Munk model is re-evaluated using GLI measurements to obtain a new relationship between the surface mean square slope and wind. The new model was found to be very close to the Cox and Munk under moderate wind speed but is much different under calm condition, where it shows similarity to the result reported by Ebuchi and Kizu. It also improves the ocean color data availability and the precision of sun-glint reflectance, based oil the evaluation result of the generated Level 3 data products. (C) 2008 COSPAR. Published by Elsevier Ltd. All rights reserved.
Keywords: Seawinds
Mission: |SeaWinds|
URL: https://doi.org/10.1016/j.asr.2008.07.013
Other URLs:
Gao, Z.Q., Wang, Q., and Zhou, M.Y. (2009). Wave-Dependence of Friction Velocity, Roughness Length, and Drag Coefficient Over Coastal and Open Water Surfaces by Using Three Databases, Advances in Atmospheric Sciences, 26(5), 887-894, 10.1007/s00376-009-8130-7. Journal Article »
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Title: Wave-Dependence of Friction Velocity, Roughness Length, and Drag Coefficient Over Coastal and Open Water Surfaces by Using Three Databases
Type: Journal Article
Publication: Advances in Atmospheric Sciences
Author(s): Gao, Z.Q., Wang, Q., and Zhou, M.Y.
Year: 2009
Formatted Citation: Gao, Z.Q., Wang, Q., and Zhou, M.Y., 2009: Wave-Dependence of Friction Velocity, Roughness Length, and Drag Coefficient Over Coastal and Open Water Surfaces by Using Three Databases, Advances in Atmospheric Sciences, 26(5), 887-894, 10.1007/s00376-009-8130-7.
Abstract: The parameterization of friction velocity, roughness length, and the drag coefficient over coastal zones and open water surfaces enables us to better understand the physical processes of air-water interaction. In context of measurements from the Humidity Exchange over the Sea Main Experiment (HEXMAX), we recently proposed wave-parameter dependent approaches to sea surface friction velocity and the aerodynamic roughness by using the dimensional analysis method. To extend the application of these approaches to a range of natural surface conditions, the present study is to assess this approach by using both coastal shallow (RASEX) and open water surface measurements (Lake Ontario and Grand Banks ERS-1 SAR) where wind speeds were greater than 6.44 m s^-1. Friction velocities, the surface aerodynamic roughness, and the neutral drag coefficient estimated by these approaches under moderate wind conditions were compared with the measurements mentioned above. Results showed that the coefficients in these approaches for coastal shallow water surface differ from those for open water surfaces, and that the aerodynamic roughness length in terms of wave age or significant wave height should be treated differently for coastal shallow and open water surfaces.
Keywords: sea surface roughness - wave parameter - friction velocity - parameterization
Mission:
URL: https://doi.org/10.1007/s00376-009-8130-7
Other URLs:
Garcia-Soto, C. and Pingree, R.D. (2009). Spring and Summer Blooms of Phytoplankton (SeaWiFS/MODIS) Along a Ferry Line in the Bay of Biscay and Western English Channel, Continental Shelf Research, 29(8), 1111-1122, 10.1016/j.csr.2008.12.012. Journal Article »
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Title: Spring and Summer Blooms of Phytoplankton (SeaWiFS/MODIS) Along a Ferry Line in the Bay of Biscay and Western English Channel
Type: Journal Article
Publication: Continental Shelf Research
Author(s): Garcia-Soto, C. and Pingree, R.D.
Year: 2009
Formatted Citation: Garcia-Soto, C. and Pingree, R.D., 2009: Spring and Summer Blooms of Phytoplankton (SeaWiFS/MODIS) Along a Ferry Line in the Bay of Biscay and Western English Channel, Continental Shelf Research, 29(8), 1111-1122, 10.1016/j.csr.2008.12.012.
Abstract: The seasonal cycle of chlorophyll concentration in the Bay of Biscay and western English Channel has been examined using satellite data (chlorophyll, sea surface temperature (SST), photosynthetically available radiation (PAR) and wind) along the line of the ferry Pride of Bilbao (Bilbao to Portsmouth). The spring phytoplankton bloom develops regularly in the oceanic region of the Bay of Biscay from mid March to the beginning of May with peak chlorophyll concentrations ranging 2-4mg m^-3. Low wind turbulence is a major factor allowing the development of productivity pulses in the Bay of Biscay during spring. Exceptional blooms of phytoplankton take place in summer (July-August) in the western English Channel with chlorophyll concentrations as high as 40mg m^-3. Some environmental factors (SST, wind, pressure and tide) are examined. Autumn blooms of phytoplankton (1-2mg m^-3) are also detected in the northern Bay of Biscay, shelf-break and Celtic Sea in October. A 11 years pluri-annual synthesis of SeaWiFS satellite measurements is presented.
Keywords: Remote sensing, Bay of Biscay, Spring bloom, Dinoflagellate bloom, Western English Channel, Cantabrian shelf
Mission:
URL: https://doi.org/10.1016/j.csr.2008.12.012
Other URLs:
Goerss, J.S. (2009). Impact of Satellite Observations on the Tropical Cyclone Track Forecasts of the Navy Operational Global Atmospheric Prediction System, Monthly Weather Review, 137(1), 41-50, 10.1175/2008MWR2601.1. Journal Article »
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Title: Impact of Satellite Observations on the Tropical Cyclone Track Forecasts of the Navy Operational Global Atmospheric Prediction System
Type: Journal Article
Publication: Monthly Weather Review
Author(s): Goerss, J.S.
Year: 2009
Formatted Citation: Goerss, J.S., 2009: Impact of Satellite Observations on the Tropical Cyclone Track Forecasts of the Navy Operational Global Atmospheric Prediction System, Monthly Weather Review, 137(1), 41-50, 10.1175/2008MWR2601.1.
Abstract: The tropical cyclone (TC) track forecasts of the Navy Operational Global Atmospheric Prediction System (NOGAPS) were evaluated for a number of data assimilation experiments conducted using observational data from two periods: July 4-October 31, 2005 and August 1-September 30, 2006. The experiments were designed to illustrate the impact of different types of satellite observations on the NOGAPS TC track forecasts. The satellite observations assimilated in these experiments consisted of feature-track winds from geostationary and polar-orbiting satellites, SSM/I total column precipitable water and wind speeds, AMSU-A radiances, and QuikSCAT and ERS-2 scatterometer winds. While there were some differences between the results from basin to basin and year to year, the combined results for the 2005 and 2006 test periods for the North Pacific and Atlantic basins indicated that the assimilation of the feature-track winds from the geostationary satellites had the most impact, ranging from 7 to 24 percent improvement in NOGAPS TC track forecasts. This impact was statistically significant at all forecast lengths. The impact of the assimilation of SSM/I precipitable water was consistently positive and statistically significant at all forecast lengths. The improvements due to the assimilation of AMSU-A radiances were also consistently positive and significant at most forecast lengths. There were no significant improvements/degradations due to the assimilation of the other satellite observation types (MODIS winds, SSM/I wind speeds, and scatterometer winds). The assimilation of all satellite observations resulted in a gain in skill of roughly 12 h for the NOGAPS 48-h and 72-h TC track forecasts and a gain in skill of roughly 24 h for the 96-h and 120-h forecasts. The percent improvement in these forecasts ranged from almost 20 percent at 24 h to over 40 percent at 120 h.
Keywords:
Mission: |SeaWinds|
URL: https://doi.org/10.1175/2008MWR2601.1
Other URLs:
Goff, J.A. (2009). Statistical Characterization of Geosat Altimetry Noise: Dependence on Environmental Parameters, Geochemistry, Geophysics, Geosystems, 10, Q08007, 10.1029/2009GC002569. Journal Article »
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Title: Statistical Characterization of Geosat Altimetry Noise: Dependence on Environmental Parameters
Type: Journal Article
Publication: Geochemistry, Geophysics, Geosystems
Author(s): Goff, J.A.
Year: 2009
Formatted Citation: Goff, J.A., 2009: Statistical Characterization of Geosat Altimetry Noise: Dependence on Environmental Parameters, Geochemistry, Geophysics, Geosystems, 10, Q08007, 10.1029/2009GC002569.
Abstract: Sea surface height (SSH) measurements from the Geosat satellite altimetry mission are analyzed to statistically characterize their noise process, which is defined here as the small-scale (<50 km), time-varying component of the altimetry data. This analysis is one component of a larger effort to extract meaningful information about seafloor roughness from the small-scale fabric of the altimetric gravity field. Both small-scale seafloor topography (e.g., abyssal hills) and SSH noise significantly influence the measured gravity fabric. Hence, a global, quantitative understanding of SSH noise is required to infer what portion of the gravity fabric is associated with the true geoid. It is also anticipated that the SSH noise analysis will prove useful in designing improvements to altimetry processing algorithms. The SSH data are first processed by differencing nearest-neighbor tracks, to minimize the static component of variability, and then by high-pass filtering, to remove variability associated with mesoscale oceanic circulation. Autocovariance analysis reveals that SSH noise can be decomposed into uncorrelated (white noise) and correlated, semiperiodic components. Three parameters are measured which characterize the variance of both components and the correlation length of the correlated component. The global distribution of uncorrelated noise variance is closely correlated to significant wave heights, directly linking the uncertainty of the altimeter return time to the roughness of the sea surface. The variance and correlation length of the correlated component of noise can be associated with three separate environmental parameters: sea ice, precipitation rates, and upper atmospheric variability associated with the subtropical jet stream. As widely differing as these environmental processes are, it is hypothesized that features like sea ice, rain storms, and atmospheric turbulence can cause sudden perturbations in the return time of the altimetry signal, creating decaying oscillations associated with the onboard tracking algorithms.
Keywords: * sea surface height * altimetry * noise * covariance analysis * significant wave height * rain
Mission:
URL: https://doi.org/10.1029/2009GC002569
Other URLs:
González-Solis, J., Felicisimo, A., Fox, J.W., Afanasyev, V., Kolbeinsson, Y., and Muñoz, J. (2009). Influence of Sea Surface Winds on Shearwater Migration Detours, Marine Ecology Progress Series, 391, 221-230, 10.3354/meps08128. Journal Article »
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Title: Influence of Sea Surface Winds on Shearwater Migration Detours
Type: Journal Article
Publication: Marine Ecology Progress Series
Author(s): González-Solis, J., Felicisimo, A., Fox, J.W., Afanasyev, V., Kolbeinsson, Y., and Muñoz, J.
Year: 2009
Formatted Citation: González-Solis, J., Felicisimo, A., Fox, J.W., Afanasyev, V., Kolbeinsson, Y., and Muñoz, J., 2009: Influence of Sea Surface Winds on Shearwater Migration Detours, Marine Ecology Progress Series, 391, 221-230, 10.3354/meps08128.
Abstract: To test the potential effects of winds on the migratory detours of shearwaters, transequatorial migrations of three shearwaters, the Manx Puffinus puffinus, the Cory's Calonectris diomedea, and the Cape Verde C. edwardsii shearwaters were tracked using geolocators. Concurrent data on the direction and strength of winds were obtained from the NASA SeaWinds scatterometer to calculate daily impedance models reflecting the resistance of sea surface winds to the shearwater movements. From these models we estimated relative wind mediated costs for the observed synthesis pathway obtained from tracked birds, for the shortest distance pathway and for other simulated alternative pathways for every day of the migration period. We also estimated daily trajectories of the minimum cost pathway and compared distance and relative costs of all pathways. Shearwaters followed 26-52% longer pathways than the shortest distance path. In general, estimated wind mediated costs of both, observed synthesis and simulated alternative pathways, were strongly dependent on the date of departure. Costs of observed synthesis pathways were about 15% greater than the synthesis pathway with the minimum cost but, in the Cory's and the Cape Verde shearwaters, these pathways were on average 15-20% shorter in distance, suggesting the extra-costs of the observed pathways are compensated by saving about 2 travelling days. In Manx shearwaters, however, the observed synthesis pathway was 25% longer distance than the lowest cost synthesis pathway, probably because birds avoided shorter but potentially more turbulent pathways. Our results suggest that winds are a major determinant of the migratory routes in seabirds.
Keywords: Migration costs, Wind influence, Bird flight, Shearwaters, Global location sensing, GLS, Geolocator
Mission: |SeaWinds|
URL: https://doi.org/10.3354/meps08128
Other URLs:
Grodsky, S.A., Bentamy, A., Carton, J.A., and Pinker, R.T. (2009). Intraseasonal Latent Heat Flux Based on Satellite Observations, Journal of Climate, 22(17), 4539-4556, 10.1175/2009JCLI2901.1. Journal Article »
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Title: Intraseasonal Latent Heat Flux Based on Satellite Observations
Type: Journal Article
Publication: Journal of Climate
Author(s): Grodsky, S.A., Bentamy, A., Carton, J.A., and Pinker, R.T.
Year: 2009
Formatted Citation: Grodsky, S.A., Bentamy, A., Carton, J.A., and Pinker, R.T., 2009: Intraseasonal Latent Heat Flux Based on Satellite Observations, Journal of Climate, 22(17), 4539-4556, 10.1175/2009JCLI2901.1.
Abstract: Weekly average satellite-based estimates of latent heat flux (LHTFL) are used to characterize spatial patterns and temporal variability in the intraseasonal band (periods shorter than 3 months). As expected, the major portion of intraseasonal variability of LHTFL is due to winds, but spatial variability of humidity and SST are also important. The strongest intraseasonal variability of LHTFL is observed at the midlatitudes. It weakens toward the equator, reflecting weak variance of intraseasonal winds at low latitudes. It also decreases at high latitudes, reflecting the effect of decreased SST and the related decrease of time-mean humidity difference between heights z = 10 m and z = 0 m. Within the midlatitude belts the intraseasonal variability of LHTFL is locally stronger (up to 50 W m^-2) in regions of major SST fronts (like the Gulf Stream and Agulhas). Here it is forced by passing storms and is locally amplified by unstable air over warm SSTs. Although weaker in amplitude (but still significant), intraseasonal variability of LHTFL is observed in the tropical Indian and Pacific Oceans due to wind and humidity perturbations produced by the Madden-Julian oscillations. In this tropical region intraseasonal LHTFL and incoming solar radiation vary out of phase so that evaporation increases just below the convective clusters. Over much of the interior ocean where the surface heat flux dominates the ocean mixed layer heat budget, intraseasonal SST cools in response to anomalously strong upward intraseasonal LHTFL. This response varies geographically, in part because of geographic variations of mixed layer depth and the resulting variations in thermal inertia. In contrast, in the eastern tropical Pacific and Atlantic cold tongue regions intraseasonal SST and LHTFL are positively correlated. This surprising result occurs because in these equatorial upwelling areas SST is controlled by advection rather than by surface fluxes. Here LHTFL responds to rather than drives SST.
Keywords: Fluxes, Latent heating/cooling, Intraseasonal variability, Mixed layer, Satellite observations
Mission:
URL: https://doi.org/10.1175/2009JCLI2901.1
Other URLs:
Gu, G. (2009). Intraseasonal Variability in the Equatorial Atlantic-West Africa During March-June, Climate Dynamics, 32(4), 457-471, 10.1007/s00382-008-0428-0. Journal Article »
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Title: Intraseasonal Variability in the Equatorial Atlantic-West Africa During March-June
Type: Journal Article
Publication: Climate Dynamics
Author(s): Gu, G.
Year: 2009
Formatted Citation: Gu, G., 2009: Intraseasonal Variability in the Equatorial Atlantic-West Africa During March-June, Climate Dynamics, 32(4), 457-471, 10.1007/s00382-008-0428-0.
Abstract: Intraseasonal (30-80 days) variability in the equatorial Atlantic-West African sector during March-June is investigated using various recently-archived satellite measurements and the NCEP/DOE AMIP-II reanalysis daily data. The global connections of regional intraseasonal signals are first examined for the period of 1979-2006 through lag-regression analyses of convection (OLR) and other dynamic components against a regional intraseasonal convective (OLR) index. The eastward-propagating features of convection can readily be seen, accompanied by coherent circulation anomalies, similar to those for the global tropical intraseasonal mode, i.e., the Madden-Julian oscillation (MJO). The regressed TRMM rainfall (3B42) anomalies during the TRMM period (1998-2006) manifest similar propagating features as for the regressed OLR anomalies during 1979-2006. These coherent features hence tend to suggest that the regional intraseasonal convective signals might be mostly a regional response to, or closely associated with the MJO, and probably contribute to the MJO`s global propagation. Atmospheric and surface intraseasonal variability during March-June of 1998-2006 are further examined using the high-quality TRMM Microwave Imager (TMI) sea surface temperature (SST), columnar water vapor, and cloud liquid water, and the QuikSCAT oceanic winds (2000-2006). Enhanced (suppressed) convection or positive (negative) rainfall anomalies approximately cover the entire basin (0A degrees-10A degrees N, 30A degrees W-10A degrees E) during the passage of intraseasonal convective signals, accompanied by anomalous surface westerly (easterly) flow. Furthermore, a unique propagating feature seems to exist within the tropical Atlantic basin. Rainfall anomalies always appear first in the northwestern basin right off the coast of South America, and gradually extend eastward to cover the entire basin. A dipolar structure of rainfall anomalies with cross-equatorial surface wind anomalies can thus be observed during this evolution, similar to the anomaly patterns on the interannual time scale discovered in past studies. Coherent intraseasonal variations and patterns can also be found in other physical components.
Keywords: QuikSCAT
Mission: |SeaWinds|
URL: https://doi.org/10.1007/s00382-008-0428-0
Other URLs:
Halkides, D., and Lee, T. (2009). Mechanisms Controlling Seasonal-to-Interannual Mixed-Layer Temperature Variability in the Southeast Tropical Indian Ocean, Journal of Geophysical Research: Oceans, 114(C2), C02012, 10.1029/2008JC004949. Journal Article »
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Title: Mechanisms Controlling Seasonal-to-Interannual Mixed-Layer Temperature Variability in the Southeast Tropical Indian Ocean
Type: Journal Article
Publication: Journal of Geophysical Research: Oceans
Author(s): Halkides, D., and Lee, T.
Year: 2009
Formatted Citation: Halkides, D., and Lee, T., 2009: Mechanisms Controlling Seasonal-to-Interannual Mixed-Layer Temperature Variability in the Southeast Tropical Indian Ocean, Journal of Geophysical Research: Oceans, 114(C2), C02012, 10.1029/2008JC004949.
Abstract: We use an Estimating the Circulation and Climate of the Ocean assimilation product to investigate seasonal-interannual mixed layer temperature (MLT) budgets in the southeastern tropical Indian Ocean (SETIO) during 1993-2006. We examine spatial inhomogeneity of the SETIO MLT budget, contrasting three subregions with different forcing/circulation characteristics to better understand the area mean budget over the full SETIO. The subregions are the equatorial zone (box 1), the Sumatra-Java upwelling zone (box 2), and east of the thermocline ridge (box 3). Seasonally, surface heat flux dominates MLT in all regions, advection and subsurface processes generally play secondary roles. On interannual scales, surface heat flux makes major contributions in all three boxes to termination of SETIO cooling associated with the Indian Ocean Zonal/Dipole Mode. Ocean dynamics show vital differences between regions: Subsurface processes cool box 1 and 2 but warm box 3. Horizontal advection warms box 1 but cools box 2 and 3. Averaging the MLT budget over the SETIO obscures regional physics. We explain spatial variations of the SETIO MLT budget in terms of differences in forcing, circulation, MLT distribution, and mixed layer and barrier layer thicknesses. We also examine SETIO MLT budget differences during 1994, 1997, and 2006, years exhibiting notable SETIO cooling events. In box 1, horizontal advection dominates warming after the 1994 and 2006 coolings, while in 1997, surface heat flux dominates warming. In box 2, cooling peaks earlier in 1994 than in 1997 and 2006 because of subsurface processes. Last, we show that the MLT budget is very different from heat budgets for fixed depth layers (e.g., the top 50-60 m).
Keywords:
Mission:
URL: https://doi.org/10.1029/2008JC004949
Other URLs:
Han, W., Moore, A., Levin, J., Zhang, B., Arango, H., Curchister, E., Di Lorenzo, E., Gordon, A., and Lin, J. (2009). Seasonal Surface Ocean Circulation and Dynamics in the Philippine Archipelago Region During 2004-2008, Dynamics of Atmospheres and Oceans, 47(1-3), 114-137, 10.1016/j.dynatmoce.2008.10.007. Journal Article »
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Title: Seasonal Surface Ocean Circulation and Dynamics in the Philippine Archipelago Region During 2004-2008
Type: Journal Article
Publication: Dynamics of Atmospheres and Oceans
Author(s): Han, W., Moore, A., Levin, J., Zhang, B., Arango, H., Curchister, E., Di Lorenzo, E., Gordon, A., and Lin, J.
Year: 2009
Formatted Citation: Han, W., Moore, A., Levin, J., Zhang, B., Arango, H., Curchister, E., Di Lorenzo, E., Gordon, A., and Lin, J., 2009: Seasonal Surface Ocean Circulation and Dynamics in the Philippine Archipelago Region During 2004-2008, Dynamics of Atmospheres and Oceans, 47(1-3), 114-137, 10.1016/j.dynatmoce.2008.10.007.
Abstract: The dynamics of the seasonal surface circulation in the Philippine Archipelago (117°E-128°E, 0°N-14°N) are investigated using a high-resolution configuration of the Regional Ocean Modeling System (ROMS) for the period of January 2004-March 2008. Three experiments were performed to estimate the relative importance of local, remote and tidal forcing. On the annual mean, the circulation in the Sulu Sea shows inflow from the South China Sea at the Mindoro and Balabac Straits, outflow into the Sulawesi Sea at the Sibutu Passage, and cyclonic circulation in the southern basin. A strong jet with a maximum speed exceeding 100 cm s^-1 forms in the northeast Sulu Sea where currents from the Mindoro and Tablas Straits converge. Within the Archipelago, strong westward currents in the Bohol Sea carry the surface water of the western Pacific (WP) from the Surigao Strait into the Sulu Sea via the Dipolog Strait. In the Sibuyan Sea, currents flow westward, which carry the surface water from the WP near the San Bernardino Strait into the Sulu Sea via the Tablas Strait. These surface currents exhibit strong variations or reversals from winter to summer. The cyclonic (anticyclonic) circulation during winter (summer) in the Sulu Sea and seasonally reversing currents within the Archipelago region during the peak of the winter (summer) monsoon result mainly from local wind forcing, while remote forcing dominates the current variations at the Mindoro Strait, western Sulu Sea and Sibutu passage before the monsoons reach their peaks. The temporal variations (with the mean removed), also referred to as anomalies, of volume transports in the upper 40 m at eight major Straits are caused predominantly by remote forcing, although local forcing can be large during sometime of a year. For example, at the Mindoro Strait, the correlation between the time series of transport anomalies due to total forcing (local, remote and tides) and that due only to the remote forcing is 0.81 above 95% significance, comparing to the correlation of 0.64 between the total and local forcing. Similarly, at the Sibutu Passage, the correlation is 0.96 for total versus remote effects, comparing to 0.53 for total versus local forcing. The standard deviations of transports from the total, remote and local effects are 0.59 Sv, 0.50 Sv, and 0.36 Sv, respectively, at the Mindoro Strait, and 1.21 Sv, 1.13 Sv, and 0.59 Sv at the Sibutu Passage. Nonlinear rectification of tides reduces the mean westward transports at the Surigao, San Bernardino and Dipolog Straits, and it also has non-negligible influence on the seasonal circulation in the Sulu Sea.
Keywords: Philippine Archipelago, Straits, Circulation and dynamics, Transport
Mission:
URL: https://doi.org/10.1016/j.dynatmoce.2008.10.007
Other URLs:
Hareesh Kumar, P.V., Joshi, M., Sanilkumar, K.V., Rao, A.D., Anand P., Anil Kumar, K., and Prasada Rao, C.V.K. (2009). Growth and Decay of the Arabian Sea Mini Warm Pool During May 2000: Observations and Simulations, Deep-Sea Research Part I: Oceanographic Research Papers, 56(4), 528-540, 10.1016/j.dsr.2008.12.004. Journal Article »
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Title: Growth and Decay of the Arabian Sea Mini Warm Pool During May 2000: Observations and Simulations
Type: Journal Article
Publication: Deep-Sea Research Part I: Oceanographic Research Papers
Author(s): Hareesh Kumar, P.V., Joshi, M., Sanilkumar, K.V., Rao, A.D., Anand P., Anil Kumar, K., and Prasada Rao, C.V.K.
Year: 2009
Formatted Citation: Hareesh Kumar, P.V., Joshi, M., Sanilkumar, K.V., Rao, A.D., Anand P., Anil Kumar, K., and Prasada Rao, C.V.K., 2009: Growth and Decay of the Arabian Sea Mini Warm Pool During May 2000: Observations and Simulations, Deep-Sea Research Part I: Oceanographic Research Papers, 56(4), 528-540, 10.1016/j.dsr.2008.12.004.
Abstract: Oceanographic surveys were carried out in the southeastern Arabian Sea in two phases during 14-17 May and 23-27 May 2000 to study the evolution of the Arabian Sea mini warm pool. The hydrographic data collected during these experiments, satellite imagery of sea surface temperature for the corresponding period and ship drift data were utilized for this purpose. Both satellite and in situ observations indicated the presence of a mini warm pool up to 14 May and its dissipation thereafter. The Arabian Sea mini warm pool region was characterized by low-salinity Bay of Bengal water (<22 sigma-t). This watermass was advected into the southeastern Arabian Sea by the East India Coastal Current mainly during November-January and recirculated in this region in an anticyclonic eddy. Immediately after the dissipation of the mini warm pool, this watermass could not be traced in this region. Simulation of mini warm pool characteristics using the Princeton Ocean Model (POM) agreed well with in situ and satellite observations. Moreover, the model showed strengthening of southerly currents in the warm pool region during its dissipation period, which caused the disappearance of the Bay of Bengal watermass. Specific experiments with the POM revealed the significance of heat flux components, low wind speed and salinity stratification in the formation and sustenance of the mini warm pool.
Keywords: QuikSCAT
Mission: |SeaWinds|
URL: https://doi.org/10.1016/j.dsr.2008.12.004
Other URLs:
Hermes, J.C. and Reason, C.J.C. (2009). Variability in Sea-Surface Temperature and Winds in the Tropical South-East Atlantic Ocean and Regional Rainfall Relationships, International Journal of Climatology, 29(1), 11-21, 10.1002/joc.1711. Journal Article »
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Title: Variability in Sea-Surface Temperature and Winds in the Tropical South-East Atlantic Ocean and Regional Rainfall Relationships
Type: Journal Article
Publication: International Journal of Climatology
Author(s): Hermes, J.C. and Reason, C.J.C.
Year: 2009
Formatted Citation: Hermes, J.C. and Reason, C.J.C., 2009: Variability in Sea-Surface Temperature and Winds in the Tropical South-East Atlantic Ocean and Regional Rainfall Relationships, International Journal of Climatology, 29(1), 11-21, 10.1002/joc.1711.
Abstract: Variability in sea-surface temperature (SST) and winds in the Angola Benguela frontal zone (ABFZ) in the tropical south-east Atlantic Ocean has previously been shown to be important for regional fisheries and for seasonal rainfall anomalies over Angola/Namibia in austral summer and coastal West Africa in boreal summer. This study investigates intraseasonal variability in winds and SST over this region using QuikSCAT and tropical rainfall measuring mission (TRMM) satellite data for 1999-2004. Wavelet analyses reveal periods of relatively strong power in the 20-30 or 30-64 day frequency bands throughout the record but that there is substantial interannual variability in the occurrence of these intraseasonal oscillations. The implications of this variability for seasonal rainfall anomalies during the main rainy seasons in southern Africa (austral summer) and coastal West Africa (boreal summer) are discussed.
Keywords: QuikSCAT
Mission: |SeaWinds|
URL: https://doi.org/10.1002/joc.1711
Other URLs:
Hong, H.S., Zhang, C.Y., Shang, S.L., Huang, B.Q., Li, Y.H., Li, X.D., and Zhang, S.M. (2009). Interannual Variability of Summer Coastal Upwelling in the Taiwan Strait, Continental Shelf Research, 29(2), 479-484, 10.1016/j.csr.2008.11.007. Journal Article »
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Title: Interannual Variability of Summer Coastal Upwelling in the Taiwan Strait
Type: Journal Article
Publication: Continental Shelf Research
Author(s): Hong, H.S., Zhang, C.Y., Shang, S.L., Huang, B.Q., Li, Y.H., Li, X.D., and Zhang, S.M.
Year: 2009
Formatted Citation: Hong, H.S., Zhang, C.Y., Shang, S.L., Huang, B.Q., Li, Y.H., Li, X.D., and Zhang, S.M., 2009: Interannual Variability of Summer Coastal Upwelling in the Taiwan Strait, Continental Shelf Research, 29(2), 479-484, 10.1016/j.csr.2008.11.007.
Abstract: This study dealt with the interannual variability of summer coastal upwelling in the Taiwan Strait, based on empirical orthogonal function (EOF) analysis. Three datasets were used for the analysis: the National Oceanic and Atmospheric Administration (NOAA), Advanced Very High Resolution Radiometer (AVHRR) sea surface temperature dataset from 1985 to 2005, hydrographic records at two coastal stations from 1970 to 2001, and cruise measurements in 1988 and 2004. The results indicated that the first mode (85.3%) of the spatial variance showed a persistent front, which was generally aligned northeast–southwestward in the western Taiwan Strait. This front separated colder water on the west side from warmer water on the east side. The eigenvector time series showed that the variability of this front with time was closely correlated with the change in the wind stress anomaly of the alongshore wind component, derived from 17 years of the European remote sensing (ERS) satellite and QuickScat wind dataset from 1992 to 2005. Records of water temperature and salinity anomaly at Pingtan Island (Is.) located in the northwestern Taiwan Strait, and Dongshan Is. located in the southwestern Taiwan Strait, showed that a negative temperature anomaly appeared along with a positive salinity anomaly in some years. This suggested a dominant influence of cold and saline upwelling water at the surface. The years of notable cooling events derived from the station measurements were generally consistent with the time series of the EOF Mode 1. The change in upwelling derived from cruise measurements further confirmed the change shown by the EOF Mode 1 time series. These 1985–2005 results indicated that for the entire western Taiwan Strait summer coastal upwelling was strong in 1987, 1993, and 1998, and that upwelling in the northwest and the southwest Taiwan Strait showed different behavior. A delayed ENSO (El Niño Southern Oscillation) effect was suggested as a major mechanism for the interannual variability of Taiwan Strait coastal upwelling.
Keywords: Coastal upwelling, EOF, Remote sensing, Interannual variability, ENSO, Taiwan Strait
Mission:
URL: https://doi.org/10.1016/j.csr.2008.11.007
Other URLs:
Hong, L., Jones, W.L., Wilheit, T.T., and Kasparis, T. (2009). Two Approaches for Inter-Satellite Radiometer Calibrations between TMI and WindSat, Journal of the Meteorological Society of Japan, 87A, 223-235, 10.2151/jmsj.87A.223. Journal Article »
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Title: Two Approaches for Inter-Satellite Radiometer Calibrations between TMI and WindSat
Type: Journal Article
Publication: Journal of the Meteorological Society of Japan
Author(s): Hong, L., Jones, W.L., Wilheit, T.T., and Kasparis, T.
Year: 2009
Formatted Citation: Hong, L., Jones, W.L., Wilheit, T.T., and Kasparis, T., 2009: Two Approaches for Inter-Satellite Radiometer Calibrations between TMI and WindSat, Journal of the Meteorological Society of Japan, 87A, 223-235, 10.2151/jmsj.87A.223.
Abstract: This paper presents recent progress in inter-satellite microwave radiometric cross-calibration to eliminate brightness temperature measurement biases between a pair of radiometer channels operating at slightly different frequencies and incidence angles. The motivation of this research is to develop robust analytical cross-calibration techniques for inter-calibration of various satellite radiometer instruments, with the first projected application being the multi-satellite Global Precipitation Measurement (GPM) constellation to be launched in 2013. The significance of this work is that it will allow the formation of consistent multi-decadal time series of geophysical measurements for multiple satellite microwave radiometers that are free of instrumental biases and other long-term changes in radiometric calibration, which will allow researchers to study global climate change. Descriptions are given for two independent calibration techniques: a Taylor series expansion of the oceanic brightness temperature (Tb) spectrum between dissimilar radiometer channels and a non-linear regression among multi-channel Tb measurements. In the first approach, predictions were made of Tb`s at a destination frequency from Tb`s of a close by source frequency by expansion of the oceanic brightness temperature spectrum in a Taylor series centered at the source frequency. The relationships between Tb`s and frequencies were derived from simulations using a radiative transfer model (RTM), which accounts for the total collected emissions from the ocean surface and the atmosphere. Further, earth incidence angle differences between radiometer channels were transformed in a similar manner using the partial derivatives of Tb with incidence angle derived from RTM simulations. In the second approach, we used a prediction algorithm that relies on the correlation between radiometer Tb`s at various frequencies and polarizations and which uses a regression on the Tb`s and their non-linear transformations developed using an independent radiative transfer model. As a demonstration, near-simultaneous pair-wise ocean Tb comparisons are presented between the TRMM Microwave Imager (TMI), which is not sun synchronous, and the sun-synchronous polar orbiting WindSat, using oceanic Tb observations from 2003-04. The corresponding results between these two inter-satellite calibration techniques are highly correlated, and results demonstrate that fixed channel-by-channel differences, of order 1-2 K exist between TMI and WindSat. These are significant radiometric calibration differences, which can be removed prior to forming joint data sets of geophysical parameter retrievals.
Keywords:
Mission: |WindSat|
URL: https://doi.org/10.2151/jmsj.87A.223
Other URLs:
Howell, S.E.L., Brown, L.C., Kang, K.-K., and Duguay, C.R. (2009). Variability in Ice Phenology on Great Bear Lake and Great Slave Lake, Northwest Territories, Canada, from SeaWinds/QuikSCAT: 2000-2006, Remote Sensing of Environment, 113(4), 816-834, 10.1016/j.rse.2008.12.007. Journal Article »
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Title: Variability in Ice Phenology on Great Bear Lake and Great Slave Lake, Northwest Territories, Canada, from SeaWinds/QuikSCAT: 2000-2006
Type: Journal Article
Publication: Remote Sensing of Environment
Author(s): Howell, S.E.L., Brown, L.C., Kang, K.-K., and Duguay, C.R.
Year: 2009
Formatted Citation: Howell, S.E.L., Brown, L.C., Kang, K.-K., and Duguay, C.R., 2009: Variability in Ice Phenology on Great Bear Lake and Great Slave Lake, Northwest Territories, Canada, from SeaWinds/QuikSCAT: 2000-2006, Remote Sensing of Environment, 113(4), 816-834, 10.1016/j.rse.2008.12.007.
Abstract: The temporal evolution of the backscatter coefficient, σ° from QuikSCAT was evaluated for monitoring ice phenology on Great Bear Lake (66^oN, 121^oW) and Great Slave Lake (614^oN, 114^oW), Northwest Territories, Canada. Results indicated that from QuikSCAT can be used to detect melt onset, water clear of ice and freeze onset dates on both lakes. An ice phenology algorithm was then developed to assess the spatiotemporal variability on both lakes from QuikSCAT for the period 2000-2006. Results showed that for Great Slave Lake, the average melt onset date occurred on year day (YD) 123, the average water clear of ice date was on YD164, and the average freeze onset date was on YD330. On Great Bear Lake, the average melt onset date occurred on YD139, the average water clear of ice date was YD191, and the average freeze onset date was YD321. Ice cover remained present for at least five weeks longer on Great Bear Lake than on Great Slave Lake and most of the difference can be explained by earlier ice melt on Great Slave Lake. Spatially, on Great Bear Lake, melt onset took place first in the eastern arm, water clear of ice occurred first in southeastern and western arms, and freeze onset appeared first in the northern arm and along the shorelines. On Great Slave Lake, melt onset began first in the central basin and then progressed to the northern and eastern arms later in the season. The central basin of Great Slave Lake cleared earlier than the periphery due to the discharge from the Slave River. Freeze onset on Great Slave Lake occurred first within the east arm, closely followed by the north and west arms, and then finally in the centre of the main basin.
Keywords: QuikSCAT, Seawinds
Mission: |SeaWinds|
URL: https://doi.org/10.1016/j.rse.2008.12.007
Other URLs:
Huang, X., Huang, B., and Li, H. (2009). A Fast Level Set Method for Synthetic Aperture Radar Ocean Image Segmentation, Sensors, 9(2), 814-829, 10.3390/s90200814. Journal Article »
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Title: A Fast Level Set Method for Synthetic Aperture Radar Ocean Image Segmentation
Type: Journal Article
Publication: Sensors
Author(s): Huang, X., Huang, B., and Li, H.
Year: 2009
Formatted Citation: Huang, X., Huang, B., and Li, H., 2009: A Fast Level Set Method for Synthetic Aperture Radar Ocean Image Segmentation, Sensors, 9(2), 814-829, 10.3390/s90200814.
Abstract: Segmentation of high noise imagery like Synthetic Aperture Radar (SAR) images is still one of the most challenging tasks in image processing. While level set, a novel approach based on the analysis of the motion of an interface, can be used to address this challenge, the cell-based iterations may make the process of image segmentation remarkably slow, especially for large-size images. For this reason fast level set algorithms such as narrow band and fast marching have been attempted. Built upon these, this paper presents an improved fast level set method for SAR ocean image segmentation. This competent method is dependent on both the intensity driven speed and curvature flow that result in a stable and smooth boundary. Notably, it is optimized to track moving interfaces for keeping up with the point-wise boundary propagation using a single list and a method of fast up-wind scheme iteration. The list facilitates efficient insertion and deletion of pixels on the propagation front. Meanwhile, the local up-wind scheme is used to update the motion of the curvature front instead of solving partial differential equations. Experiments have been carried out on extraction of surface slick features from ERS-2 SAR images to substantiate the efficacy of the proposed fast level set method.
Keywords: Image Segmentation, Fast Level set, Synthetic Aperture Radar Ocean Image
Mission:
URL: https://doi.org/10.3390/s90200814
Other URLs:
Jin, X., Dong, C., Kurian, J., McWilliams, J.C., Chelton, D.B., and Li, Z. (2009). SST-Wind Interaction in Coastal Upwelling: Oceanic Simulation with Empirical Coupling, Journal of Physical Oceanography, 39(11), 2957-2970, 10.1175/2009JPO4205.1. Journal Article »
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Title: SST-Wind Interaction in Coastal Upwelling: Oceanic Simulation with Empirical Coupling
Type: Journal Article
Publication: Journal of Physical Oceanography
Author(s): Jin, X., Dong, C., Kurian, J., McWilliams, J.C., Chelton, D.B., and Li, Z.
Year: 2009
Formatted Citation: Jin, X., Dong, C., Kurian, J., McWilliams, J.C., Chelton, D.B., and Li, Z., 2009: SST-Wind Interaction in Coastal Upwelling: Oceanic Simulation with Empirical Coupling, Journal of Physical Oceanography, 39(11), 2957-2970, 10.1175/2009JPO4205.1.
Abstract: Observations, primarily from satellites, have shown a statistical relationship between the surface wind stress and underlying sea surface temperature (SST) on intermediate space and time scales, in many regions inclusive of eastern boundary upwelling current systems. In this paper, this empirical SST–wind stress relationship is utilized to provide a simple representation of mesoscale air–sea coupling for an oceanic model forced by surface winds, namely, the Regional Oceanic Modeling System (ROMS). This model formulation is applied to an idealized upwelling problem with prevailing equatorward winds to determine the coupling consequences on flow, SST, stratification, and wind evolutions. The initially uniform wind field adjusts through coupling to a cross-shore profile with weaker nearshore winds, similar to realistic ones. The modified wind stress weakens the nearshore upwelling circulation and increases SST in the coastal zone. The SST-induced wind stress curl strengthens offshore upwelling through Ekman suction. The total curl-driven upwelling exceeds the coastal upwelling. The SST-induced changes in the nearshore wind stress field also strengthen and broaden the poleward undercurrent. The coupling also shows significant impact on the developing mesoscale eddies by damaging cyclonic eddies more than anticyclonic eddies, which leads to dominance by the latter. Dynamically, this is a consequence of cyclones with stronger SST gradients that induce stronger wind perturbations in this particular upwelling problem and that are therefore generally more susceptible to disruption than anticyclones at finite Rossby number. The net effect is a weakening of eddy kinetic energy.
Keywords: Sea surface temperature, Wind, Coastal meteorology, Upwelling/downwelling, Atmosphere-ocean interaction
Mission:
URL: https://doi.org/10.1175/2009JPO4205.1
Other URLs:
Jing, Z.-y., Qi, Y.-q., Hua, Z.-l., and Zhang, H. (2009). Numerical Study on the Summer Upwelling System in the Northern Continental Shelf of the South China Sea, Continental Shelf Research, 29(2), 467-478, 10.1016/j.csr.2008.11.008. Journal Article »
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Title: Numerical Study on the Summer Upwelling System in the Northern Continental Shelf of the South China Sea
Type: Journal Article
Publication: Continental Shelf Research
Author(s): Jing, Z.-y., Qi, Y.-q., Hua, Z.-l., and Zhang, H.
Year: 2009
Formatted Citation: Jing, Z.-y., Qi, Y.-q., Hua, Z.-l., and Zhang, H., 2009: Numerical Study on the Summer Upwelling System in the Northern Continental Shelf of the South China Sea, Continental Shelf Research, 29(2), 467-478, 10.1016/j.csr.2008.11.008.
Abstract: A three-dimensional baroclinic nonlinear numerical model is employed to investigate the summer upwelling in the northern continental shelf of the South China Sea (NCSCS) and the mechanisms of the local winds inducing the coastal upwelling, associated with the QuikSCAT wind data. First, the persistent signals of the summer upwelling are illustrated by the climatological the Advanced Very High-Resolution Radiometer (AVHRR) Sea Surface Temperature (SST) image over 1985-2006 and field observations in 2006 summer. Then, after the successful simulation of the summer upwelling in the NCSCS, four numerical experiments are conducted to explore the different effects of local winds, including the wind stress and wind stress curl, on the coastal upwelling in two typical strong summer upwelling regions of the NCSCS. The modeled results indicate that the summer upwelling is a seasonal common phenomenon during June-September in the NCSCS with the spatial extent of a basin-scale. Typical continental shelf upwelling characteristics are clearly shown in the coastal surface and subsurface water, such as low temperature, high salinity and high potential density in the east of the Hainan Island, the east of the Leizhou Peninsula and the southeast of the Zhanjiang Bay (noted as the Qiongdong-QD), and the inshore areas from the Shantou Coast to the Nanri Islands of the Fujian Coast (noted as the Yuedong-YD). The analysis of the QuikSCAT wind data and modeled upwelling index suggests that the local winds play significant roles in causing the coastal upwelling, but the alongshore wind stress and wind stress curl have different contributions to the upwelling in the Qiongdong (QDU) and the coastal upwelling in the Yuedong (YDU), respectively. Furthermore, model results from the numerical experiments show that in the YD the stable alongshore wind stress is a very important dynamic factor to induce the coastal upwelling but the wind stress curl has little contribution and even unfavorable to the YDU. However, in the QD the coastal upwelling is strongly linked to the local wind stress curl. It is also found that not only the offshore Ekman transport driven by the alongshore wind stress, the wind stress curl-induced Ekman pumping also plays a crucial effect on the QDU. Generally, the wind stress curl even has more contributions to the QDU than the alongshore wind stress.
Keywords: QuikSCAT
Mission: |SeaWinds|
URL: https://doi.org/10.1016/j.csr.2008.11.008
Other URLs:
Kara, A.B., Wallcraft, A.J., Martin, P.J., and Pauley, R.L. (2009). Optimizing Surface Winds Using QuikSCAT Measurements in the Mediterranean Sea During 2000-2006, Journal of Marine Systems, 78(Supplement), S119-S131, 10.1016/j.jmarsys.2009.01.020. Journal Article »
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Title: Optimizing Surface Winds Using QuikSCAT Measurements in the Mediterranean Sea During 2000-2006
Type: Journal Article
Publication: Journal of Marine Systems
Author(s): Kara, A.B., Wallcraft, A.J., Martin, P.J., and Pauley, R.L.
Year: 2009
Formatted Citation: Kara, A.B., Wallcraft, A.J., Martin, P.J., and Pauley, R.L., 2009: Optimizing Surface Winds Using QuikSCAT Measurements in the Mediterranean Sea During 2000-2006, Journal of Marine Systems, 78(Supplement), S119-S131, 10.1016/j.jmarsys.2009.01.020.
Abstract: Interannual variability of wind speed at 10 m above the sea surface is investigated over the Mediterranean Sea, with a particular focus near land–sea boundaries. For this purpose, monthly mean winds are formed at a resolution of 0.25° using twice-daily, rain-free, wind measurements calibrated to equivalent neutral winds from the QuikSCAT satellite during 2000–2006. A stability correction applied to these satellite-based winds reveals that the equivalent neutral winds are typically stronger by 0.2 ms? 1, and can even be stronger by > 0.5 ms? 1 in some regions, including the Adriatic and Aegean Seas. Thus, the impact of air–sea stratification on the winds cannot be neglected, even on monthly time scales. Winds from a numerical weather prediction (NWP) model, the 0.5°-resolution Navy Operational Global Atmospheric Prediction System (NOGAPS), are found to have close agreement with the satellite-based winds. However, major differences arise near coastal boundaries where the winds from NOGAPS over the sea are contaminated by wind values over the land. Land–sea mask values from NOGAPS are introduced to examine the extent of the contamination, which can be severe (e.g., 2 ms? 1 weaker) in comparison with QuikSCAT winds, especially near the northern boundaries. A creeping sea-fill methodology applied to the NOGAPS winds typically results in better agreement with the satellite winds. The accuracy of the NOGAPS winds is further improved by correcting them based on the satellite winds using a linear regression analysis. Finally, a 3.5-km-resolution HYbrid Coordinate Ocean Model (HYCOM) is forced with these original, sea-filled and regression-corrected NOGAPS winds. Sea-surface temperatures (SSTs) simulated by HYCOM demonstrate that the land-contaminated original winds from NOGAPS result in a relatively warm SST bias of > 2 °C in comparison to a satellite-SST analysis near the coastal boundaries. Sea-filled and regression-corrected winds significantly improve the accuracy of the SSTs from the model. The results presented in this paper clearly reveal that (1) stability dependence in the satellite winds cannot be ignored and (2) winds from a NWP product (NOGAPS here) over the sea may not be accurate near land–sea boundaries due to contamination by land values and can be improved either locally or via a regression against QuikSCAT winds.
Keywords: Mediterranean Sea, Coastal winds, QuikSCAT, Land contamination, HYCOM
Mission: |SeaWinds|
URL: https://doi.org/10.1016/j.jmarsys.2009.01.020
Other URLs:
Kumar, R., Bhowmick, S.A., Ray, S., Bhatt, V., Surendran, S., Basu, S., Sarkar, A., and Agarwal, V.K. (2009). Improvement in Predictability of Waves Over the Indian Ocean, Natural Hazards, 49(2), 275-291, 10.1007/s11069-008-9310-y. Journal Article »
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Title: Improvement in Predictability of Waves Over the Indian Ocean
Type: Journal Article
Publication: Natural Hazards
Author(s): Kumar, R., Bhowmick, S.A., Ray, S., Bhatt, V., Surendran, S., Basu, S., Sarkar, A., and Agarwal, V.K.
Year: 2009
Formatted Citation: Kumar, R., Bhowmick, S.A., Ray, S., Bhatt, V., Surendran, S., Basu, S., Sarkar, A., and Agarwal, V.K., 2009: Improvement in Predictability of Waves Over the Indian Ocean, Natural Hazards, 49(2), 275-291, 10.1007/s11069-008-9310-y.
Abstract: Accurate prediction of ocean surface waves is a challenging task with many associated difficulties. Availability of good quality wind and wave information from satellite platforms inspired the scientific community to assimilate such data in various spectral wave models for enhancing the accuracy of prediction. Over the Indian Ocean, which is the region of interest for the present study, wave heights in extreme situation can go up to 12-14 m, thereby increasing the probability of coastal hazards. This region is further governed by the southern ocean swells that propagate thousands of kilometers. These are, in general, not well captured by the spectral wave models. Therefore, assimilation of altimeter data in open ocean wave model WAM has been attempted with the aim of enhancing the quality of prediction of significant wave height. Further, simulated wave spectra have been assimilated in a coastal wave model SWAN. This assimilation has been found to significantly improve the prediction of the height of wind waves as well as swell waves.
Keywords: QuikSCAT
Mission: |SeaWinds|
URL: https://doi.org/10.1007/s11069-008-9310-y
Other URLs:
Kumari, B. and Babu, K.N. (2009). Provincial Nature of Chlorophyll and Sea Surface Temperature Observed by Satellite, International Journal of Remote Sensing, 30(4), 1091-1097, 10.1080/01431160802406263. Journal Article »
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Title: Provincial Nature of Chlorophyll and Sea Surface Temperature Observed by Satellite
Type: Journal Article
Publication: International Journal of Remote Sensing
Author(s): Kumari, B. and Babu, K.N.
Year: 2009
Formatted Citation: Kumari, B. and Babu, K.N., 2009: Provincial Nature of Chlorophyll and Sea Surface Temperature Observed by Satellite, International Journal of Remote Sensing, 30(4), 1091-1097, 10.1080/01431160802406263.
Abstract: Monthly composite SeaWiFS derived chlorophyll, National Oceanic and Atmospheric Administration (NOAA) Advanced Very High Resolution Radiometer (AVHRR) derived sea surface temperature (SST) and QuikScat derived wind data of 2003-2005 (January-December) were analysed to study the provincial nature of chlorophyll-a (chl-a), SST and wind speed in the Arabian sea and Bay of Bengal. The study was confined to five provinces, three in the Arabian Sea and two in the Bay of Bengal. Results indicate provincial variability in the SST-chl-a relation. It suggests that the correlation between chlorophyll and SST is not always negative. A negative correlation was observed in provinces 1, 2 and 3 for all the seasons, whereas, except for the month of January-February, it was positively correlated for province 4. Analysis shows the provincial specific nature of chlorophyll variability to physical forcing and suggests that treatment of such a problem should not be undertaken on the basin scale.
Keywords: QuikSCAT
Mission: |SeaWinds|
URL: https://doi.org/10.1080/01431160802406263
Other URLs:
Li, X., Li, X., and He, M. (2009). Coastal Upwelling Observed by Multi-Satellite Sensors, Science in China Series D-Earth Sciences, 52(7), 1030-1038, 10.1007/s11430-009-0088-x. Journal Article »
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Title: Coastal Upwelling Observed by Multi-Satellite Sensors
Type: Journal Article
Publication: Science in China Series D-Earth Sciences
Author(s): Li, X., Li, X., and He, M.
Year: 2009
Formatted Citation: Li, X., Li, X., and He, M., 2009: Coastal Upwelling Observed by Multi-Satellite Sensors, Science in China Series D-Earth Sciences, 52(7), 1030-1038, 10.1007/s11430-009-0088-x.
Abstract: Coastal upwelling phenomenon along the China coast in the Yellow Sea during August 2007 is studied using ENVISAT Advanced Synthetic Aperture Radar (ASAR) data, NOAA Advanced AVHRR series Sea Surface Temperature (SST) data, and NASA QuikSCAT Scatterometer ocean surface wind data. A dark pattern in an ASAR image is interpreted as coastal upwelling. This is because the natural biogenic slicks associated with coastal upwelling damp the Bragg waves on the sea surface and thus make the surface smoother. Most of the incoming radar energy is reflected in the forward direction. As a result, the radar backscatter signal is very weak. Analyzing the concurrent AVHRR SST image, we find that the dark pattern in the ASAR image is indeed corresponding to the low SST area. The wind retrieval in the slicks dominant region is biased due to the low Normalised Radar Cross Section (NRCS) associated with the coastal upwelling. We applied a SST correction to the NRCS values to improve the accuracy of wind retrieval from ASAR data.
Keywords: QuikSCAT
Mission: |SeaWinds|
URL: https://doi.org/10.1007/s11430-009-0088-x
Other URLs:
Liang, W., Han-cheng, L., Xiao-bin, P., and Yun, Z. (2009). Correction of Asymmetric Strengthening of Quikscat Wind Field and Assimilation Application in Typhoon Simulation, Journal of Tropical Meteorology, 15(1), 78-82, 10.3969/j.issn.1006-8775.2009.01.013. Journal Article »
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Title: Correction of Asymmetric Strengthening of Quikscat Wind Field and Assimilation Application in Typhoon Simulation
Type: Journal Article
Publication: Journal of Tropical Meteorology
Author(s): Liang, W., Han-cheng, L., Xiao-bin, P., and Yun, Z.
Year: 2009
Formatted Citation: Liang, W., Han-cheng, L., Xiao-bin, P., and Yun, Z., 2009: Correction of Asymmetric Strengthening of Quikscat Wind Field and Assimilation Application in Typhoon Simulation, Journal of Tropical Meteorology, 15(1), 78-82, 10.3969/j.issn.1006-8775.2009.01.013.
Abstract: As an approach to the technological problem that the wind data of QuikSCAT scatterometer cannot accurately describe the zone of typhoon-level strong wind speed. some objective factors such as the typhoon moving speed. direction and friction are introduced in this study to construct the asymmetric strethening of the QuikSCAT wind field. Then by adopting a technology of four-dimensional data assimilation. an experiment that includes both the assimilation and forecasting phases is designed to simulate Typhoon Rananim numerically. The results show that with model constraints and adjustment, this technology can incorporate the QuikSCAT wind data to the entire column of the model atmosphere. improve greatly the simulating effects of the whole-column wind. pressure field and the track as well as the Simulated typhoon intensity covered by the forecast phase. and work positively for the forecasting of landfall locations.
Keywords: QuikSCAT
Mission: |SeaWinds|
URL: https://doi.org/10.3969/j.issn.1006-8775.2009.01.013
Other URLs:
Lin, I.-I.; Chen, C.-H.; Pun, I.-F.; Liu, W.T.; Wu, C.-C. (2009). Warm ocean anomaly, air sea fluxes, and the rapid intensification of tropical cyclone Nargis (2008), Geophysical Research Letters, 36(3), 10.1029/2008GL035815. Journal Article »
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Title: Warm ocean anomaly, air sea fluxes, and the rapid intensification of tropical cyclone Nargis (2008)
Type: Journal Article
Publication: Geophysical Research Letters
Author(s): Lin, I.-I.; Chen, C.-H.; Pun, I.-F.; Liu, W.T.; Wu, C.-C.
Year: 2009
Formatted Citation: Lin, I.-I.; Chen, C.-H.; Pun, I.-F.; Liu, W.T.; Wu, C.-C., 2009: Warm ocean anomaly, air sea fluxes, and the rapid intensification of tropical cyclone Nargis (2008), Geophysical Research Letters, 36(3), 10.1029/2008GL035815.
Abstract:
Keywords:
Mission:
URL: http://www.agu.org/pubs/crossref/2009/2008GL035815.shtml
Other URLs:
Lin, W. and Dong, X. (2009). Wind Retrieval Simulation of a Rotating Range-Gated Fanbeam Scatterometer with Antennas of Different Gain Pattern, Acta Electronica Sinica, 37(3), 494-499. Journal Article »
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Title: Wind Retrieval Simulation of a Rotating Range-Gated Fanbeam Scatterometer with Antennas of Different Gain Pattern
Type: Journal Article
Publication: Acta Electronica Sinica
Author(s): Lin, W. and Dong, X.
Year: 2009
Formatted Citation: Lin, W. and Dong, X., 2009: Wind Retrieval Simulation of a Rotating Range-Gated Fanbeam Scatterometer with Antennas of Different Gain Pattern, Acta Electronica Sinica, 37(3), 494-499.
Abstract: A Ku-band rotating, range-gated, fanbeam spaceborne scatterometer and its main parameters are described in this paper. This scatterometer is designed for a polar-orbit satellite with an orbit height of 500km. By simulation, the wind retrieval qualities with different antenna types are compared, and then two important parameters of the antenna, the two-way antenna gain and the half power beam-width in the range direction, are optimized, for an expected swath width of more than 1000km. It is concluded that the two-way antenna gain should be no less than 51.5dB, and - 3dB beam width along the range direction (the elevation direction) is about 25degree. The results show that this new kind of scatterometer has better performance in wind retrieval compared with the spaceborne pencil-beam radar scatterometer, such as SeaWinds. Especially, the quality of retrieved wind direction can be improved significantly by this new system, under high wind-speed conditions.
Keywords: Seawinds
Mission: |SeaWinds|
URL: https://www.researchgate.net/publication/262002451_Wind_retrieval_simulation_of_a_rotating_range-gated_fanbeam_scatterometer_with_antennas_of_different_gain_pattern
Other URLs:
Liu, C.-C., Chang, C.-H., Wen, C.-G., Huang, C.-H., Hung, J.-J., and Liu, J.T. (2009). Using Satellite Observations of Ocean Color to Categorize the Dispersal Patterns of River-Borne Substances in the Gaoping (Kaoping) River, Shelf and Canyon System, Journal of Marine Systems, 76(4), 496-510, 10.1016/j.jmarsys.2007.11.013. Journal Article »
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Title: Using Satellite Observations of Ocean Color to Categorize the Dispersal Patterns of River-Borne Substances in the Gaoping (Kaoping) River, Shelf and Canyon System
Type: Journal Article
Publication: Journal of Marine Systems
Author(s): Liu, C.-C., Chang, C.-H., Wen, C.-G., Huang, C.-H., Hung, J.-J., and Liu, J.T.
Year: 2009
Formatted Citation: Liu, C.-C., Chang, C.-H., Wen, C.-G., Huang, C.-H., Hung, J.-J., and Liu, J.T., 2009: Using Satellite Observations of Ocean Color to Categorize the Dispersal Patterns of River-Borne Substances in the Gaoping (Kaoping) River, Shelf and Canyon System, Journal of Marine Systems, 76(4), 496-510, 10.1016/j.jmarsys.2007.11.013.
Abstract: Mapping the water constituents from remotely sensed ocean color data enables a better understanding of the dispersal patterns of river-borne substances in the Gaoping (formerly spelled Kaoping) River, Shelf and Canyon (KPRSC) system. Based on twelve MODIS-Aqua images in the KPRSC region taken in 2005, we apply a newly developed GA-SA approach to derive maps of chlorophyll-a concentration (Chl-a), colored dissolved organic matter (CDOM) and non-algal particle/detritus/mineral (NAP). The results demonstrated that the different characteristics of Chl-a, CDOM and NAP make them ideal tracers for observing large-scale dispersal patterns. With ancillary information of averaged daily precipitation, the daily wind field obtained from QuikSCAT (Quick Scatterometer), and the 8-day composite of the temperature field obtained from MODIS-Aqua, we categorized the surface dispersal patterns as coastal, northwestward and frontal patterns. Also, for the first time, we observed a sudden increase of biomass on a large scale from a pair of ocean color images taken over only a 2-day interval. Another remarkable feature is the interaction between the southeastward flow and the intrusion of the Kuroshio Branch, resulting in complicated patterns with various scales of vortex structures and current fronts. The observed features could be used for model validation of the flow field of the KPRSC system. 2008 Elsevier B.V. All rights reserved.
Keywords: QuikSCAT
Mission: |SeaWinds|
URL: https://doi.org/10.1016/j.jmarsys.2007.11.013
Other URLs:
Liu, H., Grodsky, S.A., and Carton, J.A. (2009). Observed Subseasonal Variability of Oceanic Barrier and Compensated Layers, Journal of Climate, 22(22), 6104-6119, 10.1175/2009JCLI2974.1. Journal Article »
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Title: Observed Subseasonal Variability of Oceanic Barrier and Compensated Layers
Type: Journal Article
Publication: Journal of Climate
Author(s): Liu, H., Grodsky, S.A., and Carton, J.A.
Year: 2009
Formatted Citation: Liu, H., Grodsky, S.A., and Carton, J.A., 2009: Observed Subseasonal Variability of Oceanic Barrier and Compensated Layers, Journal of Climate, 22(22), 6104-6119, 10.1175/2009JCLI2974.1.
Abstract: A monthly gridded analysis of barrier-layer and compensated-layer width based on observed vertical profiles of temperature and salinity and covering the period 1960-2007 is explored for evidence of subseasonal variability and its causes. In the subtropics and midlatitudes this variability is mostly evident during the local cold season when barrier layers and compensated layers are present. There is significant variability of anomalous (nonseasonal) barrier-layer and compensated-layer width on interannual periods, while in the North Pacific longer-term changes are also detectable. In the winter North Pacific a salinity-stratified barrier layer exists at subpolar latitudes. Farther south along the Kuroshio Extension a compensated layer exists. The width of the barrier layer varies from year to year by up to 60 m while compensated-layer width varies by half as much. During the observation period the barrier-layer width decreased in response to a strengthening of the Aleutian low pressure system, the resulting strengthening of dry northerly winds, and a decrease of precipitation. In contrast, the compensated-layer width increased in response to this pressure system strengthening and related amplification of the midlatitude westerly winds, the resulting increase of net surface heat loss, and its effect on the temperature and salinity of the upper-ocean water masses. The tropical Pacific, Atlantic, and Indian Oceans all have permanent barrier layers. Their interannual variability is less than 20 m but is comparable in magnitude to the time mean barrier-layer width in these areas. In the tropical Pacific west of 160°E and in the eastern tropical Indian Ocean, the barrier-layer width changes by approximately 5 m in response to a 10-unit change in the Southern Oscillation index. It thickens during La Niñas as a result of the presence of abundant rainfall and thins during dry El Niños. Interannual variations of barrier-layer width in the equatorial Pacific are weak east of 160°E with an exception of the area surrounding the eastern edge of the warm pool. Here subduction of salty water contributes to locally stronger variations of barrier-layer width.
Keywords: Seasonal variability, Oceanic variability, Temperature, Salinity
Mission:
URL: https://doi.org/10.1175/2009JCLI2974.1
Other URLs:
Long, D.G., Milliff, R.F., and Rodriguez, E. (2009). The TropSat Mission: An Observatory for Mesoscale Convective System Processes in the Global Tropics, Proceedings of the 2009 IEEE Radar Conference, 1-6, 10.1109/RADAR.2009.4977098. Conference Paper »
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Title: The TropSat Mission: An Observatory for Mesoscale Convective System Processes in the Global Tropics
Type: Conference Paper
Publication: Proceedings of the 2009 IEEE Radar Conference
Author(s): Long, D.G., Milliff, R.F., and Rodriguez, E.
Year: 2009
Formatted Citation: Long, D.G., Milliff, R.F., and Rodriguez, E., 2009: The TropSat Mission: An Observatory for Mesoscale Convective System Processes in the Global Tropics, Proceedings of the 2009 IEEE Radar Conference, 1-6, 10.1109/RADAR.2009.4977098.
Abstract: A satellite mission is proposed to provide frequent, high-resolution measurements of surface winds, rain, and temperature profiles to support critical observations of Mesoscale Convective Systems (MCS) over the global tropical oceans. The proposed mission includes an innovative active/passive microwave system coupled with IR cloud top measurements for multi-layer atmosphere observations. The TropSat system will provide frequent, high-resolution measurements of the near-surface wind vector and rain rate over the tropical oceans. The senor design is based on the proven technology of SeaWinds but includes key innovations and an integral radiometer. The main sensor will include: (1) dual-band (C- and Ku-band) and dual beam (inner/outer beams) operation (C- and Ku- band) at multiple polarizations and (2) groundbased post processing to achieve the desired high spatial resolution. Backscatter measurements over land can support vegetation and climate change studies. This paper provides a brief description of the TropSat mission, discusses various instrument and mission tradeoffs, and presents performance estimates to demonstrate the feasibility of the mission concept.
Keywords:
Mission: |SeaWinds|
URL: https://doi.org/10.1109/RADAR.2009.4977098
Other URLs:
McMillan, M., Shepherd, A., Vaughan, D.G., Laxon, S., and McAdoo, D. (2009). Amundsen Sea Bathymetry: The Benefits of Using Gravity Data for Bathymetric Prediction, IEEE Transactions on Geoscience and Remote Sensing, 47(12), 4223-4228, 10.1109/TGRS.2009.2023665. Journal Article »
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Title: Amundsen Sea Bathymetry: The Benefits of Using Gravity Data for Bathymetric Prediction
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): McMillan, M., Shepherd, A., Vaughan, D.G., Laxon, S., and McAdoo, D.
Year: 2009
Formatted Citation: McMillan, M., Shepherd, A., Vaughan, D.G., Laxon, S., and McAdoo, D., 2009: Amundsen Sea Bathymetry: The Benefits of Using Gravity Data for Bathymetric Prediction, IEEE Transactions on Geoscience and Remote Sensing, 47(12), 4223-4228, 10.1109/TGRS.2009.2023665.
Abstract: Bathymetric charts are essential for modeling oceanic processes, yet, in remote areas, direct measurements of seafloor depth are often scarce. It is possible to augment sparse depth soundings with dense satellite-derived gravity data to provide additional bathymetric detail in regions devoid of sounding data. We demonstrate this method by using marine gravity derived from the European Remote Sensing (ERS-1) satellite altimeter, combined with depth soundings, to form a bathymetric prediction of the Amundsen Sea, West Antarctica. We estimate the root mean square error of depth estimates at unsurveyed locations in our solution to be ~120 m. We use a Monte Carlo method to assess the value of gravity as a bathymetric predictor in sparsely surveyed regions by comparing our solution to predictions formed from depth soundings alone. When less than ~11% of 10-km grid cells contain depth soundings, inclusion of gravity data improves the depth accuracy of the solution by up to 17%, as compared to a minimum curvature surface interpolation of the depth soundings alone. When depth data are sparse, our gravity-derived prediction reveals additional short-wavelength bathymetric features, such as troughs on the continental shelf, which are not resolved by interpolations of the depth soundings alone.
Keywords: Altimetry Arctic regions gravity measurement satellites sea floor terrain mapping
Mission:
URL: https://doi.org/10.1109/TGRS.2009.2023665
Other URLs:
McPhaden, M.J., Foltz, G.R., Lee, T., Murty, V.S.N., Ravichandran, M., Vecchi, G.A., Vialard, J., Wiggert, J.D., and Yu, L. (2009). Ocean-Atmosphere Interactions During Cyclone Nargis, Eos Trans. AGU, 90(7), 54-55, 10.1029/2009EO070001. Journal Article »
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Title: Ocean-Atmosphere Interactions During Cyclone Nargis
Type: Journal Article
Publication: Eos Trans. AGU
Author(s): McPhaden, M.J., Foltz, G.R., Lee, T., Murty, V.S.N., Ravichandran, M., Vecchi, G.A., Vialard, J., Wiggert, J.D., and Yu, L.
Year: 2009
Formatted Citation: McPhaden, M.J., Foltz, G.R., Lee, T., Murty, V.S.N., Ravichandran, M., Vecchi, G.A., Vialard, J., Wiggert, J.D., and Yu, L., 2009: Ocean-Atmosphere Interactions During Cyclone Nargis, Eos Trans. AGU, 90(7), 54-55, 10.1029/2009EO070001.
Abstract: Cyclone Nargis (Figure 1a) made landfall in Myanmar (formerly Burma) on 2 May 2008 with sustained winds of approximately 210 kilometers per hour, equivalent to a category 3-4 hurricane. In addition, Nargis brought approximately 600 millimeters of rain and a storm surge of 3-4 meters to the low-lying and densely populated Irrawaddy River delta. In its wake, the storm left an estimated 130,000 dead or missing and more than $10 billion in economic losses. It was the worst natural disaster to strike the Indian Ocean region since the 26 December 2004 tsunami and the worst recorded natural disaster ever to affect Myanmar.
Keywords: Atmospheric Processes: Ocean/atmosphere interactions (0312, 4504), Atmospheric Processes: Tropical meteorology, Oceanography: General: Ocean observing systems, Geographic Location: Indian Ocean
Mission:
URL: https://doi.org/10.1029/2009EO070001
Other URLs:
Mladenova, I., Lakshmi, V., Walker, J.P., Long, D.G., and De Jeu, R. (2009). An Assessment of QuikSCAT Ku-Band Scatterometer Data for Soil Moisture Sensitivity, IEEE Geoscience and Remote Sensing Letters, 6(4), 640-643, 10.1109/LGRS.2009.2021492. Journal Article »
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Title: An Assessment of QuikSCAT Ku-Band Scatterometer Data for Soil Moisture Sensitivity
Type: Journal Article
Publication: IEEE Geoscience and Remote Sensing Letters
Author(s): Mladenova, I., Lakshmi, V., Walker, J.P., Long, D.G., and De Jeu, R.
Year: 2009
Formatted Citation: Mladenova, I., Lakshmi, V., Walker, J.P., Long, D.G., and De Jeu, R., 2009: An Assessment of QuikSCAT Ku-Band Scatterometer Data for Soil Moisture Sensitivity, IEEE Geoscience and Remote Sensing Letters, 6(4), 640-643, 10.1109/LGRS.2009.2021492.
Abstract: The QuikSCAT enhanced (2.225-km) backscattering product is investigated for sensitivity to changes in soil moisture and its potential for spatial disaggregation of Advanced Microwave Scanning Radiometer (AMSR-E) soil moisture. Specifically, an active-passive methodology based on temporal change detection is tested using data from the 2006 National Airborne Field Experiment data set. This campaign was carried out from October 29 to November 20, 2006 in a 60 km times 40 km area of the Murrumbidgee catchment, southeast Australia. Temporal change detection analysis and accuracy in terms of spatial pattern distribution throughout the domain were assessed using a passive microwave airborne product derived from the Polarimetric L-band Multibeam Radiometer at 1-km spatial resolution. QuikSCAT-AMSR-E intercomparisons indicated higher correlations when using C-band observations. The greatest sensitivity to soil moisture was observed when using V-polarized backscatter measurement. While backscattering data showed adequate temporal sensitivity to changes in soil moisture due to precipitation events, the spatial agreement was complicated by the presence of irrigation and standing water (rice fields). This resulted in low Cramer's Phi values (less than 0.06), which were used as a measure of spatial correspondence in terms of change in soil moisture and backscatter. In addition, the high QuikSCAT sensor frequency and existence of noise in the observed data contributed to the observed discrepancies.
Keywords:
Mission: |SeaWinds|
URL: https://doi.org/10.1109/LGRS.2009.2021492
Other URLs:
Morey, S.L., Dukhovskoy, D.S., and Bourassa, M.A. (2009). Connectivity Between Variability of the Apalachicola River Flow and the Biophysical Oceanic Properties of the Northern West Florida Shelf, Continental Shelf Research, 29(9), 1264-1275, 10.1016/j.csr.2009.02.003. Journal Article »
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Title: Connectivity Between Variability of the Apalachicola River Flow and the Biophysical Oceanic Properties of the Northern West Florida Shelf
Type: Journal Article
Publication: Continental Shelf Research
Author(s): Morey, S.L., Dukhovskoy, D.S., and Bourassa, M.A.
Year: 2009
Formatted Citation: Morey, S.L., Dukhovskoy, D.S., and Bourassa, M.A., 2009: Connectivity Between Variability of the Apalachicola River Flow and the Biophysical Oceanic Properties of the Northern West Florida Shelf, Continental Shelf Research, 29(9), 1264-1275, 10.1016/j.csr.2009.02.003.
Abstract: Maps of satellite-derived estimates of monthly averaged chlorophyll a concentration over the northern West Florida Shelf show interannual variations concentrated near the coastline, but also extending offshore over the shelf in a tongue-like pattern from the Apalachicola River during the late winter and early spring. These anomalies are significantly correlated with interannual variability in the flow rate of the Apalachicola River, which is linked to the precipitation anomalies over the watershed, over a region extending 150-200 km offshore out to roughly the 100 m isobath. This study examines the variability of the Apalachicola River and its impacts on the variability of water properties over the northern West Florida Shelf. A series of numerical model experiments show that episodic wind-driven offshore transport of the Apalachicola River plume is a likely physical mechanism for connecting the variability of the river discharge with oceanic variability over the middle and outer shelf.
Keywords: River plumes, Climate variability, Ocean color, West Florida Shelf, Apalachicola River
Mission:
URL: https://doi.org/10.1016/j.csr.2009.02.003
Other URLs:
Ngheim, S.V. and Clemete-Colon, P. (2009). Arctic Sea Ice Mapping with Satellite Radars, IEEE Aerospace and Electronic Systems Magazine, 24(11), 41-44, 10.1109/MAES.2009.5344181. Journal Article »
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Title: Arctic Sea Ice Mapping with Satellite Radars
Type: Journal Article
Publication: IEEE Aerospace and Electronic Systems Magazine
Author(s): Ngheim, S.V. and Clemete-Colon, P.
Year: 2009
Formatted Citation: Ngheim, S.V. and Clemete-Colon, P., 2009: Arctic Sea Ice Mapping with Satellite Radars, IEEE Aerospace and Electronic Systems Magazine, 24(11), 41-44, 10.1109/MAES.2009.5344181.
Abstract: The drastic reduction of Arctic sea ice in recent years demands ice monitoring over various spatial and temporal scales. Sea ice backscatter signatures from field measurements and from model analyses are obtained at L-band and C-band frequencies. Based on these signatures, capabilities for Arctic sea ice mapping are determined for current and future satellite active microwave sensors including synthetic aperture radars (SAR) and scatterometers. This study includes L-band and C-band radars such as the ERS (European Remote Sensing), Envisat (Environmental Satellite), RADARSAT-1 and 2, ALOS (Advanced Land Observing Satellite), and DESDnyl (Deformation, Ecosystem Structure, and Dynamics of Ice). SARs with resolutions from 10 to 100 m, and the SMAP (Soil Moisture Active-Passive) scatterometer with resolutions from 1 to 10 km.
Keywords:
Mission:
URL: https://doi.org/10.1109/MAES.2009.5344181
Other URLs:
Nghiem, S.V., Balk, D., Rodriguez, E., Neumann, G., Sorichetta, A., Small, C., and Elvidge, C.D. (2009). Observations of Urban and Suburban Environments with Global Satellite Scatterometer Data, ISPRS Journal of Photogrammetry and Remote Sensing, 64(4), 367-380, 10.1016/j.isprsjprs.2009.01.004. Journal Article »
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Title: Observations of Urban and Suburban Environments with Global Satellite Scatterometer Data
Type: Journal Article
Publication: ISPRS Journal of Photogrammetry and Remote Sensing
Author(s): Nghiem, S.V., Balk, D., Rodriguez, E., Neumann, G., Sorichetta, A., Small, C., and Elvidge, C.D.
Year: 2009
Formatted Citation: Nghiem, S.V., Balk, D., Rodriguez, E., Neumann, G., Sorichetta, A., Small, C., and Elvidge, C.D., 2009: Observations of Urban and Suburban Environments with Global Satellite Scatterometer Data, ISPRS Journal of Photogrammetry and Remote Sensing, 64(4), 367-380, 10.1016/j.isprsjprs.2009.01.004.
Abstract: A global and consistent characterization of land use and land change in urban and suburban environments is crucial for many fundamental social and natural science studies and applications. Presented here is a dense sampling method (DSM) that uses satellite scatterometer data to delineate urban and intraurban areas at a posting scale of about 1km. DSM results are analyzed together with information on population and housing censuses, with Landsat Enhanced Thematic Mapper Plus (ETM+) imagery, and with Defense Meteorological Satellite Program (DMSP) night-light data. The analyses include Dallas-Fort Worth and Phoenix in the United States, Bogota in Colombia, Dhaka in Bangladesh, Guangzhou in China, and Quito in Ecuador. Results show that scatterometer signatures correspond to buildings and infrastructures in urban and suburban environments. City extents detected by scatterometer data are significantly smaller than city light extents, but not all urban areas are detectable by the current SeaWinds scatterometer on the QuikSCAT satellite. Core commercial and industrial areas with high buildings and large factories are identified as high-backscatter centers. Data from DSM backscatter and DMSP nighttime lights have a good correlation with population density. However, the correlation relations from the two satellite datasets are different for different cities indicating that they contain complementary information. Together with night-light and census data, DSM and satellite scatterometer data provide new observations to study global urban and suburban environments and their changes. Furthermore, the capability of DSM to identify hydrological channels on the Greenland ice sheet and ecological biomes in central Africa demonstrates that DSM can be used to observe persistent structures in natural environments at a km scale, providing contemporaneous data to study human impacts beyond urban and suburban areas. 2009 International Society for Photogrammetry and Remote Sensing, Inc. (ISPRS).
Keywords: QuikSCAT, Seawinds
Mission: |SeaWinds|
URL: https://doi.org/10.1016/j.isprsjprs.2009.01.004
Other URLs:
Nielsen, S.N. and Long, D.G. (2009). A Wind and Rain Backscatter Model Derived From AMSR and SeaWinds Data, IEEE Trans. Geosci. Remote Sens., 47(6), 1595-1606, 10.1109/TGRS.2008.2007492. Journal Article »
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Title: A Wind and Rain Backscatter Model Derived From AMSR and SeaWinds Data
Type: Journal Article
Publication: IEEE Trans. Geosci. Remote Sens.
Author(s): Nielsen, S.N. and Long, D.G.
Year: 2009
Formatted Citation: Nielsen, S.N. and Long, D.G., 2009: A Wind and Rain Backscatter Model Derived From AMSR and SeaWinds Data, IEEE Trans. Geosci. Remote Sens., 47(6), 1595-1606, 10.1109/TGRS.2008.2007492.
Abstract: The SeaWinds scatterometer was originally designed to measure wind vectors over the ocean by exploiting the relationship between wind-induced surface roughening and the normalized radar backscatter cross section. Rain can degrade scatterometer wind estimation, however, the simultaneous wind/rain (SWR) algorithm was developed to enable SeaWinds to simultaneously retrieve wind and rain rate data. This algorithm is based on colocating data from the Precipitation Radar on the Tropical Rainfall Measuring Mission and SeaWinds on QuikSCAT. This paper develops a new wind and rain radar backscatter model for SWR using colocated data from the Advanced Microwave Scanning Radiometer (AMSR) and SeaWinds aboard the Advanced Earth Observing Satellite II. This paper accounts for rain height in the model in order to calculate surface rain rate from the integrated rain rate. The performance of SWR using the new wind/rain model is measured by comparison of wind vectors and rain rates to the previous SWR algorithm, AMSR rain rates, and National Center for Environmental Prediction numerical weather prediction winds. The new SWR algorithm produces more accurate rain estimates and improved winds, and detects rain with a low false alarm rate.
Keywords: Atmospheric measurements rain scattering wind
Mission: |SeaWinds|
URL: https://doi.org/10.1109/TGRS.2008.2007492
Other URLs:
Owen, M.P. and Long, D.G. (2009). Land-Contamination Compensation for QuikSCAT Near-Coastal Wind Retrieval, IEEE Transactions on Geoscience and Remote Sensing, 47(3), 839-850, 10.1109/TGRS.2008.2005633. Journal Article »
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Title: Land-Contamination Compensation for QuikSCAT Near-Coastal Wind Retrieval
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Owen, M.P. and Long, D.G.
Year: 2009
Formatted Citation: Owen, M.P. and Long, D.G., 2009: Land-Contamination Compensation for QuikSCAT Near-Coastal Wind Retrieval, IEEE Transactions on Geoscience and Remote Sensing, 47(3), 839-850, 10.1109/TGRS.2008.2005633.
Abstract: The QuikSCAT scatterometer is used to accurately retrieve winds over the ocean at both high (2.5 km) and low (25 km) resolutions. In near-coastal regions, land contamination of measurements results in inaccurate wind estimates using current techniques. Here, we show that identifying land-contaminated measurements allows wind retrieval to be accurately achieved in near-coastal regions using QuikSCAT data at up to 2.5-km resolution using the AVE algorithm. To identify and remove land contamination, two metrics are compared, namely, the minimum distance to land and the land contribution ratio (LCR). The LCR is used as a metric to identify and remove land-contaminated backscatter sigmao measurements before wind retrieval by discarding measurements with LCR values above a threshold. LCR thresholds used to remove land-contaminated measurements are determined using Monte Carlo simulations and set during processing using a lookup table based on the local wind speed, land brightness, and the cross-track swath location. Wind retrieval from sigmao fields generated using the LCR is more accurate closer to the coast than previously achieved using both low- and high-resolution processing.
Keywords: Wind scattering
Mission: |SeaWinds|
URL: https://doi.org/10.1109/TGRS.2008.2005633
Other URLs:
Park, S., Lee, D.-U., and Seo, J.-W. (2009). Operational Wind Wave Prediction System at KMA, Marine Geodesy, 32(2), 133-150, 10.1080/01490410902869243. Journal Article »
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Title: Operational Wind Wave Prediction System at KMA
Type: Journal Article
Publication: Marine Geodesy
Author(s): Park, S., Lee, D.-U., and Seo, J.-W.
Year: 2009
Formatted Citation: Park, S., Lee, D.-U., and Seo, J.-W., 2009: Operational Wind Wave Prediction System at KMA, Marine Geodesy, 32(2), 133-150, 10.1080/01490410902869243.
Abstract: An overview of the current operational wind wave prediction system and of new developments at the Korea Meteorological Administration (KMA) is presented. KMA has operated a numerical ocean wave prediction system since 1992. The first major upgrade was done in 1999 with the adaptation of a third-generation wave model (WAM) for both regional (ReWAM-0.25 deg resolution, covering Northeast Asia) and global (GoWAM-1.25 deg resolution) domains. In 2005, the KMA replaced its NEC SX5 computer with a 1024-CPU Cray X1E system, a Parallel Vector Processor (PVP) machine with 128 node modules. A coastal ocean wave prediction system (CoWAM) has been designed and is currently under test mode. Six CoWAM domains, each of 3 deg longitude by 2 deg latitude in size, with a mesh size of 1 km, are nested inside the regional ocean wave prediction system. The directional wave spectra at the boundaries of the CoWAM are provided from a 1/12 resolution upgraded version of the operational ReWAM. The WAVEWATCH-III code (developed at NOAA) is used for the upgraded ReWAM and new CoWAM system. To ensure the required model performance in the Massively Parallel Processor (MPP) architecture of the new supercomputer, a Message Passing Interface (MPI) has been implemented in the model source code. The sea surface wind and significant wave height are verified routinely on a monthly basis. The global moored buoy data (including the coastal buoys operated by KMA) and remote sensing data from Topex/Poseidon, and Jason (retrieved wave heights) and QuikSCAT (retrieved wind data) are used for verification of the wave prediction system. This validation and a comparison of results from the new ReWAM and CoWAM against buoy data off the coast of Korea are discussed.
Keywords: QuikSCAT,Topex/Poseidon
Mission: |SeaWinds|
URL: https://doi.org/10.1080/01490410902869243
Other URLs:
Pascual, A., Boone, C., Larnicol, G., and Le Traon, P.Y. (2009). On the Quality of Real-Time Altimeter Gridded Fields: Comparison with In Situ Data, Journal of Atmospheric and Oceanic Technology, 26(3), 556-569, 10.1175/2008JTECHO556.1. Journal Article »
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Title: On the Quality of Real-Time Altimeter Gridded Fields: Comparison with In Situ Data
Type: Journal Article
Publication: Journal of Atmospheric and Oceanic Technology
Author(s): Pascual, A., Boone, C., Larnicol, G., and Le Traon, P.Y.
Year: 2009
Formatted Citation: Pascual, A., Boone, C., Larnicol, G., and Le Traon, P.Y., 2009: On the Quality of Real-Time Altimeter Gridded Fields: Comparison with In Situ Data, Journal of Atmospheric and Oceanic Technology, 26(3), 556-569, 10.1175/2008JTECHO556.1.
Abstract: The timeliness of satellite altimeter measurements has a significant effect on their value for operational oceanography. In this paper, an Observing System Experiment (OSE) approach is used to assess the quality of real-time altimeter products, a key issue for robust monitoring and forecasting of the ocean state. In addition, the effect of two improved geophysical corrections and the number of missions that are combined in the altimeter products are also analyzed. The improved tidal and atmospheric corrections have a significant effect in coastal areas (0-100 km from the shore), and a comparison with tide gauge observations shows a slightly better agreement with the gridded delayed-time sea level anomalies (SLAs) with two altimeters [Jason-1 and European Remote Sensing Satellite-2 (ERS-2)/Envisat] using the new geophysical corrections (mean square differences in percent of tide gauge variance of 35.3%) than those with four missions [Jason-1, ERS/Envisat, Ocean Topography Experiment (TOPEX)/Poseidoninterlaced, and Geosat Follow-On] but using the old corrections (36.7%). In the deep ocean, however, the correction improvements have little influence. The performance of fast delivery products versus delayed-time data is compared using independent in situ data (tide gauge and drifter data). It clearly highlights the degradation of real-time SLA maps versus the delayed-time SLA maps: four altimeters are needed in real time to get the similar quality performance as two altimeters in delayed time (sea level error misfit around 36%, and zonal and meridional velocity estimation errors of 27% and 33%, respectively). This study proves that the continuous improvement of geophysical corrections is very important, and that it is essential to stay above a minimum threshold of four available altimetric missions to capture the main space and time oceanic scales in fast delivery products.
Keywords:
Mission:
URL: https://doi.org/10.1175/2008JTECHO556.1
Other URLs:
Plagge, A.M., Vandemark, D.C., and Long, D.G. (2009). Coastal Validation of Ultra-High Resolution Wind Vector Retrieval from QuikSCAT in the Gulf of Maine, IEEE Geoscience and Remote Sensing Letters, 6(3), 413-417, 10.1109/LGRS.2009.2014852. Journal Article »
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Title: Coastal Validation of Ultra-High Resolution Wind Vector Retrieval from QuikSCAT in the Gulf of Maine
Type: Journal Article
Publication: IEEE Geoscience and Remote Sensing Letters
Author(s): Plagge, A.M., Vandemark, D.C., and Long, D.G.
Year: 2009
Formatted Citation: Plagge, A.M., Vandemark, D.C., and Long, D.G., 2009: Coastal Validation of Ultra-High Resolution Wind Vector Retrieval from QuikSCAT in the Gulf of Maine, IEEE Geoscience and Remote Sensing Letters, 6(3), 413-417, 10.1109/LGRS.2009.2014852.
Abstract: An experimental 2.5-km ultrahigh-resolution (UHR) wind product provided by NASA`s QuikSCAT scatterometer offers the potential for new access to coastal surface wind dynamics at the mesoscale level and below. To give future users the best indication of the value of these data, the UHR wind retrievals must be fully validated in nearshore areas. Comparison with meteorological buoys and standard QuikSCAT products allows detailed investigation of UHR winds. Speed and direction residuals are calculated between all scatterometer products and collocated buoys. An ambiguity selection routine improves wind direction agreement between the UHR winds and the other products. Magnitude residuals follow the patterns of the standard QuikSCAT winds, with a 1-2 m/s positive bias in light winds (below 4 m/s) and high winds (above 16 m/s) and standard deviations consistently below 3 m/s. After application of a land contamination removal algorithm, the UHR product provides extended coverage near the coast. An example of a specific wind event illustrates the potential benefits of improved resolution measurements for examining ocean-atmosphere dynamics.
Keywords: meteorological instruments , oceanographic regions , wind Meteorology QuikSCAT scatterometer , coastal surface wind dynamics , coastal validation , meteorological buoys , ultrahigh resolution wind vector retrieval , remote sensing
Mission: |SeaWinds|
URL: https://doi.org/10.1109/LGRS.2009.2014852
Other URLs:
Portabella, M. and Stoffelen, A. (2009). On Scatterometer Ocean Stress, Journal of Atmospheric and Oceanic Technology, 26(2), 368-382, 10.1175/2008JTECHO578.1. Journal Article »
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Title: On Scatterometer Ocean Stress
Type: Journal Article
Publication: Journal of Atmospheric and Oceanic Technology
Author(s): Portabella, M. and Stoffelen, A.
Year: 2009
Formatted Citation: Portabella, M. and Stoffelen, A., 2009: On Scatterometer Ocean Stress, Journal of Atmospheric and Oceanic Technology, 26(2), 368-382, 10.1175/2008JTECHO578.1.
Abstract: Scatterometers estimate the relative atmosphere–ocean motion at spatially high resolution and provide accurate inertial-scale ocean wind forcing information, which is crucial for many ocean, atmosphere, and climate applications. An empirical scatterometer ocean stress (SOS) product is estimated and validated using available statistical information. A triple collocation dataset of scatterometer, and moored buoy and numerical weather prediction (NWP) observations together with two commonly used surface layer (SL) models are used to characterize the SOS. First, a comparison between the two SL models is performed. Although their roughness length and the stability parameterizations differ somewhat, the two models show little differences in terms of stress estimation. Second, a triple collocation exercise is conducted to assess the true and error variances explained by the observations and the SL models. The results show that the uncertainty in the NWP dataset is generally larger than in the buoy and scatterometer wind/stress datasets, but it depends on the spatial scales of interest. The triple collocation analysis also shows that scatterometer winds are as close to real winds as to equivalent neutral winds, provided that the appropriate scaling is used. An explanation for this duality is that the small stability effects found in the analysis are masked by the uncertainty in SL models and their inputs. The triple collocation analysis shows that scatterometer winds can be straightforwardly and reliably transformed to wind stress. This opens the door for the development of wind stress swath (level 2) and gridded (level 3) products for the Advanced Scatterometer (ASCAT) on board Meterological Operation (MetOp) and for further geophysical development.
Keywords:
Mission: |ASCAT|
URL: https://doi.org/10.1175/2008JTECHO578.1
Other URLs:
Rakesh, V., Singh, R., and Joshi, P.C. (2009). Intercomparison of the Performance of MM5/WRF with and without Satellite Data Assimilation in Short-Range Forecast Applications over the Indian Region, Meteorology and Atmospheric Physics, 105(3-4), 133-155, 10.1007/s00703-009-0038-3. Journal Article »
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Title: Intercomparison of the Performance of MM5/WRF with and without Satellite Data Assimilation in Short-Range Forecast Applications over the Indian Region
Type: Journal Article
Publication: Meteorology and Atmospheric Physics
Author(s): Rakesh, V., Singh, R., and Joshi, P.C.
Year: 2009
Formatted Citation: Rakesh, V., Singh, R., and Joshi, P.C., 2009: Intercomparison of the Performance of MM5/WRF with and without Satellite Data Assimilation in Short-Range Forecast Applications over the Indian Region, Meteorology and Atmospheric Physics, 105(3-4), 133-155, 10.1007/s00703-009-0038-3.
Abstract:
Keywords:
Mission: |SeaWinds|
URL: https://doi.org/10.1007/s00703-009-0038-3
Other URLs:
Roca, M., Laxon, S., and Zelli, C. (2009). The EnviSat RA-2 Instrument Design and Tracking Performance, IEEE Transactions on Geoscience and Remote Sensing, 47(10), 3489-3506, 10.1109/TGRS.2009.2020793. Journal Article »
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Title: The EnviSat RA-2 Instrument Design and Tracking Performance
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Roca, M., Laxon, S., and Zelli, C.
Year: 2009
Formatted Citation: Roca, M., Laxon, S., and Zelli, C., 2009: The EnviSat RA-2 Instrument Design and Tracking Performance, IEEE Transactions on Geoscience and Remote Sensing, 47(10), 3489-3506, 10.1109/TGRS.2009.2020793.
Abstract: The EnviSat satellite embarks an innovative radar altimeter, the RA-2 which represents a new generation of radar altimeters compared to previous instruments such as the European Remote Sensing Satellite (ERS) altimeters and The Ocean Topography Experiment/Poseidon. This is due to its integration of many new features. In particular, the RA-2 is the first satellite altimeter to incorporate autonomous resolution selection and a model-free tracker. The behavior of the instrument in orbit is controlled by onboard algorithms which determine the instrument logic, and a list of onboard parameters which control when switches in resolution occur. This logic and the choice of these parameters have a strong influence on the tracking performance. This paper describes the operation of the RA-2 onboard tracker and the resolution selection logic. We provide a detailed description of the algorithm and its configuration parameters after optimization during the EnviSat Commissioning Phase. Finally, we show the tracking performance, in particular compared to the ones of the ERS-2 altimeter, over different types of surfaces.
Keywords: Altimetry RA-2 onboard tracker radar altimeter tracking performance
Mission:
URL: https://doi.org/10.1109/TGRS.2009.2020793
Other URLs:
Rosario, R.P., Bezerra, M.O., and Vinzon, S.B. (2009). Dynamics of the Saline Front in the Northern Channel of the Amazon River - Influence of Fluvial Flow and Tidal Range (Brazil), Journal of Coastal Research, 2(56), 1414-1418. Journal Article »
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Title: Dynamics of the Saline Front in the Northern Channel of the Amazon River - Influence of Fluvial Flow and Tidal Range (Brazil)
Type: Journal Article
Publication: Journal of Coastal Research
Author(s): Rosario, R.P., Bezerra, M.O., and Vinzon, S.B.
Year: 2009
Formatted Citation: Rosario, R.P., Bezerra, M.O., and Vinzon, S.B., 2009: Dynamics of the Saline Front in the Northern Channel of the Amazon River - Influence of Fluvial Flow and Tidal Range (Brazil), Journal of Coastal Research, 2(56), 1414-1418.
Abstract: Part of the BARRANORTE project, this study analyzes the dynamics of saline intrusion in the Northern Channel of the Amazon River (0 degrees 50`N-1 degrees 50`N, 48 degrees 50`W-50 degrees W). Monitoring the saline wedge helps locate regions with large deposits of sediment and contributes to the improvement of navigational and safety aids and environmental monitoring. Two campaigns were carried out in this study, in June 2006 (maximum fluvial discharge) and July 2007. Data were collected at six stations in 2006 and eleven in 2007, with 12 hours of measurements and a vertical profile taken every hour, covering half a tidal cycle. River flow and tidal data were obtained from the National Water Agency and Brazilian Navy, respectively. Surface winds were estimated using the QuikSCAT(NASA) scatterometer. The variation in the position of the saline wedge in the Northern Channel indicates significant variation on both a seasonal and a tidal cycle. The saline wedge was located 80 km from the mouth of the channel in minimal discharge conditions (data from the AMASSEDS project) and up to 120 km at maximum discharge (present study). Differences in this distance between 2006 (106 km) and 2007 (120 km) were probably related to those in the tidal regime, with data being collected during the neap tide in 2006 (H=2.4 m) and spring tide in 2007 (H=3.7 m). Saline stratification at the mouth of the Amazon varied from a wedge form (slightly stratified) at the neap tide to and partially mixed (highly stratified) at the spring tide.
Keywords: QuikSCAT
Mission: |SeaWinds|
URL: https://www.jstor.org/stable/25738022
Other URLs:
Rudiger, C., Calvet, J.C., Gruhier, C., Holmes, T.R.H., de Jeu, R.A.M., and Wagner, W. (2009). An Intercomparison of ERS-Scat and AMSR-E Soil Moisture Observations with Model Simulations Over France, Journal of Hydrometeorology, 10(2), 431-447, 10.1175/2008JHM997.1. Journal Article »
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Title: An Intercomparison of ERS-Scat and AMSR-E Soil Moisture Observations with Model Simulations Over France
Type: Journal Article
Publication: Journal of Hydrometeorology
Author(s): Rudiger, C., Calvet, J.C., Gruhier, C., Holmes, T.R.H., de Jeu, R.A.M., and Wagner, W.
Year: 2009
Formatted Citation: Rudiger, C., Calvet, J.C., Gruhier, C., Holmes, T.R.H., de Jeu, R.A.M., and Wagner, W., 2009: An Intercomparison of ERS-Scat and AMSR-E Soil Moisture Observations with Model Simulations Over France, Journal of Hydrometeorology, 10(2), 431-447, 10.1175/2008JHM997.1.
Abstract: This paper presents a study undertaken in preparation of the work leading up to the assimilation of Soil Moisture and Ocean Salinity (SMOS) observations into the land surface model (LSM) Interaction Soil Biosphere Atmosphere (ISBA) at Météo-France. This study consists of an intercomparison experiment of different space-borne platforms providing surface soil moisture information [Advanced Microwave Scanning Radiometer for Earth Observing (AMSR-E) and European Remote Sensing Satellite Scatterometer (ERS-Scat)] with the reanalysis soil moisture predictions over France from the model suite of Système d’analyse fournissant des renseignements atmosphériques à la neige (SAFRAN), ISBA, and coupled model (MODCOU, SIM) of Météo-France for the years of 2003–05. Both modeled and remotely sensed data are initially validated against in situ observations obtained at the experimental soil moisture monitoring site Surface Monitoring of the Soil Reservoir Experiment (SMOSREX) in southwestern France. Two different AMSR-E soil moisture products are compared in the course of this study—the official AMSR-E product from the National Snow and Ice Data Center (NSIDC) and a new product developed at the Vrije Universiteit Amsterdam and NASA (VUA–NASA)—which were obtained using two different retrieval algorithms. This allows for an additional assessment of the different algorithms while using identical brightness temperature datasets. This study shows that a good correlation generally exists between AMSR-E (VUA–NASA), ERS-Scat, and SIM for low altitudes and low-to-moderate vegetation covers (1.5–3 kg m^-2 vegetation water content), with a reduction in the correlation in mountainous regions. It also shows that the AMSR-E (NSIDC) soil moisture product has significant differences when compared to the other datasets.
Keywords:
Mission:
URL: https://doi.org/10.1175/2008JHM997.1
Other URLs:
Ryan, W.B.F., Carbotte, S.M., Coplan, J.O., O'Hara, S., Melkonian, A., Arko, R., Weissel, R.A., Ferrini, V., Goodwillie, A., Nitsche, F., Bonczkowski, J., and Zemsky, R. (2009). Global Multi-Resolution Topography Synthesis, Geochemistry Geophysics Geosystems, 10(3), Q03014, 10.1029/2008GC002332. Journal Article »
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Title: Global Multi-Resolution Topography Synthesis
Type: Journal Article
Publication: Geochemistry Geophysics Geosystems
Author(s): Ryan, W.B.F., Carbotte, S.M., Coplan, J.O., O'Hara, S., Melkonian, A., Arko, R., Weissel, R.A., Ferrini, V., Goodwillie, A., Nitsche, F., Bonczkowski, J., and Zemsky, R.
Year: 2009
Formatted Citation: Ryan, W.B.F., Carbotte, S.M., Coplan, J.O., O'Hara, S., Melkonian, A., Arko, R., Weissel, R.A., Ferrini, V., Goodwillie, A., Nitsche, F., Bonczkowski, J., and Zemsky, R., 2009: Global Multi-Resolution Topography Synthesis, Geochemistry Geophysics Geosystems, 10(3), Q03014, 10.1029/2008GC002332.
Abstract: Seafloor bathymetric data acquired with modern swath echo sounders provide coverage for only a small fraction of the global seabed yet are of high value for studies of the dynamic processes of seafloor volcanism, tectonics, mass wasting, and sediment transport that create and shape the undersea landscape. A new method for compilation of global seafloor bathymetry that preserves the native resolution of swath sonars is presented. The Global Multi-Resolution Topography synthesis consists of a hierarchy of tiles with digital elevations and shaded relief imagery spanning nine magnification doublings from pole to pole (http://www.marine-geo.org/portals/gmrt). The compilation is updated and accessible as surveys are contributed, edited, and added to the tiles. Access to the bathymetry tiles is via Web services and with WMS-enabled client applications such as GeoMapApp®, Virtual Ocean, NASA World Wind®, and Google Earth®.
Keywords: * bathymetry * morphology * topography
Mission:
URL: https://doi.org/10.1029/2008GC002332
Other URLs:
Sharp, M. and Wang, L. (2009). A Five-Year Record of Summer Melt on Eurasian Arctic Ice Caps, Journal of Climate, 22(1), 133-145, 10.1175/2008JCLI2425.1. Journal Article »
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Title: A Five-Year Record of Summer Melt on Eurasian Arctic Ice Caps
Type: Journal Article
Publication: Journal of Climate
Author(s): Sharp, M. and Wang, L.
Year: 2009
Formatted Citation: Sharp, M. and Wang, L., 2009: A Five-Year Record of Summer Melt on Eurasian Arctic Ice Caps, Journal of Climate, 22(1), 133-145, 10.1175/2008JCLI2425.1.
Abstract: Climatologies and annual anomaly patterns (2000-04) of melt season duration and dates of melt onset/freeze-up on Eurasian Arctic ice masses were derived from Quick Scatterometer (QuikSCAT) backscatter data. Severnaya Zemlya, Russia, has later melt onset, earlier freeze-up, and shorter melt seasons than Svalbard, Norway/Novaya Zemlya, Russia. In all three archipelagos 2001 was the longest melt season and 2000 was the shortest. Anomalously long (short) melt seasons on Svalbard were associated with negative (positive) sea ice concentration anomalies along the north coast in June and August. Annual mean melt duration was strongly correlated with the mean (June + August) NCEP-NCAR reanalysis 850-hPa air temperature, allowing reconstruction of melt durations for the period of 1948-2005. The 2000-04 pentad had the second or third longest mean melt duration of all pentads in the 1950-2004 epoch, while the 1950-54 pentad probably had the longest. Integration of these results with previous results from Greenland and the Canadian Arctic identifies 2002 as the longest melt season in the 2000-04 period across the Arctic as a whole, and 2001 as the shortest. Correlation of melt duration anomalies for 19 discrete regions identifies seven spatially coherent areas of the Arctic with common patterns of variability in annual melt duration.
Keywords: QuikSCAT
Mission: |SeaWinds|
URL: https://doi.org/10.1175/2008JCLI2425.1
Other URLs:
Shirasawa, K., Eicken, H., Tateyama, K., Takatsuka, T., and Kawamura, T. (2009). Sea-Ice-Thickness Variability in the Chukchi Sea, Spring and Summer 2002-2004, Deep Sea Research Part II, 56(17), 1182-1200, 10.1016/j.dsr2.2008.10.015. Journal Article »
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Title: Sea-Ice-Thickness Variability in the Chukchi Sea, Spring and Summer 2002-2004
Type: Journal Article
Publication: Deep Sea Research Part II
Author(s): Shirasawa, K., Eicken, H., Tateyama, K., Takatsuka, T., and Kawamura, T.
Year: 2009
Formatted Citation: Shirasawa, K., Eicken, H., Tateyama, K., Takatsuka, T., and Kawamura, T., 2009: Sea-Ice-Thickness Variability in the Chukchi Sea, Spring and Summer 2002-2004, Deep Sea Research Part II, 56(17), 1182-1200, 10.1016/j.dsr2.2008.10.015.
Abstract: Measurements of sea-ice thickness were obtained from drill holes, an ice-based electromagnetic induction instrument (IEM), and a ship-borne electromagnetic induction instrument (SEM) during the early-melt season in the southern Chukchi Sea in 2002 and 2004, and in late summer 2003 at the time of minimum ice extent in the northern Chukchi Sea. An ice roughness criterion was applied to distinguish between level and rough or ridged ice. Ice-thickness modes in the probability density functions (PDFs) derived from drill-hole and IEM measurements agreed well, with modes at 1.5-1.6 and 1.8-1.9 m for all data from level ice. The PDFs derived from SEM measurements show that the primary modes are at 0.1 and 1.1 m in 2003 and 0.7 m in 2004. In 2002 and 2004, significant fractions (between one-third and one-half) of level ice were found to consist of rafted ice segments. Snow depth varied significantly between years, with 2004 data showing more than half the snow cover on level ice to be at or below 0.05 m depth in late spring. Ice growth simulations and examination of ice drift and deformation history indicate that impacts of atmospheric and oceanic warming on level-ice thickness in the region over the past few decades are masked to a large extent by variability in snow depth and the contribution of deformation processes. In comparison with submarine sonar ice-thickness data from previous decades, a reduction in ice thickness by about 0.5-1 m is in part explained by the replacement of multi-year with first-year ice over the Chukchi and Beaufort shelves.
Keywords: Sea-ice thickness, Snow depth, Electromagnetic induction instrument, Ice rafting, Ocean-heat flux, Chukchi Sea
Mission:
URL: https://doi.org/10.1016/j.dsr2.2008.10.015
Other URLs:
Shokr, M. (2009). Compilation of a Radar Backscatter Database of Sea Ice Types and Open Water Using Operational Analysis of Heterogeneous Ice Regimes, Canadian Journal of Remote Sensing, 35(4), 369-384, 10.5589/m09-026. Journal Article »
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Title: Compilation of a Radar Backscatter Database of Sea Ice Types and Open Water Using Operational Analysis of Heterogeneous Ice Regimes
Type: Journal Article
Publication: Canadian Journal of Remote Sensing
Author(s): Shokr, M.
Year: 2009
Formatted Citation: Shokr, M., 2009: Compilation of a Radar Backscatter Database of Sea Ice Types and Open Water Using Operational Analysis of Heterogeneous Ice Regimes, Canadian Journal of Remote Sensing, 35(4), 369-384, 10.5589/m09-026.
Abstract: A new algorithm has been developed to compile a database of radiometric measurements acquired by remote sensors from different surfaces that coexist in heterogeneous areas. An application is presented to compile a backscatter database of ice types during the freeze-up season in the Canadian Eastern Arctic using the operational visual analysis of RADARSAT-1 images from the Canadian Ice Service. The analysis identifies mostly heterogeneous areas composed of ice types and seawater. The estimated backscatter of each type is presented as a function of radar incidence angle. Backscatter from open seawater and seawater confined between ice floes is also presented as a function of radar incidence angle and surface wind speed. In general, backscatter obtained from heterogeneous areas using the present algorithm differs to some extent from backscatter obtained from homogeneous 'training' areas for each type yet still fulfils the expectations according to the underlying physics of radar interaction with sea ice. The algorithm also identifies anomalies in the visual analysis of RADARSAT images (i.e., areas in which the analysis results are not consistent with the general analysis of the entire RADARSAT record). Therefore, the algorithm presents the first quantitative assessment of the robustness of the operational visual analysis of RADARSAT-1 images.
Keywords:
Mission:
URL: https://doi.org/10.5589/m09-026
Other URLs:
Small, R.J., deSzoeke, S.P., Xie, S.-P., O'Neill, L., Seo, H., Song, Q., Cornillon, P., Spall, M., and Minobe, S. (2009). Air-Sea Interaction Over Ocean Fronts and Eddies, Dynamics of Atmospheres and Oceans, 45(3-4), 274-319, 10.1016/j.dynatmoce.2008.01.001. Journal Article »
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Title: Air-Sea Interaction Over Ocean Fronts and Eddies
Type: Journal Article
Publication: Dynamics of Atmospheres and Oceans
Author(s): Small, R.J., deSzoeke, S.P., Xie, S.-P., O'Neill, L., Seo, H., Song, Q., Cornillon, P., Spall, M., and Minobe, S.
Year: 2009
Formatted Citation: Small, R.J., deSzoeke, S.P., Xie, S.-P., O'Neill, L., Seo, H., Song, Q., Cornillon, P., Spall, M., and Minobe, S., 2009: Air-Sea Interaction Over Ocean Fronts and Eddies, Dynamics of Atmospheres and Oceans, 45(3-4), 274-319, 10.1016/j.dynatmoce.2008.01.001.
Abstract: Air-sea interaction at ocean fronts and eddies exhibits positive correlation between sea surface temperature (SST), wind speed, and heat fluxes out of the ocean, indicating that the ocean is forcing the atmosphere. This contrasts with larger scale climate modes where the negative correlations suggest that the atmosphere is driving the system. This paper examines the physical processes that lie behind the interaction of sharp SST gradients and the overlying marine atmospheric boundary layer and deeper atmosphere, using high resolution satellite data, field data and numerical models. The importance of different physical mechanisms of atmospheric response to SST gradients, such as the effect of surface stability variations on momentum transfer, pressure gradients, secondary circulations and cloud cover will be assessed. The atmospheric response is known to create small-scale wind stress curl and divergence anomalies, and a discussion of the feedback of these features onto the ocean will also be presented. These processes will be compared and contrasted for different regions such as the Equatorial Front in the Eastern Pacific, and oceanic fronts in mid-latitudes such as the Gulf Stream, Kuroshio, and Agulhas Return Current.
Keywords: Air-sea interaction, Oceanography, Meteorology, Fronts, Eddies, Boundary layers, Kuroshio, Gulf stream, Agulhas current
Mission:
URL: https://doi.org/10.1016/j.dynatmoce.2008.01.001
Other URLs:
Small, R.J., Richards, K., Xie, S.-P., Dutrieux, P., and Miyama, T. (2009). Damping of Tropical Instability Waves Caused by the Action of Surface Currents on Stress, Journal of Geophysical Research - Oceans, 114(C4), C04009, 10.1029/2008JC005147. Journal Article »
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Title: Damping of Tropical Instability Waves Caused by the Action of Surface Currents on Stress
Type: Journal Article
Publication: Journal of Geophysical Research - Oceans
Author(s): Small, R.J., Richards, K., Xie, S.-P., Dutrieux, P., and Miyama, T.
Year: 2009
Formatted Citation: Small, R.J., Richards, K., Xie, S.-P., Dutrieux, P., and Miyama, T., 2009: Damping of Tropical Instability Waves Caused by the Action of Surface Currents on Stress, Journal of Geophysical Research - Oceans, 114(C4), C04009, 10.1029/2008JC005147.
Abstract: Ocean eddies and fronts affect surface stress via two mechanisms: (1) ocean surface currents altering the relative motion between air and sea and, hence, the stress fields and (2) ocean sea surface temperature (SST) gradients forcing changes in stability and near-surface winds. In this paper, we quantify the first effect and how it impacts Tropical Instability Waves (TIW) in the eastern Pacific. High-resolution satellite data and a regional coupled model are used to distinguish between stress changes due to the surface currents and those due to the changes in stability and near-surface winds. It is found that both mechanisms affect the surface stress curl, but they do so at different latitudes, allowing for their effect on Ekman pumping to be distinguished. The Ekman pumping due to the surface current effect alone, leads to significant damping of the TIWs. In terms of the eddy kinetic energy, the inclusion of surface current in the stress leads to decay with an e-folding time comparable with the period of the TIWs. It is, thus, an important damping mechanism to be included in ocean and coupled ocean-atmosphere models.
Keywords: air-sea interaction, tropical instability waves, Ekman pumping
Mission:
URL: https://doi.org/10.1029/2008JC005147
Other URLs:
Smith, W.H.F. and Scharroo, R. (2009). Mesoscale Ocean Dynamics Observed by Satellite Altimeters in Non-Repeat Orbits, Geophysical Research Letters: Oceans, 36, L06601, 10.1029/2008GL036530. Journal Article »
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Title: Mesoscale Ocean Dynamics Observed by Satellite Altimeters in Non-Repeat Orbits
Type: Journal Article
Publication: Geophysical Research Letters: Oceans
Author(s): Smith, W.H.F. and Scharroo, R.
Year: 2009
Formatted Citation: Smith, W.H.F. and Scharroo, R., 2009: Mesoscale Ocean Dynamics Observed by Satellite Altimeters in Non-Repeat Orbits, Geophysical Research Letters: Oceans, 36, L06601, 10.1029/2008GL036530.
Abstract: We compare sea surface height anomalies observed by satellite altimeters in exact repeat mission orbits to anomalies observed by altimeters in geodetic or drifting orbits. One experiment compares data from the drift of TOPEX between its Tandem and Interleaved missions to repeat-orbit data from Jason-1, ERS-2 and GFO. A second experiment compares data from the ERS-1 non-repeating Geodetic Phases E and F to the repeating TOPEX data. Both studies cover the North Atlantic from 0° to 82°W and 15° to 55°N in order to sample both the Gulf Stream and quieter regions. Height anomalies are obtained along repeat and non-repeat orbits alike by use of a mean sea surface model. Each experiment is performed twice, once with the EGM2008 and once with the DNSC08 models, showing that the results are model-independent, DNSC08 yields an insignificant 2 mm lower RMS misfit. To compare anomalies between repeat and non-repeat orbits with different spatio-temporal sampling we grid the 1-Hz along-track point data and interpolate the grid to point values. RMS differences between grids and point values are around 4 cm in quiet areas and 6 cm over the entire region, with negligible difference between misfits to repeat and non-repeat data. A mapped sea surface height anomaly grid built solely from ERS-1 geodetic data captures at least 85% of the variance in repeat-track TOPEX point data. From these results we can conclude that altimeters in suitable non-repeating orbits are as useful for mesoscale oceanographic studies as are repeat orbit missions.
Keywords: * mesoscale * orbit * sampling
Mission:
URL: https://doi.org/10.1029/2008GL036530
Other URLs:
Song, J.-B. (2009). The Effects of Random Surface Waves on the Steady Ekman Current Solutions, Deep Sea Research Part I, 56(5), 659-671, 10.1016/j.dsr.2008.12.014. Journal Article »
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Title: The Effects of Random Surface Waves on the Steady Ekman Current Solutions
Type: Journal Article
Publication: Deep Sea Research Part I
Author(s): Song, J.-B.
Year: 2009
Formatted Citation: Song, J.-B., 2009: The Effects of Random Surface Waves on the Steady Ekman Current Solutions, Deep Sea Research Part I, 56(5), 659-671, 10.1016/j.dsr.2008.12.014.
Abstract: The response of near-surface current profiles to wind and random surface waves are studied based on the approach of Jenkins [1989. The use of a wave prediction model for driving a near surface current model. Dtsch. Hydrogr. Z. 42, 134-149] and Tang et al. [2007. Observation and modeling of surface currents on the Grand Banks: a study of the wave effects on surface currents. J. Geophys. Res. 112, C10025, doi:10.1029/2006JC004028]. Analytic steady solutions are presented for wave-modified Ekman equations resulting from Stokes drift, wind input and wave dissipation for a depth-independent constant eddy viscosity coefficient and one that varies linearly with depth. The parameters involved in the solutions can be determined by the two-dimensional wavenumber spectrum of ocean waves, wind speed, the Coriolis parameter and the densities of air and water, and the solutions reduce to those of Lewis and Belcher [2004. Time-dependent, coupled, Ekman boundary layer solutions incorporating Stokes drift. Dyn. Atmos. Oceans. 37, 313-351] when only the effects of Stokes drift are included. As illustrative examples, for a fully developed wind-generated sea with different wind speeds, wave-modified current profiles are calculated and compared with the classical Ekman theory and Lewis and Belcher`s [2004. Time-dependent, coupled, Ekman boundary layer solutions incorporating Stokes drift. Dyn. Atmos. Oceans 37, 313-351] modification by using the Donelan and Pierson [1987. Radar scattering and equilibrium ranges in wind-generated waves with application to scatterometry. J. Geophys. Res. 92, 4971-5029] wavenumber spectrum, the WAM wave model formulation for wind input energy to waves, and wave energy dissipation converted to currents. Illustrative examples for a fully developed sea and the comparisons between observations and the theoretical predictions demonstrate that the effects of the random surface waves on the classical Ekman current are important, as they change qualitatively the nature of the Ekman layer. But the effects of the wind input and wave dissipation on surface current are small, relative to the impact of the Stokes drift.
Keywords: Ekman current, Random wave, Stokes drift, Eddy viscosity coefficient
Mission:
URL: https://doi.org/10.1016/j.dsr.2008.12.014
Other URLs:
Song, Q., Chelton, D.B., Esbensen, S.K., Thum, N., and O'Neill, L.W. (2009). Coupling Between Sea-Surface Temperature and Low-Level Winds in Mesoscale Numerical Models, Journal of Climate, 22(1), 146-164, 10.1175/2008JCLI2488.1. Journal Article »
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Title: Coupling Between Sea-Surface Temperature and Low-Level Winds in Mesoscale Numerical Models
Type: Journal Article
Publication: Journal of Climate
Author(s): Song, Q., Chelton, D.B., Esbensen, S.K., Thum, N., and O'Neill, L.W.
Year: 2009
Formatted Citation: Song, Q., Chelton, D.B., Esbensen, S.K., Thum, N., and O'Neill, L.W., 2009: Coupling Between Sea-Surface Temperature and Low-Level Winds in Mesoscale Numerical Models, Journal of Climate, 22(1), 146-164, 10.1175/2008JCLI2488.1.
Abstract: This study evaluates the impacts of sea surface temperature (SST) specification and grid resolution on numerical simulations of air-sea coupling near oceanic fronts through analyses of surface winds from the European Centre for Medium-Range Weather Forecasts (ECMWF) model. The 9 May 2001 change of the boundary condition from the Reynolds SST analyses to the NOAA Real-Time Global (RTG) SST in the ECMWF model resulted in an abrupt increase in mesoscale variance of the model surface winds over the ocean. In contrast, the 21 November 2000 change of the grid resolution resulted in an abrupt increase in mesoscale variability of surface winds over mountainous regions on land, but had no significant effect on winds over the ocean. To further investigate model sensitivity to the SST boundary condition and grid resolution, a series of simulations were made with the Weather Research and Forecasting (WRF) model over a domain encompassing the Agulhas Return Current (ARC) region in the South Indian Ocean. Results from three WRF simulations with SST measured by the Advanced Microwave Scanning Radiometer on the Earth Observing System Aqua satellite (AMSR-E) and the Reynolds and RTG SST analyses indicate the vital importance of the resolution of the SST boundary condition for accurate simulation of the air-sea coupling between SST and surface wind speed. WRF simulations with grid spacings of 40 km and 25 km show that the latter increased energy only on scales shorter than 250 km. In contrast, improved resolution of SST significantly increased the mesoscale variability for scales up to 1000 km. Further sensitivity studies with the WRF model conclude that the weak coupling of surface wind speeds from the ECMWF model to SST is likely attributable primarily to the weak response of vertical turbulent mixing to SST-induced stability in the parameterization of boundary layer turbulence, with an overestimation of vertical diffusion by about 60% on average in stable conditions and an underestimation by about 40% in unstable conditions.
Keywords: Mesoscale models, Sea surface temperature, Wind, Air-sea interaction, Fronts
Mission:
URL: https://doi.org/10.1175/2008JCLI2488.1
Other URLs:
Sun, J. and Kawamura, H. (2009). Retrieval of Surface Wave Parameters from SAR Images and Their Validation in the Coastal Seas around Japan, Journal of Oceanography, 65(4), 567-577, 10.1007/s10872-009-0048-2. Journal Article »
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Title: Retrieval of Surface Wave Parameters from SAR Images and Their Validation in the Coastal Seas around Japan
Type: Journal Article
Publication: Journal of Oceanography
Author(s): Sun, J. and Kawamura, H.
Year: 2009
Formatted Citation: Sun, J. and Kawamura, H., 2009: Retrieval of Surface Wave Parameters from SAR Images and Their Validation in the Coastal Seas around Japan, Journal of Oceanography, 65(4), 567-577, 10.1007/s10872-009-0048-2.
Abstract: We have developed a scheme to retrieve surface wave parameters (wave height and wave propagation direction) from European Remote-Sensing Satellite (ERS) Synthetic Aperture Radar (SAR) image mode data in coastal seas around Japanese coastlines. SAR spectra are converted to surface wave spectra of swell-dominated or wind-wave dominated cases. The SAR spectrum and SAR-derived wind speed are used to derive the surface wave spectrum. The wind-wave dominated case and swell-dominated case are differentiated by a wind speed of 6 m/s, and processed in different ways because of their different degree of nonlinearity. It is indicated that the cutoff wavelength for retrieval of the wind-wave dominated spectrum is proportional to the root of significant wave height, which is consistent with the results of previous studies. We generated 66 match-ups using the SAR sub-images and the in-situ surface wave parameters, which were measured by wave gauges installed in near-shore seas. Among them, there are 57 swell-dominated cases, and 9 wind-wave dominated cases. The significant wave heights derived from SAR and from in-situ observation agree with the bias of 0.09 m, the standard deviation of 0.61 m and the correlation coefficient of 0.78. The averaged absolute deviation of wave propagation directions is 18.4°, and the trend of the agreement does not depend on the wave height. These results demonstrate that the SAR surface wave spectrum retrieved by the present system can be used to observe the surface wave field in the coastal seas around Japan.
Keywords: Synthetic Aperture Radar - surface wave spectrum - SAR spectrum - SAR wind speed - coastal sea - surface wave retrieval
Mission:
URL: https://doi.org/10.1007/s10872-009-0048-2
Other URLs:
Tanimoto, Y., Xie, S.-P., Kai, K., Okajima, H., Tokinaga, H., Murayama, T., Nonaka, M., and Nakamura, H. (2009). Observations of Marine Atmospheric Boundary Layer Transitions Across the Summer Kuroshio Extension, Journal of Climate, 22(6), 1360-1374, 10.1175/2008JCLI2420.1. Journal Article »
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Title: Observations of Marine Atmospheric Boundary Layer Transitions Across the Summer Kuroshio Extension
Type: Journal Article
Publication: Journal of Climate
Author(s): Tanimoto, Y., Xie, S.-P., Kai, K., Okajima, H., Tokinaga, H., Murayama, T., Nonaka, M., and Nakamura, H.
Year: 2009
Formatted Citation: Tanimoto, Y., Xie, S.-P., Kai, K., Okajima, H., Tokinaga, H., Murayama, T., Nonaka, M., and Nakamura, H., 2009: Observations of Marine Atmospheric Boundary Layer Transitions Across the Summer Kuroshio Extension, Journal of Climate, 22(6), 1360-1374, 10.1175/2008JCLI2420.1.
Abstract: The baiu and Kuroshio Extension (KE) fronts, both zonally oriented and nearly collocated east of Japan, are the dominant summertime features of the atmosphere and ocean, respectively, over the midlatitude northwest Pacific. An atmospheric sounding campaign was conducted on board the R/V Roger Revelle during the 2005 summer. Transects of soundings across the KE front are analyzed to study its effects on the atmosphere, along with continuous surface meteorological and ceilometer cloud-base observations. While the KE front remained nearly stationary during the cruise, the baiu front displayed large meridional displacements that changed wind direction across the KE front. The presence of sharp sea surface temperature (SST) gradients anchored by the KE enhanced the thermal and moisture advection, causing substantial changes in the marine atmospheric boundary layer (MABL) structure. When the baiu front was displaced north of the KE front, southwesterly winds advected warm, humid air from the subtropics over the cold water, producing a surface inversion favorable to fog formation. When the baiu front was to the south, on the other hand, northerly winds across the KE front destabilized the MABL, leading to the formation of a solid low-cloud deck beneath a strong capping inversion. The wind changes with the meridional displacement of the baiu front thus caused large variations in near-surface atmospheric stability and surface turbulent heat fluxes, with potential feedback on deep convection and fog/low-cloud formation around the front.
Keywords:
Mission:
URL: https://doi.org/10.1175/2008JCLI2420.1
Other URLs:
Tao, L., Fu, X., and Lu, W. (2009). Moisture Structure of the Quasi-Biweekly Mode Revealed by AIRS in Western Pacific, Advances in Atmospheric Sciences, 26(3), 513-522, 10.1007/s00376-009-0513-2. Journal Article »
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Title: Moisture Structure of the Quasi-Biweekly Mode Revealed by AIRS in Western Pacific
Type: Journal Article
Publication: Advances in Atmospheric Sciences
Author(s): Tao, L., Fu, X., and Lu, W.
Year: 2009
Formatted Citation: Tao, L., Fu, X., and Lu, W., 2009: Moisture Structure of the Quasi-Biweekly Mode Revealed by AIRS in Western Pacific, Advances in Atmospheric Sciences, 26(3), 513-522, 10.1007/s00376-009-0513-2.
Abstract: Using Atmospheric Infrared Sounder (AIRS) humidity profiles, rainfall from the Tropical Rainfall Measuring Mission (TRMM) Global Precipitation Index (GPI), Quick Scatterometer (QSCAT) satellite-observed surface winds, and SST from the Advanced Microwave Scanning Radiometer for NASA's Earth Observing System (AMSR_E), we analyzed the structure of the summer quasi-biweekly mode (QBM) over the western Pacific in 2003-2004. We find that the signal of 10-20-day oscillations in the western Pacific originates from the Philippine Sea, and propagates northwestward toward South China. The AIRS data reveal that the boundary-layer moisture provides preconditioning for QBM propagation, and leads the mid-troposphere moisture during the entire QBM cycle. The positive SST anomaly leads or is in-phase with the boundary-layer moistening, and may be a major contributor. Most likely, the 10-20-day SST anomaly positively feeds back to the atmosphere by moistening the boundary layer, destabilizing the troposphere, and leading the QBM to propagate northwestward in the western North Pacific. However, the ECMWF/TOGA (Tropical Ocean and Global Atmosphere) analysis does not display boundary-layer (BL) moisture anomalies leading the mid-troposphere moisture.
Keywords: AIRS, QuikSCAT
Mission: |SeaWinds|
URL: https://doi.org/10.1007/s00376-009-0513-2
Other URLs:
Tao, W.-K., Chern, J., Atlas, R., Randall, D., Lin, X., Khairoutdinov, M., Li, J.-L., Waliser, D.E., Hou, A., Peters-Lidard, C., Lau, W., and Simpson, J. (2009). A Multiscale Modeling System: Developments, Applications, and Critical Issues, Bulletin of the American Meteorological Society, 90(4), 515-534, 10.1175/2008BAMS2542.1. Journal Article »
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Title: A Multiscale Modeling System: Developments, Applications, and Critical Issues
Type: Journal Article
Publication: Bulletin of the American Meteorological Society
Author(s): Tao, W.-K., Chern, J., Atlas, R., Randall, D., Lin, X., Khairoutdinov, M., Li, J.-L., Waliser, D.E., Hou, A., Peters-Lidard, C., Lau, W., and Simpson, J.
Year: 2009
Formatted Citation: Tao, W.-K., Chern, J., Atlas, R., Randall, D., Lin, X., Khairoutdinov, M., Li, J.-L., Waliser, D.E., Hou, A., Peters-Lidard, C., Lau, W., and Simpson, J., 2009: A Multiscale Modeling System: Developments, Applications, and Critical Issues, Bulletin of the American Meteorological Society, 90(4), 515-534, 10.1175/2008BAMS2542.1.
Abstract: A multi-scale modeling framework (MMF), which replaces the conventional cloud parameterizations with a cloud-resolving model (CRM) in each grid column of a GCM, constitutes a new and promising approach for climate modeling. The MMF can provide for global coverage and two-way interactions between the CRMs and their parent GCM. The CRM allows explicit simulation of cloud processes and their interactions with radiation and surface processes and the GCM allows global coverage. A new MMF has been developed that is based on the NASA Goddard Space Flight Center (GSFC) finite volume GCM (fvGCM) and the Goddard Cumulus Ensemble (GCE) model. This Goddard MMF produces many features that are similar to another MMF that was developed at Colorado State University (CSU), such as an improved surface precipitation pattern, better cloudiness, improved diurnal variability over both oceans and continents, and a stronger, propagating Madden-Julian oscillation (MJO) compared to their parent GCMs using traditional cloud parameterizations. Both MMFs also produce a large and positive precipitation bias in the Indian Ocean and western Pacific during Northern Hemisphere summer. However, there are also notable differences between the two MMFs. For example, the CSU MMF simulates less rainfall over land than its parent GCM. This is why the CSU MMF simulated less overall global rainfall than its parent GCM. The Goddard MMF simulates more global rainfall than its parent GCM because of the high contribution from the oceanic component. A number of critical issues (i.e., the CRM's physical processes and its configuration) involving the Goddard MMF are discussed in this paper.
Keywords:
Mission:
URL: https://doi.org/10.1175/2008BAMS2542.1
Other URLs:
Tokinaga, H., and Xie, S.-P. (2009). Ocean Tidal Cooling Effect on Summer Sea Fog Over the Okhotsk Sea, Journal of Geophysical Research: Atmospheres, 114, D14102, 10.1029/2008JD011477. Journal Article »
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Title: Ocean Tidal Cooling Effect on Summer Sea Fog Over the Okhotsk Sea
Type: Journal Article
Publication: Journal of Geophysical Research: Atmospheres
Author(s): Tokinaga, H., and Xie, S.-P.
Year: 2009
Formatted Citation: Tokinaga, H., and Xie, S.-P., 2009: Ocean Tidal Cooling Effect on Summer Sea Fog Over the Okhotsk Sea, Journal of Geophysical Research: Atmospheres, 114, D14102, 10.1029/2008JD011477.
Abstract: Ocean tide is a periodic phenomenon of the rise and fall of the sea level that depends on the bathymetry and positions of the moon and sun relative to the earth. In the Okhotsk Sea, the ocean tide causes strong vertical mixing in the upper ocean, generating rich structures in summer SST with extraordinarily cold patches on Kashevarov Bank, along the Kuril Islands, northeast of the Terpeniya Peninsula, and inside Shelikhov Bay. The present study analyzes and synthesizes a suite of ship-board and satellite observations, and numerical simulations to investigate the ocean tidal cooling effect on summer sea fog over the Okhotsk Sea. Over the tide-induced cold patches, atmospheric stability increases, and surface wind weakens markedly possibly through suppressed atmospheric vertical mixing. Our analysis of ship-board observations reveals frequent sea-fog occurrence over the cold patches with a maximum exceeding 70% along the Kuril Islands in July-August. Numerical simulations with the Weather Research and Forecasting (WRF) model support that the cold patches cool air temperature, decelerate surface wind, and form a strong surface inversion layer up to 0.5 km high, creating favorable conditions for sea-fog occurrence. The WRF simulation without the tidal cooling effect reduces sea-fog occurrence by more than 20% over cold patches, illustrating the importance of SST products for climate models.
Keywords: Okhotsk Sea, tidal mixing, sea fog
Mission:
URL: https://doi.org/10.1029/2008JD011477
Other URLs:
Tokinaga, H., Tanimoto, Y., Xie, S.-P., Sampe, T., Tomita, H., and Ichikawa, H. (2009). Ocean Frontal Effects on the Vertical Development of Clouds Over the Western North Pacific: In Situ and Satellite Observations, Journal of Climate, 22(16), 4241-4260, 10.1175/2009JCLI2763.1. Journal Article »
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Title: Ocean Frontal Effects on the Vertical Development of Clouds Over the Western North Pacific: In Situ and Satellite Observations
Type: Journal Article
Publication: Journal of Climate
Author(s): Tokinaga, H., Tanimoto, Y., Xie, S.-P., Sampe, T., Tomita, H., and Ichikawa, H.
Year: 2009
Formatted Citation: Tokinaga, H., Tanimoto, Y., Xie, S.-P., Sampe, T., Tomita, H., and Ichikawa, H., 2009: Ocean Frontal Effects on the Vertical Development of Clouds Over the Western North Pacific: In Situ and Satellite Observations, Journal of Climate, 22(16), 4241-4260, 10.1175/2009JCLI2763.1.
Abstract: A suite of shipboard and satellite observations are analyzed and synthesized to investigate the three-dimensional structure of clouds and influences from sea surface temperature fronts over the western North Pacific. Sharp transitions are observed across the Kuroshio Extension (KE) front in the marine atmospheric boundary layer (MABL) and its clouds. The ocean's influence appears to extend beyond the MABL, with higher cloud tops in altitude along the KE front than the surroundings. In winter, intense turbulent heat release from the ocean takes place on the southern flank of the KE front, where the cloud top penetrates above the MABL and reaches the midtroposphere. In this band of high cloud tops, frequent lightning activity is observed. The results of this study suggest a sea level pressure mechanism for which the temperature gradient in the MABL induces strong surface wind convergence on the southern flank of the KE front, deepening the clouds there. In early summer, sea fog frequently occurs on the northern flank of the subtropical KE and subarctic fronts under southerly warm advection that suppresses surface heat flux and stabilizes the surface atmosphere. Sea fog is infrequently observed over the KE front even under southerly conditions, as the warm ocean current weakens atmospheric stratification and promotes vertical mixing. The KE front produces a narrow band of surface wind convergence, helping support a broad band of upward motion at 700 hPa that is associated with the eastward extension of the baiu rainband from Japan in June-July.
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Mission:
URL: https://doi.org/10.1175/2009JCLI2763.1
Other URLs:
Trossman, D., Thompson, L., Kelly, K.A., and Kwon, Y.-O. (2009). Estimates of North Atlantic Ventilation and Mode Water Formation for Winters 2002-2006, Cover Journal of Physical Oceanography Journal of Physical Oceanography, 39(10), 2600-2617, 10.1175/2009JPO3930.1. Journal Article »
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Title: Estimates of North Atlantic Ventilation and Mode Water Formation for Winters 2002-2006
Type: Journal Article
Publication: Cover Journal of Physical Oceanography Journal of Physical Oceanography
Author(s): Trossman, D., Thompson, L., Kelly, K.A., and Kwon, Y.-O.
Year: 2009
Formatted Citation: Trossman, D., Thompson, L., Kelly, K.A., and Kwon, Y.-O., 2009: Estimates of North Atlantic Ventilation and Mode Water Formation for Winters 2002-2006, Cover Journal of Physical Oceanography Journal of Physical Oceanography, 39(10), 2600-2617, 10.1175/2009JPO3930.1.
Abstract:
Keywords: Water masses, Remote sensing, Sea/ocean surface, Ekman pumping/transport, Lagrangian circulation/transport
Mission: |SeaWinds|
URL: https://doi.org/10.1175/2009JPO3930.1
Other URLs:
Waliser, D.E., Tian, B., Xie, X., Liu, W.T., Schwartz, M.J., and Fetzer, E.J. (2009). How Well Can Satellite Data Characterize the Water Cycle of the Madden-Julian Oscillation?, Geophysical Research Letters: Atmospheric Science, 36(21), 10.1029/2009GL040005. Journal Article »
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Title: How Well Can Satellite Data Characterize the Water Cycle of the Madden-Julian Oscillation?
Type: Journal Article
Publication: Geophysical Research Letters: Atmospheric Science
Author(s): Waliser, D.E., Tian, B., Xie, X., Liu, W.T., Schwartz, M.J., and Fetzer, E.J.
Year: 2009
Formatted Citation: Waliser, D.E., Tian, B., Xie, X., Liu, W.T., Schwartz, M.J., and Fetzer, E.J., 2009: How Well Can Satellite Data Characterize the Water Cycle of the Madden-Julian Oscillation?, Geophysical Research Letters: Atmospheric Science, 36(21), 10.1029/2009GL040005.
Abstract:
Keywords:
Mission:
URL: https://doi.org/10.1029/2009GL040005
Other URLs:
Weissman, D.E. and Bourassa, M.A. (2009). The Combined Effect of Surface Rain and Wind on Scatterometer Observations of Surface Roughness, 2009 IEEE International Geoscience and Remote Sensing Symposium, I-108 - I-111, 10.1109/IGARSS.2009.5416932. Conference Paper »
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Title: The Combined Effect of Surface Rain and Wind on Scatterometer Observations of Surface Roughness
Type: Conference Paper
Publication: 2009 IEEE International Geoscience and Remote Sensing Symposium
Author(s): Weissman, D.E. and Bourassa, M.A.
Year: 2009
Formatted Citation: Weissman, D.E. and Bourassa, M.A., 2009: The Combined Effect of Surface Rain and Wind on Scatterometer Observations of Surface Roughness, 2009 IEEE International Geoscience and Remote Sensing Symposium, I-108 - I-111, 10.1109/IGARSS.2009.5416932.
Abstract: The wind stress on the sea surface is closely related to the sea surface roughness. When rain impacts affect this roughness, we need to learn the consequences for the air-sea momentum exchange. Our data shows that areas of highest winds correlate closely with the heaviest rainfall. Changes in the sea surface radar cross section from the combined effects of wind and rain, on scales of tens of kilometers, are being studied using the QuikSCAT scatterometer and simultaneous NEXRAD three-dimensional measurements of rain within Hurricane Ike. Buoys, NOAA HRD H*Winds and related data provide the additional wind information. From the remote sensing perspective, these results will show the dependence of the sea surface radar cross section, at Ku-band, as a function of the rainrate, wind speed and relative direction, and polarization. At this microwave frequency the surface backscatter is controlled by the centimeter-scale roughness, but at these high wind speeds the simple models based on Bragg scattering are not useful. In order to study the air-sea interaction that is related to surface fluxes (e.g., momentum, sensible heat, and latent heat) during rain events, extended experimental investigations are needed. Heavy rain in the boundary layer changes the profiles of wind and stratification which alter the surface stress and turbulent heat fluxes. The wind driven rain also creates roughness properties that need to be modeled in order to interpret the Ku-band NRCS at the two polarizations, When high winds also exist (>20 m/s), the interaction is complicated by sea spray.
Keywords: atmospheric boundary layer , backscatter , ocean waves , oceanographic techniques , Hurricane Ike , Ku band radar remote sensing , NEXRAD 3D measurements , NOAA HRD H*Winds data , QuikSCAT scatterometer , air-sea momentum exchange , bu
Mission: |SeaWinds|
URL: https://doi.org/10.1109/IGARSS.2009.5416932
Other URLs:
Wikle, C.K. and Milliff, R.F. (2009). Comment on 'A Spatio-Temporal Model for Mean, Anomaly and Trend Fields of North Atlantic Sea Surface Temperature', Journal of the American Statistical Association, 104(485), 22-23, 10.1198/jasa.2009.0027. Journal Article »
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Title: Comment on 'A Spatio-Temporal Model for Mean, Anomaly and Trend Fields of North Atlantic Sea Surface Temperature'
Type: Journal Article
Publication: Journal of the American Statistical Association
Author(s): Wikle, C.K. and Milliff, R.F.
Year: 2009
Formatted Citation: Wikle, C.K. and Milliff, R.F., 2009: Comment on 'A Spatio-Temporal Model for Mean, Anomaly and Trend Fields of North Atlantic Sea Surface Temperature', Journal of the American Statistical Association, 104(485), 22-23, 10.1198/jasa.2009.0027.
Abstract:
Keywords:
Mission:
URL: https://doi.org/10.1198/jasa.2009.0027
Other URLs:
Williams, B.A., Owen, M.P., and Long, D.G. (2009). The Ultra High Resolution QuikSCAT Product, IEEE Radar Conference, 1-6, 10.1109/RADAR.2009.4977111. Conference Paper »
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Title: The Ultra High Resolution QuikSCAT Product
Type: Conference Paper
Publication: IEEE Radar Conference
Author(s): Williams, B.A., Owen, M.P., and Long, D.G.
Year: 2009
Formatted Citation: Williams, B.A., Owen, M.P., and Long, D.G., 2009: The Ultra High Resolution QuikSCAT Product, IEEE Radar Conference, 1-6, 10.1109/RADAR.2009.4977111.
Abstract: Although QuikSCAT was originally designed to measure winds at a resolution of 25 km, higher resolution wind and rain products have been developed. The 2.5 km ultra high resolution (UHR) products allow QuikSCAT data to be used for applications involving rain, meso-scale phenomena, and in coastal applications. This paper overviews and unifies the various UHR products and discusses their advantages and limitations as compared to each other and the conventional 25 km product. Theory, consequences of assumptions, and trade-offs are also discussed.
Keywords:
Mission: |SeaWinds|
URL: https://doi.org/10.1109/RADAR.2009.4977111
Other URLs:
Wingham, D.J., Wallis, D.W., and Shepherd, A. (2009). Spatial and Temporal Evolution of Pine Island Glacier Thinning, 1995-2006, Geophysical Research Letters: The Cryosphere, 36(17), L17501, 10.1029/2009GL039126. Journal Article »
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Title: Spatial and Temporal Evolution of Pine Island Glacier Thinning, 1995-2006
Type: Journal Article
Publication: Geophysical Research Letters: The Cryosphere
Author(s): Wingham, D.J., Wallis, D.W., and Shepherd, A.
Year: 2009
Formatted Citation: Wingham, D.J., Wallis, D.W., and Shepherd, A., 2009: Spatial and Temporal Evolution of Pine Island Glacier Thinning, 1995-2006, Geophysical Research Letters: The Cryosphere, 36(17), L17501, 10.1029/2009GL039126.
Abstract: We use ERS-2 and ENVISAT satellite radar altimetry to examine spatial and temporal changes in the rate of thinning of the Pine Island Glacier, West Antarctica, during the period 1995 to 2006. We show that the pattern of thinning has both accelerated and spread inland to encompass tributaries flowing into the central trunk of the glacier. Within the 5,400 km2 central trunk, the average rate of volume loss quadrupled from 2.6 ± 0.3 km3 yr^-1 in 1995 to 10.1 ± 0.3 km3 yr^-1 in 2006. The region of lightly grounded ice at the glacier terminus is extending upstream, and the changes inland are consistent with the effects of a prolonged disturbance to the ice flow, such as the effects of ocean-driven melting. If the acceleration continues at its present rate, the main trunk of PIG will be afloat within some 100 years, six times sooner than anticipated.
Keywords: * West Antarctica * altimetry
Mission:
URL: https://doi.org/10.1029/2009GL039126
Other URLs:
Wolken, G.J., Sharp, M., and Wang, L.B. (2009). Snow and Ice Facies Variability and Ice Layer Formation on Canadian Arctic Ice Caps, 1999-2005, Journal of Geophysical Research: Earth Surface, 114(F3), F03011, 10.1029/2008JF001173. Journal Article »
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Title: Snow and Ice Facies Variability and Ice Layer Formation on Canadian Arctic Ice Caps, 1999-2005
Type: Journal Article
Publication: Journal of Geophysical Research: Earth Surface
Author(s): Wolken, G.J., Sharp, M., and Wang, L.B.
Year: 2009
Formatted Citation: Wolken, G.J., Sharp, M., and Wang, L.B., 2009: Snow and Ice Facies Variability and Ice Layer Formation on Canadian Arctic Ice Caps, 1999-2005, Journal of Geophysical Research: Earth Surface, 114(F3), F03011, 10.1029/2008JF001173.
Abstract: Time series of enhanced resolution data from the SeaWinds scatterometer aboard QuikScat were used to map the distribution of snow and ice surface facies and ice layer formation in the percolation zone on ice caps in the Queen Elizabeth Islands during the period 1999–2005. Iterative Self-Organizing Data Analysis classification of the mean postfreeze-up biweekly average σ0 signal for the 7-year period resulted in the delineation of four snow and ice surface facies (interpreted as the percolation, saturation, superimposed ice, and glacier ice zones). Analysis with National Centers for Environmental Prediction/National Center for Atmospheric Research Reanalysis reveals that changes in geopotential height in the troposphere (700, 500, and 300 hPa) and air temperature (700 hPa level) are positively (negatively) correlated with area changes in the glacier ice (percolation and saturation) zones and changes in facies boundary elevation. The change in biweekly-averaged backscatter following the freeze-up periods between successive autumns was used to map changes in the distribution of ice layers formed by meltwater percolation and refreezing in the snowpack within the percolation zone. Strongly positive air temperature anomalies at the 700 hPa level in 2001 and 2005 are consistent with extensive ice layer formation in the percolation zones of all ice caps. Such large interannual changes in ice layer formation are likely associated with large changes to the density profile of the snowpack and may be associated with surface elevation changes that are unrelated to changes in surface mass balance.
Keywords: * QuikSCAT * melt * Arctic Canada
Mission: |SeaWinds|
URL: https://doi.org/10.1029/2008JF001173
Other URLs:
Wood, R., Kohler, M., Bennartz, R., and O'Dell, C. (2009). The Diurnal Cycle of Surface Divergence Over the Global Oceans, Quarterly Journal of the Royal Meteorological Society, 135(643), 1484-1493, 10.1002/qj.451. Journal Article »
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Title: The Diurnal Cycle of Surface Divergence Over the Global Oceans
Type: Journal Article
Publication: Quarterly Journal of the Royal Meteorological Society
Author(s): Wood, R., Kohler, M., Bennartz, R., and O'Dell, C.
Year: 2009
Formatted Citation: Wood, R., Kohler, M., Bennartz, R., and O'Dell, C., 2009: The Diurnal Cycle of Surface Divergence Over the Global Oceans, Quarterly Journal of the Royal Meteorological Society, 135(643), 1484-1493, 10.1002/qj.451.
Abstract: The diurnal cycle of surface divergence over the oceans is examined using 4 × daily data from the tandem SeaWinds satellite missions during April-September 2003. A statistically significant diurnal cycle of surface divergence is observed over a large fraction of the tropical and subtropical oceans. The highest amplitudes are found adjacent to tropical landmasses and decrease exponentially with distance away from the coast, with a representative e-folding distance of approximately 200 km. In most of these near-coastal regions the surface divergence peaks at 15-20 h locally and there is evidence of offshore propagation of the signal. There are regions, however, where strong cycles persist for much greater distances offshore. Over the southeast Pacific Ocean, there is evidence of a diurnal subsidence wave that propagates for over 2000 km away from the South American coast at approximately 25 m s^-1. A cloud response to the subsidence wave moving westward from the Andes mountains is detected using passive microwave observations of liquid-water path. Over the remote tropical Pacific, significant diurnal amplitude is found in and around regions of strong mean surface convergence, with a phase suggesting a surface response to the early morning diurnal maximum in precipitation and propagation away from these sources consistent with gravity waves forced by deep tropospheric heating. European Centre for Medium-Range Weather Forecasts (ECMWF) model simulations of 850 hPa subsidence show a diurnal cycle that is largely consistent with the SeaWinds divergence observations.
Keywords: surface divergence, diurnal, scatterometer, subsidence wave
Mission: |SeaWinds|
URL: https://doi.org/10.1002/qj.451
Other URLs:
Yamaguchi, S. and Kawamura, H. (2009). SAR-Imaged Spiral Eddies in Mutsu Bay and Their Dynamic and Kinematic Models, Journal of Oceanography, 65(4), 525-539, 10.1007/s10872-009-0045-5. Journal Article »
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Title: SAR-Imaged Spiral Eddies in Mutsu Bay and Their Dynamic and Kinematic Models
Type: Journal Article
Publication: Journal of Oceanography
Author(s): Yamaguchi, S. and Kawamura, H.
Year: 2009
Formatted Citation: Yamaguchi, S. and Kawamura, H., 2009: SAR-Imaged Spiral Eddies in Mutsu Bay and Their Dynamic and Kinematic Models, Journal of Oceanography, 65(4), 525-539, 10.1007/s10872-009-0045-5.
Abstract: A pattern of slick streaks winding into a spiral, known as a spiral eddy, was identified in 5 images taken by the ERS-1/2 synthetic aperture radar (SAR) in Mutsu Bay (Japan), dynamic and kinematic models of these spiral eddies have been proposed. Common characteristics of the five spiral eddies are: 1) an eddy diameter of about 15 km, 2) their location in the western part of the bay, and 3) their cyclonic direction of rotation. Moreover, the wind conditions over the bay were common: prior to acquiring the images, a strong easterly wind continued blowing for more than one day. The wind field on the bay is known to be orographically steered and has strong windstress vorticity, which generates cyclonic circulation. The diameter and location of the circulation simulated with a numerical ocean model corresponded well to those of the identified spiral eddies. Based on these facts, we propose a dynamic model for the movement of a slick streak, and a kinematic model for the formation of a spiral eddy. We have assumed calm air, a microlayer and seawater with a cyclonic circulation in the dynamic model. The balance of forces is established in the microlayer among the frictional force from the seawater, the frictional force from the calm air, the gravitational force, and the Coriolis force. As a result, the velocity vector of the microlayer deflects slightly towards the center of the cyclonic circulation. We have assumed a point source of the microlayer in the kinematic model. The shapes of a slick streak simulated with the models agree well with the identified patterns in the SAR images.
Keywords: Spiral eddy - Mutsu Bay - synthetic aperture radar - orographically steered winds
Mission:
URL: https://doi.org/10.1007/s10872-009-0045-5
Other URLs:
Yu, P., Clausi, D.A., and Howell, S.E.L. (2009). Fusing AMSR-E and QuikSCAT Imagery for Improved Sea Ice Recognition, IEEE Transactions on Geoscience and Remote Sensing, 47(7), 1980-1989, 10.1109/TGRS.2009.2013632. Journal Article »
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Title: Fusing AMSR-E and QuikSCAT Imagery for Improved Sea Ice Recognition
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Yu, P., Clausi, D.A., and Howell, S.E.L.
Year: 2009
Formatted Citation: Yu, P., Clausi, D.A., and Howell, S.E.L., 2009: Fusing AMSR-E and QuikSCAT Imagery for Improved Sea Ice Recognition, IEEE Transactions on Geoscience and Remote Sensing, 47(7), 1980-1989, 10.1109/TGRS.2009.2013632.
Abstract: The benefits of augmenting Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E) image data with Quick Scatterometer (QuikSCAT) image data for supervised sea ice classification in the Western Arctic region are investigated. Experiments compared the performance of a maximum likelihood classifier when used with the AMSR-E-only data set against using the combined data. The preferred number of bands to use for classification was examined, as well as whether principal component analysis (PCA) can be used to reduce the dimensionality of the data. The reliability of training data over time was also investigated. Adding QuikSCAT often improves classifier accuracy in a statistically significant manner and never decreases it significantly when a sufficient number of bands are used. Combining these data sets is beneficial for sea ice mapping. Using all available bands is recommended, data fusion with PCA does not offer any benefit for these data, and training data from a specific date remains reliable within 30 days.
Keywords: QuikSCAT, Seawinds, Seawinds
Mission: |SeaWinds|
URL: https://doi.org/10.1109/TGRS.2009.2013632
Other URLs:
Yuan, X., Patoux, J., and Li, C. (2009). Satellite-Based Midlatitude Cyclone Statistics Over the Southern Ocean: 2. Tracks and Surface Fluxes, Journal of Geophysical Research: Atmospheres, 114, D04106, 10.1029/2008JD010874. Journal Article »
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Title: Satellite-Based Midlatitude Cyclone Statistics Over the Southern Ocean: 2. Tracks and Surface Fluxes
Type: Journal Article
Publication: Journal of Geophysical Research: Atmospheres
Author(s): Yuan, X., Patoux, J., and Li, C.
Year: 2009
Formatted Citation: Yuan, X., Patoux, J., and Li, C., 2009: Satellite-Based Midlatitude Cyclone Statistics Over the Southern Ocean: 2. Tracks and Surface Fluxes, Journal of Geophysical Research: Atmospheres, 114, D04106, 10.1029/2008JD010874.
Abstract: Midlatitude cyclone tracks over the Southern Ocean are constructed for the 1999-2006 period using two surface data sets: European Centre for Medium-range Weather Forecasts (ECMWF) sea-level pressure analyses on one hand, and on the other hand modified analyses in which high-wavenumber pressure variability derived from scatterometer swaths has been injected with a wavelet-based method. A comparison of track statistics reveals the differences between the two data sets. The fluxes of momentum and sensible and latent heat associated with these midlatitude cyclones are calculated and sorted by life span. Three aspects of these cyclone flux statistics are investigated. (1) The momentum flux into the ocean is stronger inside cyclones than over the rest of the Southern Ocean, while the ocean loses more sensible and latent heat outside of the cyclones. (2) The momentum flux into the ocean and the loss of sensible and latent heat by the ocean are larger when calculated from the scatterometer-modified analyses than when calculated from the original ECMWF analyses. (3) Mesoscale cyclones (short-lived cyclones) contribute a significant amount of the fluxes between the atmosphere and the Southern Ocean, although over slightly different geographic areas from longer-lived cyclones.
Keywords: midlatitude cyclone tracks scatterometer air-sea fluxes
Mission:
URL: https://doi.org/10.1029/2008JD010874
Other URLs:
Zeng, L., Shi, P., Liu, W.T., and Wang, D. (2009). Evaluation of a Satellite-Derived Latent Heat Flux Product in the South China Sea: A Comparison with Moored Buoy Data and Various Products, Atmospheric Research, 94(1), 91-105, 10.1016/j.atmosres.2008.12.007. Journal Article »
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Title: Evaluation of a Satellite-Derived Latent Heat Flux Product in the South China Sea: A Comparison with Moored Buoy Data and Various Products
Type: Journal Article
Publication: Atmospheric Research
Author(s): Zeng, L., Shi, P., Liu, W.T., and Wang, D.
Year: 2009
Formatted Citation: Zeng, L., Shi, P., Liu, W.T., and Wang, D., 2009: Evaluation of a Satellite-Derived Latent Heat Flux Product in the South China Sea: A Comparison with Moored Buoy Data and Various Products, Atmospheric Research, 94(1), 91-105, 10.1016/j.atmosres.2008.12.007.
Abstract:
Keywords:
Mission:
URL: https://doi.org/10.1016/j.atmosres.2008.12.007
Other URLs:
Zhu, Y., Shang, S., Zhai, W., and Dai, M. (2009). Satellite-Derived Surface Water pCO₂ and Air-Sea CO₂ Fluxes in the Northern South China Sea in Summer, Progress in Natural Science, 19(6), 775-779, 10.1016/j.pnsc.2008.09.004. Journal Article »
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Title: Satellite-Derived Surface Water pCO₂ and Air-Sea CO₂ Fluxes in the Northern South China Sea in Summer
Type: Journal Article
Publication: Progress in Natural Science
Author(s): Zhu, Y., Shang, S., Zhai, W., and Dai, M.
Year: 2009
Formatted Citation: Zhu, Y., Shang, S., Zhai, W., and Dai, M., 2009: Satellite-Derived Surface Water pCO₂ and Air-Sea CO₂ Fluxes in the Northern South China Sea in Summer, Progress in Natural Science, 19(6), 775-779, 10.1016/j.pnsc.2008.09.004.
Abstract: An empirical approach is presented for the estimation of the partial pressure of carbon dioxide (pCO₂) and air-sea CO₂ fluxes in the northern South China Sea in summer using satellite-derived sea surface temperatures (SSTs), chlorophyll-a (Chl a) concentrations, and wind fields. Two algorithms were tested. The first used an SST-dependent equation, and the other involved the introduction of Chl a. Regression equations were developed for summer based on in situ data obtained in July, 2004. Using the monthly average SST and Chl a fields derived from the advanced very high resolution radiometer (AVHRR) and the SeaWiFS (sea-viewing wide field of view sensor), respectively, the monthly pCO₂ fields were computed. The derived pCO₂ was compared with the shipboard pCO₂ observations conducted in July, 2000. This resulted in a root-mean-square error of 4.6 mu atm, suggesting that the satellite-derived pCO₂ was in general agreement with the in situ observations. The air-sea CO₂ flux was further computed with the aid of the monthly mean QuikSCAT wind speed. We contend that more shipboard data are necessary for refining the empirical algorithms and reducing the uncertainty in the results.
Keywords: QuikSCAT
Mission: |SeaWinds|
URL: https://doi.org/10.1016/j.pnsc.2008.09.004
Other URLs:
Zieger, S., Vinoth, J., and Young, I.R. (2009). Joint Calibration of Multiplatform Altimeter Measurements of Wind Speed and Wave Height over the Past 20 Years, Journal of Atmospheric and Oceanic Technology, 26(12), 2549-2564, 10.1175/2009JTECHA1303.1. Journal Article »
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Title: Joint Calibration of Multiplatform Altimeter Measurements of Wind Speed and Wave Height over the Past 20 Years
Type: Journal Article
Publication: Journal of Atmospheric and Oceanic Technology
Author(s): Zieger, S., Vinoth, J., and Young, I.R.
Year: 2009
Formatted Citation: Zieger, S., Vinoth, J., and Young, I.R., 2009: Joint Calibration of Multiplatform Altimeter Measurements of Wind Speed and Wave Height over the Past 20 Years, Journal of Atmospheric and Oceanic Technology, 26(12), 2549-2564, 10.1175/2009JTECHA1303.1.
Abstract: Since 1985, for a period of more than 23 yr, seven altimeter missions have provided global coverage of significant wave height and wind speed. This study undertakes a long-term analysis of the accuracy and stability of altimeter-derived values of significant wave height and wind speed from the following satellites: European Remote Sensing-1 (ERS-1), ERS-2, Environmental Satellite (Envisat), Geosat, Geosat Follow-On (GFO), Jason-1, and the Ocean Topography Experiment (TOPEX). This study is a necessary step in developing a quality-controlled and fully calibrated and validated dataset from the combined satellites. Calibration of all altimeters is performed against National Oceanographic Data Center (NODC) buoy data over the extended period. These calibrations are validated using intercomparisons between satellite missions at crossover ground points. This analysis shows that, for a number of the satellites, small 'step like' changes occur during the missions. These inconsistencies are removed by subdividing these missions and undertaking a partial calibration for each section of the mission. The analysis also highlights that care is necessary when attempting to apply relationships between radar cross section and wind speed derived for one altimeter to other platforms. Before undertaking such steps, it is first necessary to apply a platform-specific radar cross-sectional offset to the data.
Keywords:
Mission:
URL: https://doi.org/10.1175/2009JTECHA1303.1
Other URLs:
Adams, I.S., Gaiser, P.W., and Jones, W.L. (2008). Simulation of the Stokes Vector in Inhomogeneous Precipitation, Radio Science, 43(5), RS5006, 10.1029/2007RS003744. Journal Article »
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Title: Simulation of the Stokes Vector in Inhomogeneous Precipitation
Type: Journal Article
Publication: Radio Science
Author(s): Adams, I.S., Gaiser, P.W., and Jones, W.L.
Year: 2008
Formatted Citation: Adams, I.S., Gaiser, P.W., and Jones, W.L., 2008: Simulation of the Stokes Vector in Inhomogeneous Precipitation, Radio Science, 43(5), RS5006, 10.1029/2007RS003744.
Abstract:
Keywords:
Mission:
URL: https://doi.org/10.1029/2007RS003744
Other URLs:
Ahmad, K., Jones, W.L., and Kasparis, T. (2008). An Improved Oceanic Rainfall Retrieval Algorithm and Results from SeaWinds, International Geoscience and Remote Sensing Symposium (IGARSS), 10.1109/IGARSS.2008.4779716. Conference Paper »
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Title: An Improved Oceanic Rainfall Retrieval Algorithm and Results from SeaWinds
Type: Conference Paper
Publication: International Geoscience and Remote Sensing Symposium (IGARSS)
Author(s): Ahmad, K., Jones, W.L., and Kasparis, T.
Year: 2008
Formatted Citation: Ahmad, K., Jones, W.L., and Kasparis, T., 2008: An Improved Oceanic Rainfall Retrieval Algorithm and Results from SeaWinds, International Geoscience and Remote Sensing Symposium (IGARSS), 10.1109/IGARSS.2008.4779716.
Abstract: This paper describes the development of an oceanic rainfall retrieval algorithm that combines both the simultaneous active (radar backscatter) and passive (microwave brightness temperatures) observations from the SeaWinds scatterometer on the QuikSCAT satellite. The retrieval algorithm is statistically based, and has been developed using collocated measurements from SeaWinds, the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) rain rates, and the National Center for Environmental Prediction (NCEP) wind fields. The rain is retrieved on a wind vector cell (WVC) measurement grid that has a spatial resolution of 25 km. Due to its broad swath coverage, SeaWinds affords additional independent sampling of the oceanic rainfall, which may contribute to NASA`s future Global Precipitation Mission. Results emphasize the powerful rain detection capabilities of the SeaWinds retrieval algorithm. 2008 IEEE.
Keywords: QuikSCAT, Seawinds
Mission:
URL: https://doi.org/10.1109/IGARSS.2008.4779716
Other URLs:
Ahmad, K.A., Jones, W.L., and Kasparis, T. (2008). Oceanic Rainfall Retrievals Using Passive and Active Measurements from SeaWinds Remote Sensor, 2007 IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2007, June 23, 2007 - June 28, 10.1109/IGARSS.2007.4423601. Conference Paper »
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Title: Oceanic Rainfall Retrievals Using Passive and Active Measurements from SeaWinds Remote Sensor
Type: Conference Paper
Publication: 2007 IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2007, June 23, 2007 - June 28
Author(s): Ahmad, K.A., Jones, W.L., and Kasparis, T.
Year: 2008
Formatted Citation: Ahmad, K.A., Jones, W.L., and Kasparis, T., 2008: Oceanic Rainfall Retrievals Using Passive and Active Measurements from SeaWinds Remote Sensor, 2007 IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2007, June 23, 2007 - June 28, 10.1109/IGARSS.2007.4423601.
Abstract: The SeaWinds sensor was launched onboard two satellite missions. The first was the QuikSCAT mission launched in mid 1999 by NASA, and the second was the ADEOS II mission launched by JAXA in late 2002. SeaWinds operates at a ku-band frequency of 13.4 GHz, and was originally designed to measure the speed and direction of the ocean surface wind vector by relating the normalized radar backscatter measurements to the near surface wind vector through a geophysical model function. In addition to the backscatter measurement capability, SeaWinds simultaneously measures the polarized radiometric emission from the surface and atmosphere, utilizing a ground signal processing algorithm known as the QuikSCAT / SeaWinds Radiometer (QRad / SRad). This paper presents an oceanic rainfall retrieval algorithm that combines the simultaneous active radar backscatter and the passive microwave brightness temperatures observed by the SeaWinds sensor. The retrieval algorithm is statistically based, and has been developed using collocated measurements from SeaWinds, the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) rain rates, and the National Center for Environmental Prediction (NCEP) wind fields. The rain is retrieved on a wind vector cell (WVC) measurement grid that has a spatial resolution of 25 km. Examples of the rain estimates from SeaWinds are presented, and comparisons are made with the standard TRMM 2A12 rain data product. Validation results demonstrate that SeaWinds rain measurements are in good agreement with the independent microwave rain observations obtained from TMI. Further, by applying a threshold on the retrieved rain rates, SeaWinds rain estimates can be utilized as a rain flag. In order to evaluate the performance of the SeaWinds flag, comparisons are made with the Impact based Multidimensional Histogram (IMUDH) rain flag developed by JPL. Results emphasize the powerful rain detection capabilities of the SeaWinds retrieval algorithm. Due to its broad swath coverage, SeaWinds affords additional independent sampling of the oceanic rainfall, which may contribute to the future NASA`s Precipitation Measurement Mission (PMM) objectives of improving the global sampling of oceanic rain within 3 hour windows. Also, since SeaWinds is the only sensor onboard QuikSCAT, the SeaWinds rain estimates can be used to improve the flagging of rain-contaminated oceanic wind vector retrievals. The passive-only rainfall retrieval algorithm (QRad /SRad) has been implemented by JPL as part of the level 2B science data product, and can be obtained from the Physical Oceanography Distributed Data Archive (PO.DAAC). 2007 IEEE.
Keywords: QuikSCAT, Seawinds
Mission:
URL: https://doi.org/10.1109/IGARSS.2007.4423601
Other URLs:
Alford, M.H. (2008). Observations of Parametric Subharmonic Instability of the Diurnal Internal Tide in the South China Sea, Geophysical Research Letters: Oceans, 35(15), L15602, 10.1029/2008GL034720. Journal Article »
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Title: Observations of Parametric Subharmonic Instability of the Diurnal Internal Tide in the South China Sea
Type: Journal Article
Publication: Geophysical Research Letters: Oceans
Author(s): Alford, M.H.
Year: 2008
Formatted Citation: Alford, M.H., 2008: Observations of Parametric Subharmonic Instability of the Diurnal Internal Tide in the South China Sea, Geophysical Research Letters: Oceans, 35(15), L15602, 10.1029/2008GL034720.
Abstract: Shipboard observations are presented that suggest the occurrence of parametric subharmonic instability (PSI) of diurnal K1 and O1 internal tides at critical latitudes of 14.52N and 13.44N, respectively. In a transect spanning 12.5-18N, depth-mean shear squared shows sharp peaks at 14.52N (elevated relative to that at 15N by a factor of ten) and at 13.44N (by a factor of 7). Wind speed measured from the ship and Quikscat scatterometer during and before the transect was less than or equal 10 m s-1 at these latitudes. Eight-hour time series (about 1/6 of an inertial period) of shear and isopycnal depth at 14.52N are sufficient to associate the elevated shear with alternating, clockwise-rotating layers analogous to those observed at the M2 critical latitude of 28.8N. Copyright 2008 by the American Geophysical Union.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1029/2008GL034720
Other URLs:
Aloysius, M., Mohan, M., Babu, S.S., Nair, V.S., Parameswaran, K., and Moorthy, K.K. (2008). Influence of Circulation Parameters on the AOD Variations Over the Bay of Bengal During ICARB, Journal of Earth System Science, 117, 353-360, 10.1007/s12040-008-0038-6. Journal Article »
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Title: Influence of Circulation Parameters on the AOD Variations Over the Bay of Bengal During ICARB
Type: Journal Article
Publication: Journal of Earth System Science
Author(s): Aloysius, M., Mohan, M., Babu, S.S., Nair, V.S., Parameswaran, K., and Moorthy, K.K.
Year: 2008
Formatted Citation: Aloysius, M., Mohan, M., Babu, S.S., Nair, V.S., Parameswaran, K., and Moorthy, K.K., 2008: Influence of Circulation Parameters on the AOD Variations Over the Bay of Bengal During ICARB, Journal of Earth System Science, 117, 353-360, 10.1007/s12040-008-0038-6.
Abstract: MODIS (Moderate Resolution Imaging Spectroradiometer) level-3 aerosol data, NCEP (National Centers for Environmental Prediction) reanalysis winds and QuikSCAT ocean surface winds were made use of to examine the role of atmospheric circulation in governing aerosol variations over the Bay of Bengal (BoB) during the first phase of the ICARB (Integrated Campaign for Aerosols, gases and Radiation Budget) campaign (March 18-April 12, 2006). An inter-comparison between MODIS level-3 aerosol optical depth (AOD) data and ship-borne MICROTOPS measurements showed good agreement with correlation 0.92 (p 0.0001) and a mean MODIS underestimation by 0.01. During the study period, the AOD over BoB showed high values in the northern/north western regions, which reduced towards the central and southern BoB. The wind patterns in lower atmospheric layers (> 850 hPa) indicated that direct transport of aerosols from central India was inhibited by the presence of a high pressure and a divergence over BoB in the lower altitudes. On the other hand, in the upper atmospheric levels, winds from central and northern India stretched south eastwards and converged over BoB with a negative vorticity indicative of a downdraft. These wind patterns pointed to the possibility of aerosol transport from central India to BoB by upper level winds. This mechanism was further confirmed by the significant correlations that AOD variations over BoB showed with aerosol flux convergence and flux vorticity at upper atmospheric levels (600-500 hPa). AOD in central and southern BoB away from continental influences displayed an exponential dependence on the QuikSCAT measured ocean surface wind speed. This study shows that particles transported from central and northern India by upper atmospheric circulations as well as the marine aerosols generated by ocean surface winds contributed to the AOD over the BoB during the first phase of ICARB.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1007/s12040-008-0038-6
Other URLs:
Alpers, W., Ivanov, A.Y., and Horstmann, J. (2008). Bora Events Over the Adriatic Sea and Black Sea Studied by Multi-Sensor Satellite Imagery, 2007 IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2007, June 23, 2007 - June 28, 10.1109/IGARSS.2007.4423046. Conference Paper »
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Title: Bora Events Over the Adriatic Sea and Black Sea Studied by Multi-Sensor Satellite Imagery
Type: Conference Paper
Publication: 2007 IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2007, June 23, 2007 - June 28
Author(s): Alpers, W., Ivanov, A.Y., and Horstmann, J.
Year: 2008
Formatted Citation: Alpers, W., Ivanov, A.Y., and Horstmann, J., 2008: Bora Events Over the Adriatic Sea and Black Sea Studied by Multi-Sensor Satellite Imagery, 2007 IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2007, June 23, 2007 - June 28, 10.1109/IGARSS.2007.4423046.
Abstract: Bora events over the Adriatic Sea and Black Sea are investigated by using synthetic aperture radar (SAR) images acquired by the Advanced Synthetic Aperture Radar (ASAR) onboard the Envisat satellite, optical and infrared images acquired by the MODIS sensor onboard the Terra satellite, and sea surface wind data acquired by the scatterometer onboard the Quikscat satellite. Quantitative information on the sea surface wind field is extracted from the ASAR images by using the CMOD4 wind scatterometer model. It is shown that SAR images yield information of the spatial structure of bora events over coastal waters with high spatial resolution that cannot be obtained by other spaceborne instruments. Furthermore, by using ASAR data in combination with MODIS data we are able to detect cyclonic atmospheric eddies, which are often generated by lateral wind shear associated with bora events. 2007 IEEE.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1109/IGARSS.2007.4423046
Other URLs:
Alsweiss, S., Laupattarakasem, P., Jones, W.L., and Roeder, R. (2008). A Ku-Band Active/Passive Wind Vector Retrieval Over the Ocean, International Geoscience and Remote Sensing Symposium (IGARSS), 1(1), I110-I113, 10.1109/IGARSS.2008.4778805. Journal Article »
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Title: A Ku-Band Active/Passive Wind Vector Retrieval Over the Ocean
Type: Journal Article
Publication: International Geoscience and Remote Sensing Symposium (IGARSS)
Author(s): Alsweiss, S., Laupattarakasem, P., Jones, W.L., and Roeder, R.
Year: 2008
Formatted Citation: Alsweiss, S., Laupattarakasem, P., Jones, W.L., and Roeder, R., 2008: A Ku-Band Active/Passive Wind Vector Retrieval Over the Ocean, International Geoscience and Remote Sensing Symposium (IGARSS), 1(1), I110-I113, 10.1109/IGARSS.2008.4778805.
Abstract: This work investigates the design of an innovative conical scanning Ku-band (13.4 GHz) scatterometer / radiometer for measuring ocean vector winds. The sensor design is based upon actual measurements obtained by the SeaWinds scatterometer and the Advanced Microwave Scanning Radiometer (AMSR), which operated simultaneously on JAXA`s Advanced Earth Observing Satellite-II (ADEOS-II) during 2003. This new design combines the conventional forward and aft-looking two-beam microwave scatterometer (SeaWinds) measurements with simultaneous linearly polarized passive microwave brightness temperatures. The unique aspect of this remote sensing technique is that it operates at a single microwave frequency, and it combines vertical and horizontal polarized microwave brightness temperatures with the scatterometer normalized cross sections to retrieve unambiguous ocean wind vectors. This technique has the potential to significantly improve the Ocean Vector Winds retrievals for future conical-scanning microwave scatterometers. 2008 IEEE.
Keywords: Seawinds
Mission:
URL: https://doi.org/10.1109/IGARSS.2008.4778805
Other URLs:
Alvarez, I., Gomez-Gesteira, M., deCastro, M., and Dias, J.M. (2008). Spatiotemporal Evolution of Upwelling Regime Along the Western Coast of the Iberian Peninsula, Journal of Geophysical Research-Oceans, 113(C7), C07020, 10.1029/2008JC004744. Journal Article »
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Title: Spatiotemporal Evolution of Upwelling Regime Along the Western Coast of the Iberian Peninsula
Type: Journal Article
Publication: Journal of Geophysical Research-Oceans
Author(s): Alvarez, I., Gomez-Gesteira, M., deCastro, M., and Dias, J.M.
Year: 2008
Formatted Citation: Alvarez, I., Gomez-Gesteira, M., deCastro, M., and Dias, J.M., 2008: Spatiotemporal Evolution of Upwelling Regime Along the Western Coast of the Iberian Peninsula, Journal of Geophysical Research-Oceans, 113(C7), C07020, 10.1029/2008JC004744.
Abstract: The spatial and temporal variability of upwelling regime along the western coast of the Iberian Peninsula (IP) has been analyzed by means of two different but complementary databases: QuikSCAT satellite database, which is available from mid-1999 with a high spatial resolution (0.25 degrees x 0.25 degrees), and Pacific Fisheries Environmental Laboratory (PFEL) database, with a coarser spatial resolution (1 degrees x 1 degrees) but extending back to 1967. The combined use of both databases allows determination of the spatial variability of Ekman transport and pumping, and identification of temporal trends in upwelling signal. Upwelling-favorable conditions are observed during spring and summer. Apart from this well-known seasonality on upwelling regime along the western coast of the IP, some other features have been identified: (1) Upwelling occurs simultaneously along the entire western coast of the IP, but is undoubtedly more complex closer to particular features of the shoreline. (2) Positive Ekman pumping is more intense near Capes Sao Vicente and Rocha during spring-summer and near Cape Finisterre all over the year. (3) More favorable upwelling conditions have been observed in February and November during the last decade. This result is corroborated by Sea Level Pressure composites, which show the existence of abnormally high pressures close to the IP during the last decade compared to the historical records (1948-2006). (4) The decadal variability of UI is higher in autumn-winter than in spring-summer. (5) Monthly upwelling trends indicate a weakening in upwelling intensity during most of the year with the exception of February, June, and July.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1029/2008JC004744
Other URLs:
Anonymous (2008). Ocean Wind Maps Reveal Possible Energy Sources, Spaceflight, 50(9), 333. Journal Article »
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Title: Ocean Wind Maps Reveal Possible Energy Sources
Type: Journal Article
Publication: Spaceflight
Author(s): Anonymous
Year: 2008
Formatted Citation: Anonymous, 2008: Ocean Wind Maps Reveal Possible Energy Sources, Spaceflight, 50(9), 333.
Abstract: Efforts to harness the energy potential of Earth`s ocean winds could soon gain an important new tool - global satellite maps. Scientists have been creating maps using nearly a decade of data from NASA`s QuikSCAT satellite that reveal ocean areas where winds could produce energy. The new maps have many potential uses including planning the location of offshore wind farms to convert wind energy into electric energy.
Keywords: QuikSCAT
Mission:
URL: https://www.jpl.nasa.gov/news/ocean-wind-power-maps-reveal-possible-wind-energy-sources/
Other URLs:
Aoki, K., and Kutsuwada, K. (2008). Verification of the Wind-Driven Transport in the North Pacific Subtropical Gyre Using Gridded Wind-Stress Products, Journal of Oceanography, 64(1), 49-60, 10.1007/s10872-008-0004-6. Journal Article »
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Title: Verification of the Wind-Driven Transport in the North Pacific Subtropical Gyre Using Gridded Wind-Stress Products
Type: Journal Article
Publication: Journal of Oceanography
Author(s): Aoki, K., and Kutsuwada, K.
Year: 2008
Formatted Citation: Aoki, K., and Kutsuwada, K., 2008: Verification of the Wind-Driven Transport in the North Pacific Subtropical Gyre Using Gridded Wind-Stress Products, Journal of Oceanography, 64(1), 49-60, 10.1007/s10872-008-0004-6.
Abstract: Wind-stress products supplied by satellite scatterometers carried the European Remote-sensing Satellite (ERS) and QuikSCAT (QSCAT), together with numerical weather predictions from the European Centre for Medium Range Weather Forecasting (ECMWF) and the National Centre for Environmental Prediction (NCEP) were used to estimate wind-driven transports of the North Pacific subtropical gyre. At 30 degrees N, we compared the wind-driven transports with geostrophic transports calculated from World Ocean Database 2005. The wind-driven transports for QSCAT and NCEP are in good agreement with the geostrophic transport within reasonable error, except for a regional difference in the eastern part of the section. The difference in the eastern part suggests an anti-cyclonic deviation of the geostrophic transport, resulting from an anti-cyclonic anomalous flow in the surface layer. It is suggested that this anomalous flow is the Eastern Gyral, produced by the thermohaline process associated with the formation of the Eastern Subtropical Mode Water. To investigate the validity of QSCAT and NCEP data, we examined whether or not the Sverdrup transports for these products are consistent with the transport of the western boundary current estimated by past studies. The net southward transport, given by the sum of the Sverdrup transport for QSCAT and NCEP and the thermohaline transport, agrees well with the net northward transport of the western boundary current. From this result, together with the fact that the wind-driven transports for these products are in good agreement with the geostrophic transport, we conclude that the Sverdrup balance can hold in the North Pacific subtropical gyre.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1007/s10872-008-0004-6
Other URLs:
Atlas, R., Ardizzone, J.,Hoffman, and Ross N.H. (2008). Application of Satellite Surface Wind Data to Ocean Wind Analysis, Proceedings of the SPIE, Proc. SPIE 7087, 70870B, 10.1117/12.795371. Conference Paper »
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Title: Application of Satellite Surface Wind Data to Ocean Wind Analysis
Type: Conference Paper
Publication: Proceedings of the SPIE
Author(s): Atlas, R., Ardizzone, J.,Hoffman, and Ross N.H.
Year: 2008
Formatted Citation: Atlas, R., Ardizzone, J.,Hoffman, and Ross N.H., 2008: Application of Satellite Surface Wind Data to Ocean Wind Analysis, Proceedings of the SPIE, Proc. SPIE 7087, 70870B, 10.1117/12.795371.
Abstract: A new set of cross-calibrated, multi-satellite ocean surface wind data is described. The principal data set covers the global ocean for the period beginning in 1987 with six-hour and 25-km resolution, and is produced by combining all ocean surface wind speed observations from SSM/I, AMSR-E, and TMI, and all ocean surface wind vector observations from QuikSCAT and SeaWinds. An enhanced variational analysis method (VAM) performs quality control and combines these data with available conventional ship and buoy data and ECMWF analyses. The VAM analyses fit the data used very closely and contain small-scale structures not present in operational analyses. Comparisons with withheld WindSat observations are also shown to be very good. These data sets should be extremely useful to atmospheric and oceanic research, and to air-sea interaction studies.
Keywords: QuikSCAT, Seawinds
Mission:
URL: https://doi.org/10.1117/12.795371
Other URLs:
Atlas, R., Hoffman, R.N., Ardizzone, J., Leidner, M., and Jusem, J.C. (2008). A New Cross-Calibrated, Multi-Satellite Ocean Surface Wind Product, International Geoscience and Remote Sensing Symposium (IGARSS), 10.1109/IGARSS.2008.4778804. Conference Paper »
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Title: A New Cross-Calibrated, Multi-Satellite Ocean Surface Wind Product
Type: Conference Paper
Publication: International Geoscience and Remote Sensing Symposium (IGARSS)
Author(s): Atlas, R., Hoffman, R.N., Ardizzone, J., Leidner, M., and Jusem, J.C.
Year: 2008
Formatted Citation: Atlas, R., Hoffman, R.N., Ardizzone, J., Leidner, M., and Jusem, J.C., 2008: A New Cross-Calibrated, Multi-Satellite Ocean Surface Wind Product, International Geoscience and Remote Sensing Symposium (IGARSS), 10.1109/IGARSS.2008.4778804.
Abstract: A new set of cross-calibrated, multi-satellite ocean surface wind data sets is introduced. The principal data set covers the global ocean for the period beginning in 1987 with sixhour and 25-km resolution and is produced by combining all ocean surface wind speed observations from SSM/I, AMSR-E, and TMI, and all ocean surface wind vector observations from QuikSCAT and SeaWinds. An enhanced variational analysis method (VAM) performs quality control and combines these data with available conventional ship and buoy data and ECMWF analyses. The VAM analyses fit the data used very closely. Comparisons with withheld WindSat observations are very good. 2008 IEEE.
Keywords: QuikSCAT, Seawinds
Mission:
URL: https://doi.org/10.1109/IGARSS.2008.4778804
Other URLs:
Bartsch, A., Wagner, W., Rupp, K., and Kidd, R. (2008). Application of C and Ku-Band Scatterometer Data for Catchment Hydrology in Northern Latitudes, 2007 IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2007, June 23, 2007 - June 28, 3702-3705, 10.1109/IGARSS.2007.4423647. Conference Paper »
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Title: Application of C and Ku-Band Scatterometer Data for Catchment Hydrology in Northern Latitudes
Type: Conference Paper
Publication: 2007 IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2007, June 23, 2007 - June 28
Author(s): Bartsch, A., Wagner, W., Rupp, K., and Kidd, R.
Year: 2008
Formatted Citation: Bartsch, A., Wagner, W., Rupp, K., and Kidd, R., 2008: Application of C and Ku-Band Scatterometer Data for Catchment Hydrology in Northern Latitudes, 2007 IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2007, June 23, 2007 - June 28, 3702-3705, 10.1109/IGARSS.2007.4423647.
Abstract: Spatially continuous soil moisture information is on high demand globally. A database which is available from active microwave data (ERS scatterometer, C-band, 50km) has been assessed over two large basins (Mackenzie and Lena) in northern latitudes. This information was combined with snowmelt patterns which can be derived based on diurnal thaw-refreeze of the snow cover from a further scatterometer (Quikscat, Ku-band, 25km). Relative soil water information has been averaged over each basin and compared to discharge measurements for the summer periods 1996-2000. A correlation (logarithmic function) of 0.78 is observed for the Lena basin. The Mackenzie is much more complex and thus the relationship is less obvious. This is also reflected in the snowmelt data. Whereas 80% of basin area undergoes melting at the same time in the Lena basin in 2000, at maximum 40% can be observed for the Mackenzie during the same year. Maximum runoff in the Lena basin is observed when snowmelt ceases for the entire basin. This is delayed by three weeks for the Mackenzie although increased runoff can be observed already after 70% of the basin is snow-free. 2007 IEEE.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1109/IGARSS.2007.4423647
Other URLs:
Bentamy, A., Croize-Fillon, D., and Perigaud, C. (2008). Characterization of ASCAT Measurements Based on Buoy and QuikSCAT Wind Vector Observations, Ocean Science, 4(4), 265-274, 10.5194/os-4-265-2008. Journal Article »
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Title: Characterization of ASCAT Measurements Based on Buoy and QuikSCAT Wind Vector Observations
Type: Journal Article
Publication: Ocean Science
Author(s): Bentamy, A., Croize-Fillon, D., and Perigaud, C.
Year: 2008
Formatted Citation: Bentamy, A., Croize-Fillon, D., and Perigaud, C., 2008: Characterization of ASCAT Measurements Based on Buoy and QuikSCAT Wind Vector Observations, Ocean Science, 4(4), 265-274, 10.5194/os-4-265-2008.
Abstract: The new scatterometer Advanced SCATterometer (ASCAT) onboard MetOp-A satellite provides surface wind speed and direction over global ocean with a spatial resolution of 25 km square over two swaths of 550 km widths. The accuracy of ASCAT wind retrievals is determined through various comparisons with moored buoys. The comparisons indicate that the remotely sensed wind speeds and directions agree well with buoy data. The root-mean-squared differences of the wind speed and direction are less than 1.72 m/s and 18 degrees, respectively. At global scale, ASCAT winds are compared with surface winds derived from QuikSCAT scatterometer. The results confirm the buoy analyses, especially for wind speed ranging between 3 m/s and 20 m/s. For higher wind conditions. ASCAT is biased low. The ASCAT underestimation with respect to QuikSCAT winds is wind speed dependent. The comparisons based on the collocated scatterometer data collected after 17 of October 2007 indicate that there are significant improvements compared to previous periods.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.5194/os-4-265-2008
Other URLs:
Bourassa, M.A. and Weissman, D.E. (2008). The Influence of Air Density on Scatterometer Retrievals of Surface Turbulent Stress, International Geoscience and Remote Sensing Symposium (IGARSS), II-343-II-346, 10.1109/IGARSS.2008.4778998. Conference Paper »
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Title: The Influence of Air Density on Scatterometer Retrievals of Surface Turbulent Stress
Type: Conference Paper
Publication: International Geoscience and Remote Sensing Symposium (IGARSS)
Author(s): Bourassa, M.A. and Weissman, D.E.
Year: 2008
Formatted Citation: Bourassa, M.A. and Weissman, D.E., 2008: The Influence of Air Density on Scatterometer Retrievals of Surface Turbulent Stress, International Geoscience and Remote Sensing Symposium (IGARSS), II-343-II-346, 10.1109/IGARSS.2008.4778998.
Abstract: There has long been speculation that scatterometers respond to surface stress rather than wind, however, all previous efforts to demonstrate this suggestion have had negative results. Previous efforts have focused on wave-related changes in stress. Herein, the dependence of stress on near surface air density is examined. The biases expected for such a dependency are found in data similar to those used to calibrate the QuikSCAT (QSCAT) scatterometer. 2008 IEEE.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1109/IGARSS.2008.4778998
Other URLs:
Buermann, W., Saatchi, S., Smith, T.B., Zutta, B.R., Chaves, J.A., Milá, B., and Graham, C.H. (2008). Predicting Species Distributions Across the Amazonian and Andean Regions Using Remote Sensing Data, Journal of Biogeography, 35(7), 1160-1176, 10.1111/j.1365-2699.2007.01858.x. Journal Article »
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Title: Predicting Species Distributions Across the Amazonian and Andean Regions Using Remote Sensing Data
Type: Journal Article
Publication: Journal of Biogeography
Author(s): Buermann, W., Saatchi, S., Smith, T.B., Zutta, B.R., Chaves, J.A., Milá, B., and Graham, C.H.
Year: 2008
Formatted Citation: Buermann, W., Saatchi, S., Smith, T.B., Zutta, B.R., Chaves, J.A., Milá, B., and Graham, C.H., 2008: Predicting Species Distributions Across the Amazonian and Andean Regions Using Remote Sensing Data, Journal of Biogeography, 35(7), 1160-1176, 10.1111/j.1365-2699.2007.01858.x.
Abstract: AimWe explore the utility of newly available optical and microwave remote sensing data from the Moderate Resolution Imaging Spectroradiometer (MODIS) and QuikSCAT (QSCAT) instruments for species distribution modelling at regional to continental scales. Using eight Neotropical species from three taxonomic groups, we assess the extent to which remote sensing data can improve predictions of their geographic distributions. For two bird species, we investigate the specific contributions of different types of remote sensing variables to the predictions and model accuracy at the regional scale, where the benefits of the MODIS and QSCAT satellite data are expected to be most significant. LocationSouth America, with a focus on the tropical and subtropical Andes and the Amazon Basin. MethodsPotential geographic distributions of eight species, namely two birds, two mammals and four trees, were modelled with the maxent algorithm at 1-km resolution over the South American continent using climatic and remote sensing data separately and combined. For each species and model scenario, we assess model performance by testing the agreement between observed and simulated distributions across all thresholds and, in the case of the two focal bird species, at selected thresholds. ResultsQuantitative performance tests showed that models built with remote sensing and climatic layers in isolation performed well in predicting species distributions, suggesting that each of these data sets contains useful information. However, predictions created with a combination of remote sensing and climatic layers generally resulted in the best model performance across the three taxonomic groups. In Ecuador, the inclusion of remote sensing data was critical in resolving the known geographically isolated populations of the two focal bird species along the steep Amazonian-Andean elevational gradients. Within remote sensing subsets, microwave-based data were more important than optical data in the predictions of the two bird species. Main conclusionsOur results suggest that the newly available remote sensing data (MODIS and QSCAT) have considerable utility in modelling the contemporary geographical distributions of species at both regional and continental scales and in predicting range shifts as a result of large-scale land-use change.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1111/j.1365-2699.2007.01858.x
Other URLs:
Cabanes, C., Lee, T., and Fu, L.L. (2008). Mechanisms of Interannual Variations of the Meridional Overturning Circulation of the North Atlantic Ocean, Journal of Physical Oceanography, 38(2), 467-480, 10.1175/2007JPO3726.1. Journal Article »
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Title: Mechanisms of Interannual Variations of the Meridional Overturning Circulation of the North Atlantic Ocean
Type: Journal Article
Publication: Journal of Physical Oceanography
Author(s): Cabanes, C., Lee, T., and Fu, L.L.
Year: 2008
Formatted Citation: Cabanes, C., Lee, T., and Fu, L.L., 2008: Mechanisms of Interannual Variations of the Meridional Overturning Circulation of the North Atlantic Ocean, Journal of Physical Oceanography, 38(2), 467-480, 10.1175/2007JPO3726.1.
Abstract: The authors investigate the nature of the interannual variability of the meridional overturning circulation (MOC) of the North Atlantic Ocean using an Estimating the Circulation and Climate of the Ocean (ECCO) assimilation product for the period of 19932003. The time series of the first empirical orthogonal function of the MOC is found to be correlated with the North Atlantic Oscillation (NAO) index, while the associated circulation anomalies correspond to cells extending over the full ocean depth. Model sensitivity experiments suggest that the wind is responsible for most of this interannual variability, at least south of 40N. A dynamical decomposition of the meridional streamfunction allows a further look into the mechanisms. In particular, the contributions associated with 1) the Ekman flow and its depth-independent compensation, 2) the vertical shear flow, and 3) the barotropic gyre flowing over zonally varying topography are examined. Ekman processes are found to dominate the shorter time scales (1.53 yr), while for longer time scales (310 yr) the MOC variations associated with vertical shear flow are of greater importance. The latter is primarily caused by heaving of the pycnocline in the western subtropics associated with the stronger wind forcing. Finally, how these changes in the MOC affect the meridional heat transport (MHT) is examined. It is found that overall, Ekman processes explain a larger part of interannual variability (310 yr) for MHT (57%) than for the MOC (33%).
Keywords: SEA-SURFACE HEIGHT, HEAT-TRANSPORT, PACIFIC-OCEAN, VARIABILITY, MODEL
Mission:
URL: https://doi.org/10.1175/2007JPO3726.1
Other URLs:
Capps, S.B., and Zender, C.S. (2008). Observed and CAM3 GCM Sea Surface Wind Speed Distributions: Characterization Comparison, and Bias Reduction, Journal of Climate, 21(24), 6569-6585, 10.1175/2008JCLI2374.1. Journal Article »
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Title: Observed and CAM3 GCM Sea Surface Wind Speed Distributions: Characterization Comparison, and Bias Reduction
Type: Journal Article
Publication: Journal of Climate
Author(s): Capps, S.B., and Zender, C.S.
Year: 2008
Formatted Citation: Capps, S.B., and Zender, C.S., 2008: Observed and CAM3 GCM Sea Surface Wind Speed Distributions: Characterization Comparison, and Bias Reduction, Journal of Climate, 21(24), 6569-6585, 10.1175/2008JCLI2374.1.
Abstract: Climatological surface wind speed probability density functions (PDFs) estimated from observations are characterized and used to evaluate, for the first time, contemporaneous wind PDFs predicted by a GCM. The observations include NASA`s global Quick Scatterometer (QuikSCAT) dataset, the NCEP/Department of Energy Global Reanalysis 2 (NCEP-2) 6-hourly reanalysis, and the Tropical Atmosphere Ocean (TAO)/Triangle Trans-Ocean Buoy Network (TRITON) moored buoy data, all from 2000 to 2005. Wind speed mean, 90th percentile, standard deviation, and Weibull shape parameter climatologies are constructed from these data. New features that emerge from the analysis include the identification of a stationary pattern to the wind speed variance in the equatorial Pacific. Interestingly, a distinct wind speed shape anomaly migrates with the ITCZ across this stationary background. The GCM despite its coarser spatial and temporal resolution predicts wind speed PDFs in general agreement with observations. Relative to QuikSCAT, the NCAR Community Atmosphere Model, version 3 (CAM3) GCM has a globally averaged positive mean wind speed bias of about 0.2 m s-1 originating primarily within the trades and Southern Hemisphere storm track. Global standard deviation biases are largest in the winter hemisphere storm tracks. The largest shape biases occur along the equatorial peripheries of the Northern Hemisphere and southern Indian Ocean anticyclones. Year-round negative shape and mean wind speed biases persist along the ITCZ. The GCM`s overactive tropical convection and slight subtropical anticyclone displacement contribute to positive mean speed, standard deviation, and shape trade biases. Surface heat and energy fluxes depend nonlinearly on wind speed magnitude, are sensitive to the tails of the wind distribution, and hence vary significantly on spatiotemporal scales not resolved by GCMs. Limited computing resources force the use of coarse-resolution GCMs, which do not resolve finer-scale wind speed fluctuations. Rather, surface fluxes are determined from the mean wind speed computed by averaging spatially and temporally over subgrid-scale features. Some surface flux routines account for gustiness during low mean winds resulting from thermally driven convection. The authors hypothesize that GCMs systematically underestimate surface momentum flux nonlinearities and that this biases surface wind predictions most in regions of strong winds with high variability. To test this, climate simulations that account for surface fluxes due to subgrid-scale GCM winds are performed. This significantly improves climatological surface wind speed statistics, particularly in the Southern Hemisphere storm track, consistent with the hypothesis. These wind speed improvements can be attributed to a reduction in GCM sea level pressure biases throughout the globe. 2008 American Meteorological Society.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1175/2008JCLI2374.1
Other URLs:
Carton, J.A., Grodsky, S.A., and Liu, H. (2008). Variability of the Oceanic Mixed Layer, 1960-2004, Journal of Climate, 21(5), 1029-1047, 10.1175/2007JCLI1798.1. Journal Article »
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Title: Variability of the Oceanic Mixed Layer, 1960-2004
Type: Journal Article
Publication: Journal of Climate
Author(s): Carton, J.A., Grodsky, S.A., and Liu, H.
Year: 2008
Formatted Citation: Carton, J.A., Grodsky, S.A., and Liu, H., 2008: Variability of the Oceanic Mixed Layer, 1960-2004, Journal of Climate, 21(5), 1029-1047, 10.1175/2007JCLI1798.1.
Abstract: A new monthly uniformly gridded analysis of mixed layer properties based on the World Ocean Atlas 2005 global ocean dataset is used to examine interannual and longer changes in mixed layer properties during the 45-yr period 19602004. The analysis reveals substantial variability in the winterspring depth of the mixed layer in the subtropics and midlatitudes. In the North Pacific an empirical orthogonal function analysis shows a pattern of mixed layer depth variability peaking in the central subtropics. This pattern occurs coincident with intensification of local surface winds and may be responsible for the SST changes associated with the Pacific decadal oscillation. Years with deep winterspring mixed layers coincide with years in which winterspring SST is low. In the North Atlantic a pattern of winterspring mixed layer depth variability occurs that is not so obviously connected to local changes in winds or SST, suggesting that other processes such as advection are more important. Interestingly, at decadal periods the winterspring mixed layers of both basins show trends, deepening by 1040 m over the 45-yr period of this analysis. The long-term mixed layer deepening is even stronger (50100 m) in the North Atlantic subpolar gyre. At tropical latitudes the boreal winter mixed layer varies in phase with the Southern Oscillation index, deepening in the eastern Pacific and shallowing in the western Pacific and eastern Indian Oceans during El Ni???? In boreal summer the mixed layer in the Arabian Sea region of the western Indian Ocean varies in response to changes in the strength of the southwest monsoon.
Keywords: ATMOSPHERIC pressure, FUNCTIONS, Orthogonal, OCEAN circulation, SOUTHERN oscillation, winds, monsoons
Mission:
URL: https://doi.org/10.1175/2007JCLI1798.1
Other URLs:
Chang, L.T.-C., Chen, G.T.-J., and Cheung, K.K.W. (2008). Mesoscale Simulation and Moisture Budget Analyses of a Heavy Rain Event Over Southern Taiwan in the Meiyu Season, Meteorology and Atmospheric Physics, 101, 43-63, 10.1007/s00703-008-0286-7. Journal Article »
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Title: Mesoscale Simulation and Moisture Budget Analyses of a Heavy Rain Event Over Southern Taiwan in the Meiyu Season
Type: Journal Article
Publication: Meteorology and Atmospheric Physics
Author(s): Chang, L.T.-C., Chen, G.T.-J., and Cheung, K.K.W.
Year: 2008
Formatted Citation: Chang, L.T.-C., Chen, G.T.-J., and Cheung, K.K.W., 2008: Mesoscale Simulation and Moisture Budget Analyses of a Heavy Rain Event Over Southern Taiwan in the Meiyu Season, Meteorology and Atmospheric Physics, 101, 43-63, 10.1007/s00703-008-0286-7.
Abstract: During the period of 29-30 May 2001, the development and northeastward propagation of a series of mesoscale convective systems (MCSs) produced heavy rainfall with a maximum 6-h accumulated rainfall of 120 mm in southern Taiwan. Moisture budget analyses of the MCSs evolution associated with this heavy rain event was carried out by utilizing high-resolution numerical simulation results from the atmospheric part of the triply nested, nonhydrostatic Coupled Ocean/Atmospheric Mesoscale Prediction Systems (COAMPS). The control (CTRL) run experiment successfully simulated the synoptic environment, although it did not reproduce well the magnitude of the low-level horizontal moisture flux convergence and the precipitation distribution along the Meiyu front over the Taiwan Strait presumably due to insufficient data over the ocean. As QuikSCAT oceanic winds were taken into the assimilation cycles (QUIK run), the experiment reproduced better precipitation in terms of both amount and spatial distribution especially the precipitation over the ocean, and received higher equitable threat score for precipitation forecast. The MCSs evolution was also better simulated as compared to that of the CTRL run. Moisture budget analyses in the subcloud layer revealed that the grid-scale horizontal moisture flux convergence and upward vertical moisture flux divergence represented the major contribution for moisture transport in all stages of MCS evolution, and their values increased substantially during the convection development. The value of subgrid-scale vertical moisture flux convergence in the 5-km grid (mainly turbulence) was more than double that for convection developed over land than over the ocean. Relative contribution from disturbances under 5 km and cumulus convection were also examined by comparing the subgrid-scale moisture budget terms in the 15-km and 5-km grids, which showed that transport from disturbances under 5 km was dominating for both MCS development over the ocean and land. It was also found that surface evaporation played a relatively important role in the upward moisture transport processes before the development of MCS over the ocean as compared to that during the development of MCS over both land and the ocean. Contribution from orographic effect to rain associated with the MCS and vertical moisture flux convergence in the subcloud layer was discussed based on a flux model of orographic rain.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1007/s00703-008-0286-7
Other URLs:
Chu, P.C. and Cheng, K.-F. (2008). South China Sea Wave Characteristics During Typhoon Muifa Passage in Winter 2004, Journal of Oceanography, 64(1), 1-21, 10.1007/s10872-008-0001-9. Journal Article »
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Title: South China Sea Wave Characteristics During Typhoon Muifa Passage in Winter 2004
Type: Journal Article
Publication: Journal of Oceanography
Author(s): Chu, P.C. and Cheng, K.-F.
Year: 2008
Formatted Citation: Chu, P.C. and Cheng, K.-F., 2008: South China Sea Wave Characteristics During Typhoon Muifa Passage in Winter 2004, Journal of Oceanography, 64(1), 1-21, 10.1007/s10872-008-0001-9.
Abstract: The responses to tropical cyclones of ocean wave characteristics in deep water of the western Atlantic Ocean have been investigated extensively, but not the regional seas in the western Pacific such as the South China Sea (SCS), due to a lack of observational and modeling studies there. Since monsoon winds prevail in the SCS but not in the western Atlantic Ocean, the SCS is unique for investigating wave characteristics during a typhoon`s passage in conjunction with steady monsoon wind forcing. To do so, the Wavewatch-III (WW3) is used to study the response of the SCS to Typhoon Muifa (2004), which passed over not only deep water but also the shallow shelf of the SCS. The WW3 model is forced by the NASA QuikSCAT winds and tropical cyclone wind profile model during Typhoon Muifa`s passage from 0000UTC 16 on November to 1200UTC on 25 November 2004. The results reveal the unique features of the SCS wave characteristics in response to Muifa, such as non-decaying, monsoon-generated swell throughout the typhoon period and strong topographic effects on the directional wave spectrum.
Keywords: QuikSCAT,Topex/Poseidon
Mission:
URL: https://doi.org/10.1007/s10872-008-0001-9
Other URLs:
Ciesielski, P.E. and Johnson, R.H. (2008). Diurnal Cycle of Surface Flows During 2004 NAME and Comparison to Model Reanalysis, Journal of Climate, 21(15), 3890-3913, 10.1175/2008JCLI2206.1. Journal Article »
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Title: Diurnal Cycle of Surface Flows During 2004 NAME and Comparison to Model Reanalysis
Type: Journal Article
Publication: Journal of Climate
Author(s): Ciesielski, P.E. and Johnson, R.H.
Year: 2008
Formatted Citation: Ciesielski, P.E. and Johnson, R.H., 2008: Diurnal Cycle of Surface Flows During 2004 NAME and Comparison to Model Reanalysis, Journal of Climate, 21(15), 3890-3913, 10.1175/2008JCLI2206.1.
Abstract: During the North American Monsoon Experiment (NAME), an unprecedented surface dataset was collected over the core monsoon region. Observations from 157 surface sites in this region along with twice-daily Quick Scatterometer (QuikSCAT) oceanic winds were quality, controlled and processed into a gridded dataset covering the domain (15-40N, 90-120W) at 1-h, 0.25 resolution for the period from 1 July to 15 August. Using this dataset, the mean, temporal variability, and diurnal characteristics of the monsoon surface flow are documented with detail not previously possible. Being independent of model data over land, these objectively analyzed surface products are compared to similar analyses from a special North American Regional Reanlysis for NAME (NARR_NAME) that was produced for the same period. Observed surface fields indicate that a robust land-sea breeze circulation is present over most of the Gulf of California (GoC) region in response to the strong diurnal heating of landmasses on both sides of the gulf. Many details of this land-sea breeze circulation are either missing (e.g., the nighttime/early morning land breeze) or poorly represented in the NARR_NAME. Observations from high elevation sites in the Sierra Madre Occidental (SMO) show weak downslope flows (0.5 m s-1), near-saturated conditions, and low cloud bases during nighttime hours. These observations are consistent with the notion that high-terrain nocturnal clouds limit radiational cooling and, thus, nocturnal downslope flows as well. Over land, a cool and dry bias is observed in the NARR_NAME surface fields. This dry bias appears to limit the formation of nighttime cloudiness at high elevations, resulting in stronger radiational cooling at night and slope flows in the NARR_NAME that are 2-3 times stronger than observed. In addition, the daytime transition to surface convergence and rising motion over the western slopes of the SMO occurs about 3 h earlier in the NARR_NAME than observed, which indicates the tendency in the reanalyses to initiate the daily convective cycle too early, similar to that observed in operational forecast models over this region. Following significant rainfall events, increased soil moisture and evapotranspiration due to vegetative green-up result in a smaller diurnal temperature signal over land and weaker slope flowsover the SMO. In response to this weaker heating cycle, the magnitude and offshore extent of the land-sea breeze circulation is observed to diminish as the monsoon progresses. 2008 American Meteorological Society.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1175/2008JCLI2206.1
Other URLs:
Contreras, R., Frasier, S., Chu, T., Perkovic, D., Mcmanus, J., Chang, P., Jelenak, Z., Carswell, J., and Esteban-Fernandez, D. (2008). The Imaging Wind and Rain Airborne Profiler (IWRAP) Data Archive, International Geoscience and Remote Sensing Symposium (IGARSS), IV - 1181-IV - 1184, 10.1109/IGARSS.2008.4779939. Conference Paper »
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Title: The Imaging Wind and Rain Airborne Profiler (IWRAP) Data Archive
Type: Conference Paper
Publication: International Geoscience and Remote Sensing Symposium (IGARSS)
Author(s): Contreras, R., Frasier, S., Chu, T., Perkovic, D., Mcmanus, J., Chang, P., Jelenak, Z., Carswell, J., and Esteban-Fernandez, D.
Year: 2008
Formatted Citation: Contreras, R., Frasier, S., Chu, T., Perkovic, D., Mcmanus, J., Chang, P., Jelenak, Z., Carswell, J., and Esteban-Fernandez, D., 2008: The Imaging Wind and Rain Airborne Profiler (IWRAP) Data Archive, International Geoscience and Remote Sensing Symposium (IGARSS), IV - 1181-IV - 1184, 10.1109/IGARSS.2008.4779939.
Abstract: The Microwave Remote Sensing Laboratory (MIRSL) at the University of Massachusetts developed and operates the Imaging Wind and Rain Airborne Profiler (IWRAP). With support from NASA, NOAA, and ONR, UMASS has collaborated with NOAA-NESDIS and NOAA-AOC to operate the instrument aboard the NOAA WP-3D Hurricane Hunter aircraft since the 2002 hurricane season and for four winter experiments sampling high-latitude storms. The goals of these experiments have been to characterize storm boundary layers and to develop improved retrievals for space-based scatterometers, specifically, NASA SeaWinds Scatterometer on QuikSCAT and Advanced Scatterometer (ASCAT) which was developed by ESA on behalf of EUMETSAT. IWRAP is a conically-scanning, dual-frequency (C- and Ku-band) coherent radar with dual-polarization capability. The incidence angles are nominally: 30, 35, 40, and 50 degrees. At times, the instrument has been configured to address specific scientific and engineering problems. Examples include: C-band measurements of high incidence angle backscatter for ASCAT validation, and C-band horizontal polarization measurements to develop a high wind speed geophysical model function (GMF). Independent measurements of surface wind speed and column integrated rain rate are made coincidently with the UMass Simultaneous Frequency Radiometer (USFMR) and AOC Stepped Frequency Microwave Radiometer (SFMR). Since 2005, IWRAP has operated in a raw data mode, recording individual radar pulses to enable the separation of near surface backscatter contributions (i.e. surface scattering versus volume scattering). The intensity of tropical cyclones ranged from tropical storm to category five hurricane, and high-latitude storms with up to hurricane force winds. Currently, we are post-processing and standardizing IWRAP raw data collected since 2005. This effort is intended to expand the utility of IWRAP and (USFMR/SFMR) measurements beyond the scope of the initially proposed research projects by making a standardized dataset available to the larger scatterometer community as well as the hurricane and high-latitude storms research communities. We provide an overview of IWRAP, the data it has collected, describe the processing effort, give the current status, and outline a schedule of data availability. 2008 IEEE.
Keywords: QuikSCAT, Seawinds
Mission:
URL: https://doi.org/10.1109/IGARSS.2008.4779939
Other URLs:
D'Sa, E.J. and Ko, D.S. (2008). Short-Term Influences on Suspended Particulate Matter Distribution in the Northern Gulf of Mexico: Satellite and Model Observations, Sensors, 8(7), 4249-4264, 10.3390/s8074249. Journal Article »
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Title: Short-Term Influences on Suspended Particulate Matter Distribution in the Northern Gulf of Mexico: Satellite and Model Observations
Type: Journal Article
Publication: Sensors
Author(s): D'Sa, E.J. and Ko, D.S.
Year: 2008
Formatted Citation: D'Sa, E.J. and Ko, D.S., 2008: Short-Term Influences on Suspended Particulate Matter Distribution in the Northern Gulf of Mexico: Satellite and Model Observations, Sensors, 8(7), 4249-4264, 10.3390/s8074249.
Abstract: Energetic meteorological events such as frontal passages and hurricanes often impact coastal regions in the northern Gulf of Mexico that influence geochemical processes in the region. Satellite remote sensing data such as winds from QuikSCAT, suspended particulate matter (SPM) concentrations derived from SeaWiFS and the outputs ( sea level and surface ocean currents) of a nested navy coastal ocean model (NCOM) were combined to assess the effects of frontal passages between 23-28 March 2005 on the physical properties and the SPM characteristics in the northern Gulf of Mexico. Typical changes in wind speed and direction associated with frontal passages were observed in the latest 12.5 km wind product from QuikSCAT with easterly winds before the frontal passage undergoing systematic shifts in direction and speed and turning northerly, northwesterly during a weak and a strong front on 23 and 27 March, respectively. A quantitative comparison of model sea level results with tide gauge observations suggest better correlations near the delta than in the western part of the Gulf with elevated sea levels along the coast before the frontal passage and a large drop in sea level following the frontal passage on 27 March. Model results of surface currents suggested strong response to wind forcing with westward and onshore currents before the frontal passage reversing into eastward, southeastward direction over a six day period from 23 to 28 March 2005. Surface SPM distribution derived from SeaWiFS ocean color data for two clear days on 23 and 28 March 2005 indicated SPM plumes to be oriented with the current field with increasing concentrations in nearshore waters due to resuspension and discharge from the rivers and bays and its seaward transport following the frontal passage. The backscattering spectral slope., a parameter sensitive to particle size distribution also indicated lower. values ( larger particles) in nearshore waters that decreased offshore ( smaller particles). The use of both satellite and model results revealed the strong interactions between physical processes and the surface particulate field in response to the frontal passage in a large riverdominated coastal margin.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.3390/s8074249
Other URLs:
D'Sa, E.J., Korobkin, M., Walker, N., and Stone, G. (2008). Using NASA Remote Sensing Data for Coastal Monitoring in the Northern Gulf of Mexico: A Case Study, Proceedings of the SPIE, 7106, 10.1117/12.800390. Conference Paper »
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Title: Using NASA Remote Sensing Data for Coastal Monitoring in the Northern Gulf of Mexico: A Case Study
Type: Conference Paper
Publication: Proceedings of the SPIE
Author(s): D'Sa, E.J., Korobkin, M., Walker, N., and Stone, G.
Year: 2008
Formatted Citation: D'Sa, E.J., Korobkin, M., Walker, N., and Stone, G., 2008: Using NASA Remote Sensing Data for Coastal Monitoring in the Northern Gulf of Mexico: A Case Study, Proceedings of the SPIE, 7106, 10.1117/12.800390.
Abstract: The coastal region comprising the states of Louisiana, Mississippi, and Texas is frequently impacted by meteorological events such as frontal passages and hurricanes. The region is also influenced by the Mississippi river, which is seventh largest in terms of water and sediment discharge among the major rivers of the world that strongly influences the physical and biogeochemical properties in the northern Gulf of Mexico. NASA remote sensing data such as winds from QuikSCAT, sea surface height anomaly (SSHA) from Jason-1, ocean color and sea surface temperature (SST) from MODIS satellite sensors were assessed during the period that Hurricane Rita made landfall on 24 September 2005 along the Louisiana-Texas border in the western Gulf of Mexico. QuikSCAT winds revealed the northwestward movement of the hurricane and gradients in the distribution of wind speed around the hurricane center. Altimeter data indicated changes in pattern of the SSH anomaly field and a displacement of the warm and cold core eddies following the hurricane. Although limited by cloud cover, the MODIS 8-day average chlorophyll imagery obtained before and after the hurricane indicated an offshore displacement of higher chlorophyll concentrations while the MODIS 250 m resolution true color imagery showed high levels of suspended particulate matter in the impacted coastal region. MODIS SST indicated a cooling of the surface waters around and east of the track following Hurricane Rita. The use of multiple remote sensing products provided better insights of the oceanographic response to Hurricane Rita. 2008 SPIE.
Keywords: QuikSCAT, Jason
Mission:
URL: https://doi.org/10.1117/12.800390
Other URLs:
Davis,R.E., Painter, T.H., Cline, D., Armstrong, R., Haran, T., McDonald, K., Forster, R.,and Elder, K. (2008). NASA Cold Land Processes Experiment (CLPX 2002/03): Spaceborne Remote Sensing, Journal of Hydrometeorology, 9(6), 1427-1433, 10.1175/2008JHM926.1. Journal Article »
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Title: NASA Cold Land Processes Experiment (CLPX 2002/03): Spaceborne Remote Sensing
Type: Journal Article
Publication: Journal of Hydrometeorology
Author(s): Davis,R.E., Painter, T.H., Cline, D., Armstrong, R., Haran, T., McDonald, K., Forster, R.,and Elder, K.
Year: 2008
Formatted Citation: Davis,R.E., Painter, T.H., Cline, D., Armstrong, R., Haran, T., McDonald, K., Forster, R.,and Elder, K., 2008: NASA Cold Land Processes Experiment (CLPX 2002/03): Spaceborne Remote Sensing, Journal of Hydrometeorology, 9(6), 1427-1433, 10.1175/2008JHM926.1.
Abstract: This paper describes satellite data collected as part of the 2002/03 Cold Land Processes Experiment (CLPX). These data include multispectral and hyperspectral optical imaging, and passive and active microwave observations of the test areas. The CLPX multispectral optical data include the Advanced Very High Resolution Radiometer (AVHRR), the Landsat Thematic Mapper/Enhanced Thematic Mapper Plus (TM/ETM+), the Moderate Resolution Imaging Spectroradiometer (MODIS), and the Multi-angle Imaging Spectroradiometer (MISR). The spaceborne hyperspectral optical data consist of measurements acquired with the NASA Earth Observing-1 (EO-1) Hyperion imaging spectrometer. The passive microwave data include observations from the Special Sensor Microwave Imager (SSM/I) and the Advanced Microwave Scanning Radiometer (AMSR) for Earth Observing System (EOS, AMSR-E). Observations from the Radarsat synthetic aperture radar and the SeaWinds scatterometer flown on QuikSCAT make up the active microwave data.
Keywords: MISR, QuikSCAT, Seawinds
Mission:
URL: https://doi.org/10.1175/2008JHM926.1
Other URLs:
Dickey, T.D., Nencioli, F., Kuwahara, V.S., Leonard, C., Black, W., Rii, Y.M., Bidigare, R.R., and Zhang, Q. (2008). Physical and Bio-Optical Observations of Oceanic Cyclones West of the Island of Hawai'i, Deep-Sea Research Part II: Topical Studies in Oceanography, 55(10-13), 1195-1217, 10.1016/j.dsr2.2008.01.006. Journal Article »
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Title: Physical and Bio-Optical Observations of Oceanic Cyclones West of the Island of Hawai'i
Type: Journal Article
Publication: Deep-Sea Research Part II: Topical Studies in Oceanography
Author(s): Dickey, T.D., Nencioli, F., Kuwahara, V.S., Leonard, C., Black, W., Rii, Y.M., Bidigare, R.R., and Zhang, Q.
Year: 2008
Formatted Citation: Dickey, T.D., Nencioli, F., Kuwahara, V.S., Leonard, C., Black, W., Rii, Y.M., Bidigare, R.R., and Zhang, Q., 2008: Physical and Bio-Optical Observations of Oceanic Cyclones West of the Island of Hawai'i, Deep-Sea Research Part II: Topical Studies in Oceanography, 55(10-13), 1195-1217, 10.1016/j.dsr2.2008.01.006.
Abstract: Interdisciplinary observations of mesoscale eddies were made to the west of the island of Hawai`i. A central goal of the studies is to improve our understanding of the coupling of physical, biological, and biogeochemical processes that occur within these eddies. A specific objective was to test the hypothesis that the physical mechanisms of mesoscale eddies result in increases in nutrient availability to the euphotic layer, increases in primary production, changes in biological community compositions and size distributions, and increases in carbon flux to the deep sea. Data were obtained from ships, surface drifters, and satellite sensors during three separate field experiments. Variability was associated with two well-developed cyclonic, cold-core mesoscale eddies, Cyclone Noah and Cyclone Opal, which were observed during the E-Flux I (survey November 6-20, 2004) and E-Flux III (survey March 10-27, 2005) field campaigns, respectively. No mesoscale eddies were found during E-Flux II (survey January 10-19) when winds were erratic in magnitude and direction, supporting the hypothesis that persistent trade winds drive the production of cold-core mesoscale eddies in the lee of the Hawaiian Islands. Cold-core eddies were present in the E-Flux study area for about 2/3 of a year beginning May 1, 2004 and trade winds prevailed for about 3/4 of the same year. Both Cyclone Noah and Cyclone Opal were generated during strong, persistent northeasterly trade wind conditions and appeared downwind of the `Alenuihaha Channel separating the islands of Maui and Hawai`i. The likely production mechanism for both mesoscale cold-core eddies involves localized wind-stress-curl-induced upwelling produced by trade wind forcing. Cyclone Noah was likely spun up by strong trade winds just to the southwest of the `Alenuihaha Channel ( 20 . 10{ring operator} N, 156 . 40{ring operator} W) between August 13 and 21, 2004 based on MODIS satellite sea-surface temperature (SST) imagery and QuikScat satellite wind data, and apparently began to dissipate by mid-December 2004. Cyclone Opal was likely spun up by strong trade winds between February 2 and 18, 2005 southwest of the `Alenuihaha Channel ( 20 . 30{ring operator} N, 156 . 30{ring operator} W), but was no longer evident in April 2005. Both Cyclone Noah and Cyclone Opal had strong physical, chemical, and biological expressions and displayed similar maximum tangential current speeds of 60 cm s- 1. However, Cyclone Opal was more symmetric and larger in scale (roughly 180-200 km in diameter compared to 160 km in horizontal scale for Cyclone Noah). Both mesoscale eddies displayed significant doming in their centers and in some cases outcroppings of isothermal, isopycnal, nutrient, and chlorophyll a isopleths. After formation and a slow drift southward, Cyclone Noah remained in nearly the same location (roughly 19 . 60{ring operator} N, 156 . 50{ring operator} W) during the 3-week in situ sampling period, whereas Cyclone Opal drifted southward by 165 km over a similar time span of sampling. Interestingly, the physical manifestations of both features were relatively unchanged during the ship-based surveys, however, the biology appears to have evolved within Cyclone Opal. The present report sets the context for several other E-Flux studies. 2008 Elsevier Ltd. All rights reserved.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1016/j.dsr2.2008.01.006
Other URLs:
Dwivedi, R.M., Raman, M., Babu, K.N., Singh, S.K., Vyas, N.K., and Matondkar, S.G.P. (2008). Formation of Algal Bloom in the Northern Arabian Sea Deep Waters During January-March: A Study Using Pooled In Situ and Satellite Data, International Journal of Remote Sensing, 29(15), 4537-4551, 10.1080/01431160802029693. Journal Article »
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Title: Formation of Algal Bloom in the Northern Arabian Sea Deep Waters During January-March: A Study Using Pooled In Situ and Satellite Data
Type: Journal Article
Publication: International Journal of Remote Sensing
Author(s): Dwivedi, R.M., Raman, M., Babu, K.N., Singh, S.K., Vyas, N.K., and Matondkar, S.G.P.
Year: 2008
Formatted Citation: Dwivedi, R.M., Raman, M., Babu, K.N., Singh, S.K., Vyas, N.K., and Matondkar, S.G.P., 2008: Formation of Algal Bloom in the Northern Arabian Sea Deep Waters During January-March: A Study Using Pooled In Situ and Satellite Data, International Journal of Remote Sensing, 29(15), 4537-4551, 10.1080/01431160802029693.
Abstract: The formation of winter bloom (January-March) was studied in deep waters of the northeastern Arabian Sea (NAS) during 2003 and 2004. Six ship cruises were undertaken at different phases of the bloom to examine its formation. Along with physical and biological observations, optical parameters including profiles of upwelling and downwelling irradiance were collected using a Satlantic underwater radiometer and photosynthetically active radiation (PAR) was calculated using prosoft software. Satellite data sets for chlorophyll concentration, aerosol optical depth (AOD), PAR from the Oceansat-I Ocean Colour Monitor (OCM), and sea winds vectors from the QuikSCAT scatterometer were also used to study the winter algal bloom formation. This study attempts to explain the probable mechanisms that activate the bloom and its dynamics, particularly those due to the influence of wind. The study also presents an intercomparison of relevant parameters during different phases of the event, from the late winter to early spring intermonsoon season. The causes of winter bloom reported by other investigators have been verified with the use of satellite data. An additional observation was attempted that strengthened the explanation of convective mixing and resulting intensification of the bloom. The higher wind speed in February-March 2003 compared to that in 2004 caused a higher aerosol concentration in the overlying atmosphere, thus leading to reduced shortwave solar radiation and PAR over the surface in 2003. This caused a cooling effect in the NAS deep waters. This cooling is thought to be supplementary to the already reported winter cooling, and to cooling due to evaporation. As a result, a substantial increase in surface seawater density was observed, consequently enhancing convective action due to densification and nutrient concentration. The result is that the bloom was homogeneous in space and had a larger concentration during March 2003 than March 2004.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1080/01431160802029693
Other URLs:
Ebuchi, N. (2008). Cross-Validation of Wind Products from Seawinds and AMSR on ADEOS-II, International Geoscience and Remote Sensing Symposium (IGARSS), 2(1), II339-II342, 10.1109/IGARSS.2008.4778997. Journal Article »
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Title: Cross-Validation of Wind Products from Seawinds and AMSR on ADEOS-II
Type: Journal Article
Publication: International Geoscience and Remote Sensing Symposium (IGARSS)
Author(s): Ebuchi, N.
Year: 2008
Formatted Citation: Ebuchi, N., 2008: Cross-Validation of Wind Products from Seawinds and AMSR on ADEOS-II, International Geoscience and Remote Sensing Symposium (IGARSS), 2(1), II339-II342, 10.1109/IGARSS.2008.4778997.
Abstract: The Advanced Earth Observing Satellite-II (ADEOS-II), which carried a microwave radiometer, AMSR, and microwave scatterometer, SeaWinds, provided us with unique opportunity to validate wind products from the both sensors. Two examples of the cross-validation of wind observations by spaceborne active and passive microwave sensors are presented in this paper. These examples clearly exhibited importance of the sensor synergy of the active and passive microwave sensors, and demonstrated needs of future missions with a combination of microwave scatterometer and radiometer onboard the same satellite to achieve simultaneous observation. 2008 IEEE.
Keywords: Seawinds
Mission:
URL: https://doi.org/10.1109/IGARSS.2008.4778997
Other URLs:
Else, B.G..T., Yackel, J.J., and Papakyriakou, T.N. (2008). Application of Satellite Remote Sensing Techniques for Estimating Air-Sea CO2 Fluxes in Hudson Bay, Canada During the Ice-Free Season, Remote Sensing of Environment, 112(9), 3550-3562, 10.1016/j.rse.2008.04.013. Journal Article »
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Title: Application of Satellite Remote Sensing Techniques for Estimating Air-Sea CO2 Fluxes in Hudson Bay, Canada During the Ice-Free Season
Type: Journal Article
Publication: Remote Sensing of Environment
Author(s): Else, B.G..T., Yackel, J.J., and Papakyriakou, T.N.
Year: 2008
Formatted Citation: Else, B.G..T., Yackel, J.J., and Papakyriakou, T.N., 2008: Application of Satellite Remote Sensing Techniques for Estimating Air-Sea CO2 Fluxes in Hudson Bay, Canada During the Ice-Free Season, Remote Sensing of Environment, 112(9), 3550-3562, 10.1016/j.rse.2008.04.013.
Abstract: The role of coastal seas as either a sink or a source of CO2 is subject to a great deal of uncertainty. This uncertainty largely arises from a lack of observations in the coastal zones. Remote sensing offers an avenue for expanding these observations by allowing for the extrapolation of relatively limited data sets of dissolved CO2 (pCO2sw). In this paper, predictive algorithms for pCO2sw that could be applied to remote sensing products were created from a field data set collected from September-October, 2005 in Hudson Bay, Canada. The field data showed that an effective pCO2sw interpolation algorithm could be created using sea surface temperature (SST) as a predictor, and that a slight improvement of the algorithm could be achieved if measurements of absorption due to coloured dissolved organic material (aCDOM) were included. Unfortunately, satellite retrievals of aCDOM did not match well with in situ observations, and so only SST (obtained from the MODIS Aqua sensor) was used to create monthly maps of pCO2sw for the period of August-October. To estimate fluxes of CO2, constructed surfaces of pCO2sw were combined with estimates of gas transfer velocity derived from QuikSCAT wind retrievals, and pCO2air based on field observations. The results of these calculations revealed that Hudson Bay acts as a source of CO2 during August and September, but reverts to a sink of CO2 in October as the water temperature decreases. Overall, a positive flux of 1.60TgC was estimated for the region during the ice-free season. This result is in contrast to most Arctic or sub-Arctic continental shelf seas, where usually strong absorptions of CO2 are observed. 2008 Elsevier Inc. All rights reserved.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1016/j.rse.2008.04.013
Other URLs:
Else, B.GT. (2008). Estimation of air-sea carbon dioxide flux in Hudson Bay during the ice-free season using a combination of field data and satellite remote sensing products, Thesis »
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Title: Estimation of air-sea carbon dioxide flux in Hudson Bay during the ice-free season using a combination of field data and satellite remote sensing products
Type: Thesis
Publication:
Author(s): Else, B.GT.
Year: 2008
Formatted Citation: Else, B.GT., 2008: Estimation of air-sea carbon dioxide flux in Hudson Bay during the ice-free season using a combination of field data and satellite remote sensing products,
Abstract: The lack of baseline estimates of air-sea CO(2) exchange in Arctic and sub-Arctic regions represents a major shortfall in our ability to understand how climate change may affect CO(2) fluxes at high latitude. The 2005 ArcticNet cruise of Hudson Bay provided a rare comprehensive oceanographic survey of one such region. Ship-based observations of sea-surface fugacity of CO(2) (fCO(2sw)) were made at 56 locations between September 15 and October 26, and were found to range from 259muatm in Hudson Strait to 425muatm at the entrance to James Bay. Strong relationships between fCO( 2sw) and river discharge were identified, with coastal waters observed to be supersaturated in fCO(2sw) with respect to the atmosphere (and thus a source of CO(2)), while off-shore waters were undersaturated (thus a sink). High correlation of fCO( 2sw) with salinity, sea surface temperature (SST), and colored dissolved organic matter (CDOM) suggest that thermodynamic effects and possibly the oxidation of riverine carbon were driving supersaturation in the coastal zone. To expand the spatial and temporal domain of the study, a remote sensing approach was applied. Predictive algorithms for fCO( 2sw) were created from relationships with CDOM and SST, variables which can be measured from satellite remote sensing platforms. A SST-f CO(2sw) algorithm was used with monthly maps of SST obtained from the MODIS aqua sensor to extrapolate fCO(2sw ) in Hudson Bay for the 2005 ice-free season (August-October). Gas transfer velocities were estimated using twice-daily QuikSCAT wind retrievals, and by using a bulk aerodynamic approach the monthly flux of CO(2) in Hudson Bay was calculated. The results of these calculations revealed that Hudson Bay acts as a source of CO(2) during August and September (4.10 and 5.29 mmol m -2 day -1 , respectively), but reverts to a sink of CO(2) in October as the water temperature cools (-5.83 mmol -2 day -1 ). By integrating over the spatial extent of Hudson Bay and the 92 day open-water season, a positive flux of 0.93 TgC was estimated. This result is in contrast to most Arctic or sub-Arctic continental shelf seas, where usually strong absorptions of CO(2) are observed. It is hypothesized that this difference is related to the strong influence of river discharge. Future studies are necessary to constrain fluxes in Hudson Bay over an annual cycle and to determine the oceanographic controls on CO(2) flux. However, this study is significant since it represents the first-ever examination of air-sea CO(2) exchange in Hudson Bay.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.11575/PRISM/1685
Other URLs:
Felicisimo, A.M., Munoz, J., Gonzalez-Solis, J., and Figuerola, J. (2008). Ocean Surface Winds Drive Dynamics of Transoceanic Aerial Movements, PloS ONE, 3(8), e2928, 10.1371/journal.pone.0002928. Journal Article »
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Title: Ocean Surface Winds Drive Dynamics of Transoceanic Aerial Movements
Type: Journal Article
Publication: PloS ONE
Author(s): Felicisimo, A.M., Munoz, J., Gonzalez-Solis, J., and Figuerola, J.
Year: 2008
Formatted Citation: Felicisimo, A.M., Munoz, J., Gonzalez-Solis, J., and Figuerola, J., 2008: Ocean Surface Winds Drive Dynamics of Transoceanic Aerial Movements, PloS ONE, 3(8), e2928, 10.1371/journal.pone.0002928.
Abstract: Global wind patterns influence dispersal and migration processes of aerial organisms, propagules and particles, which ultimately could determine the dynamics of colonizations, invasions or spread of pathogens. However, studying how wind-mediated movements actually happen has been hampered so far by the lack of high resolution global wind data as well as the impossibility to track aerial movements. Using concurrent data on winds and actual pathways of a tracked seabird, here we show that oceanic winds define spatiotemporal pathways and barriers for large-scale aerial movements. We obtained wind data from NASA SeaWinds scatterometer to calculate wind cost (impedance) models reflecting the resistance to the aerial movement near the ocean surface. We also tracked the movements of a model organism, the Cory`s shearwater (Calonectris diomedea), a pelagic bird known to perform long distance migrations. Cost models revealed that distant areas can be connected through `wind highways` that do not match the shortest great circle routes. Bird routes closely followed the low-cost `wind-highways` linking breeding and wintering areas. In addition, we found that a potential barrier, the near surface westerlies in the Atlantic sector of the Intertropical Convergence Zone (ITCZ), temporally hindered meridional trans-equatorial movements. Once the westerlies vanished, birds crossed the ITCZ to their winter quarters. This study provides a novel approach to investigate wind-mediated movements in oceanic environments and shows that large-scale migration and dispersal processes over the oceans can be largely driven by spatiotemporal wind patterns.
Keywords: Seawinds
Mission:
URL: https://doi.org/10.1371/journal.pone.0002928
Other URLs:
Fu, R., Hu, L., Gu, G.J., and Li, Y.D. (2008). A Comparison Study of Summer-Time Synoptic-Scale Waves in South China and the Yangtze River Basin Using the TRMM Multi-Satellite Precipitation Analysis Daily Product, Science in China Series D: Earth Sciences, 51(1), 114-122, 10.1007/s11430-007-0125-6. Journal Article »
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Title: A Comparison Study of Summer-Time Synoptic-Scale Waves in South China and the Yangtze River Basin Using the TRMM Multi-Satellite Precipitation Analysis Daily Product
Type: Journal Article
Publication: Science in China Series D: Earth Sciences
Author(s): Fu, R., Hu, L., Gu, G.J., and Li, Y.D.
Year: 2008
Formatted Citation: Fu, R., Hu, L., Gu, G.J., and Li, Y.D., 2008: A Comparison Study of Summer-Time Synoptic-Scale Waves in South China and the Yangtze River Basin Using the TRMM Multi-Satellite Precipitation Analysis Daily Product, Science in China Series D: Earth Sciences, 51(1), 114-122, 10.1007/s11430-007-0125-6.
Abstract: Summer-time synoptic-scale waves in South China and the Yangtze River basin are quantified and compared by means of analyzing the 6-year (19982004) TRMM Multi-Satellite Precipitation Analysis (TMPA) daily product. An innovative 3-dimensional spectrum analysis method is applied. The results indicate that synoptic-scale waves appearing in South China prominently propagate westward within a zonal wavenumber range of 921 and a frequency range of −,0.12−,0.22 cycles day−,1, while those in the Yangtze River basin primarily move eastward with the same characteristic wavenumbers of 921, but within a frequency range of 0.20.29 cycles day−,1. Zonal and meridional distributions, and seasonal variations of these waves are further explored and compared. It shows that summer-time synoptic-scale waves in the South China result from the northward migration and oscillation of the Intertropical Convergence Zone (ITCZ) in the western Pacific, whereas the ones in the Yangtze River basin are generally related to the synoptic troughs within the westerly flow, originating from the Qinghai-Tibet Plateau.
Keywords: TRMM - 3-dimensional spectrum analysis - synoptic-scale waves - South China - Yangtze River basin
Mission:
URL: https://doi.org/10.1007/s11430-007-0125-6
Other URLs:
Gao, H., Fu, R., Dickinson, R.E., and Juarez, R.I.N. (2008). A Practical Method for Retrieving Land Surface Temperature from AMSR-E Over the Amazon Forest, IEEE Transactions on Geoscience and Remote Sensing, 46(1), 193-199, 10.1109/TGRS.2007.906478. Journal Article »
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Title: A Practical Method for Retrieving Land Surface Temperature from AMSR-E Over the Amazon Forest
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Gao, H., Fu, R., Dickinson, R.E., and Juarez, R.I.N.
Year: 2008
Formatted Citation: Gao, H., Fu, R., Dickinson, R.E., and Juarez, R.I.N., 2008: A Practical Method for Retrieving Land Surface Temperature from AMSR-E Over the Amazon Forest, IEEE Transactions on Geoscience and Remote Sensing, 46(1), 193-199, 10.1109/TGRS.2007.906478.
Abstract: Remote sensing of land surface temperature (LST) using infrared (IR) sensors, such as the Moderate Resolution Imaging Spectroradiometer (MODIS), is only capable of retrieval under clear-sky conditions. Such LST observations over tropical forests are very limited due to clouds and rainfall, particularly during the wet season and high atmospheric water-vapor content. In comparison, low-frequency microwave radiances are minimally influenced by meteorological conditions. Exploring this advantage, we have developed an algorithm to retrieve LST over the Amazonian forest. The algorithm uses multifrequency polarized microwave brightness temperatures from the Advanced Microwave Scanning Radiometer on NASA`s Earth Observing System (AMSR-E). Relationships between polarization ratio and surface emissivity are established for forested and nonforested areas, such that LST can solely be calculated from microwave radiance. Results are presented over three time scales: at each orbit, daily, and monthly. Results are evaluated by comparing with available air-temperature records on daily and monthly intervals. Our findings indicate that the AMSR-E-derived LST agrees well with in situ measurements. Results during the wet season over the tropical forest suggest that the AMSR-E LST is robust under all-weather conditions and shows higher correlation to meteorological data (r = 0.70) than the IR-based LST approaches (r = 0.42).
Keywords: Infrared (IR) radiometry microwave radiometry remote sensing temperature measurement
Mission:
URL: https://doi.org/10.1109/TGRS.2007.906478
Other URLs:
Gohil, B.S., Sarkar, A., and Agarwal, V.K. (2008). A New Algorithm for Wind-Vector Retrieval from Scatterometers, IEEE Geoscience and Remote Sensing Letters, 5(3), 387-391, 10.1109/LGRS.2008.917129. Journal Article »
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Title: A New Algorithm for Wind-Vector Retrieval from Scatterometers
Type: Journal Article
Publication: IEEE Geoscience and Remote Sensing Letters
Author(s): Gohil, B.S., Sarkar, A., and Agarwal, V.K.
Year: 2008
Formatted Citation: Gohil, B.S., Sarkar, A., and Agarwal, V.K., 2008: A New Algorithm for Wind-Vector Retrieval from Scatterometers, IEEE Geoscience and Remote Sensing Letters, 5(3), 387-391, 10.1109/LGRS.2008.917129.
Abstract: A new efficient algorithm for retrieving wind-vector solutions from scatterometers is developed based on a criterion of minimum normalized standard deviation (NSD) of wind speed derived from backscatter measurements using a geophysical model function (GMF). Its performance has been evaluated through simulations using QSCAT-1 GMF and the QuikSCAT observational geometry. The present algorithm, named the NSD algorithm, is found to be computationally more efficient (two to three times) besides being at par with the maximum-likelihood estimator (MLE) algorithm in terms of retrieval skill, retrieval errors, and distribution of solutions, on the basis of simulations as well as comparison of limited QuikSCAT-data-derived winds with National Centers for Environmental Prediction and European Centre for MediumRange Weather Forecasts model winds. Simulation results and analysis of sample QuikSCAT data are presented. 2008 IEEE.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1109/LGRS.2008.917129
Other URLs:
Grodsky, S.A., Carton, J.A., and McClain, C.R. (2008). Variability of Upwelling and Chlorophyll in the Equatorial Atlantic, Geophysical Research Letters, 35(3), L03610, 10.1029/2007GL032466. Journal Article »
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Title: Variability of Upwelling and Chlorophyll in the Equatorial Atlantic
Type: Journal Article
Publication: Geophysical Research Letters
Author(s): Grodsky, S.A., Carton, J.A., and McClain, C.R.
Year: 2008
Formatted Citation: Grodsky, S.A., Carton, J.A., and McClain, C.R., 2008: Variability of Upwelling and Chlorophyll in the Equatorial Atlantic, Geophysical Research Letters, 35(3), L03610, 10.1029/2007GL032466.
Abstract: The primary seasonal phytoplankton bloom in the equatorial Atlantic occurs in boreal summer in response to seasonal strengthening of zonal winds. However, the equatorial Atlantic also has a secondary bloom in late fall early winter. This secondary bloom is weaker than the primary bloom by a factor of two, but is subject to year-to-year variability that is similar in magnitude. Here, observational evidence, including sea level and SeaWiFS-derived chlorophyll-a concentration, is used to examine several potential causes of this secondary bloom. The secondary bloom varies independently of blooms along the eastern coastal zones. Also, the secondary bloom has a relationship with the cessation of the Northwest African monsoon, which propotes the secondary seasonal strengthening of the trade winds. The variability of the secondary bloom results from perturbations in the depth of the thermocline induced by zonal wind anomalies in the western tropical Atlantic. These wind anomalies are correlated with mean sea level atmospheric pressure anomalies in the region of the northern subtropical high as well as over the Amazon.
Keywords: equatorial Atlantic, chlorophyll, sea level
Mission:
URL: https://doi.org/10.1029/2007GL032466
Other URLs:
Gunn, B.A. and Long, D.G. (2008). Spatial Resolution Enhancement of AMSR Tb Images Based on Measurement Local Time of Day, 2008 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `08), V - 33-V - 36, 10.1109/IGARSS.2008.4780020. Conference Paper »
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Title: Spatial Resolution Enhancement of AMSR Tb Images Based on Measurement Local Time of Day
Type: Conference Paper
Publication: 2008 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `08)
Author(s): Gunn, B.A. and Long, D.G.
Year: 2008
Formatted Citation: Gunn, B.A. and Long, D.G., 2008: Spatial Resolution Enhancement of AMSR Tb Images Based on Measurement Local Time of Day, 2008 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `08), V - 33-V - 36, 10.1109/IGARSS.2008.4780020.
Abstract: Daily images of Advanced Microwave Sensor Radiometer (AMSR) brightness temperature (Tb) measurements are used in variety of applications, particularly in the polar regions. Several methods for generating Tb images have been developed, including averaging of all measurements collected during the day and using only the most recent measurements. The former can compromise the temporal resolution of the images, while the lack of averaging in the latter results in more noise. By carefully considering the local time-of-day (LTOD) the measurements are collected and averaging all the measurements within location-dependent time period, two images with high temporal locality and reduced noise can be produced per day. The LTOD scheme supports the application of spatial resolution enhancement algorithms which can provide improved image resolution. AMSR-E flies in a near-polar sun-synchronous orbit. Because its orbit geometry and wide swath, this instrument scans areas near the poles multiple (2-7, depending on latitude) times each day. This frequent scanning is valuable in studies over over regions of extreme latitudes, especially those involving transient phenomena such as weather or ice. Since the orbit is sun- synchronous, measurements are made at the nearly the same local-time each day with a several day repeat cycle. Over a single 24 hour period at given point at high (> 60 ◦, ) latitudes, groups of temporally closely-spaced samples occur at nearly 12 hours apart (thus offering sampling of diurnal cycles). The precise timing of the sampling is location dependent. While time-of-day variations in Tb can be significant, Tb values are similar over the LTOD groups in the polar regions. This can be exploited to average measurements or apply spatial resolution enhancement, which requires multiple overlapping measurements to be effective. This paper briefly describes an AMSR Tb image dataset produced as part of the Scatterometer Climate Record Pathfinder (SCP) Project [www.scp.byu.edu] that incorporates both LTOD and spatial resolution enhancement to produce twice-daily Tb images. Each enhanced AMSR TB image consists of measurements collected during a narrow local time window and processing using the radiometer version of the Scatterometer Image Reconstruction (SIR) algorithm [1]. Images are produced on the same grids as scatterometer backscatter images maintained by the SCP. LTOD images are compared to daily average images using both gridded and enhanced resolution imagery. Issues associated with the temporal sampling, image temporal/spatial boundaries, LTOD, and image artifacts are explored. The relative advantages of LTOD processing and the effective spatial resolution of the images are considered. A sample application of the image dataset for tracking rapid sea ice movement in the Arctic is presented which illustrates the utility of the dataset. Typical applications of the image data set include melt/freeze mapping, sea ice motion, and percent ice coverage.
Keywords:
Mission:
URL: https://doi.org/10.1109/IGARSS.2008.4780020
Other URLs:
Haack, T., Chelton, D., Pullen, J., Doyle, J., and Schlax, M. (2008). Summertime Influence of SST on Surface Wind Stress off the U.S. West Coast from the U.S. Navy COAMPS Model, Journal of Physical Oceanography, 38(11), 2414-2437, 10.1175/2008JPO3870.1. Journal Article »
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Title: Summertime Influence of SST on Surface Wind Stress off the U.S. West Coast from the U.S. Navy COAMPS Model
Type: Journal Article
Publication: Journal of Physical Oceanography
Author(s): Haack, T., Chelton, D., Pullen, J., Doyle, J., and Schlax, M.
Year: 2008
Formatted Citation: Haack, T., Chelton, D., Pullen, J., Doyle, J., and Schlax, M., 2008: Summertime Influence of SST on Surface Wind Stress off the U.S. West Coast from the U.S. Navy COAMPS Model, Journal of Physical Oceanography, 38(11), 2414-2437, 10.1175/2008JPO3870.1.
Abstract: High-resolution mesoscale model sea surface temperature (SST) analyses and surface wind stress forecasts off the U.S. West Coast are analyzed on monthly time scales for robust signatures of air-sea interaction as the surface winds encounter ocean surface features such as SST fronts, filaments, and eddies. This interaction is manifest by the linear relationship, or coupling coefficient, between the downwind SST gradient and wind stress divergence and between the crosswind SST gradient and wind stress curl evident from analysis of fields averaged over 29 days. This study examines fields from the Coupled Ocean-Atmosphere Mesoscale Prediction System (COAMPS) model, spanning the summer months, June-September, for four consecutive years, 2002-05. Relative to several models evaluated previously, coupling coefficients are much closer to those calculated from Quick Scatterometer (QuikSCAT) satellite measurements. In addition, the summertime correlation between the wind stress derivative field and its corresponding SST gradient field on monthly time scales agrees well with satellite-derived correlations. Sensible and latent heat flux fields are also analyzed for features indicative of pronounced air-sea exchange associated with SST influence.
Keywords:
Mission: |SeaWinds|
URL: https://doi.org/10.1175/2008JPO3870.1
Other URLs:
Hallikainen, M., Sievinen, P., Yuanzhi, Z., and Halme, P. (2008). Use of Quikscat Ku-B and Scatterometer Data for Retrieval of Seasonal Snow Characteristics in Finland, 2007 IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2007, June 23, 2007 - June 28, 10.1109/IGARSS.2007.4423027. Conference Paper »
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Title: Use of Quikscat Ku-B and Scatterometer Data for Retrieval of Seasonal Snow Characteristics in Finland
Type: Conference Paper
Publication: 2007 IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2007, June 23, 2007 - June 28
Author(s): Hallikainen, M., Sievinen, P., Yuanzhi, Z., and Halme, P.
Year: 2008
Formatted Citation: Hallikainen, M., Sievinen, P., Yuanzhi, Z., and Halme, P., 2008: Use of Quikscat Ku-B and Scatterometer Data for Retrieval of Seasonal Snow Characteristics in Finland, 2007 IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2007, June 23, 2007 - June 28, 10.1109/IGARSS.2007.4423027.
Abstract: The feasibility of using scatterometer data from the spaceborne QuikScat instrument for retrieval of snow characteristics in Finland has been studied. QuikScat data for the winters of 1999-2000 through 2005-2006 have been used along with in situ data for 21 test sites. 2007 IEEE.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1109/IGARSS.2007.4423027
Other URLs:
Han W., Webster, P.J., Lin, J., Liu, W.T., Fu, R., Yuan, D., and Hu, A. (2008). Dynamics of Intraseasonal Sea Level and Thermocline Variability in the Equatorial Atlantic During 2002-03, Journal of Physical Oceanography, 38(5), 945-967, 10.1175/2008JPO3854.1. Journal Article »
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Title: Dynamics of Intraseasonal Sea Level and Thermocline Variability in the Equatorial Atlantic During 2002-03
Type: Journal Article
Publication: Journal of Physical Oceanography
Author(s): Han W., Webster, P.J., Lin, J., Liu, W.T., Fu, R., Yuan, D., and Hu, A.
Year: 2008
Formatted Citation: Han W., Webster, P.J., Lin, J., Liu, W.T., Fu, R., Yuan, D., and Hu, A., 2008: Dynamics of Intraseasonal Sea Level and Thermocline Variability in the Equatorial Atlantic During 2002-03, Journal of Physical Oceanography, 38(5), 945-967, 10.1175/2008JPO3854.1.
Abstract: Satellite and in situ observations in the equatorial Atlantic Ocean during 2002-03 show dominant spectral peaks at 40-60 days and secondary peaks at 10-40 days in sea level and thermocline within the intraseasonal period band (10-80 days). A detailed investigation of the dynamics of the intraseasonal variations is carried out using an ocean general circulation model, namely, the Hybrid Coordinate Ocean Model (HYCOM). Two parallel experiments are performed in the tropical Atlantic Ocean basin for the period 2000-03: one is forced by daily scatterometer winds from the Quick Scatterometer (QuikSCAT) satellite together with other forcing fields, and the other is forced by the low-passed 80-day version of the above fields. To help in understanding the role played by the wind-driven equatorial waves, a linear continuously stratified ocean model is also used. Within 3 degrees S-3 degrees N of the equatorial region, the strong 40-60-day sea surface height anomaly (SSHA) and thermocline variability result mainly from the first and second baroclinic modes equatorial Kelvin waves that are forced by intraseasonal zonal winds, with the second baroclinic mode playing a more important role. Sharp 40-50-day peaks of zonal and meridional winds appear in both the QuikSCAT and Pilot Research Moored Array in the Tropical Atlantic (PIRATA) data for the period 2002-03, and they are especially strong in 2002. Zonal wind anomaly in the central-western equatorial basin for the period 2000-06 is significantly correlated with SSHA across the equatorial basin, with simultaneous/ lag correlation ranging from-0.62 to 0.74 above 95% significance. Away from the equator (3 degrees-5 degrees N), however, sea level and thermocline variations in the 40-60-day band are caused largely by tropical instability waves (TIWs). On 10-40-day time scales and west of 10 degrees W, the spectral power of sea level and thermocline appears to be dominated by TIWs within 5 degrees S-5 degrees N of the equatorial region. The wind-driven circulation, however, also provides a significant contribution. Interestingly, east of 10 W, SSHA and thermocline variations at 10 40- day periods result almost entirely from wind-driven equatorial waves. During the boreal spring of 2002 when TIWs are weak, Kelvin waves dominate the SSHA across the equatorial basin (2 degrees S-2 degrees N). The observed quasi-biweekly Yanai waves are excited mainly by the quasi-biweekly meridional winds, and they contribute significantly to the SSHA and thermocline variations in 1 degrees-5 degrees N and 1 degrees-5 degrees S regions.
Keywords: TROPICAL INSTABILITY WAVES, WEST-AFRICAN MONSOON, INDIAN-OCEAN, LONG WAVES, NUMERICAL-MODEL, PACIFIC-OCEAN, KELVIN WAVES, CURRENT OSCILLATIONS, SURFACE TEMPERATURE, ROSSBY WAVES
Mission: |SeaWinds|
URL: https://doi.org/10.1175/2008JPO3854.1
Other URLs:
Hanna, R. and Jones, W. L. (2008). Brightness Temperature Validation for SeaWinds Radiometer Using Advanced Microwave Scanning Radiometer on ADEOS-II, 2007 IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2007, June 23, 2007 - June 28, 10.1109/IGARSS.2007.4423834. Conference Paper »
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Title: Brightness Temperature Validation for SeaWinds Radiometer Using Advanced Microwave Scanning Radiometer on ADEOS-II
Type: Conference Paper
Publication: 2007 IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2007, June 23, 2007 - June 28
Author(s): Hanna, R. and Jones, W. L.
Year: 2008
Formatted Citation: Hanna, R. and Jones, W. L., 2008: Brightness Temperature Validation for SeaWinds Radiometer Using Advanced Microwave Scanning Radiometer on ADEOS-II, 2007 IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2007, June 23, 2007 - June 28, 10.1109/IGARSS.2007.4423834.
Abstract: After the launch of NASA`s SeaWinds scatterometer in 1999, a radiometer function was implemented in the Science Ground Data Processing Systems to allow the measurement of the earth`s microwave brightness temperature. This paper presents the validation of the SeaWinds radiometer (SRad) ocean brightness temperatures using the Advanced Microwave Scanning Radiometer (AMSR) as a brightness temperature standard. Results are presented which compare collocated and simultaneously measured ocean brightness temperatures while operating on Japan`s ADEOS-II satellite. 2007 IEEE.
Keywords: Seawinds
Mission:
URL: https://doi.org/10.1109/IGARSS.2007.4423834
Other URLs:
Hasager, C.B., Astrup, P., and Nielsen, P. (2008). QuikSCAT and SSM/I Ocean Surface Winds for Wind Energy, 2007 IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2007, June 23, 2007 - June 28, 10.1109/IGARSS.2007.4423602. Conference Paper »
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Title: QuikSCAT and SSM/I Ocean Surface Winds for Wind Energy
Type: Conference Paper
Publication: 2007 IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2007, June 23, 2007 - June 28
Author(s): Hasager, C.B., Astrup, P., and Nielsen, P.
Year: 2008
Formatted Citation: Hasager, C.B., Astrup, P., and Nielsen, P., 2008: QuikSCAT and SSM/I Ocean Surface Winds for Wind Energy, 2007 IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2007, June 23, 2007 - June 28, 10.1109/IGARSS.2007.4423602.
Abstract: Ocean surface winds observed by satellite scatterometer (QuikSCAT) and passive microwave (SMM/I) provide valuable information for wind energy applications. In wind energy two long-term aspects on the offshore wind climate is of concern. One is the 20-year average necessary for the estimation of produced wind power during the life-time of a wind turbine (i.e. wind resource assessment), the other is the month-to-month variation in produced wind power (i.e. wind-indexing). In the present study, the offshore wind resource is estimated from QuikSCAT wind maps. The offshore wind climates at the North-European mid-latitudes and in the Atlantic trade belt zone are compared. Distinct differences are identified and these agree well with independent data from meteorological masts in the two regions. Seven years of twice daily observations from QuikSCAT are used for the offshore wind resource assessment. Wind-indexing is based on long-term trends observed in wind climate statistics. It is customary to observe winds and produced power in parallel in order to keep track of performance. Wind-indexing is based on long-term wind observations and the present study investigate variation in offshore and land-based variations during 18 years observed from SSM/I, other wind observations, model results and produced wind power. Very interestingly it is found that the offshore wind climate is different from wind climates over land in the North-European mid-latitudes. 2007 IEEE.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1109/IGARSS.2007.4423602
Other URLs:
He, Y., Shen, H., Guo, J., and Perrie, W. (2008). A Comparison of Models for Retrieving High Wind Speeds, 2007 IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2007, June 23, 2007 - June 28, 10.1109/IGARSS.2007.4423358. Conference Paper »
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Title: A Comparison of Models for Retrieving High Wind Speeds
Type: Conference Paper
Publication: 2007 IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2007, June 23, 2007 - June 28
Author(s): He, Y., Shen, H., Guo, J., and Perrie, W.
Year: 2008
Formatted Citation: He, Y., Shen, H., Guo, J., and Perrie, W., 2008: A Comparison of Models for Retrieving High Wind Speeds, 2007 IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2007, June 23, 2007 - June 28, 10.1109/IGARSS.2007.4423358.
Abstract: Based on polarization ratio from ENVISAT ASAR, we compared the wind vectors retrieved from CMOD5 with = 0.6, = 0.5, our polarization ratio, W HWGMF with our polarization ratio and HH HWGMF with results from QuikSCAT and buoy, respectively. We found that CMOD5 with = 0.5 polarization ratio is best one for retrieving high wind speed from RADARSAT SAR, and error between QuikSCAT and HH HWGMF is the least. The polarization ratio and GMF for high wind need be improved. 2007 IEEE.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1109/IGARSS.2007.4423358
Other URLs:
Hilburn, K.A. and Wentz, F.J. (2008). Intercalibrated Passive Microwave Rain Products from the Unified Microwave Ocean Retrieval Algorithm (UMORA), Cover Journal of Applied Meteorology and Climatology Journal of Applied Meteorology and Climatology, 47(3), 778-794, 10.1175/2007JAMC1635.1. Journal Article »
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Title: Intercalibrated Passive Microwave Rain Products from the Unified Microwave Ocean Retrieval Algorithm (UMORA)
Type: Journal Article
Publication: Cover Journal of Applied Meteorology and Climatology Journal of Applied Meteorology and Climatology
Author(s): Hilburn, K.A. and Wentz, F.J.
Year: 2008
Formatted Citation: Hilburn, K.A. and Wentz, F.J., 2008: Intercalibrated Passive Microwave Rain Products from the Unified Microwave Ocean Retrieval Algorithm (UMORA), Cover Journal of Applied Meteorology and Climatology Journal of Applied Meteorology and Climatology, 47(3), 778-794, 10.1175/2007JAMC1635.1.
Abstract: The Unified Microwave Ocean Retrieval Algorithm (UMORA) simultaneously retrieves sea surface temperature, surface wind speed, columnar water vapor, columnar cloud water, and surface rain rate from a variety of passive microwave radiometers including the Special Sensor Microwave Imager (SSM/I), the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI), and the Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E). The rain component of UMORA explicitly parameterizes the three physical processes governing passive microwave rain retrievals: the beamfilling effect, cloud and rainwater partitioning, and effective rain layer thickness. Rain retrievals from the previous version of UMORA disagreed among different sensors and were too high in the tropics. These issues have been fixed with more realistic rain column heights and proper modeling of saturation and footprint-resolution effects in the beamfilling correction. The purpose of this paper is to describe the rain algorithm and its recent improvements and to compare UMORA retrievals with Goddard Profiling Algorithm (GPROF) and Global Precipitation Climatology Project (GPCP) rain rates. On average, TMI retrievals from UMORA agree well with GPROF, however, large differences become apparent when the instantaneous retrievals are compared on a pixel-to-pixel basis. The differences are due to fundamental algorithm differences. For example, UMORA generally retrieves higher total liquid water, but GPROF retrieves a higher surface rain rate for a given amount of total liquid water because of differences in microphysical assumptions. Comparison of UMORA SSM/I retrievals with GPCP shows similar spatial patterns, but GPCP has higher global averages because of greater amounts of precipitation in the extratropics. UMORA and GPCP have similar linear trends over the period 19882005 with similar spatial patterns.
Keywords: RADIOMETER DATA, BRIGHTNESS TEMPERATURES, PRECIPITATION, SATELLITE, SSM/I
Mission:
URL: https://doi.org/10.1175/2007JAMC1635.1
Other URLs:
Ho, S.-S. and Talukder, A. (2008). Automated Cyclone Identification From Remote QuikSCAT Satellite Data, IEEE Aerospace Conference Proceedings 2008, 10.1109/AERO.2008.4526521. Conference Paper »
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Title: Automated Cyclone Identification From Remote QuikSCAT Satellite Data
Type: Conference Paper
Publication: IEEE Aerospace Conference Proceedings 2008
Author(s): Ho, S.-S. and Talukder, A.
Year: 2008
Formatted Citation: Ho, S.-S. and Talukder, A., 2008: Automated Cyclone Identification From Remote QuikSCAT Satellite Data, IEEE Aerospace Conference Proceedings 2008, 10.1109/AERO.2008.4526521.
Abstract: We discuss a fully automated remote cyclone identification and tracking approach using the QuikSCAT wind sensor data. Our approach consists of five main automated steps: QuikSCAT data retrieval, QuikSCAT feature extraction & data preprocessing, cyclone identification, motion/location prediction, and cyclone tracking. Ensemble learning based on a committee of support vector machines using features extracted from QuikSCAT wind sensor data are used for cyclone identification. Experimental results demonstrates the feasibility and usefulness of our automated approach.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1109/AERO.2008.4526521
Other URLs:
Ho, S.-S. and Talukder, A. (2008). Automated Cyclone Discovery and Tracking Using Knowledge Sharing in Multiple Heterogeneous Satellite Data, Proceedings of the ACM SIGKDD International Conference on Knowledge Discovery and Data Mining, 10.1145/1401890.1402001. Conference Paper »
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Title: Automated Cyclone Discovery and Tracking Using Knowledge Sharing in Multiple Heterogeneous Satellite Data
Type: Conference Paper
Publication: Proceedings of the ACM SIGKDD International Conference on Knowledge Discovery and Data Mining
Author(s): Ho, S.-S. and Talukder, A.
Year: 2008
Formatted Citation: Ho, S.-S. and Talukder, A., 2008: Automated Cyclone Discovery and Tracking Using Knowledge Sharing in Multiple Heterogeneous Satellite Data, Proceedings of the ACM SIGKDD International Conference on Knowledge Discovery and Data Mining, 10.1145/1401890.1402001.
Abstract: Current techniques for cyclone detection and tracking employ NCEP (National Centers for Environmental Prediction) models from in-situ measurements. This solution does not provide true global coverage, unlike remote satellite observations. However it is impractical to use a single Earth orbiting satellite to detect and track events such as cyclones in a continuous manner due to limited spatial and temporal coverage. One solution to alleviate such persistent problems is to utilize heterogeneous sensor data from multiple orbiting satellites. However, this solution requires overcoming other new challenges such as varying spatial and temporal resolution between satellite sensor data, the need to establish correspondence between features from different satellite sensors, and the lack of definitive indicators for cyclone events in some sensor data. We describe an automated cyclone discovery and tracking approach using heterogeneous near real-time sensor data from multiple satellites. This approach addresses the unique challenges associated with knowledge discovery and mining from heterogeneous satellite data streams. We consider two remote sensor measurements in our current implementation, namely: QuikSCAT wind satellite measurements, and merged precipitation data from TRMM and other satellites. More satellites will be incorporated in the near future and our solution is sufficiently powerful that it generalizes to multiple sensor measurement modalities. Our approach consists of three main components: (i) feature extraction from each sensor measurement, (ii) an ensemble classifier for cyclone discovery, and (iii) knowledge sharing between the different remote sensor measurements based on a linear Kalman filter for predictive cyclone tracking. Experimental results on historical hurricane datasets demonstrate the superior performance of our approach compared to previous work. 2008 ACM.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1145/1401890.1402001
Other URLs:
Hudson, D. and Long, D.G. (2008). Optimal Estimation of Calibration Parameters in Polarimetric Microwave Radiometers, IEEE Trans. Geosci. Remote Sens., 46(10, Part 2), 3223-3237, 10.1109/TGRS.2008.921636. Journal Article »
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Title: Optimal Estimation of Calibration Parameters in Polarimetric Microwave Radiometers
Type: Journal Article
Publication: IEEE Trans. Geosci. Remote Sens.
Author(s): Hudson, D. and Long, D.G.
Year: 2008
Formatted Citation: Hudson, D. and Long, D.G., 2008: Optimal Estimation of Calibration Parameters in Polarimetric Microwave Radiometers, IEEE Trans. Geosci. Remote Sens., 46(10, Part 2), 3223-3237, 10.1109/TGRS.2008.921636.
Abstract: Methods for internal calibration of a certain class of microwave polarimetric radiometers are presented by Piepmeier. In that work, the calibration parameters are estimated algebraically. We demonstrate that Bayesian estimation decreases the root-mean-square error of the estimates by a factor of two. This improvement is obtained by using knowledge of the noise structure of the measurements and by utilizing all of the information provided by the measurements. Drawbacks are the increased complexity of the method and an increase in computation. We also extend the method to estimate several hardware component parameters of interest in system calibration.
Keywords: Bayes methods calibration geophysical equipment parameter estimation polarimetry radiometry Bayesian estimation calibration parameters optimal estimation polarimetric microwave radiometers
Mission:
URL: https://doi.org/10.1109/TGRS.2008.921636
Other URLs:
Jeong, J.-Y., Shim, J.-S, Lee, D.-K, Min, I.-K, and Kwon, J.-I (2008). Validation of QuikSCAT Wind with Resolution of 12.5 km in the Vicinity of Korean Peninsula, Ocean and Polar Research, 30(1), 47-58, 10.4217/OPR.2008.30.1.047. Journal Article »
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Title: Validation of QuikSCAT Wind with Resolution of 12.5 km in the Vicinity of Korean Peninsula
Type: Journal Article
Publication: Ocean and Polar Research
Author(s): Jeong, J.-Y., Shim, J.-S, Lee, D.-K, Min, I.-K, and Kwon, J.-I
Year: 2008
Formatted Citation: Jeong, J.-Y., Shim, J.-S, Lee, D.-K, Min, I.-K, and Kwon, J.-I, 2008: Validation of QuikSCAT Wind with Resolution of 12.5 km in the Vicinity of Korean Peninsula, Ocean and Polar Research, 30(1), 47-58, 10.4217/OPR.2008.30.1.047.
Abstract: Several validation studies have been made for QuikSCAT(QSCAT) wind data around the world, mainly in the offshore. However, until now, there were no validation studies for QSCAT wind with resolution of 12.5 km (`QSCAT 12.5 km wind`) in the vicinity of Korean Peninsula. To validate `QSCAT 12.5 km wind` and to investigate its characteristics around Korean Peninsula, the wind data from Ieodo Ocean Research Station, KMA buoys, and KORDI Realtime Observation Stations have been compared. Validation results showed that `QSCAT 12.5 km wind` RMSE of wind direction and speed were 25.85 degree and 1.83 m/s, respectively, at Ieodo Station. The mean wind speed correlation coefficient of KMA buoys and KORDI Realtime Observation Station were 0.78 and 0.61, and the mean wind speed RMSE were 2.2 m/s and 3.2 m/s, respectively. This seems to be mainly because of the distance between QSCAT and in-situ observation stations. The RMSE of wind direction were bigger than 40 degree at all in-situ observation stations located near the shore, within 20 km from coastlines. Geophysical features where in-situ observation stations are located seem to affect wind validation scores.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.4217/OPR.2008.30.1.047
Other URLs:
Jiang, C, Thompson, L., and Kelly, K.A. (2008). Equatorial Influence of QuikSCAT Winds in an Isopycnal Ocean Model Compared to NCEP2 Winds, Ocean Modelling, 24(1-2), 65-71, 10.1016/j.ocemod.2008.05.003. Journal Article »
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Title: Equatorial Influence of QuikSCAT Winds in an Isopycnal Ocean Model Compared to NCEP2 Winds
Type: Journal Article
Publication: Ocean Modelling
Author(s): Jiang, C, Thompson, L., and Kelly, K.A.
Year: 2008
Formatted Citation: Jiang, C, Thompson, L., and Kelly, K.A., 2008: Equatorial Influence of QuikSCAT Winds in an Isopycnal Ocean Model Compared to NCEP2 Winds, Ocean Modelling, 24(1-2), 65-71, 10.1016/j.ocemod.2008.05.003.
Abstract: An ocean model was used to examine whether the scatterometer winds can improve the model performance both dynamically and thermodynamically. Comparisons were done using QuikSCAT and NCEP2 winds for both the mean and variability from 2000 to 2004. The comparisons showed that the model forced by QuikSCAT winds gives more realistic mean SST, 20 °C isotherm depth (Z20), and latent heat flux than NCEP2 winds do. Sensitivity experiments indicated that QuikSCAT mean wind stress is important for the improved mean SST, Z20, and latent heat release to the atmosphere in the eastern Pacific. QuikSCAT wind speed, through its effect on the turbulent heat fluxes, is most important for the mean SST in the western Pacific. Finally, there were comparable correlations with observations of both SST and Z20 on the intra-seasonal time scale between the model forced with QuikSCAT winds and the model forced with NCEP2 winds.
Keywords:
Mission: |SeaWinds|
URL: https://doi.org/10.1016/j.ocemod.2008.05.003
Other URLs:
Jiang, C.L., Thompson, L.A., Kelly, K.A., and Cronin, M.F. (2008). The Roles of Intraseasonal Kelvin Waves and Tropical Instability Waves in SST Variability Along Equatorial Pacific in an Isopycnal Ocean Model, Journal of Climate, 22(12), 3470-3487, 10.1175/2009JCLI2767.1. Journal Article »
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Title: The Roles of Intraseasonal Kelvin Waves and Tropical Instability Waves in SST Variability Along Equatorial Pacific in an Isopycnal Ocean Model
Type: Journal Article
Publication: Journal of Climate
Author(s): Jiang, C.L., Thompson, L.A., Kelly, K.A., and Cronin, M.F.
Year: 2008
Formatted Citation: Jiang, C.L., Thompson, L.A., Kelly, K.A., and Cronin, M.F., 2008: The Roles of Intraseasonal Kelvin Waves and Tropical Instability Waves in SST Variability Along Equatorial Pacific in an Isopycnal Ocean Model, Journal of Climate, 22(12), 3470-3487, 10.1175/2009JCLI2767.1.
Abstract: The roles of intra-seasonal Kelvin waves and tropical instability waves (TIWs) in the intra-seasonal and low-frequency mixed-layer temperature budget were examined in an isopycnal ocean model forced by QuikSCAT winds from 2000 to 2004. Correlations between temperature tendency and other terms of the intra-seasonal budget compare well with previous results using TAO observations: the net heat flux has the largest correlation in the western Pacific, and zonal advection has the largest correlation in the central Pacific. In the central Pacific, the intra-seasonal variations in zonal advection were due to both the zonal background velocity acting on the Kelvin wave temperature anomaly and the Kelvin wave`s anomalous velocity acting on the background temperature. In the eastern Pacific, three of the four temperature budget terms have comparable correlations. In particular, the vertical processes acting on the shallow thermocline cause large SST anomalies in phase with the intra-seasonal thermocline anomalies. On intra-seasonal time scales, the influence of individual composite upwelling and downwelling Kelvin waves cancel each other. However, because the intra-seasonal SST anomalies increase to the east, a zonal gradient of SST is generated that is in phase with intra-seasonal zonal velocity. Consequently, heat advection by the Kelvin waves rectifies into lower frequencies in the eastern Pacific. Rectification due to TIWs was also seen. The prevalence of intra-seasonal Kelvin waves and the zonal structure of intra-seasonal SST from 2002 to early 2004 suggested that they might be important in setting the eastern Pacific SST on interannual time scales.
Keywords:
Mission: |SeaWinds|
URL: https://doi.org/10.1175/2009JCLI2767.1
Other URLs:
Kantha, L., Rojsiraphisal, T., and Lopez, J. (2008). The North Indian Ocean Circulation and its Variability as Seen in a Numerical Hindcast of the Years 1993-2004, Progress in Oceanography, 76(1), 111-147, 10.1016/j.pocean.2007.05.006. Journal Article »
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Title: The North Indian Ocean Circulation and its Variability as Seen in a Numerical Hindcast of the Years 1993-2004
Type: Journal Article
Publication: Progress in Oceanography
Author(s): Kantha, L., Rojsiraphisal, T., and Lopez, J.
Year: 2008
Formatted Citation: Kantha, L., Rojsiraphisal, T., and Lopez, J., 2008: The North Indian Ocean Circulation and its Variability as Seen in a Numerical Hindcast of the Years 1993-2004, Progress in Oceanography, 76(1), 111-147, 10.1016/j.pocean.2007.05.006.
Abstract: A 12-year hindcast of the physical state of the North Indian Ocean has been carried out for the period 1993-2004, using a data-assimilative, primitive equation, multi-level circulation model that assimilated altimetric sea surface height anomalies and weekly MCSST, and was driven by 6-h ECMWF winds. This period encompasses the anomalous wind events in 1994 and 1997-1998 that led to anomalous oceanic state including anomalous sea surface heights and sea surface temperatures, especially in the equatorial regions. Since the in situ database in the Indian Ocean is rather sparse, the hindcast provides an alternative means of examining the state of the ocean, including its interior, during these anomalous years, as well as normal years during this period. By comparison with observations available during this period, it is shown that the model possesses reasonable skill to be useful in the description of various events in the North Indian Ocean. In this paper, we examine the circulation and its variability over the 12 years of the hindcast. We discuss equatorial events, as well as events in the Bay of Bengal and the Arabian Sea, including the Somali Current system. The heat and mass fluxes are examined. Finally, the hindcast is repeated with QuikSCAT wind stress fields available from July 1999 onwards. Comparison of the 2000-2004 hindcasts forced by ECMWF winds and QS wind stresses shows that in the former, the currents and fluxes are underestimated by 20-30%, but the circulation patterns are roughly similar. 2007 Elsevier Ltd. All rights reserved.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1016/j.pocean.2007.05.006
Other URLs:
Kara, A.B., Wallcraft, A.J., and Bourassa, M.A. (2008). Air-Sea Stability Effects on the 10 m Winds Over the Global Ocean: Evaluations of Air-Sea Flux Algorithms, Journal of Geophysical Research: Oceans, 113(C4), 10.1029/2007JC004324. Journal Article »
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Title: Air-Sea Stability Effects on the 10 m Winds Over the Global Ocean: Evaluations of Air-Sea Flux Algorithms
Type: Journal Article
Publication: Journal of Geophysical Research: Oceans
Author(s): Kara, A.B., Wallcraft, A.J., and Bourassa, M.A.
Year: 2008
Formatted Citation: Kara, A.B., Wallcraft, A.J., and Bourassa, M.A., 2008: Air-Sea Stability Effects on the 10 m Winds Over the Global Ocean: Evaluations of Air-Sea Flux Algorithms, Journal of Geophysical Research: Oceans, 113(C4), 10.1029/2007JC004324.
Abstract: Spatial and temporal variability of the impact of air-sea stratification on the differences between satellite-derived 10 m equivalent neutral wind speeds and stability-dependent (e.g., in situ) 10 m wind speeds are quantitatively examined over the global ocean. The influences of stability are compared with three air-sea flux algorithms, Coupled Ocean-Atmosphere Response Experiment (version 3.0), Bourassa-Vincent-Wood, and Liu-Katsaros-Businger. Analyses are first presented at many individual buoy locations and then are extended to the global ocean with the use of rain-free wind measurements from the SeaWinds scatterometer on the QuikSCAT satellite, gridded at a resolution of 0.25 ?0.25. Overall, stability-dependent winds are found to be weaker than equivalent neutral winds by 0.2 m s−,1 on the basis of 7619 monthly mean values from 208 buoys during 20002005. Differences based on hourly winds can be as large as 0.5 m s−,1. Results remain robust regardless of which air-sea flux algorithm is used. Monthly rain-free gridded QuikSCAT measurements, combined with atmospheric stability determined using near-surface variables from the European Centre for Medium-Range Weather Forecasts 40-year reanalysis, demonstrate the effects of stratification on the 10 m winds globally. Differences in stability-dependent and neutral winds are substantially nonsymmetrical and reveal locations where the former is stronger than the latter. These differences may cause physically significant biases in air-sea fluxes if they are not properly considered, especially near the Kuroshio and Gulf Stream current systems.
Keywords: equivalent neutral wind, air-sea stability, height adjustment
Mission: |SeaWinds|
URL: https://doi.org/10.1029/2007JC004324
Other URLs:
Kara, A.B., Wallcraft, A.J., Barron, C.N., Metzger, E.J., Hurlburt, H.E., and Bourassa, M.A. (2008). Accuracy of 10 m Wind Speeds from Satellites and NWP Products Near Land-Sea Boundaries, Journal of Geophysical Research - Oceans, 113, C10020, 10.1029/2007JC004516. Journal Article »
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Title: Accuracy of 10 m Wind Speeds from Satellites and NWP Products Near Land-Sea Boundaries
Type: Journal Article
Publication: Journal of Geophysical Research - Oceans
Author(s): Kara, A.B., Wallcraft, A.J., Barron, C.N., Metzger, E.J., Hurlburt, H.E., and Bourassa, M.A.
Year: 2008
Formatted Citation: Kara, A.B., Wallcraft, A.J., Barron, C.N., Metzger, E.J., Hurlburt, H.E., and Bourassa, M.A., 2008: Accuracy of 10 m Wind Speeds from Satellites and NWP Products Near Land-Sea Boundaries, Journal of Geophysical Research - Oceans, 113, C10020, 10.1029/2007JC004516.
Abstract: Through a comprehensive analysis, reliability of 10 m wind speeds is presented near the land-sea boundaries over the global ocean. Winds from three numerical weather prediction (NWP) centers and two satellite-based products are analyzed. NWP products are 1.875° × 1.875° National Center Environmental Prediction reanalyses, 1.125° × 1.125° European Centre for Medium-Range Weather Forecasts 40-year Reanalysis (ERA-40), and 1.0° × 1.0° Navy Operational Global Atmospheric Prediction System (NOGAPS) operational product. These are compared to much finer resolution (0.25° × 0.25°) satellite winds, Quick Scatterometer (QSCAT) and Special Sensor Microwave/Imager. Large biases (e.g., >3 m s?1) may exist in NWP products near the land-sea boundaries, because wind speeds from the uniformly gridded global fields are generally at a spatial scale too coarse to appropriately define the contrast between water and land grid points. This so-called land contamination of ocean-only winds varies, and typically depends on the extent of the land-sea mask. A creeping sea-fill methodology is introduced to reduce errors in winds. It is based on the elimination of land-corrupted NWP grid points and replacement by adjacent, purely over-ocean values. In comparison to winds from many moored buoys, the methodology diminishes RMS errors (from >4 m s?1 to <1 m s?1) for NOGAPS and ERA-40. The creeping sea-fill is not advised for NCEP winds which have low contrast between land and sea points, thereby resulting in little impact from the land contamination.
Keywords: landmask, errors, gridding, validation, QSCAT
Mission: |SeaWinds|
URL: https://doi.org/10.1029/2007JC004516
Other URLs:
Karnauskas, K.B., Busalacchi, A.J., and Murtugudde, R. (2008). Low-Frequency Variability and Remote Forcing of Gap Winds Over the East Pacific Warm Pool, Journal of Climate, 21(19), 4901-4918, 10.1175/2008JCLI1771.1. Journal Article »
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Title: Low-Frequency Variability and Remote Forcing of Gap Winds Over the East Pacific Warm Pool
Type: Journal Article
Publication: Journal of Climate
Author(s): Karnauskas, K.B., Busalacchi, A.J., and Murtugudde, R.
Year: 2008
Formatted Citation: Karnauskas, K.B., Busalacchi, A.J., and Murtugudde, R., 2008: Low-Frequency Variability and Remote Forcing of Gap Winds Over the East Pacific Warm Pool, Journal of Climate, 21(19), 4901-4918, 10.1175/2008JCLI1771.1.
Abstract: The low-frequency variability of gap winds at the Isthmuses of Tehuantepec and Papagayo is investigated using a 17-yr wind stress dataset merging the remotely sensed observations of Special Sensor Microwave Imager (SSM/I) and Quick Scatterometer (QuikSCAT) satellite sensors. A decadal signal is identified in the Tehuantepec gap winds, which is shown to be related to the Atlantic tripole pattern (ATP). Using linear regression and spectral analysis, it is demonstrated that the low-frequency variability of the Tehuantepec gap winds is remotely forced by the ATP, and the Papagayo gap winds are primarily governed by El Nino-Southern Oscillation (ENSO) with the ATP being of secondary importance. The Tehuantepec (Papagayo) time series of wind stress anomalies can be better reconstructed when the local cross-isthmus pressure difference and large-scale climate information such as the ATP (ENSO) are included, suggesting that there is important information in the large-scale flow that is not transmitted directly through the background sea level pressure gradient. The geostrophic modulation of the easterly trades in the western Caribbean also serve as a remote driver of the Papagayo gap winds, which is itself not fully independent from ENSO. Finally, it is suggested that precipitation variability in the Inter-Americas region is closely related to the same remote forcing as that of the Tehuantepec gap winds, being the ATP and associated large-scale atmospheric circulation. 2008 American Meteorological Society.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1175/2008JCLI1771.1
Other URLs:
Kobashi, F., Xie, S.-P., Iwasaka, N., and Sakamoto, T. (2008). Deep Atmospheric Response to the North Pacific Oceanic Subtropical Front in Spring, J. Climate, 21(22), 5960-5975, 10.1175/2008JCLI2311.1. Journal Article »
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Title: Deep Atmospheric Response to the North Pacific Oceanic Subtropical Front in Spring
Type: Journal Article
Publication: J. Climate
Author(s): Kobashi, F., Xie, S.-P., Iwasaka, N., and Sakamoto, T.
Year: 2008
Formatted Citation: Kobashi, F., Xie, S.-P., Iwasaka, N., and Sakamoto, T., 2008: Deep Atmospheric Response to the North Pacific Oceanic Subtropical Front in Spring, J. Climate, 21(22), 5960-5975, 10.1175/2008JCLI2311.1.
Abstract: The North Pacific subtropical front (STF) is a zone of high sea surface temperature (SST) gradients located around 25°N in the western basin and is most pronounced in spring. The STF's atmospheric effects are investigated using satellite observations and an atmospheric reanalysis. During April-May along the STF, surface wind stress curl turns weakly cyclonic in the general background of anticyclonic curls. Atmospheric column-integrated water vapor displays a pronounced meridional maximum along this surface trough, suggesting a deep vertical structure. Cyclonic wind curls occur intermittently at intervals of a few days along the STF in subsynoptic low pressure systems accompanying larger, synoptic highs in the main storm track to the north. In the subsynoptic surface lows, convective rain takes place with deep upward motion moistening the entire troposphere. The lows are enhanced by condensational heating, leading to the formation of weak cyclonic wind curls. The lows display vertical structure characteristic of baroclinic instability, suggesting that they are triggered by the passage of synoptic migratory highs and grow on the baroclinicity anchored by the SST front. The cyclonic wind curls appear to be related to a cloud/rainband associated with the so-called pre-baiu/meiyu front in May.
Keywords:
Mission:
URL: https://doi.org/10.1175/2008JCLI2311.1
Other URLs:
Kuo, N.-J., Ho, C.-R., Lo, Y.-T., Huang, S.-J., and Tsao, C.-C. (2008). Variability of Chlorophyll-a Concentration and Sea Surface Wind in the South China Sea Associated with the El Niño-Soutern Oscillation, OCEANS`08 MTS/IEEE Kobe-Techno-Ocean`08 - Voyage toward the Future, OTO`08, April 9, 2008 - April 11, 10.1109/OCEANSKOBE.2008.4531064. Conference Paper »
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Title: Variability of Chlorophyll-a Concentration and Sea Surface Wind in the South China Sea Associated with the El Niño-Soutern Oscillation
Type: Conference Paper
Publication: OCEANS`08 MTS/IEEE Kobe-Techno-Ocean`08 - Voyage toward the Future, OTO`08, April 9, 2008 - April 11
Author(s): Kuo, N.-J., Ho, C.-R., Lo, Y.-T., Huang, S.-J., and Tsao, C.-C.
Year: 2008
Formatted Citation: Kuo, N.-J., Ho, C.-R., Lo, Y.-T., Huang, S.-J., and Tsao, C.-C., 2008: Variability of Chlorophyll-a Concentration and Sea Surface Wind in the South China Sea Associated with the El Niño-Soutern Oscillation, OCEANS`08 MTS/IEEE Kobe-Techno-Ocean`08 - Voyage toward the Future, OTO`08, April 9, 2008 - April 11, 10.1109/OCEANSKOBE.2008.4531064.
Abstract: In this paper, the seasonal and interannual variability of the chlorophyll-a concentration (Chl-a) and sea surface wind (SSW) fields in the South China Sea (SCS) are analyzed using Orbview-2/SeaWiFS, and ERS-1/2 and QuikSCAT satellite data. The mode 1 results of the empirical orthogonal function (EOF) analysis for Chl-a indicate the higher Chl-a is mainly along the coastal areas in the SCS, while the EOF mode 2 results show a summer-winter oscillation of the Chl-a distribution in the SCS. Through the comparison between EOF mode 2 results of the Chl-a anomaly and Nino 3.4 index, it is found that the Chl-a variation in the SCS is highly related to the El Nino-Southern Oscillation (ENSO) events. The SSW EOF mode 1 results indicate that the northeasterly monsoon in winter is much stronger than the southwesterly monsoon in summer. The SSW EOF mode 2 results show the zonal line near 15o N can be a boundary to separate the wind pattern into two parts in fall, the northeasterly wind is in its north and southwesterly wind in its south. The EOF results of the SSW anomaly show the weaker monsoon occurring during the 1997/1998 El Nino winter. Comparing Chl-a EOF mode 2 and SSW EOF mode 1 results, we can find that Chl-a in the SCS is mainly influenced by the monsoon wind, wind-induced coastal upwelling makes the Chl-a increasing along the western SCS in summer but along the eastern SCS in winter.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1109/OCEANSKOBE.2008.4531064
Other URLs:
Lambert, B. and Long, D.G. (2008). Monitoring Changes in the Antarctic Ice Sheet from 1978 to 2007, 2008 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `08), 10.1109/IGARSS.2008.4779726. Conference Paper »
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Title: Monitoring Changes in the Antarctic Ice Sheet from 1978 to 2007
Type: Conference Paper
Publication: 2008 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `08)
Author(s): Lambert, B. and Long, D.G.
Year: 2008
Formatted Citation: Lambert, B. and Long, D.G., 2008: Monitoring Changes in the Antarctic Ice Sheet from 1978 to 2007, 2008 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `08), 10.1109/IGARSS.2008.4779726.
Abstract:
Keywords: Cryosphere: Land Ice and Snow
Mission:
URL: https://doi.org/10.1109/IGARSS.2008.4779726
Other URLs:
Laupattarakasem, P., Jones, W.L., and Hennon, C.C. (2008). Seawinds Hurricane Wind Retrievals and Comparisons with H*Wind Surface Winds Analyses, International Geoscience and Remote Sensing Symposium (IGARSS), 10.1109/IGARSS.2008.4778849. Conference Paper »
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Title: Seawinds Hurricane Wind Retrievals and Comparisons with H*Wind Surface Winds Analyses
Type: Conference Paper
Publication: International Geoscience and Remote Sensing Symposium (IGARSS)
Author(s): Laupattarakasem, P., Jones, W.L., and Hennon, C.C.
Year: 2008
Formatted Citation: Laupattarakasem, P., Jones, W.L., and Hennon, C.C., 2008: Seawinds Hurricane Wind Retrievals and Comparisons with H*Wind Surface Winds Analyses, International Geoscience and Remote Sensing Symposium (IGARSS), 10.1109/IGARSS.2008.4778849.
Abstract: This paper describes recent developments of an improved geophysical ocean wind vector retrieval algorithm that uses both active and passive measurements from QuikSCAT. This algorithm results in significant improvements in wind vector measurements in hurricanes and better rain-flagging of severely rain contaminated areas than does NASA`s standard wind vector product (L2B). By using a combined active/passive approach, we are able to infer wind estimates in the presence of light to moderate rain using the SeaWinds scatterometer. Rain effects (attenuation and volume scattering) are determined passively and then used to correct the measured ocean sigma-0 at 12.5 km wind vector cell resolution. Wind retrievals are performed using an improved geophysical model function (GMF) tuned for extreme wind events These ocean vector wind retrievals, known as Q-Winds, are compared with surface winds products from the NOAA Hurricane Research Division`s H*Wind Analysis System, which assimilates near-simultaneous measurements from insitu and remote sensors, such as, the Stepped Frequency Microwave Radiometer (SFMR), GPS dropsondes, and flight-level inertial navigation winds. Comparisons to H*Wind are presented for Q-Winds and the SeaWinds Project`s new L2B-12.5km ocean vector winds products. 2008 IEEE.
Keywords: QuikSCAT, Seawinds
Mission:
URL: https://doi.org/10.1109/IGARSS.2008.4778849
Other URLs:
Lee, T. and McPhaden, M.J. (2008). Decadal Phase Change in Large-Scale Sea Level and Winds in the Indo-Pacific Region at the End of the 20th Century, Geophysical Research Letters: Oceans, 35(1), 10.1029/2007GL032419. Journal Article »
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Title: Decadal Phase Change in Large-Scale Sea Level and Winds in the Indo-Pacific Region at the End of the 20th Century
Type: Journal Article
Publication: Geophysical Research Letters: Oceans
Author(s): Lee, T. and McPhaden, M.J.
Year: 2008
Formatted Citation: Lee, T. and McPhaden, M.J., 2008: Decadal Phase Change in Large-Scale Sea Level and Winds in the Indo-Pacific Region at the End of the 20th Century, Geophysical Research Letters: Oceans, 35(1), 10.1029/2007GL032419.
Abstract: Satellite observations of sea surface height (SSH) and wind stress for the period of 19932006 reveal a near-coherent large-scale decadal variability in much of the Indo-Pacific region with a phase change at the turn of the 20th century. Trade wind variations in the tropical Pacific and South Indian Ocean are anti-correlated with each other as are SSH differences across these two basins, implying anti-correlated variation of the subtropical cells in the two oceans. Decadal changes in large-scale SSH in the extra-tropics are mostly associated with well-defined patterns of wind stress curl indicating a near-coherent decadal variation in the strength of subtropical and subpolar gyres. Together, these variations reflect a linkage in the circulation of the Pacific and Indian Oceans via atmospheric and oceanic bridges. The phase change in the tropical Pacific tends to occur earlier than elsewhere, suggesting a potential role of the tropical Pacific in regulating decadal variability of the entire region.
Keywords: decadal variability, sea level, wind
Mission:
URL: https://doi.org/10.1029/2007GL032419
Other URLs:
Lee, T., Wang, O., Tang, W.-Q., and Liu, W.T. (2008). Wind Stress Measurements from the QuikSCAT-SeaWinds Scatterometer Tandem Mission and the Impact on an Ocean Model, Journal of Geophysical Research, 113(C12), C12019, 10.1029/2008JC004855. Journal Article »
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Title: Wind Stress Measurements from the QuikSCAT-SeaWinds Scatterometer Tandem Mission and the Impact on an Ocean Model
Type: Journal Article
Publication: Journal of Geophysical Research
Author(s): Lee, T., Wang, O., Tang, W.-Q., and Liu, W.T.
Year: 2008
Formatted Citation: Lee, T., Wang, O., Tang, W.-Q., and Liu, W.T., 2008: Wind Stress Measurements from the QuikSCAT-SeaWinds Scatterometer Tandem Mission and the Impact on an Ocean Model, Journal of Geophysical Research, 113(C12), C12019, 10.1029/2008JC004855.
Abstract:
Keywords:
Mission: |SeaWinds|
URL: https://doi.org/10.1029/2008JC004855
Other URLs:
Lee,T., Wang, O., Tang, W., and Liu, W.T. (2008). Wind Stress Measurements from the QuikSCAT-SeaWinds Scatterometer Tandem Mission and the Impact on an Ocean Model, Journal of Geophysical Research: Oceans, 113(C12), C12019, 10.1029/2008JCX004855. Journal Article »
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Title: Wind Stress Measurements from the QuikSCAT-SeaWinds Scatterometer Tandem Mission and the Impact on an Ocean Model
Type: Journal Article
Publication: Journal of Geophysical Research: Oceans
Author(s): Lee,T., Wang, O., Tang, W., and Liu, W.T.
Year: 2008
Formatted Citation: Lee,T., Wang, O., Tang, W., and Liu, W.T., 2008: Wind Stress Measurements from the QuikSCAT-SeaWinds Scatterometer Tandem Mission and the Impact on an Ocean Model, Journal of Geophysical Research: Oceans, 113(C12), C12019, 10.1029/2008JCX004855.
Abstract:
Keywords:
Mission:
URL: https://doi.org/10.1029/2008JC004855
Other URLs:
Li, J., Sorooshian, S., Higgins, W., Gao, X., Imam, B., and Hsu, K. (2008). Influence of Spatial Resolution on Diurnal Variability During the North American Monsoon, Journal of Climate, 21(16), 3967-3988, 10.1175/2008JCLI2022.1. Journal Article »
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Title: Influence of Spatial Resolution on Diurnal Variability During the North American Monsoon
Type: Journal Article
Publication: Journal of Climate
Author(s): Li, J., Sorooshian, S., Higgins, W., Gao, X., Imam, B., and Hsu, K.
Year: 2008
Formatted Citation: Li, J., Sorooshian, S., Higgins, W., Gao, X., Imam, B., and Hsu, K., 2008: Influence of Spatial Resolution on Diurnal Variability During the North American Monsoon, Journal of Climate, 21(16), 3967-3988, 10.1175/2008JCLI2022.1.
Abstract: Diurnal variability is an important yet poorly understood aspect of the warm-season precipitation regime over southwestern North America. In an effort to improve its understanding, diurnal variability is investigated numerically using the fifth-generation Pennsylvania State University (PSU)-NCAR Mesoscale Model (MM5). The goal herein is to determine the possible influence of spatial resolution on the diurnal cycle. The model is initialized every 48 h using the operational NCEP Eta Model 212 grid (40 km) model analysis. Model simulations are carried out at horizontal resolutions of both 9 and 3 km. Overall, the model reproduces the basic features of the diurnal cycle of rainfall over the core monsoon region of northwestern Mexico and the southwestern United States. In particular, the model captures the diurnal amplitude and phase, with heavier rainfall at high elevations along the Sierra Madre Occidental in the early-afternoon that shifts to lower elevations along the west slopes in the evening. A comparison to observations (gauge and radar data) shows that the high-resolution (3 km) model generates better rainfall distributions on time scales from monthly to hourly than the coarse-resolution (9 km) model, especially along the west slopes of the Sierra Madre Occidental. The model has difficulty with nighttime rainfall along the slopes, over the Gulf of California, and over Arizona. A comparison of surface wind data from three NCAR Integrated Sounding System (ISS) stations and the Quick Scatterometer (QuikSCAT) to the model reveals a low bias in the strength of the Gulf of California low-level jet, even at high resolution. The model results indicate that outflow from convection over northwestern Mexico can modulate the low-level jet, though the extent to which these relationships occur in nature was not investigated. 2008 American Meteorological Society.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1175/2008JCLI2022.1
Other URLs:
Li, L., Gaiser, P., Alberg, M., Long, D.G., and Twarog, E.M. (2008). WindSat Passive Microwave Polarimetric Signatures of the Greenland Ice Sheet, IEEE Transactions on Geoscience and Remote Sensing, 46(9), 2622-2631, 10.1109/TGRS.2008.917727. Journal Article »
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Title: WindSat Passive Microwave Polarimetric Signatures of the Greenland Ice Sheet
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Li, L., Gaiser, P., Alberg, M., Long, D.G., and Twarog, E.M.
Year: 2008
Formatted Citation: Li, L., Gaiser, P., Alberg, M., Long, D.G., and Twarog, E.M., 2008: WindSat Passive Microwave Polarimetric Signatures of the Greenland Ice Sheet, IEEE Transactions on Geoscience and Remote Sensing, 46(9), 2622-2631, 10.1109/TGRS.2008.917727.
Abstract: WindSat Passive Microwave Polarimetric Signatures of the Greenland Ice Sheet
Keywords: glaciology polarimetry radiometers remote sensing snow wind Antarctic ice sheet Greenland ice sheet Stokes parameters WindSat passive microwave polarimetric signatures dry snow zone empirical observation model sastrugi erosion sas
Mission: |WindSat|
URL: https://doi.org/10.1109/TGRS.2008.917727
Other URLs:
Li, W.H., Fu, R. Juarez, R.I.N., and Fernandes, K. (2008). Observed Change of the Standardized Precipitation Index, its Potential Cause and Implications to Future Climate Change in the Amazon Region, Philosophical Transactions of the Royal Society B - Biological Sciences, 363(1498), 1767-1772, 10.1098/rstb.2007.0022. Journal Article »
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Title: Observed Change of the Standardized Precipitation Index, its Potential Cause and Implications to Future Climate Change in the Amazon Region
Type: Journal Article
Publication: Philosophical Transactions of the Royal Society B - Biological Sciences
Author(s): Li, W.H., Fu, R. Juarez, R.I.N., and Fernandes, K.
Year: 2008
Formatted Citation: Li, W.H., Fu, R. Juarez, R.I.N., and Fernandes, K., 2008: Observed Change of the Standardized Precipitation Index, its Potential Cause and Implications to Future Climate Change in the Amazon Region, Philosophical Transactions of the Royal Society B - Biological Sciences, 363(1498), 1767-1772, 10.1098/rstb.2007.0022.
Abstract: Observations show that the standard precipitation index (SPI) over the southern Amazon region decreased in the period of 19701999 by 0.32 per decade, indicating an increase in dry conditions. Simulations of constant pre-industrial climate with recent climate models indicate a low probability (p=0%) that the trends are due to internal climate variability. When the 23 models are forced with either anthropogenic factors or both anthropogenic and external natural factors, approximately 13% of sampled 30-year SPI trends from the models are found to be within the range of the observed SPI trend at 95% confidence level. This suggests a possibility of anthropogenic and external forcing of climate change in the southern Amazon. On average, the models project no changes in the frequency of occurrence of low SPI values in the future, however, those models which produce more realistic SPI climatology, variability and trend over the period 19701999 show more of a tendency towards more negative values of SPI in the future. The analysis presented here suggests a potential anthropogenic influence on Amazon drying, which warrants future, more in-depth, study.
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URL: https://doi.org/10.1098/rstb.2007.0022
Other URLs:
Li, X. and Lehner, S. (2008). Coastal Wind Analysis Based on Active Radar in Qingdao for Olympic Sailing Event, European Space Agencey Special Publication, ESA SP. Conference Paper »
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Title: Coastal Wind Analysis Based on Active Radar in Qingdao for Olympic Sailing Event
Type: Conference Paper
Publication: European Space Agencey Special Publication, ESA SP
Author(s): Li, X. and Lehner, S.
Year: 2008
Formatted Citation: Li, X. and Lehner, S., 2008: Coastal Wind Analysis Based on Active Radar in Qingdao for Olympic Sailing Event, European Space Agencey Special Publication, ESA SP.
Abstract: Purpose of this research is to investigate the Qingdao coastal wind field properties for the 2008 Olympic sailing event based on the remote sensing data, i.e. Scatterometer and Synthetic Aperture Radar (SAR). Scatterometer data from SeaWinds instrument on QuikSCAT from 1999 to 2007 are collected as the main data source for spatial and temporal wind field analysis near the Qingdao coast. Envisat Advanced Synthetic Aperture Radar (ASAR) images are used, too for this case study for the Qingdao 2007 International Regatta Sailing Competition. Wind speed retrieved from the ASAR image is compared to QuikSCAT data and insitu buoy measurements.
Keywords: QuikSCAT, Seawinds
Mission:
URL: https://www.isprs.org/proceedings/XXXVII/congress/8_pdf/6_WG-VIII-6/02.pdf
Other URLs:
Li, X., Lehner, S., and Brusch, S. (2008). Coastal Wind Field Analysis Based on Spaceborne Active Radar for the Olympic Sailing Competition in Qingdao, China, European Space Agencey Special Publication, ESA SP.
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Title: Coastal Wind Field Analysis Based on Spaceborne Active Radar for the Olympic Sailing Competition in Qingdao, China
Type: Conference Paper
Publication: European Space Agencey Special Publication, ESA SP
Author(s): Li, X., Lehner, S., and Brusch, S.
Year: 2008
Formatted Citation: Li, X., Lehner, S., and Brusch, S., 2008: Coastal Wind Field Analysis Based on Spaceborne Active Radar for the Olympic Sailing Competition in Qingdao, China, European Space Agencey Special Publication, ESA SP.
Abstract: The purpose of this research is to investigate the Qingdao coastal wind field properties as a preparation for the 2008 Olympic sailing event based on spaceborne Scatterometer and Synthetic Aperture Radar (SAR). Scatterometer data from SeaWinds instrument onboard QuikSCAT from 1999 to 2007 are collected as the main data source for a spatial and temporal wind field analysis near the Qingdao coast. Envisat Advanced Synthetic Aperture Radar (ASAR) images are used, too for this case study for the Qingdao 2007 International Regatta Sailing Competition. Wind speed retrieved from the ASAR image is compared to QuikSCAT data and in-situ buoy measurements.
Keywords: QuikSCAT, Seawinds
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URL:
Other URLs:
Lin, J.-L., Han, W., and Lin, X. (2008). Observational Analysis of the Wind-Evaporation-SST Feedback Over the Tropical Pacific Ocean, Atmospheric Science Letters, 9(4), 231-236, 10.1002/asl.195. Journal Article »
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Title: Observational Analysis of the Wind-Evaporation-SST Feedback Over the Tropical Pacific Ocean
Type: Journal Article
Publication: Atmospheric Science Letters
Author(s): Lin, J.-L., Han, W., and Lin, X.
Year: 2008
Formatted Citation: Lin, J.-L., Han, W., and Lin, X., 2008: Observational Analysis of the Wind-Evaporation-SST Feedback Over the Tropical Pacific Ocean, Atmospheric Science Letters, 9(4), 231-236, 10.1002/asl.195.
Abstract: Theoretical studies suggested that the wind-evaporation-sea surface temperature (SST) (WES) feedback plays an important role in maintaining the latitudinal asymmetry of the intertropical convergence zone (ITCZ) in the tropical Pacific Ocean. This study examines the geographical distribution of the strength of WES feedback over the tropical Pacific Ocean using multiple long-term observational datasets. The results show that the WES feedback is very weak over the eastern Pacific warm pool and stratocumulus regions, where the strongest latitudinal asymmetry of the ITCZ exists, suggesting that some other mechanisms are responsible for the asymmetry. To the west of 120W, the WES feedback has larger magnitude but is often statistically insignificant. This is because the effect of the air-sea humidity difference tends to offset the wind effect, which is a factor not considered in the original WES feedback theory.
Keywords: tropical climate; ITCZ; ocean-atmosphere feedback
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URL: https://doi.org/10.1002/asl.195
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Lin, J.L., Mapes, B.E., and Han, W.Q. (2008). What are the Sources of Mechanical Damping in Matsuno-Gill-Type Models?, Journal of Climate, 21(2), 165-179, 10.1175/2007JCLI1546.1. Journal Article »
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Title: What are the Sources of Mechanical Damping in Matsuno-Gill-Type Models?
Type: Journal Article
Publication: Journal of Climate
Author(s): Lin, J.L., Mapes, B.E., and Han, W.Q.
Year: 2008
Formatted Citation: Lin, J.L., Mapes, B.E., and Han, W.Q., 2008: What are the Sources of Mechanical Damping in Matsuno-Gill-Type Models?, Journal of Climate, 21(2), 165-179, 10.1175/2007JCLI1546.1.
Abstract: The MatsunoGill model has been widely used to study the tropical large-scale circulations and atmosphereocean interactions. However, a common critique of this model is that it requires a strong equivalent linear mechanical damping to get realistic wind response and it is unclear what could provide such a strong damping above the boundary layer. This study evaluates the sources and strength of equivalent linear mechanical damping in the Walker circulation by calculating the zonal momentum budget using 15 yr (197993) of daily global reanalysis data. Two different reanalyses [NCEPNCAR and 15-yr ECMWF Re-Analysis (ERA-15)] give qualitatively similar results for all major terms, including the budget residual, whose structure is consistent with its interpretation as eddy momentum flux convergence by convective momentum transport (CMT). The Walker circulation is characterized by two distinct regions: a deep convection region over the Indo-Pacific warm pool and a shallow convection region over the eastern Pacific cold tongue. These two regions are separated by a strong upper-tropospheric ridge and a strong lower-tropospheric trough in the central Pacific. The resultant pressure gradient forces on both sides require strong (approximately 510 days) damping to balance them because Coriolis force near the equator is too small to provide the balance. In the deep convection region, the damping is provided by CMT and advection together in both the upper and lower troposphere. In the shallow convection region, on the other hand, the damping is provided mainly by advection in the upper troposphere and by CMT in the lower troposphere. In other words, the upper-level tropical easterly jet and the low-level trade wind are both braked by CMT. These results support the use of strong damping in the MatsunoGill-type models but suggest that the damping rate is spatially inhomogeneous and the CMT-related damping increases with the strength of convection. Implications for GCMs simulation of tropical mean climate are discussed.
Keywords: CONVECTIVE MOMENTUM TRANSPORT, INDUCED TROPICAL CIRCULATION, OCEAN ATMOSPHERE MODEL, TOGA COARE IOP, CUMULUS CONVECTION, VERTICAL TRANSPORT, EL-NINO, PARAMETERIZATION, CLOUDS, OSCILLATION
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URL: https://doi.org/10.1175/2007JCLI1546.1
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Liu, W.T. and Xie, X. (2008). Ocean-Atmosphere Momentum Coupling in the Kuroshio Extension Observed from Space, Journal of Oceanography, 64(4), 631-637, 10.1007/s10872-008-0053-x. Journal Article »
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Title: Ocean-Atmosphere Momentum Coupling in the Kuroshio Extension Observed from Space
Type: Journal Article
Publication: Journal of Oceanography
Author(s): Liu, W.T. and Xie, X.
Year: 2008
Formatted Citation: Liu, W.T. and Xie, X., 2008: Ocean-Atmosphere Momentum Coupling in the Kuroshio Extension Observed from Space, Journal of Oceanography, 64(4), 631-637, 10.1007/s10872-008-0053-x.
Abstract: Using a combination of Quick Scatterometer (QuikSCAT), Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E), and Lagrangian drifter measurements, we demonstrate that wind data alone are not sufficient to derive ocean surface stress (momentum flux) over mid-latitude ocean fronts, specifically the Kuroshio Extension. There was no continuous and large-scale stress measurement over ocean until the launch of the scatterometers. Stress had been derived from winds through a drag coefficient, and our concept of stress distribution may be largely influenced by our knowledge of wind distribution. QuikSCAT reveals that the variability of stress could be very different from wind. The spatial coherence between the magnitude of stress and sea surface temperature (SST), between the divergence of surface stress and the downwind SST gradient, and between the vorticity of stress and crosswind SST gradient, are the inherent characteristics of stress (turbulence production by buoyancy) that would exist even under a uniform wind field. The coherence between stress vorticity and SST gradient is masked by the rotation of ocean currents over the Kuroshio meanders. Surface stress rotates in the opposite direction to surface currents because stress is the vector difference between wind and current. The results are in agreement with a previous study of the Agulhas Extension and confirm the unique stress measuring capability of the scatterometer.
Keywords:
Mission: |SeaWinds|
URL: https://doi.org/10.1007/s10872-008-0053-x
Other URLs:
Liu, W.T., Tang, W., and Xie, X. (2008). Wind Power Distribution Over the Ocean, Geophysical Research Letters, 35(13), 10.1029/2008GL034172. Journal Article »
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Title: Wind Power Distribution Over the Ocean
Type: Journal Article
Publication: Geophysical Research Letters
Author(s): Liu, W.T., Tang, W., and Xie, X.
Year: 2008
Formatted Citation: Liu, W.T., Tang, W., and Xie, X., 2008: Wind Power Distribution Over the Ocean, Geophysical Research Letters, 35(13), 10.1029/2008GL034172.
Abstract: Probability distribution and power density of wind speed over global oceans are computed from eight years of QuikSCAT measurements. They describe the variation and higher moments of wind speed that are critical in relating the non-linear effects of wind on electric power generation capability, shipping hazard, and air-sea exchanges in heat, water, and greenhouse gases. The power density distribution confirms our general knowledge of atmospheric circulation related to mid-latitude storm tracks, trade winds, and monsoons. It also reveals regions of high wind power associated with flow distortion by land, wind channeled by land topography, and buoyancy effect on turbulent stress driven by ocean fronts.
Keywords: wind power density, remote sensing, air-sea interaction
Mission:
URL: https://doi.org/10.1029/2008GL034172
Other URLs:
Liu, W.T., Tang, W., and Xie, X. (2008). High Wind and Power Density Over Global Oceans, International Geoscience and Remote Sensing Symposium (IGARSS), 10.1109/IGARSS.2008.4779082. Conference Paper »
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Title: High Wind and Power Density Over Global Oceans
Type: Conference Paper
Publication: International Geoscience and Remote Sensing Symposium (IGARSS)
Author(s): Liu, W.T., Tang, W., and Xie, X.
Year: 2008
Formatted Citation: Liu, W.T., Tang, W., and Xie, X., 2008: High Wind and Power Density Over Global Oceans, International Geoscience and Remote Sensing Symposium (IGARSS), 10.1109/IGARSS.2008.4779082.
Abstract: Spacebased scatterometer measures ocean surface roughness, which is in equilibrium with surface stress (momentum flux). Under general conditions, the variation of stress is reflected in the variation of winds. Eight years of QuikSCAT data are used to give a good representation of the probability distribution and power density of wind speed over global oceans and to provide useful applications. For hurricane-scale winds (35 m/s), present scatterometer measurements are not sensitive to increase in winds. Although strong efforts have been made to adjust the model functions for retrieving winds under moderate wind to the strong wind conditions and to improve the sensor design to retrieve strong winds, such effort is likely to be limited by the natural process of turbulent transport. Surface stress does not increase with wind in hurricane-scale winds due to flow separation.
Keywords: QuikSCAT
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URL: https://doi.org/10.1109/IGARSS.2008.4779082
Other URLs:
Liu, W.T., Tang, W., Xie, X., Navalgund, R., and Xu, K. (2008). Power Density of Ocean Surface Wind-Stress from International Scatterometer Tandem Missions, International Journal of Remote Sensing, 29(21), 6109-6116, 10.1080/01431160802175439. Journal Article »
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Title: Power Density of Ocean Surface Wind-Stress from International Scatterometer Tandem Missions
Type: Journal Article
Publication: International Journal of Remote Sensing
Author(s): Liu, W.T., Tang, W., Xie, X., Navalgund, R., and Xu, K.
Year: 2008
Formatted Citation: Liu, W.T., Tang, W., Xie, X., Navalgund, R., and Xu, K., 2008: Power Density of Ocean Surface Wind-Stress from International Scatterometer Tandem Missions, International Journal of Remote Sensing, 29(21), 6109-6116, 10.1080/01431160802175439.
Abstract:
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URL: https://doi.org/10.1080/01431160802175439
Other URLs:
Long, D.G. (2008). Microwave Sensors - Active and Passive, Manual of Remote Sensing, Volume 1: Earth Observing Platforms and Sensors, 119.
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Title: Microwave Sensors - Active and Passive
Type: Chapter
Publication: Manual of Remote Sensing, Volume 1: Earth Observing Platforms and Sensors
Author(s): Long, D.G.
Year: 2008
Formatted Citation: Long, D.G., 2008: Microwave Sensors - Active and Passive, Manual of Remote Sensing, Volume 1: Earth Observing Platforms and Sensors, 119.
Abstract:
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URL:
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Longdill, P.C., Healy, T.R., and Black, K.P. (2008). Transient Wind-Driven Coastal Upwelling on a Shelf with Varying Width and Orientation, New Zealand Journal of Marine and Freshwater Research, 42(2), 181-196, 10.1080/00288330809509947. Journal Article »
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Title: Transient Wind-Driven Coastal Upwelling on a Shelf with Varying Width and Orientation
Type: Journal Article
Publication: New Zealand Journal of Marine and Freshwater Research
Author(s): Longdill, P.C., Healy, T.R., and Black, K.P.
Year: 2008
Formatted Citation: Longdill, P.C., Healy, T.R., and Black, K.P., 2008: Transient Wind-Driven Coastal Upwelling on a Shelf with Varying Width and Orientation, New Zealand Journal of Marine and Freshwater Research, 42(2), 181-196, 10.1080/00288330809509947.
Abstract: Cross-correlations between along-shelf wind stress and both along- and cross-shelf currents within the central Bay of Plenty, New Zealand show the circulation during spring-summer to be highly responsive to wind events. Current meter records indicate that upwelling-favourable wind stresses generate upwelling dynamics in both mean and fluctuating senses. Both thermistor moorings and satellite inferred temperature data record the outcropping of this cool water following upwelling-favourable wind stresses. The upwelling circulation provides an efficient mechanism for the periodic delivery of cool (c. 80 mu g litre super(-1)) water to the coastal zone during spring. Historical wind forcing data suggest that the wind-forced dynamics described were responsible for a major toxic algal bloom within the Bay of Plenty during 1992-93.
Keywords: QuikSCAT
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URL: https://doi.org/10.1080/00288330809509947
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Lopez-Calderon, J., Martinez, A., Gonzalez-Silvera, A., Santamaria-del-Angel, E., and Millan-Nuñez, R. (2008). Mesoscale Eddies and Wind Variability in the Northern Gulf of California, Journal of Geophysical Research-Oceans, 113(C10), C10001, 10.1029/2007JC004630. Journal Article »
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Title: Mesoscale Eddies and Wind Variability in the Northern Gulf of California
Type: Journal Article
Publication: Journal of Geophysical Research-Oceans
Author(s): Lopez-Calderon, J., Martinez, A., Gonzalez-Silvera, A., Santamaria-del-Angel, E., and Millan-Nuñez, R.
Year: 2008
Formatted Citation: Lopez-Calderon, J., Martinez, A., Gonzalez-Silvera, A., Santamaria-del-Angel, E., and Millan-Nuñez, R., 2008: Mesoscale Eddies and Wind Variability in the Northern Gulf of California, Journal of Geophysical Research-Oceans, 113(C10), C10001, 10.1029/2007JC004630.
Abstract: Surface mesoscale structures and wind variability in the northern Gulf of California (NGC) were analyzed using data from SeaWiFS (1 km) and QuikSCAT (1 day). The months of February and March were selected as representative of winter and the months of August and September were selected as representative of summer. Chlorophyll-a (Chla) and wind time series were constructed using 16 points to analyze temporal variability and wind magnitude-Chla temporal and spatial linear correlation. Wind components along and across the NGC were found to play an equally significant role regarding wind variability, contrary to what is currently recognized. Wind magnitude tended to be stronger in winter and had less wind direction variability than in summer. A bimodal wind pattern was registered for each season, each wind direction explaining less than 30% of total variability. The zone with minimum variability in wind direction and maximum variability in wind magnitude was located northwest of the NGC, the same area where wind magnitude-Chla correlation was significant (p < 0.05). Winter and summer surface circulation patterns are more complex than currently documented. Summer is characterized by numerous plumes and eddies (especially anticyclonic), some traveling from coast to coast, enhancing the exchange of suspended material. Winter varied greatly interannualy, also showing many plumes and eddies (especially cyclonic), but was very heterogeneous, opposite to summer. Significant summer correlation was mostly positive, whereas in winter the significant correlation was equally positive and negative, maybe as a consequence of higher nutrient availability during this season.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1029/2007JC004630
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Luis, A.J. and Ravindra, R. (2008). QuikSCAT-Based Momentum Flux Analysis Over the Southern Ocean, Indian Journal of Marine Sciences, 37(1), 47-54. Journal Article »
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Title: QuikSCAT-Based Momentum Flux Analysis Over the Southern Ocean
Type: Journal Article
Publication: Indian Journal of Marine Sciences
Author(s): Luis, A.J. and Ravindra, R.
Year: 2008
Formatted Citation: Luis, A.J. and Ravindra, R., 2008: QuikSCAT-Based Momentum Flux Analysis Over the Southern Ocean, Indian Journal of Marine Sciences, 37(1), 47-54.
Abstract: Using QuikSCAT vector winds, the seasonal and interannual variability of momentum flux were studied to explore the underlining dynamics for its modulation over the Southern Ocean (SO) during August 1999 to July 2003. The wind speed validation of ship and QuikSCAT measurements in the western Indian sector of the SO showed a bias and root mean square error of 0.3 and 1.6 m/s, respectively. On seasonal time scales, the spatial wind stress patterns reveal a basin-wide variability and the boreal summer monsoon significantly influencing it in the Indian Ocean (10) sector. The temporal march of the momentum flux for different ocean sectors exhibit a seasonal cycle with a maximum range between 0.13 and 0.18 N/m(2) during August-September and a minimum range between 0.07 and 0.11 N/m(2) during December - January, with a temporal shift of 1 month between the sectors. The atmospheric pressure gradient between tropics and high latitudes enhances the momentum flux in the 10 sector during austral winter. On interannual time scales the momentum flux maps indicate a marked regional variability which is highest in 10 sector and an evolution of cyclonic circulation south of 50 degrees S during austral winter. Based on earlier studies and after a detailed examination of SST and wind stress curl fields, it is argued that orientation of the SST gradient relative to direction of wind stress drive an atmospheric response through wind stress curl and divergence modulations, which in turn dictates the intensity of momentum flux on seasonal time scales.
Keywords: QuikSCAT
Mission:
URL: https://www.researchgate.net/publication/228781892_QuikSCAT-based_momentum_flux_analysis_over_the_Southern_Ocean
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Maloney, E.D., Chelton, D.B., and Esbensen, S.K. (2008). Subseasonal SST Variability in the Tropical Eastern North Pacific During Boreal Summer, Journal of Climate, 21(17), 4149-4167, 10.1175/2007JCLI1856.1. Journal Article »
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Title: Subseasonal SST Variability in the Tropical Eastern North Pacific During Boreal Summer
Type: Journal Article
Publication: Journal of Climate
Author(s): Maloney, E.D., Chelton, D.B., and Esbensen, S.K.
Year: 2008
Formatted Citation: Maloney, E.D., Chelton, D.B., and Esbensen, S.K., 2008: Subseasonal SST Variability in the Tropical Eastern North Pacific During Boreal Summer, Journal of Climate, 21(17), 4149-4167, 10.1175/2007JCLI1856.1.
Abstract: Boreal summer intraseasonal (30-90-day time scale) sea surface temperature (SST) variability in the east Pacific warm pool is examined using Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) sea surface temperatures during 1998-2005. Intraseasonal SST variance maximizes at two locations in the warm pool: in the vicinity of 9°N, 92°W near the Costa Rica Dome and near the northern edge of the warm pool in the vicinity of 19°N, 108°W. Both locations exhibit a significant spectral peak at 50-60-day periods, time scales characteristic of the Madden-Julian oscillation (MJO). Complex empirical orthogonal function (CEOF) and spectra coherence analyses are used to show that boreal summer intraseasonal SST anomalies are coherent with precipitation anomalies across the east Pacific warm pool. Spatial variations of phase are modest across the warm pool, although evidence exists for the northward progression of intraseasonal SST and precipitation anomalies. Intraseasonal SSTs at the north edge of the warm pool lag those in the vicinity of the Costa Rica Dome by about 1 week. The MJO explains 30%-40% of the variance of intraseasonal SST anomalies in the east Pacific warm pool during boreal summer. Peak-to-peak SST variations of 0.8°-1.0°C occur during MJO events. SST is approximately in quadrature with MJO precipitation, with suppressed (enhanced) MJO precipitation anomalies leading positive (negative) SST anomalies by 7-10 days. Consistent with the CEOF and coherence analyses, MJO-related SST and precipitation anomalies near the Costa Rica Dome lead those at the northern edge of the warm pool by about 1 week.
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Mission:
URL: https://doi.org/10.1175/2007JCLI1856.1
Other URLs:
Mapes, B.E., Milliff, R., and Morzel, J. (2008). Composite Life Cycle of Maritime Tropical Mesoscale Convective Systems, Journal of Atmospheric Sciences, 66(1), 199-208, 10.1175/2008JAS2746.1. Journal Article »
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Title: Composite Life Cycle of Maritime Tropical Mesoscale Convective Systems
Type: Journal Article
Publication: Journal of Atmospheric Sciences
Author(s): Mapes, B.E., Milliff, R., and Morzel, J.
Year: 2008
Formatted Citation: Mapes, B.E., Milliff, R., and Morzel, J., 2008: Composite Life Cycle of Maritime Tropical Mesoscale Convective Systems, Journal of Atmospheric Sciences, 66(1), 199-208, 10.1175/2008JAS2746.1.
Abstract: This study examines scatterometer-observed surface wind divergence and vorticity, along with precipitable water (PW), across the life cycle of tropical maritime mesoscale convective systems (MCSs) as resolved in 0.5 degree data. Very simple composites were constructed around first appearances of cold (< 210K) cloud tops in infrared (IR) data at 3 hourly resolution. Many thousands of such events from the tropical Indo-Pacific in 2000 were used. Composites of sub-populations were also constructed, by subdividing the dataset according to IR event size and duration, and prevailing values of PW and vorticity at 5° scale. The composite MCS life cycle here spans about a day and covers a few hundred km, with a remarkable sameness across sub-populations. Surface wind convergence and PW buildup lead cold cloud appearance by many hours. Afterward there are many hours of divergence indicative of downdrafts. Contrary to motivating hypotheses, the strength of this divergence relative to convergence is scarcely different in humid and dry sub-population composites. Normalized time series of composite vorticity show an evolution that seems consistent with vortex stretching by this convergence-divergence cycle, with peak vorticity near the end of the period of convergence (3h prior to cold cloud appearance). In rotating conditions, the common 1 day MCS life cycle is superposed on large-scale mean vorticity and convergence, approximately in proportion, that appear to be well scale separated (covering the whole of the 48 hour and 5?10° averages), and are as strong or stronger than the MCS signature.
Keywords: QSCAT, convection, composite
Mission: |SeaWinds|
URL: https://doi.org/10.1175/2008JAS2746.1
Other URLs:
McBeth-Ford, K. (2008). Uncertainty of Scatterometer-Derived Vorticity, M.S. Thesis, 24. Thesis »
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Title: Uncertainty of Scatterometer-Derived Vorticity
Type: Thesis
Publication: M.S. Thesis
Author(s): McBeth-Ford, K.
Year: 2008
Formatted Citation: McBeth-Ford, K., 2008: Uncertainty of Scatterometer-Derived Vorticity, M.S. Thesis, 24.
Abstract:
Keywords: uncertainy, error, QSCAT, scatterometry, scatterometer, vorticity
Mission: |SeaWinds|
URL: https://diginole.lib.fsu.edu/islandora/object/fsu:182550/datastream/PDF/view
Other URLs:
McPhaden, M.J., Cronin, M.F., and McClurg, D.C. (2008). Meridional Structure of the Seasonally Varying Mixed Layer Temperature Balance in the Eastern Tropical Pacific, Journal of Climate, 21(13), 3240-3260, 10.1175/2007JCLI2115.1. Journal Article »
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Title: Meridional Structure of the Seasonally Varying Mixed Layer Temperature Balance in the Eastern Tropical Pacific
Type: Journal Article
Publication: Journal of Climate
Author(s): McPhaden, M.J., Cronin, M.F., and McClurg, D.C.
Year: 2008
Formatted Citation: McPhaden, M.J., Cronin, M.F., and McClurg, D.C., 2008: Meridional Structure of the Seasonally Varying Mixed Layer Temperature Balance in the Eastern Tropical Pacific, Journal of Climate, 21(13), 3240-3260, 10.1175/2007JCLI2115.1.
Abstract: The eastern tropical Pacific Ocean is important climatically because of its influence on the El Nino-Southern Oscillation (ENSO) cycle and the American monsoon. Accurate prediction of these phenomena requires a better understanding of the background climatological conditions on which seasonal-to-interannual time-scale anomalies develop in the region. This study addresses the processes responsible for the seasonal cycle of sea surface temperature (SST) in the eastern tropical Pacific using 3 yr (April 2000-March 2003) of moored buoy and satellite data between 8 degree S and 12 degree N along 95 degree W. Results indicate that at all latitudes, surface heat fluxes are important in the mixed layer temperature balance. At 8 degree S, in a region of relatively deep mean thermocline and mixed layer, local storage of heat crossing the air-sea interface accounts for much of the seasonal cycle in SST. In the equatorial cold tongue and the intertropical convergence zone, where mean upwelling leads to relatively thin mixed layers, vertical turbulent mixing with the upper thermocline is a major contributor to SST change. Lateral temperature advection by seasonally varying large-scale currents is most significant near the equator but is generally of secondary importance. There is a hemispheric asymmetry in seasonal SST variations, with larger amplitudes in the Southern Hemisphere than in the Northern Hemisphere. This asymmetry is mainly due to forcing from the southerly component of the trade winds, which shifts the axis of equatorial upwelling south of the equator while creating an oceanic convergence zone to the north that limits the northward spread of cold upwelled water. In general, results support the Mitchell and Wallace hypothesis about the importance of southerly winds and ocean-atmosphere feedbacks in establishing seasonally varying climatological conditions in the eastern tropical Pacific.
Keywords: QuikSCAT
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URL: https://doi.org/10.1175/2007JCLI2115.1
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Milliff, R.F. and Stamus, P.A. (2008). QuikSCAT Impacts on Coastal Forecasts and Warnings: Operational Utility of Satellite Ocean Surface Vector Wind Data, Weather and Forecasting, 23(5), 878-890, 10.1175/2008WAF2007081.1. Journal Article »
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Title: QuikSCAT Impacts on Coastal Forecasts and Warnings: Operational Utility of Satellite Ocean Surface Vector Wind Data
Type: Journal Article
Publication: Weather and Forecasting
Author(s): Milliff, R.F. and Stamus, P.A.
Year: 2008
Formatted Citation: Milliff, R.F. and Stamus, P.A., 2008: QuikSCAT Impacts on Coastal Forecasts and Warnings: Operational Utility of Satellite Ocean Surface Vector Wind Data, Weather and Forecasting, 23(5), 878-890, 10.1175/2008WAF2007081.1.
Abstract: This study reports on the operational utility of ocean surface vector wind (SVW) data from QuikSCAT observations in National Ocean and Atmosphere Administration (NOAA), National Weather Service (NWS) Weather Forecast Offices (WFOs) covering the coastal United States, including island states and territories. Thirty-three US coastal WFOs were surveyed, and sixteen WFO site visits were conducted, from late summer 2005 through the 2005?2006 winter season, in order to quantify the impact of QuikSCAT SVW data on forecasts and warnings, with a particular focus on operations affecting marine users. Details of the survey design and site visit strategies are described. Survey results are quantified and site visit impressions are discussed. Key findings include: a) QuikSCAT data supplement primary datasets and numerical weather prediction fields, in the manual production of local public (weather) and marine forecasts and warnings, b) operational utility of satellite SVW data would be enhanced by SVW retrievals of finer temporal resolution, closer to the coasts, and c) rain flags in the SVW data have little impact on utility for WFO operations.
Keywords:
Mission: |SeaWinds|
URL: https://doi.org/10.1175/2008WAF2007081.1
Other URLs:
Minobe, S., Kuwano-Yoshida, A., Komori, N., Xie, S.-P., and Small, R.J. (2008). Influence of the Gulf Stream on the Troposphere, Nature, 452, 206-209, 10.1038/nature06690. Journal Article »
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Title: Influence of the Gulf Stream on the Troposphere
Type: Journal Article
Publication: Nature
Author(s): Minobe, S., Kuwano-Yoshida, A., Komori, N., Xie, S.-P., and Small, R.J.
Year: 2008
Formatted Citation: Minobe, S., Kuwano-Yoshida, A., Komori, N., Xie, S.-P., and Small, R.J., 2008: Influence of the Gulf Stream on the Troposphere, Nature, 452, 206-209, 10.1038/nature06690.
Abstract: The Gulf Stream transports large amounts of heat from the tropics to middle and high latitudes, and thereby affects weather phenomena such as cyclogenesis1, 2 and low cloud formation3. But its climatic influence, on monthly and longer timescales, remains poorly understood. In particular, it is unclear how the warm current affects the free atmosphere above the marine atmospheric boundary layer. Here we consider the Gulf Stream`s influence on the troposphere, using a combination of operational weather analyses, satellite observations and an atmospheric general circulation model4. Our results reveal that the Gulf Stream affects the entire troposphere. In the marine boundary layer, atmospheric pressure adjustments to sharp sea surface temperature gradients lead to surface wind convergence, which anchors a narrow band of precipitation along the Gulf Stream. In this rain band, upward motion and cloud formation extend into the upper troposphere, as corroborated by the frequent occurrence of very low cloud-top temperatures. These mechanisms provide a pathway by which the Gulf Stream can affect the atmosphere locally, and possibly also in remote regions by forcing planetary waves5, 6. The identification of this pathway may have implications for our understanding of the processes involved in climate change, because the Gulf Stream is the upper limb of the Atlantic meridional overturning circulation, which has varied in strength in the past7 and is predicted to weaken in response to human-induced global warming in the future8.
Keywords:
Mission:
URL: https://doi.org/10.1038/nature06690
Other URLs:
Mitnik, L.M. (2008). Advanced Land Observing Satellite Palsar Observations of the Oceanic Dynamic Phenomena in the Coastal Zone, International Geoscience and Remote Sensing Symposium (IGARSS), II-351-II-354, 10.1109/IGARSS.2008.4779000. Conference Paper »
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Title: Advanced Land Observing Satellite Palsar Observations of the Oceanic Dynamic Phenomena in the Coastal Zone
Type: Conference Paper
Publication: International Geoscience and Remote Sensing Symposium (IGARSS)
Author(s): Mitnik, L.M.
Year: 2008
Formatted Citation: Mitnik, L.M., 2008: Advanced Land Observing Satellite Palsar Observations of the Oceanic Dynamic Phenomena in the Coastal Zone, International Geoscience and Remote Sensing Symposium (IGARSS), II-351-II-354, 10.1109/IGARSS.2008.4779000.
Abstract: Satellite SAR is a valuable tool providing all-weather data on the mesoscale and fine-scale features of phenomena and processes both in the open ocean and in the coastal zones. Analysis of C-band ERS-1/2 SAR and Envisat ASAR ocean images allowed selecting the areas for detailed study with L-band ALOS PALSAR data. The Kuroshio-Oyashio confluence zone, Soya Warm Current, Okhotsk Sea shelf, the Kuril Straits, Pacific Ocean east of Kamchatka, Peter the Great and Toyama Bays in the Japan Sea, Taiwan Strait and several areas in the East-and South-China Seas are among them. A rather remarkable assemblage of oceanic dynamic phenomena such as currents, coastal fronts, eddies, internal waves, river plumes, etc. were evident in the PALSAR images. The detailed study was carried out for the images with well-defined imprints of oceanic dynamic, for which ancillary data consisting of Terra and Aqua MODIS and NOAA AVHRR images, QuikSCAT-derived wind fields, ocean color, surface analysis maps, bathymetry maps, etc. were available. 2008 IEEE.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1109/IGARSS.2008.4779000
Other URLs:
Mitnik, L.M. and Mitnik, M.L. (2008). Microwave Characteristics of Organized Mesoscale Convection Over the Ocean, 2008 Microwave Radiometry and Remote Sensing of the Environment - 10th Specialist Meeting, MICRORAD, March 11, 2008 - March 14, 1-4, 10.1109/MICRAD.2008.4579456. Conference Paper »
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Title: Microwave Characteristics of Organized Mesoscale Convection Over the Ocean
Type: Conference Paper
Publication: 2008 Microwave Radiometry and Remote Sensing of the Environment - 10th Specialist Meeting, MICRORAD, March 11, 2008 - March 14
Author(s): Mitnik, L.M. and Mitnik, M.L.
Year: 2008
Formatted Citation: Mitnik, L.M. and Mitnik, M.L., 2008: Microwave Characteristics of Organized Mesoscale Convection Over the Ocean, 2008 Microwave Radiometry and Remote Sensing of the Environment - 10th Specialist Meeting, MICRORAD, March 11, 2008 - March 14, 1-4, 10.1109/MICRAD.2008.4579456.
Abstract: Fields of AMSR-E brightness temperatures TBs of organized mesoscale convection over the ocean are analyzed together with MODIS visible images, Envisat ASAR images and QuikSCAT-derived wind fields. Cloud liquid water content Q and water vapor content V are estimated for the areas with mesoscale convection and for individual large cells. Models describing distribution of wind speed and direction, water vapor and cloud water in convective rolls, open and closed cells were suggested to simulate TBs and imprints of convective cells on SAR images. Computed passive microwave and radar pattern are in a good agreement with satellite measurements and can be used for retrieval algorithm advancement, estimation of effects of spatial smoothing, etc. 2008 IEEE.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1109/MICRAD.2008.4579456
Other URLs:
Mitnik, L.M., Mitnik, M.L., and Gurvich, I.A. (2008). Severe Weather Study in Middle and High Oceanic Latitudes Using Aqua AMSR-E, International Geoscience and Remote Sensing Symposium (IGARSS), V-330 - V-333, 10.1109/IGARSS.2008.4780095. Conference Paper »
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Title: Severe Weather Study in Middle and High Oceanic Latitudes Using Aqua AMSR-E
Type: Conference Paper
Publication: International Geoscience and Remote Sensing Symposium (IGARSS)
Author(s): Mitnik, L.M., Mitnik, M.L., and Gurvich, I.A.
Year: 2008
Formatted Citation: Mitnik, L.M., Mitnik, M.L., and Gurvich, I.A., 2008: Severe Weather Study in Middle and High Oceanic Latitudes Using Aqua AMSR-E, International Geoscience and Remote Sensing Symposium (IGARSS), V-330 - V-333, 10.1109/IGARSS.2008.4780095.
Abstract: A variety of severe weather events impact the coastal zones, ships and offshore industry year round, however, only part of mesoscale events was marked on the weather maps. The Aqua AMSR-E higher spatial resolution and availability of simultaneous visible and infrared MODIS data have produced measurements of the marine weather systems that are not available from any other satellite. Efficiency of AMSR-E measurements is shown by detailed consideration of severe weather events over the Northwest Pacific Ocean. They include heavy rains and snowfalls caused by passing of cyclones from the Yellow Sea to the Japan Sea, strong winds in the areas of polar lows and cold air outbreaks over the Asian Marginal Seas and in the Northwest Pacific. QuikSCAT-derived wind fields and Aqua MODIS images and surface analysis maps are used as supplementary information. The satellite information provided by AMSR-E and other sensors is a good tool for monitoring the events and issuing a reasonable nowcast. 2008 IEEE.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1109/IGARSS.2008.4780095
Other URLs:
Mladenova, I., Lakshmi, V., Jackson, T., and Walker, J. (2008). Ku-Band Sensitivity to Soil Moisture. An Evaluation Study for Monitoring Temporal Soil Moisture Change Detection Over the NAFE06 Study Area, International Geoscience and Remote Sensing Symposium (IGARSS), II-805-II-808, 10.1109/IGARSS.2008.4779116. Conference Paper »
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Title: Ku-Band Sensitivity to Soil Moisture. An Evaluation Study for Monitoring Temporal Soil Moisture Change Detection Over the NAFE06 Study Area
Type: Conference Paper
Publication: International Geoscience and Remote Sensing Symposium (IGARSS)
Author(s): Mladenova, I., Lakshmi, V., Jackson, T., and Walker, J.
Year: 2008
Formatted Citation: Mladenova, I., Lakshmi, V., Jackson, T., and Walker, J., 2008: Ku-Band Sensitivity to Soil Moisture. An Evaluation Study for Monitoring Temporal Soil Moisture Change Detection Over the NAFE06 Study Area, International Geoscience and Remote Sensing Symposium (IGARSS), II-805-II-808, 10.1109/IGARSS.2008.4779116.
Abstract: The combination of radiometer and radar observations is a very promising technique for spatial disaggregation of soil moisture. The enhanced QuikSCAT sigma-0 product (2.225 km) offers a possibility for overcoming the temporal and spatial limitations of the available radar systems. The current study investigates QuikSCAT sensitivity to soil moisture and its capability to accurately monitor and capture change in soil moisture. The research was undertaken for the National Airborne Field Experiment area located in the Murrumbidgee catchment, SE Australia. Validation of the temporal change detection analysis was undertaken using an airborne soil moisture product derived from the Polarimetrie Lband Multibeam Radiometer (PLMR). The main propose of the PLMR use was to assess accuracy in terms of spatial patterns distribution. The results reveal expected temporal variability and adequate response of the active sensor to change in meteorological conditions. The presence of irrigation and standing water (rice fields) in the region challenges the spatial agreement throughout the study area. 2008 IEEE.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1109/IGARSS.2008.4779116
Other URLs:
Montroty, R., Rabier, F., Westrelin, S., Faure, G., and Viltard, N. (2008). Impact of Wind Bogus and Cloud- and Rain-Affected SSM/I Data on Tropical Cyclone Analyses and Forecasts, Quarterly Journal of the Royal Meteorological Society, 134(636), 1673-1699, 10.1002/qj.308. Journal Article »
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Title: Impact of Wind Bogus and Cloud- and Rain-Affected SSM/I Data on Tropical Cyclone Analyses and Forecasts
Type: Journal Article
Publication: Quarterly Journal of the Royal Meteorological Society
Author(s): Montroty, R., Rabier, F., Westrelin, S., Faure, G., and Viltard, N.
Year: 2008
Formatted Citation: Montroty, R., Rabier, F., Westrelin, S., Faure, G., and Viltard, N., 2008: Impact of Wind Bogus and Cloud- and Rain-Affected SSM/I Data on Tropical Cyclone Analyses and Forecasts, Quarterly Journal of the Royal Meteorological Society, 134(636), 1673-1699, 10.1002/qj.308.
Abstract: In the context of its responsibilities as a Regional Specialised Meteorological Centre (RSMC) for the Southwest Indian Ocean, Meteo-France operates a tropical cyclone warning centre which sends advisories to all the concerned countries in the area. In assistance to the forecasters and as part of the operational suite for the short-range forecasts, a limited-area model (ALADIN Reunion) is run with four daily analyses. Assimilated observations include conventional observations - radiosondes, buoys, surface stations, aircraft reports, upper-wind reports - and satellite observations. The latter include QuikSCAT surface winds, atmospheric motion vectors from geostationary satellites, and radiances from polar-orbiting satellites. Assimilation of satellite radiance data is done in clear-sky conditions, and thus cannot be used in the vicinity of tropical cyclones. Two new sources of pseudo-observations are investigated that can bring new information content to those regions: Total Column Water Vapour (TCWV) pseudo-observations deduced from cloudy/rainy SSM/I data, as well as a 3D wind bogus. The TCWV algorithm is obtained from SSM/I brightness temperatures through a simple statistical regression from the 1D-Var analyses of the European Centre for Medium-Range Weather Forecasts, which are derived from complex inversion methods using moist physics and radiative transfer models. The 3D wind bogus is derived from structural information contained in the tropical cyclone advisories issued by the RSMC and contains a low-level vortex composed of two concentric rings of eight winds each, at each of the surface, 850, 700 and 500 hPa levels. Forecast scores and fit of the model to the observations are improved and indicate a positive impact of those new datasets. Structural validation is investigated through the comparison of model and TMI `observed` rain rates: it is found that assimilating and cycling cloudy/ rainy TCWV helps achieve more realistic cyclonic features. Copyright 2008 Royal Meteorological Society.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1002/qj.308
Other URLs:
Moore, G.W.K., Pickart, R.S., and Renfrew, I.A. (2008). Buoy Observations from the Windiest Location in the World Ocean, Cape Farewell, Greenland, Geophysical Research Letters, 35(18), L18802, 10.1029/2008GL034845. Journal Article »
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Title: Buoy Observations from the Windiest Location in the World Ocean, Cape Farewell, Greenland
Type: Journal Article
Publication: Geophysical Research Letters
Author(s): Moore, G.W.K., Pickart, R.S., and Renfrew, I.A.
Year: 2008
Formatted Citation: Moore, G.W.K., Pickart, R.S., and Renfrew, I.A., 2008: Buoy Observations from the Windiest Location in the World Ocean, Cape Farewell, Greenland, Geophysical Research Letters, 35(18), L18802, 10.1029/2008GL034845.
Abstract: Cape Farewell, Greenland`s southernmost point, is a region of significant interest in the meteorological and oceanographic communities in that atmospheric flow distortion associated with the high topography of the region leads to a number of high wind speed jets. The resulting large air-sea fluxes of momentum and buoyancy have a dramatic impact on the region`s weather and ocean circulation. Here the first in-situ observations of the surface meteorology in the region, collected from an instrumented buoy, are presented. The buoy wind speeds are compared to 10 m wind speeds from the QuikSCAT satellite and the North American Regional Reanalysis (NARR). We show that the QuikSCAT retrievals have a high wind speed bias that is absent from the NARR winds. The spatial characteristics of the high wind speed events are also presented. Copyright 2008 by the American Geophysical Union.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1029/2008GL034845
Other URLs:
Morrow, R., Valladeau, G., and Sallee, J.B. (2008). Observed Subsurface Signature of Southern Ocean Sea Level Rise, Progress in Oceanography, 77(4), 351-366, 10.1016/j.pocean.2007.03.002. Journal Article »
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Title: Observed Subsurface Signature of Southern Ocean Sea Level Rise
Type: Journal Article
Publication: Progress in Oceanography
Author(s): Morrow, R., Valladeau, G., and Sallee, J.B.
Year: 2008
Formatted Citation: Morrow, R., Valladeau, G., and Sallee, J.B., 2008: Observed Subsurface Signature of Southern Ocean Sea Level Rise, Progress in Oceanography, 77(4), 351-366, 10.1016/j.pocean.2007.03.002.
Abstract: Satellite altimetry data show a strong increase in sea level in various parts of the Southern Ocean over the 1990s. In this paper, we examine the causes of the observed sea level rise in the region south of Australia, using 13 years of repeat hydrographic data from the WOCE SR3 sections, and the SURVOSTRAL XBT and surface salinity data. The hydrographic data show a poleward shift in the position of the Subtropical and the Subantarctic Fronts over the period. In the Antarctic Zone, the Antarctic Surface Water has become warmer and fresher, and the Winter Water tongue has become warmer, fresher, thinner and shallower. Increased freshening south of the Polar Front is linked to increased precipitation over the 1990s. Temperature changes over the upper 500m account for only part of the altimetric sea level rise. The CTD sections show that the deeper layers are also warmer and slightly saltier and the observed sea level can be explained by steric expansion over the upper 2000m. ENSO variability impacts on the northern part of the section, and a simple Sverdrup transport model shows how large-scale changes in the wind forcing, related to the Southern Annular Mode, may contribute to the deeper warming to the south.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1016/j.pocean.2007.03.002
Other URLs:
Navarra, A., Gualdi, S., Masina, S., Behera, S., Luo, J., Masson, S., Guilyardi, E., Delecluse, P., and Yamagata,T. (2008). Atmospheric Horizontal Resolution Affects Tropical Climate Variability in Coupled Models, Journal of Climate, 21(4), 730-750, 10.1175/2007JCLI1406.1. Journal Article »
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Title: Atmospheric Horizontal Resolution Affects Tropical Climate Variability in Coupled Models
Type: Journal Article
Publication: Journal of Climate
Author(s): Navarra, A., Gualdi, S., Masina, S., Behera, S., Luo, J., Masson, S., Guilyardi, E., Delecluse, P., and Yamagata,T.
Year: 2008
Formatted Citation: Navarra, A., Gualdi, S., Masina, S., Behera, S., Luo, J., Masson, S., Guilyardi, E., Delecluse, P., and Yamagata,T., 2008: Atmospheric Horizontal Resolution Affects Tropical Climate Variability in Coupled Models, Journal of Climate, 21(4), 730-750, 10.1175/2007JCLI1406.1.
Abstract: The effect of atmospheric horizontal resolution on tropical variability is investigated within the modified Scale Interaction Experiment (SINTEX) coupled model, SINTEX-Frontier (SINTEX-F), developed jointly at Istituto Nazionale di Geofisica e Vulcanologia (INGV), L`Institut Pierre-Simon Laplace (IPSL), and the Frontier Research System. The ocean resolution is not changed as the atmospheric model resolution is modified from spectral resolution 30 (T30) to spectral resolution 106 (T106). The horizontal resolutions of the atmospheric model T30 and T106 are investigated in terms of the coupling characteristics, frequency, and variability of the tropical ocean-atmosphere interactions. It appears that the T106 resolution is generally beneficial even if it does not eliminate all the major systematic errors of the coupled model. There is an excessive shift west of the cold tongue and ENSO variability, and high resolution also has a somewhat negative impact on the variability in the east Indian Ocean. A dominant 2-yr peak for the Nino-3 variability in the T30 model is moderated in the T106 as it shifts to a longer time scale. At high resolution, new processes come into play, such as the coupling of tropical instability waves, the resolution of coastal flows at the Pacific-Mexican coasts, and improved coastal forcing along the coast of South America. The delayed oscillator seems to be the main mechanism that generates the interannual variability in both models, but the models realize it in different ways. In the T30 model it is confined close to the equator, involving relatively fast equatorial and near-equatorial modes, and in the high-resolution model, it involves a wider latitudinal region and slower waves. It is speculated that the extent of the region that is involved in the interannual variability may be linked to the time scale of the variability itself.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1175/2007JCLI1406.1
Other URLs:
Nie, C. and Long, D.G. (2008). A C-Band Scatterometer Simultaneous Wind/Rain Retrieval Method, IEEE Trans. Geosci. Remote Sens., 46(11), 3618-3631, 10.1109/TGRS.2008.922146. Journal Article »
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Title: A C-Band Scatterometer Simultaneous Wind/Rain Retrieval Method
Type: Journal Article
Publication: IEEE Trans. Geosci. Remote Sens.
Author(s): Nie, C. and Long, D.G.
Year: 2008
Formatted Citation: Nie, C. and Long, D.G., 2008: A C-Band Scatterometer Simultaneous Wind/Rain Retrieval Method, IEEE Trans. Geosci. Remote Sens., 46(11), 3618-3631, 10.1109/TGRS.2008.922146.
Abstract: Using collocated ERS scatterometer (ESCAT), Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR), and European Centre for Medium-Range Weather Forecasts (ECMWF) data, the effects of rain on ESCAT wind-only retrieval are evaluated. Additional scattering from rain causes estimated wind speeds to appear higher than expected. Selected directions of the rain-corrupted wind vectors are biased toward along-track directions under conditions of heavy rain, which is regardless of the true wind direction. Rain becomes more significant for data acquired at a high incidence angle. To compensate for rain-induced backscatter, a simultaneous wind/rain retrieval (SWRR) method, which simultaneously retrieves wind velocity and surface rain rate from ESCAT measurements with an incidence angle >40deg, is developed by using a C-band wind/rain backscatter model. The performance of SWRR under typical wind/rain conditions is evaluated through simulation and validation with collocated TRMM PR and ECMWF data sets. SWRR is shown to significantly improve wind velocity estimates, and the SWRR estimated surface rain rate has relatively high accuracy in moderate to heavy rain cases. Although SWRR-retrieved rain is somewhat biased, it can be corrected. We note that for ESCAT, about 1.5% of all the collocated measurements is affected by significant rain.
Keywords: Atmospheric measurements radar cross section radar meteorological factors
Mission:
URL: https://doi.org/10.1109/TGRS.2008.922146
Other URLs:
Nie, C., and Long, D.G. (2008). RADARSAT ScanSAR Wind Retrieval and Rain Effects on ScanSAR Measurements Under Hurricane Conditions, 2008 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `08), II-493-II-496, 10.1109/IGARSS.2008.4779036. Conference Paper »
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Title: RADARSAT ScanSAR Wind Retrieval and Rain Effects on ScanSAR Measurements Under Hurricane Conditions
Type: Conference Paper
Publication: 2008 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `08)
Author(s): Nie, C., and Long, D.G.
Year: 2008
Formatted Citation: Nie, C., and Long, D.G., 2008: RADARSAT ScanSAR Wind Retrieval and Rain Effects on ScanSAR Measurements Under Hurricane Conditions, 2008 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `08), II-493-II-496, 10.1109/IGARSS.2008.4779036.
Abstract: In this paper, RADARSAT-1 ScanSAR SWA images of Hurricane Katrina are used to retrieve near surface wind vectors over the ocean. Rain effects on ScanSAR SWA measurements are studied and analyzed. Due to the inadequate spatial resolution of the ScanSAR SWA images, the spectrum method cannot be implemented to estimate the wind direction. Instead, collocated H*wind wind directions are used as wind direction estimates. The wind speed is derived from the SAR backscatter images by inversion of a new C-band HH-polarization Geophysical Model Function (GMF), which is derived from C-band VV-polarization GMF using a polarization ratio model. Because existing polarization models dont t the ScanSAR SWA data well, a recalibration model is proposed to recalibrate the ScanSAR SWA backscatter images. The coef cients of the recalibration model are tuned using collocated H*wind surface wind elds. Wind retrievals are performed using the recalibrated backscatter. To validate the SAR-retrieved wind speed, the mean and the RMS difference between SAR-retrieved and H*wind wind speed estimates are calculated. The mean of difference is negligible small and the RMS is below 4 m/s. Except for the in uence from rain, the largest errors occur at high wind speed (over 20 m/s), which is mainly due to the saturation of the C-band GMF CMOD5. While wind speed estimates over 20 m/s are noisy, no obvious bias is found, suggesting that the wind retrieval algorithm can work under hurricane conditions. Using the recalibrated ScanSAR SWA measurements, collocated ground-based Doppler weather radar (NEXRAD) and air-borne weather radar (WP-3D) measurements, and collocated H*wind eld, the complicated rain effects on the ScanSAR SWA measurements are studied. Rain effects on ScanSAR SWA measurements include atmospheric effects (attenuation and backscattering) and surface effects. Although rain atmospheric effect is insigni cant for C-band signal, it can signi cantly alter the surface backscatter. This is because of the SAR-observed atmospheric backscatter is the integration of the rain-induced backscatter along the circle perpendicular to the SAR slant range. Rain surface effects on C-band SAR measurements can dominate the surface backscatter in moderate to heavy rains. For C-band, the rain surface effect varies with incidence angle. At incidence angle lower than 30 ◦, , rain generally dampens the surface backscatter while it enhances the surface backscatter at incidence angle higher than 40 ◦, . At incidence angles between 30 ◦, and 40 ◦, , rain may increase or decrease the surface backscatter. RADARSAT-1 ScanSAR SWA measurements have incidence angles between 20 ◦, and 50 ◦, , providing a good opportunity to study the complicated rain effects for different incidence angles under hurricane conditions. Using a simple wind/rain backscatter model and the collocated data set, we quantitatively analyzed different rain effects on the ScanSAR measurements for different incidence angles. The rain-induced backscatter on the ScanSAR measurements at incidence angles higher than 40 ◦, are also validated with the rain backscatter computed by a rain backscatter model developed from C-band wind scatterometer ERS scatterometer measurements.
Keywords: High Wind Speed Retrievals from SAR and Scatterometry
Mission:
URL: https://doi.org/10.1109/IGARSS.2008.4779036
Other URLs:
Otero, P. and Ruiz-Villarreal, M. (2008). Wind Forcing of the Coastal Circulation off North and Northwest Iberia: Comparison of Atmospheric Models, Journal of Geophysical Research: Oceans, 113(C10), C10019, 10.1029/2008JC004740. Journal Article »
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Title: Wind Forcing of the Coastal Circulation off North and Northwest Iberia: Comparison of Atmospheric Models
Type: Journal Article
Publication: Journal of Geophysical Research: Oceans
Author(s): Otero, P. and Ruiz-Villarreal, M.
Year: 2008
Formatted Citation: Otero, P. and Ruiz-Villarreal, M., 2008: Wind Forcing of the Coastal Circulation off North and Northwest Iberia: Comparison of Atmospheric Models, Journal of Geophysical Research: Oceans, 113(C10), C10019, 10.1029/2008JC004740.
Abstract: Comparisons between observed winds and winds from reanalysis (National Centers for Environmental Prediction (NCEP) Reanalysis 1 and 2) and forecast meteorological models (High-Resolution Limited Area Model (HIRLAM)-Agencia Estatal de Meteorologia 0.2 degrees and Atmospheric Research Mesoscale Model version 5-MeteoGalicia with 30 km and 10 km resolution) have been performed for the coastal region around northwest and north Iberia during a typical autumn downwelling period (September-December 2002). Observations at buoys and coastal stations and QuikSCAT-derived winds were employed. The analyzed period was dominated by southerly and southwesterly winds associated to the passage of low-pressure systems. Our results show that the westward component is higher on the north coast than on the west coast and that winds are intensified at the western north coast. In this situation, the performance is similar in all model products in general terms, but only HIRLAM represents the reduction of winds in the Cantabrian Sea and NCEP and MM5 overestimate the magnitude of south-southwest winds. Spatial differences in winds are also obtained for upwelling favorable events, associated either with a high-pressure system north from Iberia at the beginning of the autumn transition ( northeasterly winds) or with conditions after the passage of a low-pressure system ( northwesterly winds). The existence of sea surface temperature (SST) gradients in the coastal region implies that higher-resolution boundary SST products for meteorological models are necessary. Finally, the effect of these wind products on the coastal circulation was assessed with a 3-D numerical simulation. Differences in the expansion/confinement of river plumes and the surface speed of the slope current are induced by differences in wind patterns over the shelf and slope area among atmospheric models.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1029/2008JC004740
Other URLs:
Otero, P., Ruiz-Villarreal, M., and Peliz, A. (2008). Variability of River Plumes off Northwest Iberia in Response to Wind Events, Journal of Marine Systems, 72(1-4), 238-255, 10.1016/j.jmarsys.2007.05.016. Journal Article »
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Title: Variability of River Plumes off Northwest Iberia in Response to Wind Events
Type: Journal Article
Publication: Journal of Marine Systems
Author(s): Otero, P., Ruiz-Villarreal, M., and Peliz, A.
Year: 2008
Formatted Citation: Otero, P., Ruiz-Villarreal, M., and Peliz, A., 2008: Variability of River Plumes off Northwest Iberia in Response to Wind Events, Journal of Marine Systems, 72(1-4), 238-255, 10.1016/j.jmarsys.2007.05.016.
Abstract: The Western Iberian Buoyant Plume (WIBP) is a low-salinity lens formed by river discharge and continental run-off extending along the shelf off Northwest Iberia. The variability of this structure is evaluated with a numerical model forced by real meteorological data and climatologic river discharge during late 2002, when conditions were those of a typical autumn. The direction and intensity of the wind-induced Ekman transport, but also the previous conditions and the duration of the event are found to determine plume behavior. We have identified three characteristic situations: a) confinement of the plume to the coast during downwelling - southerly-winds, b) expansion of the plume during the declining phase of the downwelling event by relaxation of the wind, and c) expansion of the plume by upwelling - northerly-winds. The short time scale of the response of the plume (1-3 h) adds timing between wind events and the phase of the tide as an additional source of variability. In all cases the Iberian Poleward Current (IPC), a saltier and warmer poleward current flowing over the slope, responds as well to wind changes. Furthermore, our simulations illustrate how topography and differences in the river discharge induce local differences in dynamics. Comparisons to available observations show a reasonable model skill. Differences between wind measurements and wind forcing applied to the model appear to be a major source of uncertainty in model results.
Keywords: Seawinds
Mission:
URL: https://doi.org/10.1016/j.jmarsys.2007.05.016
Other URLs:
Owen, M.P. and Long, D.G. (2008). Land Contamination Compensation for QuikSCAT Near-Coastal Wind Retrieval, IEEE Trans. Geosci. Remote Sens., 47(3), 839-850, 10.1109/TGRS.2008.2005633. Journal Article »
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Title: Land Contamination Compensation for QuikSCAT Near-Coastal Wind Retrieval
Type: Journal Article
Publication: IEEE Trans. Geosci. Remote Sens.
Author(s): Owen, M.P. and Long, D.G.
Year: 2008
Formatted Citation: Owen, M.P. and Long, D.G., 2008: Land Contamination Compensation for QuikSCAT Near-Coastal Wind Retrieval, IEEE Trans. Geosci. Remote Sens., 47(3), 839-850, 10.1109/TGRS.2008.2005633.
Abstract: The QuikSCAT scatterometer is used to accurately retrieve winds over the ocean at both high (2.5 km) and low (25 km) resolutions. In near-coastal regions, land contamination of measurements results in inaccurate wind estimates using current techniques. Here, we show that identifying land-contaminated measurements allows wind retrieval to be accurately achieved in near-coastal regions using QuikSCAT data at up to 2.5-km resolution using the AVE algorithm. To identify and remove land contamination, two metrics are compared, namely, the minimum distance to land and the land contribution ratio (LCR). The LCR is used as a metric to identify and remove land-contaminated backscatter $sigma^{o}$ measurements before wind retrieval by discarding measurements with LCR values above a threshold. LCR thresholds used to remove land-contaminated measurements are determined using Monte Carlo simulations and set during processing using a lookup table based on the local wind speed, land brightness, and the cross-track swath location. Wind retrieval from $sigma^{o}$ fields generated using the LCR is more accurate closer to the coast than previously achieved using both low- and high-resolution processing.
Keywords: Wind scattering
Mission: |SeaWinds|
URL: https://doi.org/10.1109/TGRS.2008.2005633
Other URLs:
Owen, M.P. and Long, D.G. (2008). Progress Toward Validation of Quikscat Ultra-High-Resolution Rain Rates Using TRMM PR, International Geoscience and Remote Sensing Symposium (IGARSS), IV - 299-IV - 302, 10.1109/IGARSS.2008.4779717. Conference Paper »
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Title: Progress Toward Validation of Quikscat Ultra-High-Resolution Rain Rates Using TRMM PR
Type: Conference Paper
Publication: International Geoscience and Remote Sensing Symposium (IGARSS)
Author(s): Owen, M.P. and Long, D.G.
Year: 2008
Formatted Citation: Owen, M.P. and Long, D.G., 2008: Progress Toward Validation of Quikscat Ultra-High-Resolution Rain Rates Using TRMM PR, International Geoscience and Remote Sensing Symposium (IGARSS), IV - 299-IV - 302, 10.1109/IGARSS.2008.4779717.
Abstract: Although originally designed solely for wind retrieval, the QuikSCAT scatterometer has also proved to be a useful tool for rain retrieval. Resolution enhancement algorithms designed for QuikSCAT allow for ultra-high-resolution (UHR) (2.5 km) simultaneous wind and rain (SWR) retrieval. To enable SWR retrieval, we adjust the geophysical model function (GMF) to account for rain effects such as attenuation or increased backscatter due to increased surface roughness. Comparisons of a co-located data set show that QuikSCAT UHR SWR rain rates are comparable to those from Tropical Rainfall Measuring Mission Precipitation Radar (TRMM PR) but have higher variance. The noise level of the QuikSCAT rain estimates can be reduced by forming the reduced resolution rain rate estimates. As expected, rain estimates are significantly worse in regions where wind dominates the backscatter. 2008 IEEE.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1109/IGARSS.2008.4779717
Other URLs:
Oza, S.R., Panigrally, S., and Parihar, J.S. (2008). Concurrent Use of Active and Passive Microwave Remote Sensing Data for Monitoring of Rice Crop, International Journal of Applied Earth Observation and Geoinformation, 10(3), 296-304, 10.1016/j.jag.2007.12.002. Journal Article »
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Title: Concurrent Use of Active and Passive Microwave Remote Sensing Data for Monitoring of Rice Crop
Type: Journal Article
Publication: International Journal of Applied Earth Observation and Geoinformation
Author(s): Oza, S.R., Panigrally, S., and Parihar, J.S.
Year: 2008
Formatted Citation: Oza, S.R., Panigrally, S., and Parihar, J.S., 2008: Concurrent Use of Active and Passive Microwave Remote Sensing Data for Monitoring of Rice Crop, International Journal of Applied Earth Observation and Geoinformation, 10(3), 296-304, 10.1016/j.jag.2007.12.002.
Abstract: Estimation of crop area, growth and phenological information is very important for monitoring of agricultural crops. However, judicious combination of spatial and temporal data from different spectral regions is necessary to meet the requirement. This study highlights the use of active microwave QuikSCAT Ku-band scatterometer and Special Sensor Microwave/Imager (SSM/I) passive microwave radiometer data to derive information on important phenological phases of rice crop. The wetness index, a weekly composite product derived using brightness temperatures from 19, 37 and 85 GHz channels of SSM/I, was used to identify the puddling period. Ku-band scatterometer data provided the signal of transplanted rice seedlings since they acts as scatterers and increases the backscattering. Dual peak nature of temporal backscatter curve around the heading stage of rice crop was observed in Ku-band. The decrease of backscatter after first peak was associated with the threshold value of 60% crop canopy cover. The symmetric (Gaussian) and asymmetric (lognormal) curve fits were attempted to derive the date of initiation of the heading phase. The temporal signature from each of these sensors was found to complement each other in crop growth monitoring. Image showing pixel-wise timings of heading stage revealed the differences exists in various parts of the study area. (C) 2008 Elsevier B.V. All rights reserved.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1016/j.jag.2007.12.002
Other URLs:
Padin, X.A., Castro, C.G., Rios, A.F., and Perez, F.F. (2008). fCO₂^sw Variability in the Bay of Biscay During ECO Cruises, Continental Shelf Research, 28(7), 904-914, 10.1016/j.csr.2008.01.004. Journal Article »
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Title: fCO₂^sw Variability in the Bay of Biscay During ECO Cruises
Type: Journal Article
Publication: Continental Shelf Research
Author(s): Padin, X.A., Castro, C.G., Rios, A.F., and Perez, F.F.
Year: 2008
Formatted Citation: Padin, X.A., Castro, C.G., Rios, A.F., and Perez, F.F., 2008: fCO₂^sw Variability in the Bay of Biscay During ECO Cruises, Continental Shelf Research, 28(7), 904-914, 10.1016/j.csr.2008.01.004.
Abstract: The Bay of Biscay is part of the North Atlantic Ocean, the most important sink of CO sub(2), and a subduction zone of mode waters that favours the entry of carbon to the ocean interior. To investigate the seasonal and interannual variability of CO sub(2) uptake, continuous underway measurements of the partial pressure of CO sub(2) at sea surface were performed along a commercial route between Vigo (Spain) and St. Nazaire (France). An unattended measuring system of CO sub(2) fugacity (fCO sub(2)), with meteorological station, and temperature, salinity, oxygen and fluorescence sensors, was installed on board of ships of opportunity (RO-RO L`Audace and RO-RO Surprise). The dataset collected between December 2002 and December 2004 reported a significant interannual variability, mainly for the winter season. The noticeable increase of fCO sub(2) super(s) super(w) during the winter mixing period of 2004 was associated to biogeochemical differences related to nutrient ratios, phytoplankton activity and atmospheric CO sub(2) uptake. Dividing the seasonal cycle into three periods, prebloom (October-February), bloom (March-May) and postbloom (June-September), the fCO sub(2) super(s) super(w) for the entire seasonal cycle was correctly predicted by empirical relationships with an error lower than 10 mu atm in spite of the high interannual variability. The fCO sub(2) super(s) super(w) variability at seasonal scale was mainly controlled by processes of synthesis and remineralization of organic matter during prebloom and bloom periods whereas SST was the key parameter during postbloom period. The surface waters of the Bay of Biscay showed a clear role as atmospheric CO sub(2) sink ranging from -2.7+/-2.8 (+/-0.3) to -0.08+ /-0.41 (+/-0.04)molCm super(-) super(2)yr super(-) super(1) (mean+/-standard deviation (+ /-error)) throughout each complete period although CO sub(2) release to atmosphere was also observed during short episodes of summer. Using the regular wind speed sources of CO sub(2) fluxes estimation ranged from -1.3+/-1.7 (+/-0.1) to -2.4+/-2.7 (+/-0.1)molCm super(-) super(2)yr super(-) super(1) at annual scale, exceeding the sink capacity of the nearby regions of the North Atlantic Ocean.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1016/j.csr.2008.01.004
Other URLs:
Park, J.D., Byon, J.-Y., Sohn, E., and Kim, Y. (2008). Operational Technique in Typhoon Wind Radii Using Satellite Microwave Remote Sensor Data, International Geoscience and Remote Sensing Symposium (IGARSS), I-343-I-346, 10.1109/IGARSS.2008.4778864. Conference Paper »
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Title: Operational Technique in Typhoon Wind Radii Using Satellite Microwave Remote Sensor Data
Type: Conference Paper
Publication: International Geoscience and Remote Sensing Symposium (IGARSS)
Author(s): Park, J.D., Byon, J.-Y., Sohn, E., and Kim, Y.
Year: 2008
Formatted Citation: Park, J.D., Byon, J.-Y., Sohn, E., and Kim, Y., 2008: Operational Technique in Typhoon Wind Radii Using Satellite Microwave Remote Sensor Data, International Geoscience and Remote Sensing Symposium (IGARSS), I-343-I-346, 10.1109/IGARSS.2008.4778864.
Abstract: In this paper, the system will be introduced and explain for the practical techniques might consider and use the typhoon wind radii on near real-time using satellite microwave remote sensor data. The system is created to use Typhoon weather forecast and validation of radii of 15 and 25 m/s (around 30 and 50 kts) gale-force wind over the ocean using satellite data. Korean Meteorological Administration (KMA) is receiving Defense Meteorological Satellite Program (DMSP), AQUA, and QuikSCAT data directly or indirectly via File Transfer Protocol (FTP) over the Global Telecommunication System (GTS) and process the wind speed. Also it receives Satellite Report (SAREP) which reports the position of the center of typhoon and it will be used for radius calculation. The system will calculate the radii of 15 and 25 m/s winds for four quadrants and also plot the each directional winds according to the distance from the center of the typhoon. It will run every 6 hours from the beginning of tropical depression to touch down to the land. With this system, 2006-2007 typhoon cases are processed to compare with the Regional Specialized Meteorological Center (RSMC) - Tokyo Typhoon Center best track and KMA forecasted data as well as the track errors.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1109/IGARSS.2008.4778864
Other URLs:
Patoux, J., Foster, R.C., and Brown, R.A. (2008). An Evaluation of Scatterometer-Derived Oceanic Surface Pressure fields, JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY, 47(3), 835-852, 10.1175/2007JAMC1683.1. Journal Article »
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Title: An Evaluation of Scatterometer-Derived Oceanic Surface Pressure fields
Type: Journal Article
Publication: JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY
Author(s): Patoux, J., Foster, R.C., and Brown, R.A.
Year: 2008
Formatted Citation: Patoux, J., Foster, R.C., and Brown, R.A., 2008: An Evaluation of Scatterometer-Derived Oceanic Surface Pressure fields, JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY, 47(3), 835-852, 10.1175/2007JAMC1683.1.
Abstract: Oceanic surface pressure fields are derived from the NASA Quick Scatterometer (QuikSCAT) surface wind vector measurements using a two-layer similarity planetary boundary layer model in the midlatitudes and a mixed layer planetary boundary layer model in the tropics. These swath-based surface pressure fields are evaluated using the following three methods: 1) a comparison of bulk pressure gradients with buoy pressure measurements in the North Pacific and North Atlantic Oceans, 2) a least squares difference comparison with the European Centre for Medium-Range Weather Forecasts (ECMWF) surface pressure analyses, and 3) a parallel spectral analysis of the QuikSCAT and ECMWF surface pressure fields. The correlation coefficient squared between scatterometer-derived pressure fields and buoys is found to be R2 = 0.936. The average root-mean-square difference between the scatterometer-derived and the ECMWF pressure fields ranges from 1 to 3 hPa, depending on the latitude and season, and decreases after the assimilation of QuikSCAT winds in the ECMWF numerical weather prediction model. The spectral components of the scatterometer-derived pressure fields are larger than those of ECMWF surface analyses at all scales in the midlatitudes and only at shorter wavelengths in the tropics.
Keywords: PLANETARY BOUNDARY-LAYER, SOUTHERN-OCEAN, SATELLITE SCATTEROMETER, NASA SCATTEROMETER, WEATHER PREDICTION, TROPICAL PACIFIC, ROLL VORTICES, WIND, MODEL, INSTABILITIES
Mission:
URL: https://doi.org/10.1175/2007JAMC1683.1
Other URLs:
Penabad, E., Alvarez, I., Balseiro, C.F., deCastro, M., Gómez, B., Pérez-Muñuzuri, V., and Gómez-Gesteira, M. (2008). Comparative Analysis Between Operational Weather Prediction Models and QuikSCAT Wind Data Near the Galician Coast, Journal of Marine Systems, 72(4-Jan), 256-270, 10.1016/j.jmarsys.2007.07.008. Journal Article »
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Title: Comparative Analysis Between Operational Weather Prediction Models and QuikSCAT Wind Data Near the Galician Coast
Type: Journal Article
Publication: Journal of Marine Systems
Author(s): Penabad, E., Alvarez, I., Balseiro, C.F., deCastro, M., Gómez, B., Pérez-Muñuzuri, V., and Gómez-Gesteira, M.
Year: 2008
Formatted Citation: Penabad, E., Alvarez, I., Balseiro, C.F., deCastro, M., Gómez, B., Pérez-Muñuzuri, V., and Gómez-Gesteira, M., 2008: Comparative Analysis Between Operational Weather Prediction Models and QuikSCAT Wind Data Near the Galician Coast, Journal of Marine Systems, 72(4-Jan), 256-270, 10.1016/j.jmarsys.2007.07.008.
Abstract: Wind measurements from SeaWinds scatterometer on the NASA QuikSCAT satellite and wind forecasts from two different operational numerical models provided by MeteoGalicia were compared for a 4-year period (2002-2005) in Galician coast environment. Available wind data buoy measurements were also used to complement the analysis. A statistical analysis based on mean errors, root mean square errors and complex correlation was performed from spatial, temporal and directional points of view. In the spatial comparison no significant differences between models and satellite were observed and the error magnitudes of the models are compatible with typical QuikSCAT errors. The suitability of satellite wind estimations for data assimilation in these models must be further investigated. Negative bias of models with respect to the satellite was also confirmed with buoy data, in such a way that models overestimation is smaller than the satellite one. Big errors in wind direction appear in southeasterly and southwesterly winds for both satellite and models, contributing to high RMSE values when compared to buoy data. These errors were mainly attributed to the effect of insufficient spatial resolution near shore.
Keywords: QuikSCAT, Seawinds
Mission:
URL: https://doi.org/10.1016/j.jmarsys.2007.07.008
Other URLs:
Peng, J. and Ruf, C.S. (2008). Covariance Statistics of Polarimetric Brightness Temperature Measurements, IEEE Transactions on Geoscience and Remote Sensing, 46(10), 3238-3251, 10.1109/TGRS.2008.921413. Journal Article »
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Title: Covariance Statistics of Polarimetric Brightness Temperature Measurements
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Peng, J. and Ruf, C.S.
Year: 2008
Formatted Citation: Peng, J. and Ruf, C.S., 2008: Covariance Statistics of Polarimetric Brightness Temperature Measurements, IEEE Transactions on Geoscience and Remote Sensing, 46(10), 3238-3251, 10.1109/TGRS.2008.921413.
Abstract: All microwave radiometer measurements of brightness temperature (TB) include an additive noise component. With conventional linearly polarized radiometers, the variance of the noise is a well-understood function of the system temperature, the predetection bandwidth, and the integration time according to the so-called radiometer uncertainty equation. The noise has generally been considered to be uncorrelated between orthogonally polarized channels. The variance and the correlation statistics of the additive noise component of fully polarimetric radiometer measurements are derived from theoretical considerations, and the resulting relationships are experimentally verified. It is found that the noise can be correlated between polarimetric channels, and the correlation statistics will vary as a function of the polarization state of the scene under observation. For example, a strong correlation is typical between the noise in either vertically or horizontally polarized TB and the 45 slant linear polarizations that are often used to derive the third Stokes TB. A weak, but nonzero, correlation is also possible between the additive noise in the vertically and horizontally polarized TB's themselves. This is a correction to the common assumption that they are uncorrelated.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1109/TGRS.2008.921413
Other URLs:
Perrie, W., Zhang, W., Bourassa, M., Shen, H., and Vachon, P.W. (2008). Impact of Satellite Winds on Marine Wind Simulations, Weather and Forecasting, 23(2), 290-303, 10.1175/2007WAF2006093.1. Journal Article »
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Title: Impact of Satellite Winds on Marine Wind Simulations
Type: Journal Article
Publication: Weather and Forecasting
Author(s): Perrie, W., Zhang, W., Bourassa, M., Shen, H., and Vachon, P.W.
Year: 2008
Formatted Citation: Perrie, W., Zhang, W., Bourassa, M., Shen, H., and Vachon, P.W., 2008: Impact of Satellite Winds on Marine Wind Simulations, Weather and Forecasting, 23(2), 290-303, 10.1175/2007WAF2006093.1.
Abstract: A variational data assimilation method is applied to remotely sensed wind data from Hurricanes Gustav (2002) and Isabel (2003) to produce enhanced marine wind estimates. The variational method utilizes constraints to ensure that an optimum combination of winds is determined, in the sense of minimization of a cost function measuring the misfit between observations and background input field data and constraining nongeophysical features in the spatial derivatives. Constraints are multiplied by weights, which are objectively determined by cross validation. Verification is obtained by comparison with available operational in situ buoy observations and analyses winds. It is shown that the newly constructed midlatitude wind fields represent an improvement relative to background wind field estimates and also relative to Quick ScatterometerNational Centers for Environmental Prediction reanalysis blended winds, and that the new winds have an impact on simulations of waves and upper-ocean currents.
Keywords: SCATTEROMETER DATA, HURRICANE, MODEL
Mission:
URL: https://doi.org/10.1175/2007WAF2006093.1
Other URLs:
Piepmeier, J.R., Njoku, E.G., and Long, D.G. (2008). Stokes Antenna Temperatures, IEEE Transactions on Geoscience and Remote Sensing, 46(2), 516-527, 10.1109/TGRS.2007.909597. Journal Article »
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Title: Stokes Antenna Temperatures
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Piepmeier, J.R., Njoku, E.G., and Long, D.G.
Year: 2008
Formatted Citation: Piepmeier, J.R., Njoku, E.G., and Long, D.G., 2008: Stokes Antenna Temperatures, IEEE Transactions on Geoscience and Remote Sensing, 46(2), 516-527, 10.1109/TGRS.2007.909597.
Abstract: The growing importance of polarimetric radiometers has led to the need for a detailed theory for Stokes antenna temperatures. In this paper, we provide a full Stokes vector formulation of an antenna temperature that accounts for the entire antenna pattern, which includes polarization mixing in the main-beam and sidelobe effects. To derive the Stokes antenna temperatures, we follow the conventional methods in the Earth remote sensing literature while relying on a coherency algebra approach from radio astronomy. Connections and parallels to the conventional approaches are noted along the way. We also introduce generalizations of beam efficiency and cross polarization for use with polarimetric radiometers. These provide important metrics in the design of future systems.
Keywords: algebra antenna theory radar polarimetry radiometry remote sensing Stokes antenna temperature theory Stokes vector formulation antenna pattern beam efficiency coherency algebra cross polarization mainbeam effects polarimetric radio
Mission:
URL: https://doi.org/10.1109/TGRS.2007.909597
Other URLs:
Pimenta, F., Kempton, W., and Garvine, R. (2008). Combining Meteorological Stations and Satellite Data to Evaluate the Offshore Wind Power Resource of Southeastern Brazil, Renewable Energy, 33(11), 2375-2387, 10.1016/j.renene.2008.01.012. Journal Article »
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Title: Combining Meteorological Stations and Satellite Data to Evaluate the Offshore Wind Power Resource of Southeastern Brazil
Type: Journal Article
Publication: Renewable Energy
Author(s): Pimenta, F., Kempton, W., and Garvine, R.
Year: 2008
Formatted Citation: Pimenta, F., Kempton, W., and Garvine, R., 2008: Combining Meteorological Stations and Satellite Data to Evaluate the Offshore Wind Power Resource of Southeastern Brazil, Renewable Energy, 33(11), 2375-2387, 10.1016/j.renene.2008.01.012.
Abstract: Wind is strong and steady over the ocean, but on-site marine meteorological data are sparse for evaluation of oceanic wind power. Here, we draw on meteorological station, satellite data (QuikSCAT), and both theoretical and practical measures of wind turbine performance. The meteorological stations measure directly at high time resolution but low spacial resolution, and provide validation and adjustment of the satellite data. The satellite data provide near-complete spacial coverage at lower time resolution. For the southern coast of Brazil, we use both data sets to evaluate the location, seasonal timing, and availability of the wind power resource. Then, using bathymetry and the properties of current wind-electric technology, we develop maps of wind speed, wind power density, and practical turbine output in power units (MW). In the shallower waters of south Brazil, the most favorable conditions are along the coast between 28S and 33S. In just this one coastal area, we find a total resource of 102 GW average electrical production, approximately equal to the electric demand of the entire country.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1016/j.renene.2008.01.012
Other URLs:
Plagge, A.M., Vandemark, D.C., and Long, D.G. (2008). Validation and Evaluation of QuikSCAT Ultra-High Resolution Wind Retrieval in the Gulf of Maine, International Geoscience and Remote Sensing Symposium (IGARSS), IV - 204-IV - 207, 10.1109/IGARSS.2008.4779693. Conference Paper »
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Title: Validation and Evaluation of QuikSCAT Ultra-High Resolution Wind Retrieval in the Gulf of Maine
Type: Conference Paper
Publication: International Geoscience and Remote Sensing Symposium (IGARSS)
Author(s): Plagge, A.M., Vandemark, D.C., and Long, D.G.
Year: 2008
Formatted Citation: Plagge, A.M., Vandemark, D.C., and Long, D.G., 2008: Validation and Evaluation of QuikSCAT Ultra-High Resolution Wind Retrieval in the Gulf of Maine, International Geoscience and Remote Sensing Symposium (IGARSS), IV - 204-IV - 207, 10.1109/IGARSS.2008.4779693.
Abstract: Researchers at Brigham Young University have created an experimental 2.5 km ultra-high resolution (UHR) wind product from the QuikSCAT scatterometer. This product adds to the standard 25 km and new 12.5 km resolution data provided by that satellite, and offers the potential for new access to coastal surface wind dynamics at the sub-mesoscale level. With its nineteen meteorological buoys, the Gulf of Maine provides an excellent test site for evaluating the UHR wind retrievals. Comparison with these buoys, mesoscale meteorological model winds, and standard QuikSCAT products throughout the month of October 2006 allows detailed investigation of UHR wind speed and direction. Even with a land contamination mask, the UHR product provides extended coverage near the coast. An additional ambiguity reselection routine improves wind direction agreement between the UHR winds and the other products. With this refinement, the ultra-high resolution winds show great promise in the coastal region.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1109/IGARSS.2008.4779693
Other URLs:
Powell, B.S., Arango, H.G., Moore, A.M., Di Lorenzo, E., Milliff, R.F., and Foley, D. (2008). 4DVAR Data Assimilation in the Intra-Americas Sea with the Regional Ocean Modeling System, Ocean Modelling, 23(3-4), 130-145, 10.1016/j.ocemod.2008.04.008. Journal Article »
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Title: 4DVAR Data Assimilation in the Intra-Americas Sea with the Regional Ocean Modeling System
Type: Journal Article
Publication: Ocean Modelling
Author(s): Powell, B.S., Arango, H.G., Moore, A.M., Di Lorenzo, E., Milliff, R.F., and Foley, D.
Year: 2008
Formatted Citation: Powell, B.S., Arango, H.G., Moore, A.M., Di Lorenzo, E., Milliff, R.F., and Foley, D., 2008: 4DVAR Data Assimilation in the Intra-Americas Sea with the Regional Ocean Modeling System, Ocean Modelling, 23(3-4), 130-145, 10.1016/j.ocemod.2008.04.008.
Abstract: We present the background, development, and preparation of a state-of-the-art 4D variational (4DVAR) data assimilation system in the Regional Ocean Modeling System (ROMS) with an application in the Intra-Americas Sea (IAS). This initial application with a coarse model shows the efficacy of the 4DVAR methodology for use within complex ocean environments, and serves as preparation for deploying an operational, real-time assimilation system onboard the Royal Caribbean Cruise Lines ship Explorer of the Seas. Assimilating satellite sea surface height and temperature observations with in situ data from the ship in 14 day cycles over 2 years from January 2005 through March 2007, reduces the observation-model misfit by over 75%. Using measures of the Loop Current dynamics, we show that the assimilated solution is consistent with observed statistics.
Keywords: Data assimilation, 4DVAR, ROMS, Predictability, Intra-Americas Sea, Gulf of Mexico
Mission:
URL: https://doi.org/10.1016/j.ocemod.2008.04.008
Other URLs:
Pu, Z., Li, X., Velden, C.S., Aberson, S.D., and Liu, W.T. (2008). The Impact of Aircraft Dropsonde and Satellite Wind Data on Numerical Simulations of Two Landfalling Tropical Storms During the Tropical Cloud Systems and Processes Experiment, Weather and Forecasting, 23(1), 62-79, 10.1175/2007WAF2007006.1. Journal Article »
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Title: The Impact of Aircraft Dropsonde and Satellite Wind Data on Numerical Simulations of Two Landfalling Tropical Storms During the Tropical Cloud Systems and Processes Experiment
Type: Journal Article
Publication: Weather and Forecasting
Author(s): Pu, Z., Li, X., Velden, C.S., Aberson, S.D., and Liu, W.T.
Year: 2008
Formatted Citation: Pu, Z., Li, X., Velden, C.S., Aberson, S.D., and Liu, W.T., 2008: The Impact of Aircraft Dropsonde and Satellite Wind Data on Numerical Simulations of Two Landfalling Tropical Storms During the Tropical Cloud Systems and Processes Experiment, Weather and Forecasting, 23(1), 62-79, 10.1175/2007WAF2007006.1.
Abstract: Dropwindsonde, Geostationary Operational Environmental Satellite-11 (GOES-11) rapid-scan atmospheric motion vectors, and NASA Quick Scatterometer (QuikSCAT) near-surface wind data collected during NASAs Tropical Cloud Systems and Processes (TCSP) field experiment in July 2005 were assimilated into an advanced research version of the Weather Research and Forecasting (WRF) model using its three-dimensional variational data assimilation (3DVAR) system. The impacts of the mesoscale data assimilation on WRF numerical simulation of Tropical Storms Cindy and Gert (2005) near landfall are examined. Sensitivity of the forecasts to the assimilation of each single data type is investigated. Specifically, different 3DVAR strategies with different analysis update cycles and resolutions are compared in order to identify the better methodology for assimilating the data from research aircraft and satellite for tropical cyclone study. The results presented herein indicate the following. 1) Assimilation of dropwindsonde and satellite wind data into the WRF model improves the forecasts of the two tropical storms up to the landfall time. The QuikSCAT wind information is very important for improving the storm track forecast, whereas the dropwindsonde and GOES-11 wind data are also necessary for improved forecasts of intensity and precipitation. 2) Data assimilation also improves the quantitative precipitation forecasts (QPFs) near landfall of the tropical storms. 3) A 1-h rapid-update analysis cycle at high resolution (9 km) provides more accurate tropical cyclone forecasts than a regular 6-h analysis cycle at coarse (27 km) resolution. The high-resolution rapidly updated 3DVAR analysis cycle might be a practical way to assimilate the data collected from tropical cyclone field experiments.
Keywords: VARIATIONAL DATA ASSIMILATION, CONVECTIVE ADJUSTMENT SCHEME, TROPOSPHERIC WINDS, INTENSITY CHANGE, TRACK FORECASTS, HURRICANE, PREDICTION, MODEL, DROPWINDSONDE, RAINFALL
Mission:
URL: https://doi.org/10.1175/2007WAF2007006.1
Other URLs:
Rao, V.B., Giarolla, E., do Espirito Santo, C.M., and Franchito, S.H. (2008). Comparison of surface wind stress characteristics over the tropical Atlantic (10^oN-40^oS) in fields derived from the UWM/COADS, NCEP/NCAR and QuikSCAT datasets, Journal of Oceanography, 64(4), 551-560, 10.1007/s10872-008-0046-9. Journal Article »
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Title: Comparison of surface wind stress characteristics over the tropical Atlantic (10^oN-40^oS) in fields derived from the UWM/COADS, NCEP/NCAR and QuikSCAT datasets
Type: Journal Article
Publication: Journal of Oceanography
Author(s): Rao, V.B., Giarolla, E., do Espirito Santo, C.M., and Franchito, S.H.
Year: 2008
Formatted Citation: Rao, V.B., Giarolla, E., do Espirito Santo, C.M., and Franchito, S.H., 2008: Comparison of surface wind stress characteristics over the tropical Atlantic (10^oN-40^oS) in fields derived from the UWM/COADS, NCEP/NCAR and QuikSCAT datasets, Journal of Oceanography, 64(4), 551-560, 10.1007/s10872-008-0046-9.
Abstract: A comparison of monthly wind stress derived from winds of NCEP/NCAR (National Centers for Environmental Prediction/National Center for Atmospheric Research) reanalysis and UWM/COADS (The University of Wisconsin -Milwaukee/Comprehensive Ocean-Atmosphere Data Set) dataset (1950-1993), and of NCEP/NCAR reanalysis and satellite-based QuikSCAT dataset (2000-2006), is made over the South Atlantic (10 degrees N-40 degrees S). On a mean seasonal scale, the comparison shows that these three wind stress datasets have qualitatively similar patterns. Quantitatively, in general, from about the equator to 20 degrees S in the mid-Atlantic the wind stress values are stronger in NCEP/NCAR data than those in UWM/COADS data. On the other hand, in the Intertropical Convergence Zone (ITCZ) area the wind stress values in NCEP/NCAR data are slightly weaker than those in UWM/COADS data. In the South Atlantic, between 20 degrees S-40 degrees S, the QuikSCAT dataset presents complex circulation structures which are not present in NCEP/NCAR and UWM/COADS data. The wind stress is used in a numerical ocean model to simulate ocean currents, which are compared to a drifting-buoy observed climatology. The modeled South Equatorial Current agrees better with observations between March-May and June-August. Between December-February, the South Equatorial Current from UWM/COADS and QuikSCAT experiments is stronger and more developed than that from NCEP/NCAR experiment. The Brazil Current, in turn, is better represented in the QuikSCAT experiment. Comparison of the annual migration of ITCZ at 20 degrees and 30 degrees W in UWM/COADS and NCEP/NCAR data sources show that the southernmost position of ITCZ at 30 degrees W in February, March and April coincides with the rainy season in NE Brazil, while the northernmost position of ITCZ at 20 degrees W in August coincides with the maximum rainfall of Northwest Africa.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1007/s10872-008-0046-9
Other URLs:
Risien, C.M. and Chelton, D.B. (2008). A Global Climatology of Surface Wind and Wind Stress Fields from Eight Years of QuikSCAT Scatterometer Data, Journal of Physical Oceanography, 38(11), 2379-2413, 10.1175/2008JPO3881.1. Journal Article »
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Title: A Global Climatology of Surface Wind and Wind Stress Fields from Eight Years of QuikSCAT Scatterometer Data
Type: Journal Article
Publication: Journal of Physical Oceanography
Author(s): Risien, C.M. and Chelton, D.B.
Year: 2008
Formatted Citation: Risien, C.M. and Chelton, D.B., 2008: A Global Climatology of Surface Wind and Wind Stress Fields from Eight Years of QuikSCAT Scatterometer Data, Journal of Physical Oceanography, 38(11), 2379-2413, 10.1175/2008JPO3881.1.
Abstract: Global seasonal cycles of the wind and wind stress fields estimated from the 8-yr record (September 1999-August 2007) of wind measurements by the NASA Quick Scatterometer (QuikSCAT) are presented. While this atlas, referred to here as the Scatterometer Climatology of Ocean Winds (SCOW), consists of 12 variables, the focus here is on the wind stress and wind stress derivative (curl and divergence) fields. SCOW seasonal cycles are compared with seasonal cycles estimated from NCEP-NCAR reanalysis wind fields. These comparisons show that the SCOW atlas is able to capture small-scale features that are dynamically important to both the ocean and the atmosphere but are not resolved in other observationally based wind atlases or in NCEP-NCAR reanalysis fields. This is particularly true of the wind stress derivative fields in which topographic, SST gradient, and ocean current influences on surface winds are plainly visible. Discussions of five example regions are presented to highlight these seasonally recurring small-scale features. It is expected that the SCOW atlas will prove valuable to researchers conducting hydrographic and modeling studies.
Keywords:
Mission: |SeaWinds|
URL: https://doi.org/10.1175/2008JPO3881.1
Other URLs:
Romero, L. (2008). Airborne Observations and Numerical Modeling of Fetch-Limited Waves in the Gulf of Tehuantepec, Journal of Physical Oceanography, 40(3), 441-465, 10.1175/2009JPO4127.1. Thesis »
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Title: Airborne Observations and Numerical Modeling of Fetch-Limited Waves in the Gulf of Tehuantepec
Type: Thesis
Publication: Journal of Physical Oceanography
Author(s): Romero, L.
Year: 2008
Formatted Citation: Romero, L., 2008: Airborne Observations and Numerical Modeling of Fetch-Limited Waves in the Gulf of Tehuantepec, Journal of Physical Oceanography, 40(3), 441-465, 10.1175/2009JPO4127.1.
Abstract: We present airborne observations of fetch-limited waves generated during strong offshore winds, ranging between 10 and 25 m s^-1, in the Gulf of Tehuantepec. The measurements were collected over a wide range of fetches, from young to fully-developed seas, and include one- and two-dimensional wavenumber spectra, wind velocities, and atmospheric turbulent fluxes. The observed evolution of the wave field is compared to numerical simulations using a recently proposed wave dissipation formulation. In particular, we compare the observed and computed evolution of the directional spectra for fetch-limited conditions under realistic wind forcing. The thesis is composed of two main chapters, both of which are self contained and can be read independently of one another. The first chapter focuses on the analysis of the wind and wave measurements collected in the Gulf of Tehuantepec during February, 2004. It provides a description of the environmental conditions, the instrumentation, as well as the techniques used in the analysis for the characterization of the wind-wave spectrum with respect the wave age or fetch. The results are discussed in the context of previous observations and current numerical wind-wave prediction models. The second chapter describes the comparison of the measured wavenumber spectra with numerical simulations using state-of-the-art wind-wave models. It provides general background information on the physics and the development of numerical wind-wave models. The model is first implemented and tested under the idealized conditions of spectral evolution in one spatial direction with stationary uniform winds. The two-dimensional simulations are carried out over the Gulf of Tehuantepec for two research flights with the assumed steady wind forcing based on the airborne wind measurements, QuikSCAT scatterometer winds, and reanalysis model winds from NCEP/NARR. The computed wave spectra are directly compared to the airborne observations over a wide range of wave ages. The comparison between the observations and the numerical simulations highlights some of the issues associated with the source term balance in the tail of the spectrum. The performance of the model suggests that the Alves and Banner (2003) dissipation is a good first step for realistic simulations of the wind-wave spectrum. The possible reasons for differences between the measurements and the simulations are discussed.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1175/2009JPO4127.1
Other URLs:
Said, F. and Long, D.G. (2008). Effectiveness of QuikSCAT's Ultra-High Resolution Images in Determining Tropical Cyclone Eye Location, Proceedings of the International Geoscience and Remote Sensing Symposium, Vol. I, 351-354, 10.1109/IGARSS.2008.4778866. Conference Paper »
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Title: Effectiveness of QuikSCAT's Ultra-High Resolution Images in Determining Tropical Cyclone Eye Location
Type: Conference Paper
Publication: Proceedings of the International Geoscience and Remote Sensing Symposium, Vol. I
Author(s): Said, F. and Long, D.G.
Year: 2008
Formatted Citation: Said, F. and Long, D.G., 2008: Effectiveness of QuikSCAT's Ultra-High Resolution Images in Determining Tropical Cyclone Eye Location, Proceedings of the International Geoscience and Remote Sensing Symposium, Vol. I, 351-354, 10.1109/IGARSS.2008.4778866.
Abstract: The 25km resolution standard wind products (L2B) are available operationally in near-real time from SeaWinds on QuikSCAT. This relatively low resolution can be enhanced to yield a 2.5km ultra-high resolution (UHR) product that can be used to identify hurricane eye centers more accurately. A comparison is made between the analyst`s choice of eye location based on UHR images and interpolated best-track position. In this analysis, the UHR images are divided into two categories based on the analyst`s confidence level of finding the eye center location. In each category, statistical error quantities are computed. UHR images within the high-confidence category can provide, for a given year and basin, mean error distance as small as 15km with a 9km standard deviation. The use of these categories may facilitate the realization of QuikSCAT`s effectiveness in helping to identify and track hurricane eye centers. 2008 IEEE.
Keywords: QuikSCAT, Seawinds
Mission: |SeaWinds|
URL: https://doi.org/10.1109/IGARSS.2008.4778866
Other URLs:
Salinas, S.V. (2008). On the Possible Retrieval of Windwave States from Optical and NearIR Remote Sensing Imagery of the Ocean, 2007 IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2007, June 23, 2007 - June 28, 769-772, 10.1109/IGARSS.2007.4422910. Conference Paper »
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Title: On the Possible Retrieval of Windwave States from Optical and NearIR Remote Sensing Imagery of the Ocean
Type: Conference Paper
Publication: 2007 IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2007, June 23, 2007 - June 28
Author(s): Salinas, S.V.
Year: 2008
Formatted Citation: Salinas, S.V., 2008: On the Possible Retrieval of Windwave States from Optical and NearIR Remote Sensing Imagery of the Ocean, 2007 IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2007, June 23, 2007 - June 28, 769-772, 10.1109/IGARSS.2007.4422910.
Abstract: Since the pioneering work of Cox Munk , who first investigated the probability distribution of liquid surface facets using the analysis of aerial photographs of the Sun glitter, it has been widely recognized that the dominant parameter that determines the sea surface roughness is the mean square slope (MSS) of the sea surface which is mainly related to short wind waves and other surface effects in a lesser degree. Liquid surface reflection has been studied experimentally over the years and several empirical algorithms have been formulated relating wind speed directly to the MSS. Using these empirical formulations, the reflectivity of the liquid surface can be computed using a normal probability distribution of water surface facets and applying Fresnel relations to each surface facet. However, these approaches do not include the influence of wave states or the physical properties of the sea surface on the computation of the MSS. In a recent work, Salinas [1] has developed a radiative transfer model that incorporates a new windwave description for the MSS of the sea surface [2] . This model includes wind interaction and windwave states, such as wave age, as the main factors contributing to surface roughness. In this work, we apply the above mentioned radiative transfer model to the analysis of remote sensing data obtained from TERRA-MODIS satellite imagery taken near Sun glint regions. As as ancillary step, wind speed data, corresponding to TERRA-MODIS date of measurements and obtained from the SeaWinds instrument on the QuikScat satellite, are used to constrain the range of wind speed in our calculations.
Keywords: QuikSCAT, Seawinds
Mission:
URL: https://doi.org/10.1109/IGARSS.2007.4422910
Other URLs:
Shalina, E.V. and Johannessen, O.M. (2008). Multi Year Sea Ice Concentration Mapping Using Passive and Active Microwave Satellite Data, 2008 Microwave Radiometry and Remote Sensing of the Environment - 10th Specialist Meeting, MICRORAD, March 11, 2008 - March 14, 1-4, 10.1109/MICRAD.2008.4579513. Conference Paper »
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Title: Multi Year Sea Ice Concentration Mapping Using Passive and Active Microwave Satellite Data
Type: Conference Paper
Publication: 2008 Microwave Radiometry and Remote Sensing of the Environment - 10th Specialist Meeting, MICRORAD, March 11, 2008 - March 14
Author(s): Shalina, E.V. and Johannessen, O.M.
Year: 2008
Formatted Citation: Shalina, E.V. and Johannessen, O.M., 2008: Multi Year Sea Ice Concentration Mapping Using Passive and Active Microwave Satellite Data, 2008 Microwave Radiometry and Remote Sensing of the Environment - 10th Specialist Meeting, MICRORAD, March 11, 2008 - March 14, 1-4, 10.1109/MICRAD.2008.4579513.
Abstract: Though changes of the full ice cover in the Arctic are well described due to availability for processing SMMR/SSMI passive microwave data, changes of the composition of the arctic ice cover, in terms of ice types still need to be quantified, at least for winter season. Algorithms for mapping multiyear ice concentrations based on passive microwave data suffer from a number of problems. In this paper, those problems are described and it has been shown that QuikSCAT scatterometer data can add complimentary information to that available from passive microwave, which can assist in fixing the boundary between first-year and multiyear ice and in removing erroneously classified by passive microwave algorithm multiyear ice in the ice edge area. 2008 IEEE.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1109/MICRAD.2008.4579513
Other URLs:
Shanmugam, P., Ahn, Y.-H., and Ram, P.S. (2008). SeaWiFS Sensing of Hazardous Algal Blooms and Their Underlying Mechanisms in Shelf-Slope Waters of the Northwest Pacific During Summer, Remote Sensing of Environment, 112(7), 3248-3270, 10.1016/j.rse.2008.04.002. Journal Article »
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Title: SeaWiFS Sensing of Hazardous Algal Blooms and Their Underlying Mechanisms in Shelf-Slope Waters of the Northwest Pacific During Summer
Type: Journal Article
Publication: Remote Sensing of Environment
Author(s): Shanmugam, P., Ahn, Y.-H., and Ram, P.S.
Year: 2008
Formatted Citation: Shanmugam, P., Ahn, Y.-H., and Ram, P.S., 2008: SeaWiFS Sensing of Hazardous Algal Blooms and Their Underlying Mechanisms in Shelf-Slope Waters of the Northwest Pacific During Summer, Remote Sensing of Environment, 112(7), 3248-3270, 10.1016/j.rse.2008.04.002.
Abstract: RCA-chlorophyll (red tide index chlorophyll algorithm - RCA) estimates from the SeaWiFS, sea surface height (SSH) variations/geostrophic currents from the multi-satellite altimeters, sea surface temperature (SST) from the NOAA-AVHRR, and wind speed/direction from the QuikSCAT are used in conjugation with field observation data to first describe comprehensively the occurrences of various hazardous algal blooms (HABs) and their underlying mechanisms and link to nutrient enrichment during the summer (June-September) in shelf-slope waters off the Northwest Pacific (NWP) covering China, Korea, Japan and Russia (perhaps this is the first satellite-based study in Russia). These datasets provide a coherent view of the summertime evolution of HABs and related physical processes in the above regional segments with four common dynamic regions: coastal cold/estuary water zones, upwelling zones next to the coast, repeated meanders/eddies, and frontal regimes induced by the Kuroshio and its tributaries. Summer HABs numerically dominated by dinoflagellates and diatoms (only in few cases) were initiated in these hydrodynamically active coastal regions and subsequently transported throughout their coastal and oceanic ranges by major currents and eddy systems. As a consequence, dense and colossal blooms displayed mean RCA of 7mg m- 3 and TBCA (total bloom covered area) of 20 103km2, which limits the research vessels to observe concomitantly their spatially explicit phases together with physical oceanographic features in such large regions. Less dense and spatially disbanded blooms were characterized by mean RCA of 3mg m- 3 and TBCA of 8 103km2. Besides those of the nutrient-abundant zones, high blooms coincided with the coastal upwelling and cyclonic eddy regimes that followed SST minimum and large negative SSH along with favorable phase of winds. By contrast, relatively low mean RCA were consistent with the fronts and anticyclonic meanders revealing moderate-high SSH fields along with variable winds blown off the NWP coast. These anticyclonic meanders, on some occasions, when nutrient-containing coastal water setoff higher chlorophyll biomass and major currents gained force in August, straddled the continental margin, entraining high chlorophyll water from the coast and from the adjacent cyclonic eddies (and upwelling) located nearby into their outer rings that formed a conveyer-belt system of transport to inject coastal blooms into the deep-sea (e.g., East Sea) region of the NWP. The above findings based on satellite data combined with field hydrographic/bloom observation data evidently illustrated richness of the response of summer HABs to the surface circulation and nutrient enrichment processes in shelf-slope waters off the NWP coast.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1016/j.rse.2008.04.002
Other URLs:
Sharma, N. and D'Sa, E. (2008). Assessment and Analysis of QuikSCAT Vector Wind Products for the Gulf of Mexico: A Long-Term and Hurricane Analysis, Sensors, 8(3), 1927-1949, 10.3390/s8031927. Journal Article »
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Title: Assessment and Analysis of QuikSCAT Vector Wind Products for the Gulf of Mexico: A Long-Term and Hurricane Analysis
Type: Journal Article
Publication: Sensors
Author(s): Sharma, N. and D'Sa, E.
Year: 2008
Formatted Citation: Sharma, N. and D'Sa, E., 2008: Assessment and Analysis of QuikSCAT Vector Wind Products for the Gulf of Mexico: A Long-Term and Hurricane Analysis, Sensors, 8(3), 1927-1949, 10.3390/s8031927.
Abstract: The northern Gulf of Mexico is a region that has been frequently impacted in recent years by natural disasters such as hurricanes. The use of remote sensing data such as winds from NASA`s QuikSCAT satellite sensor would be useful for emergency preparedness during such events. In this study, the performance of QuikSCAT products, including JPL`s latest Level 2B (L2B) 12.5 km swath winds, were evaluated with respect to buoy-measured winds in the Gulf of Mexico for the period January 2005 to February 2007. Regression analyses indicated better accuracy of QuikSCAT`s L2B DIRTH, 12.5 km than the Level 3 (L3), 25 km wind product. QuikSCAT wind data were compared directly with buoy data keeping a maximum time interval of 20 min and spatial interval of 0.1 (approximate to 10 km). R-2 values for moderate wind speeds were 0.88 and 0.93 for L2B, and 0.75 and 0.89 for L3 for speed and direction, respectively. QuikSCAT wind comparisons for buoys located offshore were better than those located near the coast. Hurricanes that took place during 2002-06 were studied individually to obtain regressions of QuikSCAT versus buoys for those events. Results show QuikSCAT`s L2B DIRTH wind product compared well with buoys during hurricanes up to the limit of buoy measurements. Comparisons with the National Hurricane Center (NHC) best track analyses indicated QuikSCAT winds to be lower than those obtained by NHC, possibly due to rain contamination, while buoy measurements appeared to be constrained at high wind speeds. This study has confirmed good agreement of the new QuikSCAT L2B product with buoy measurements and further suggests its potential use during extreme weather conditions in the Gulf of Mexico.
Keywords: QuikSCAT, NSCAT, Seawinds, Seawinds
Mission:
URL: https://doi.org/10.3390/s8031927
Other URLs:
Shay, L.K. and Uhlhorn, E.W. (2008). Loop Current Response to Hurricanes Isidore and Lili, Monthly Weather Review, 136(9), 3248-3274, 10.1175/2007MWR2169.1. Journal Article »
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Title: Loop Current Response to Hurricanes Isidore and Lili
Type: Journal Article
Publication: Monthly Weather Review
Author(s): Shay, L.K. and Uhlhorn, E.W.
Year: 2008
Formatted Citation: Shay, L.K. and Uhlhorn, E.W., 2008: Loop Current Response to Hurricanes Isidore and Lili, Monthly Weather Review, 136(9), 3248-3274, 10.1175/2007MWR2169.1.
Abstract: Recent hurricane activity over the Gulf of Mexico basin has underscored the importance of the Loop Current (LC) and its deep, warm thermal structure on hurricane intensity. During Hurricanes Isidore and Lili in 2002, research flights were conducted from both National Oceanic and Atmospheric Administration (NOAA) WP-3D aircraft to observe pre-, in- and poststorm ocean conditions using airborne expendable ocean profilers to measure temperature, salinity, and current structure. Atmospheric thermodynamic and wind profiles and remotely sensed surface winds were concurrently acquired as each storm moved over the LC. Observed upper-ocean cooling was about 1 degree C as Isidore moved across the Yucatan Straits at a speed of 4 m s-1. Given prestorm ocean heat content (OHC) levels exceeding 100 kJ cm-2 in the LC (current velocities >1 m s-1), significant cooling and deepening of the ocean mixed layer (OML) did not occur in the straits. Estimated surface enthalpy flux at Isidore`s eyewall was 1.8 kW m-2, where the maximum observed wind was 49 m s-1. Spatially integrating these surface enthalpy fluxes suggested a maximum surface heat loss of 9.5 kJ cm-2 at the eyewall. Over the Yucatan Shelf, observed ocean cooling of 4.5 degree C was caused by upwelling processes induced by wind stress and an offshore wind-driven transport. During Hurricane Lili, ocean cooling in the LC was similar to 1 degree C but more than 2 degree C in the Gulf Common Water, where the maximum estimated surface enthalpy flux was 1.4 kW m-2, associated with peak surface winds of 51 m s-1. Because of Lili`s asymmetric structure and rapid translational speed of 7 m s-1, the maximum surface heat loss resulting from the surface enthalpy flux was less than 5 kJ cm-2. In both hurricanes, the weak ocean thermal response in the LC was primarily due to the lack of energetic near-inertial current shears that develop across the thin OML observed in quiescent regimes. Bulk Richardson numbers remained well above criticality because of the strength of the upper-ocean horizontal pressure gradient that forces northward current and thermal advection of warm water distributed over deep layers. As these oceanic regimes are resistive to shear-induced mixing, hurricanes experience a more sustained surface enthalpy flux compared to storms moving over shallow quiescent mixed layers. Because ocean cooling levels induced by hurricane force winds depend on the underlying oceanic regimes, features must be accurately initialized in coupled forecast models.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1175/2007MWR2169.1
Other URLs:
Shimada, T. and Kawamura, H. (2008). Wind Jet Transition and Its Localized Impact on Wave Height Distribution Along the Pacific Coast of Northern Japan, 2007 IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2007, June 23, 2007 - June 28, 10.1109/IGARSS.2007.4423605. Conference Paper »
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Title: Wind Jet Transition and Its Localized Impact on Wave Height Distribution Along the Pacific Coast of Northern Japan
Type: Conference Paper
Publication: 2007 IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2007, June 23, 2007 - June 28
Author(s): Shimada, T. and Kawamura, H.
Year: 2008
Formatted Citation: Shimada, T. and Kawamura, H., 2008: Wind Jet Transition and Its Localized Impact on Wave Height Distribution Along the Pacific Coast of Northern Japan, 2007 IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2007, June 23, 2007 - June 28, 10.1109/IGARSS.2007.4423605.
Abstract: We present a case study of low-level wind jets induced in sequence by orographic effects off the Pacific coast of northern Japan during 7-11 June 2003, and demonstrate that the transition of the wind jets causes areal differences of the wave height variations along the coast. First, we analyze SeaWinds scatterometer wind measurements. Under the easterly wind, a strong wind jet formed after passing by Cape Erimo. As the wind shifted to the southeast, the wind jet started to decay. In turn, the southerly wind along the coast led to another wind jet in the lee of the easternmost tip of the Sanriku coast. Then, we identify onsets and decays of the wind jets from time series of wind speed at meteorological stations. Finally, we demonstrate that the transition of the wind jets has local impacts on wave height variations. Significant wave heights measured by altimeters were correlated positively with local wind energy, i.e., squares of wind speeds. Accompanying the wind jet formation/decline, significant differences of wave height variations became marked among wave observation stations located along the coast at intervals of up to 50 km. 2007 IEEE.
Keywords: Seawinds
Mission:
URL: https://doi.org/10.1109/IGARSS.2007.4423605
Other URLs:
Sikora, T.D., Dierking, C.F., and Winstead, N.S. (2008). Summary of the North Pacific Environmental Satellite Workshop for Coastal and Marine Applications, National Weather Digest, 32(1), 55-60. Journal Article »
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Title: Summary of the North Pacific Environmental Satellite Workshop for Coastal and Marine Applications
Type: Journal Article
Publication: National Weather Digest
Author(s): Sikora, T.D., Dierking, C.F., and Winstead, N.S.
Year: 2008
Formatted Citation: Sikora, T.D., Dierking, C.F., and Winstead, N.S., 2008: Summary of the North Pacific Environmental Satellite Workshop for Coastal and Marine Applications, National Weather Digest, 32(1), 55-60.
Abstract: This paper summarizes the North Pacific Environmental Satellite Workshop for Coastal and Marine Applications, which was held 29-30 May 2007 at The University of Alaska Southeast, Juneau, AK. The two goals of the workshop were: 1) to provide a forum for presentation and discussion of research and development regarding the application of environmental satellite data to a variety of coastal and marine issues in the North Pacific Ocean, and 2) to solicit feedback from the local user community regarding current and desired environmental satellite user products. This paper outlines the workshop`s 21 oral presentations, two panel discussions, and the resulting list of recommendations.
Keywords: QuikSCAT
Mission:
URL: http://nwafiles.nwas.org/digest/papers/2008/Vol32No1/Pg55-Sikora-MeetingSummary.pdf
Other URLs:
Singer, J. (2008). NOAA Chief Seeks International Sources for Hurricane Data, Space News, 19(9), 13, 17. Journal Article »
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Title: NOAA Chief Seeks International Sources for Hurricane Data
Type: Journal Article
Publication: Space News
Author(s): Singer, J.
Year: 2008
Formatted Citation: Singer, J., 2008: NOAA Chief Seeks International Sources for Hurricane Data, Space News, 19(9), 13, 17.
Abstract: The U.S. National Oceanic and Atmospheric Administration (NOAA) is looking to international partners, including China and India, as possible sources of critical hurricane forecasting measurements that today are taken by an aging NASA satellite. NOAA Administrator Conrad Lautenbacher told the House Science and Technology energy and environment subcommittee during a Feb. 26 hearing that the agency is having discussions with those Asian space powers about obtaining ocean-surface wind data from their planned satellites to mitigate the eventual loss of NASA`s Quick Scatterometer, or QuikScat, spacecraft, which is already well past its expected lifetime.
Keywords: QuikSCAT
Mission:
URL: https://spacenews.com/noaa-chief-seeks-international-source-hurricane-data/
Other URLs:
Skourup, H., Forsberg, R., and Jolicoeur, P. (2008). Geoid, Sea Level and Vertical Datum of the Arctic, Improved by ICESat and GRACE, Geomatica (Ottawa), 62(2), 189-201, 10.5623/geomat-2008-0022. Journal Article »
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Title: Geoid, Sea Level and Vertical Datum of the Arctic, Improved by ICESat and GRACE
Type: Journal Article
Publication: Geomatica (Ottawa)
Author(s): Skourup, H., Forsberg, R., and Jolicoeur, P.
Year: 2008
Formatted Citation: Skourup, H., Forsberg, R., and Jolicoeur, P., 2008: Geoid, Sea Level and Vertical Datum of the Arctic, Improved by ICESat and GRACE, Geomatica (Ottawa), 62(2), 189-201, 10.5623/geomat-2008-0022.
Abstract: In the Arctic, a vertical reference system is typically based on local sea-level and tide gauge observations. When using GPS for height measurement, a local geoid model, fitted to sea level, must therefore be used. Developments in satellite altimetry, such as NASA ICESat, which has since 2003 provided laser altimetry over the ice-covered regions up to 86??N, allows the direct measurement of sea level (or sea ice surface heights) even in narrow straits and fjords. Improved geoid models from GRACE, in combination with local gravity data, provide a new way to define a uniform vertical datum at sub-dm accuracy across larger regions of the Arctic, suitable for height measurement using GPS. This paper describes the use of ICESat laser altimetry data to estimate a mean sea surface (MSS) for the Arctic, using a low-level filtering method, in combination with an updated geoid model, based on updated surface, airborne and satellite gravity data (ArcGP and GRACE). As part of the ICESat MSS determination, we also determine sea ice freeboard heights, which show a good correlation to multi-year ice distribution as determined from QuikSCAT. Using the MSS and geoid model, the dynamic ocean topography can be determined. Some comparisons are shown of this ocean topography to oceanographic models derived in a recent ESA European-Canadian study called ??ArcGICE??. The variations in local ocean topography are the primary source of vertical datum offsets, and we illustrate the local variation of the sea-surface heights, tides and geoid by recent GPS profiles along fjords in western Greenland, carried out to validate local geoid models.
Keywords: GRACE, QuikSCAT
Mission:
URL: https://doi.org/10.5623/geomat-2008-0022
Other URLs:
Soisuvarn, S., Jelenak, Z., and Chang, P.S. (2008). A Geophysical Model Function for WindSat Polarimetric Radiometer Wind Retrievals Using Linear Polarizations, 2007 IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2007, June 23, 2007 - June 28, 2523-2526, 10.1109/IGARSS.2007.4423357. Conference Paper »
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Title: A Geophysical Model Function for WindSat Polarimetric Radiometer Wind Retrievals Using Linear Polarizations
Type: Conference Paper
Publication: 2007 IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2007, June 23, 2007 - June 28
Author(s): Soisuvarn, S., Jelenak, Z., and Chang, P.S.
Year: 2008
Formatted Citation: Soisuvarn, S., Jelenak, Z., and Chang, P.S., 2008: A Geophysical Model Function for WindSat Polarimetric Radiometer Wind Retrievals Using Linear Polarizations, 2007 IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2007, June 23, 2007 - June 28, 2523-2526, 10.1109/IGARSS.2007.4423357.
Abstract: In this paper, we develop a novel geophysical model function (GMF) for the WindSat radiometer relating the vertically (V-pol) and horizontally (H-pol) polarized brightness temperature (TB) to the ocean surface wind field. The brightness temperature data from the 10, 18 and 37 GHz channels were used in this analysis. The brightness temperature combination of the form (AV-H) is found to be mostly independent of the atmospheric variations, where A is a constant number for each frequency. The GMF was developed empirically using the collocated wind vectors from the QuikSCAT scatterometer retrieval as truth and the WindSat`s (AV-H) TB`s. We examined the characteristic of the GMF and explored the opportunity to improve our current WindSat wind direction retrieval that utilizes only 3rd and 4th Stokes measurements, by integrating this GMF. The strength of the wind directional signals is encouraging for moderate wind speed at 8 m/s and higher. 2007 IEEE.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1109/IGARSS.2007.4423357
Other URLs:
Soisuvarn, S., Jelenak, Z., Chang, P.S., Zhu, Q., and Sindic-Rancic, G. (2008). Validation of NOAA's Near Real-Time ASCAT Ocean Vector Winds, International Geoscience and Remote Sensing Symposium (IGARSS), I-118-I-121, 10.1109/IGARSS.2008.4778807. Conference Paper »
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Title: Validation of NOAA's Near Real-Time ASCAT Ocean Vector Winds
Type: Conference Paper
Publication: International Geoscience and Remote Sensing Symposium (IGARSS)
Author(s): Soisuvarn, S., Jelenak, Z., Chang, P.S., Zhu, Q., and Sindic-Rancic, G.
Year: 2008
Formatted Citation: Soisuvarn, S., Jelenak, Z., Chang, P.S., Zhu, Q., and Sindic-Rancic, G., 2008: Validation of NOAA's Near Real-Time ASCAT Ocean Vector Winds, International Geoscience and Remote Sensing Symposium (IGARSS), I-118-I-121, 10.1109/IGARSS.2008.4778807.
Abstract: The ASCAT, launched on board MetOp-A satellite on October 19th 2006, is a C-band scatterometer operating at 5.255 GHz using fan-beam antennae to measure near surface vector wind over the world`s ocean. NOAA produces near-real-time ASCAT wind product at 50 and 25km resolutions. These wind data are validated against global wind field model and satellite observation from QuikSCAT. The results show ASCAT wind speed retrievals perform well for low to moderate wind speed under most weather conditions, but are underestimated for wind speeds 15 m/s. The standard deviation wind direction errors are well below 20 degrees for wind speed 5 m/s. 2008 IEEE.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1109/IGARSS.2008.4778807
Other URLs:
Stoffelen, A., Portabella, M., Verhoef, A., Verspeek, J., and Vogelzang, J. (2008). High-Resolution ASCAT Scatterometer Winds Near the Coast, International Geoscience and Remote Sensing Symposium (IGARSS), 1(1), I114-I117, 10.1109/IGARSS.2008.4778806. Journal Article »
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Title: High-Resolution ASCAT Scatterometer Winds Near the Coast
Type: Journal Article
Publication: International Geoscience and Remote Sensing Symposium (IGARSS)
Author(s): Stoffelen, A., Portabella, M., Verhoef, A., Verspeek, J., and Vogelzang, J.
Year: 2008
Formatted Citation: Stoffelen, A., Portabella, M., Verhoef, A., Verspeek, J., and Vogelzang, J., 2008: High-Resolution ASCAT Scatterometer Winds Near the Coast, International Geoscience and Remote Sensing Symposium (IGARSS), 1(1), I114-I117, 10.1109/IGARSS.2008.4778806.
Abstract: The Advanced scatterometer, ASCAT, on MetOp-A was launched on 19 October 2006 as the third wind scatterometer currently in space joining up with the ERS-2 and the SeaWinds scatterometers. Scatterometers measure the radar backscatter from wind-generated cm-size gravitycapillary waves and provide high-resolution wind vector fields over the sea with high quality. In this paper we show progress in high resolution processing and its verification and in processing closer to the coast.
Keywords: Seawinds
Mission:
URL: https://doi.org/10.1109/IGARSS.2008.4778806
Other URLs:
Stuart, K.M. and Long, D.G. (2008). Analysis of Antarctic Iceberg and Sea Ice Melting Patterns Using Quikscat, International Geoscience and Remote Sensing Symposium (IGARSS), 10.1109/IGARSS.2008.4780060. Conference Paper »
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Title: Analysis of Antarctic Iceberg and Sea Ice Melting Patterns Using Quikscat
Type: Conference Paper
Publication: International Geoscience and Remote Sensing Symposium (IGARSS)
Author(s): Stuart, K.M. and Long, D.G.
Year: 2008
Formatted Citation: Stuart, K.M. and Long, D.G., 2008: Analysis of Antarctic Iceberg and Sea Ice Melting Patterns Using Quikscat, International Geoscience and Remote Sensing Symposium (IGARSS), 10.1109/IGARSS.2008.4780060.
Abstract: QuikSCAT tracking of Antarctic icebergs is discussed, and iceberg movement trends are illustrated. Iceberg melting factors are explored and a backscatter time-series is presented. Interactions between iceberg and sea ice are examined using QuikSCAT data. To improve QuikSCAT sea ice mapping capability, a threshold algorithm to detect polynyas is developed. The 2006-2007 Antarctic ablation season is analyzed and correlations between polynya formation and sea ice melting are explored. General sea ice melting patterns are discussed, and statistics are derived from QuikSCAT`s life mission and compared with SSM/I measurements. This study finds that while average Antarctic sea ice coverage is increasing, minimum sea ice extent is decreasing. 2008 IEEE.
Keywords: QuikSCAT
Mission: |SeaWinds|
URL: https://doi.org/10.1109/IGARSS.2008.4780060
Other URLs:
Thadathil, P., Thoppil, P., Rao, R.R., Muraleedharan, P.M., Somayajulu, Y.K., Gopalakrishna, V.V., Murthugudde, R., Reddy, G.V., and Revichandran, C. (2008). Seasonal Variability of the Observed Barrier Layer in the Arabian Sea, Journal of Physical Oceanography, 38(3), 624-638, 10.1175/2007JPO3798.1. Journal Article »
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Title: Seasonal Variability of the Observed Barrier Layer in the Arabian Sea
Type: Journal Article
Publication: Journal of Physical Oceanography
Author(s): Thadathil, P., Thoppil, P., Rao, R.R., Muraleedharan, P.M., Somayajulu, Y.K., Gopalakrishna, V.V., Murthugudde, R., Reddy, G.V., and Revichandran, C.
Year: 2008
Formatted Citation: Thadathil, P., Thoppil, P., Rao, R.R., Muraleedharan, P.M., Somayajulu, Y.K., Gopalakrishna, V.V., Murthugudde, R., Reddy, G.V., and Revichandran, C., 2008: Seasonal Variability of the Observed Barrier Layer in the Arabian Sea, Journal of Physical Oceanography, 38(3), 624-638, 10.1175/2007JPO3798.1.
Abstract: The formation mechanisms of the barrier layer (BL) and its seasonal variability in the Arabian Sea (AS) are studied using a comprehensive dataset of temperature and salinity profiles from Argo and other archives for the AS. Relatively thick BL of 20-60 m with large spatial extent is found in the central-southwestern AS (CSWAS), the convergence zone of the monsoon wind, during the peak summer monsoon (July-August) and in the southeastern AS (SEAS) and northeastern AS (NEAS) during the winter (January-February). Although the BL in the SEAS has been reported before, the observed thick BL in the central-southwestern AS during the peak summer monsoon and in the northeastern AS during late winter are the new findings of this study. The seasonal variability of BL thickness (BLT) is closely related to the processes that occur during summer and winter monsoons. During both seasons, the Ekman processes and the distribution of low-salinity waters in the surface layer show a dominant influence on the observed BLT distributions. In addition, Kelvin and Rossby waves also modulate the observed BL thickness in the AS. The relatively low salinity surface water overlying the Arabian Sea high-salinity water (ASHSW) provides an ideal ground for strong haline stratification in the CSWAS (during summer monsoon) and in NEAS (during winter monsoon). During summer, northward advection of equatorial low-salinity water by the Somali Current and the offshore advection of low-salinity water from the upwelling region facilitate the salinity stratification that is necessary to develop the observed BL in the CSWAS. In the SEAS, during winter, the winter monsoon current (WMC) carries less saline water over relatively high salinity ambient water to form the observed BL there. The winter West India Coastal Current (WICC) transports the low-salinity water from the SEAS to the NEAS, where it lies over the subducted ASHSW leading to strong haline stratification. Ekman pumping together with the downwelling Kelvin wave in the NEAS deepen the thermocline to cause the observed thick BL in the NEAS.
Keywords: Jason, QuikSCAT
Mission:
URL: https://doi.org/10.1175/2007JPO3798.1
Other URLs:
Trenary, L.L. and Han, W. (2008). Causes of Decadal Subsurface Cooling in the Tropical Indian Ocean During 1961-2000, Geophysical Research Letters, 35(17), 10.1029/2008GL034687. Journal Article »
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Title: Causes of Decadal Subsurface Cooling in the Tropical Indian Ocean During 1961-2000
Type: Journal Article
Publication: Geophysical Research Letters
Author(s): Trenary, L.L. and Han, W.
Year: 2008
Formatted Citation: Trenary, L.L. and Han, W., 2008: Causes of Decadal Subsurface Cooling in the Tropical Indian Ocean During 1961-2000, Geophysical Research Letters, 35(17), 10.1029/2008GL034687.
Abstract: The vertical structure of temperature change in the Indian Ocean (IO) during 1961-2000 indicates that a region of tropical thermocline cooling accompanies the upper level warming. Results from data analysis and ocean general circulation model experiments suggest that the cooling signals exceed the cross-data and cross-model differences. Spatial patterns of the temperature trend above 200 m resemble the negative IO dipole structure, with the strongest cooling occurring in the western-central basin south of the equator. The upper thermocline cooling is mainly caused by enhanced Ekman pumping velocity, which shoals the thermocline. The enhanced upwelling is consistent with the strengthened Southern subtropical cell. Enhanced equatorial westerly winds contribute to the negative dipole pattern. Remote forcing from the Pacific may contribute to the cooling below 200 m and further south.
Keywords: Indian Ocean; decadal variability; thermocline cooling
Mission:
URL: https://doi.org/10.1029/2008GL034687
Other URLs:
Vinodkumar, Chandrasekar, A., Alapaty, K., and Niyogi, D. (2008). The Impacts of Indirect Soil Moisture Assimilation and Direct Surface Temperature and Humidity Assimilation on a Mesoscale Model Simulation of an Indian Monsoon Depression, Journal of Applied Meteorology and Climatology, 47(5), 1393-1412, 10.1175/2007JAMC1599.1. Journal Article »
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Title: The Impacts of Indirect Soil Moisture Assimilation and Direct Surface Temperature and Humidity Assimilation on a Mesoscale Model Simulation of an Indian Monsoon Depression
Type: Journal Article
Publication: Journal of Applied Meteorology and Climatology
Author(s): Vinodkumar, Chandrasekar, A., Alapaty, K., and Niyogi, D.
Year: 2008
Formatted Citation: Vinodkumar, Chandrasekar, A., Alapaty, K., and Niyogi, D., 2008: The Impacts of Indirect Soil Moisture Assimilation and Direct Surface Temperature and Humidity Assimilation on a Mesoscale Model Simulation of an Indian Monsoon Depression, Journal of Applied Meteorology and Climatology, 47(5), 1393-1412, 10.1175/2007JAMC1599.1.
Abstract: This study investigates the impact of the Flux-Adjusting Surface Data Assimilation System (FASDAS) and the four-dimensional data assimilation (FDDA) using analysis nudging on the simulation of a monsoon depression that formed over India during the 1999 Bay of Bengal Monsoon Experiment (BOBMEX) field campaign. FASDAS allows for the indirect assimilation/ adjustment of soil moisture and soil temperature together with continuous direct surface data assimilation of surface temperature and surface humidity. Two additional numerical experiments [control (CTRL) and FDDA] were conducted to assess the relative improvements to the simulation by FASDAS. To improve the initial analysis for the FDDA and the surface data assimilation (SDA) runs, the fifth-generation Pennsylvania State University-NCAR Mesoscale Model (MM5) simulation utilized the humidity and temperature profiles from the NOAA Television Infrared Observation Satellite (TIROS) Operational Vertical Sounder (TOVS), surface winds from the Quick Scatterometer (QuikSCAT), and the conventional meteorological upper-air (radiosonde/rawinsonde, pilot balloon) and surface data. The results from the three simulations are compared with each other as well as with NCEP-NCAR reanalysis, the Tropical Rainfall Measuring Mission (TRMM), and the special buoy, ship, and radiosonde observations available during BOBMEX. As compared with the CTRL, the FASDAS and the FDDA runs resulted in (i) a relatively better-developed cyclonic circulation and (ii) a larger spatial area as well as increased rainfall amounts over the coastal regions after landfall. The FASDAS run showed a consistently improved model simulation performance in terms of reduced rms errors of surface humidity and surface temperature as compared with the CTRL and the FDDA runs.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1175/2007JAMC1599.1
Other URLs:
Volkov, D.L., Lee, T., and Fu, L.-L. (2008). Eddy-Induced Meridional Heat Transport in the Ocean, Geophysical Research Letters: Oceans, 35, L20601, 10.1029/2008GL035490. Journal Article »
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Title: Eddy-Induced Meridional Heat Transport in the Ocean
Type: Journal Article
Publication: Geophysical Research Letters: Oceans
Author(s): Volkov, D.L., Lee, T., and Fu, L.-L.
Year: 2008
Formatted Citation: Volkov, D.L., Lee, T., and Fu, L.-L., 2008: Eddy-Induced Meridional Heat Transport in the Ocean, Geophysical Research Letters: Oceans, 35, L20601, 10.1029/2008GL035490.
Abstract: A global ocean data synthesis product at eddy-permitting resolution from Estimating the Circulation and Climate of the Ocean, Phase II (ECCO2) project are used to estimate the oceanic eddy heat transport. We show that in a number of locations the time-mean eddy heat transport constitutes a considerable portion of the total time-mean heat transport, in particular, in the tropics, in the Southern Ocean and in the Kuroshio Current. This research demonstrates that the variability of the eddy heat transport is a significant contributor to the variability of the total heat transport and globally it explains about 1/3 of its variance. Eddies are also found to explain a significant portion of the seasonal-interannual heat transport variance.
Keywords: eddy heat transport, oceanic heat transport
Mission:
URL: https://doi.org/10.1029/2008GL035490
Other URLs:
Wang, H., Fu, R., Schemm, J.K., Tang, W., and Liu, W.T. (2008). Predictability of South American Low-Level Jet Using QuikSCAT Ocean Surface Wind, International Journal of Remote Sensing, 29(21), 6117-6127, 10.1080/01431160802175512. Journal Article »
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Title: Predictability of South American Low-Level Jet Using QuikSCAT Ocean Surface Wind
Type: Journal Article
Publication: International Journal of Remote Sensing
Author(s): Wang, H., Fu, R., Schemm, J.K., Tang, W., and Liu, W.T.
Year: 2008
Formatted Citation: Wang, H., Fu, R., Schemm, J.K., Tang, W., and Liu, W.T., 2008: Predictability of South American Low-Level Jet Using QuikSCAT Ocean Surface Wind, International Journal of Remote Sensing, 29(21), 6117-6127, 10.1080/01431160802175512.
Abstract: The applicability of NASA QuikSCAT ocean surface wind was tested for predicting South American low-level jets (SALLJs) with a statistical model. Our previous study (Wang, H. and Fu, R., 2004, Influence of cross-Andes flow on the South American low-level jet. Journal of Climate, 17, pp. 1247-1262) has examined the dynamic process associated with austral winter SALLJs using the ECMWF Reanalyses (ERA) and identified the mechanism that controls the seasonal and synoptic variations of the SALLJ. It was found that the SALLJ is maintained by strong zonal pressure gradients, with a maximum near 850 hPa caused by deflection of upstream zonal flow crossing the Andes and lee cyclogenesis. The robustness of this mechanism was further examined in this study using the NCEP-NCAR Reanalysis 1 (NCEP-R1) and NCEP-DOE Reanalysis 2 (NCEP-R2). The northerly LLJs to the east of the Andes are strongest in ERA, with wind speeds well above 15 ms-1. In NCEP-R1 and R2, typical wind speeds are about 12 and 10 m s-1, respectively. A statistical analysis of the three reanalysis datasets indicates that the SALLJ significantly correlates with the zonal wind of previous days over the South Pacific, particularly with the surface zonal wind. Based on this result, a statistical model introduced in Wang and Fu (2004) was employed in this study for forecasting the SALLJ using the QuikSCAT ocean surface wind as a predictor. The model was applied to June, July and August of 1999 to 2006 for up to 5 day forecasts of the SALLJ. Cross validations of the hindcasts indicate significant predictability of strong LLJ events with the QuikSCAT ocean surface wind data.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1080/01431160802175512
Other URLs:
Wang, L., Derksen, C., and Brown, R. (2008). Detection of Pan-Arctic Terrestrial Snowmelt from QuikSCAT, 2000-2005, Remote Sensing of Environment, 112(10), 3794-3805, 10.1016/j.rse.2008.05.017. Journal Article »
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Title: Detection of Pan-Arctic Terrestrial Snowmelt from QuikSCAT, 2000-2005
Type: Journal Article
Publication: Remote Sensing of Environment
Author(s): Wang, L., Derksen, C., and Brown, R.
Year: 2008
Formatted Citation: Wang, L., Derksen, C., and Brown, R., 2008: Detection of Pan-Arctic Terrestrial Snowmelt from QuikSCAT, 2000-2005, Remote Sensing of Environment, 112(10), 3794-3805, 10.1016/j.rse.2008.05.017.
Abstract: New pan-Arctic (>60N) snowmelt onset and end date records (2000-2005) were produced from enhanced resolution (4.45km) QuikSCAT (QSCAT) Ku-band backscatter measurements. A modified threshold method was used to detect multiple melt events and the main melt event was identified by the longest melt duration or the largest melt intensity. Algorithm validation was performed with a Circum-Arctic network of station measurements extracted from the Global Surface Summary of Day product maintained by the National Climatic Data Center (NCDC). Estimates of melt onset date corresponded to a clear shift in the statistical distribution of mean daily air temperatures from largely below freezing to above freezing. Melt was not detected in 7% of the cases mainly over dense boreal forest cover, or very shallow tundra snow cover. QSCAT- derived melt end dates were significantly correlated with station-derived snow-off estimates (r2 = 0.79, RMSE = 11.6days). The difference between the two estimates was within one week for 70% of the cases so there is good potential to use QSCAT-derived melt end dates to approximate snow-off dates across the pan-Arctic region. There was a tendency for QSCAT-derived snow-off dates to be biased early over dense forest regions due to a diminished backscatter melt signature.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1016/j.rse.2008.05.017
Other URLs:
Wang, L., Lau, K. -H, Fung, C. -H, and Zhang, Q. (2008). Features of Ocean Surface Winds Observed by the QuikSCAT Satellite Before Tropical Cyclogenesis over the South China Sea, Journal of Ocean University of China, 7(3), 241-245, 10.1007/s11802-008-0241-8. Journal Article »
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Title: Features of Ocean Surface Winds Observed by the QuikSCAT Satellite Before Tropical Cyclogenesis over the South China Sea
Type: Journal Article
Publication: Journal of Ocean University of China
Author(s): Wang, L., Lau, K. -H, Fung, C. -H, and Zhang, Q.
Year: 2008
Formatted Citation: Wang, L., Lau, K. -H, Fung, C. -H, and Zhang, Q., 2008: Features of Ocean Surface Winds Observed by the QuikSCAT Satellite Before Tropical Cyclogenesis over the South China Sea, Journal of Ocean University of China, 7(3), 241-245, 10.1007/s11802-008-0241-8.
Abstract:
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1007/s11802-008-0241-8
Other URLs:
Weissman, D.E. and Bourassa, M.A. (2008). Estimating Air-Sea Momentum Flux Within Rain Using Measurements of Rain-Induced Sea Surface Roughness from Satellite Scatterometer Radar Cross Section, Ocean Sciences Meeting, American Geophysical Union.
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Title: Estimating Air-Sea Momentum Flux Within Rain Using Measurements of Rain-Induced Sea Surface Roughness from Satellite Scatterometer Radar Cross Section
Type: Conference Paper
Publication: Ocean Sciences Meeting, American Geophysical Union
Author(s): Weissman, D.E. and Bourassa, M.A.
Year: 2008
Formatted Citation: Weissman, D.E. and Bourassa, M.A., 2008: Estimating Air-Sea Momentum Flux Within Rain Using Measurements of Rain-Induced Sea Surface Roughness from Satellite Scatterometer Radar Cross Section, Ocean Sciences Meeting, American Geophysical Union.
Abstract: The momentum exchange between the boundary layer and the sea surface is dependent on the short water waves. In some ranges of wind speeds and rain intensities, the impacts of rain droplets will create waves and similar disturbances that will alter momentum transfer. Ku-band scatterometer measurements are affected by the presence of rain through this change in roughness. These satellite observations are also affected by atmospheric scattering and attenuation. We present a technique that removes the effects of the precipitation in the atmosphere and estimates the change related to surface roughness. This study combines satellite based Ku-band data with high-resolution 3-D volumetric rain measurements, from simultaneous NEXRAD data. The results to be presented were acquired during a significant rain event in the Gulf of Mexico. This rain-modified surface will alter the transfer of momentum, and in effect will change the drag coefficient and stress. These changes are particularly interesting because rain is often associated with active weather and strong ocean forcing. Neglecting these changes causes systematic errors in the climatic distribution of surface forcing, and hence the ocean response.
Keywords:
Mission:
URL:
Other URLs:
Weissman, D.E. and Bourassa, M.A. (2008). Measurements of the Effect of Rain-Induced Sea Surface Roughness on the QuikSCAT Scatterometer Radar Cross Section, IEEE Transactions on Geoscience and Remote Sensing, 46(10), 2882-2894, 10.1109/TGRS.2008.2001032. Journal Article »
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Title: Measurements of the Effect of Rain-Induced Sea Surface Roughness on the QuikSCAT Scatterometer Radar Cross Section
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Weissman, D.E. and Bourassa, M.A.
Year: 2008
Formatted Citation: Weissman, D.E. and Bourassa, M.A., 2008: Measurements of the Effect of Rain-Induced Sea Surface Roughness on the QuikSCAT Scatterometer Radar Cross Section, IEEE Transactions on Geoscience and Remote Sensing, 46(10), 2882-2894, 10.1109/TGRS.2008.2001032.
Abstract: Radar measurements of the sea surface, with satellite scatterometers that operate at Ku-band, are affected by the presence of rain through modification of the sea surface roughness by rain impacts. This is in addition to wind driven roughness, atmospheric scattering, and attenuation that affect the measured normalized radar cross section (NRCS). This paper presents a case study of the increase of the total radar cross section, averaged across surface illuminated areas (individual footprints) of the Sea Winds scatterometer (on QuikSCAT) caused by rain striking the sea surface. This effort combines satellite-based Ku-band data with high-resolution 3-D volumetric rain measurements, from simultaneous collocated Next Generation Weather Radar data. The results to be presented were acquired during a significant rain event in the Gulf of Mexico, to the east of Corpus Christi, and just south of Houston, TX, in May 2005. The results of this paper show dependence on wind speed, rainrate, and polarization. They agree with numerous surface-based studies (single point measurements), using ocean platforms and wind-wave tanks, whose data were collected under similar conditions. For example, at rainrates less than 10 mm/hr, the relative change in surface roughness is seen to decrease as the wind magnitude increases from S to 7 m/s. Another consistent observation is that the vertical polarization NRCS shows less sensitivity to rainrate than does horizontal.
Keywords: QuikSCAT,Seawinds
Mission:
URL: https://doi.org/10.1109/TGRS.2008.2001032
Other URLs:
Weissman, D.E. and Bourassa, M.A. (2008). The Effect of Rain on Satellite Sensor Estimates of Surface Roughness Conditions and on the Air-Sea Momentum Flux, International Geoscience and Remote Sensing Symposium (IGARSS), II-165-II-168, 10.1109/IGARSS.2008.4778953. Conference Paper »
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Title: The Effect of Rain on Satellite Sensor Estimates of Surface Roughness Conditions and on the Air-Sea Momentum Flux
Type: Conference Paper
Publication: International Geoscience and Remote Sensing Symposium (IGARSS)
Author(s): Weissman, D.E. and Bourassa, M.A.
Year: 2008
Formatted Citation: Weissman, D.E. and Bourassa, M.A., 2008: The Effect of Rain on Satellite Sensor Estimates of Surface Roughness Conditions and on the Air-Sea Momentum Flux, International Geoscience and Remote Sensing Symposium (IGARSS), II-165-II-168, 10.1109/IGARSS.2008.4778953.
Abstract: Changes in the sea surface roughness from the combined effects of wind and rain, on scales of tens of kilometers, are being studied using the QuikSCAT scatterometer (NRCS) and simultaneous NEXRAD three-dimensional measurements of rain. The studies of air-sea interaction, related to surface fluxes. The results to be presented were acquired during a significant rain event in the Gulf of Mexico, to the east of Corpus Christi, and just south, of Houston, TX in May 2005. Preliminary results in NRCS caused by rain, relative to that in nearby regions with negligible rain shows distinct characteristics. Three regions with different wind speeds (4-6,6-8 and 8-10 m/s) show definitive variation of this total NRCS with respect to wind magnitude, satellite-relative wind direction, polarization and rainrate. Relative changes are stronger in the lower wind region for both polarizations, with H-pol providing a more definitive signature. At higher wind speeds (e.g. 1.0 m/s) the relative splash induced increases in NRCS are still significant, and show distinct differences between polarizations.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1109/IGARSS.2008.4778953
Other URLs:
Wijffels, S.E., Meyers, G., and Godfrey, J.S. (2008). A 20-Yr Average of the Indonesian Throughflow: Regional Currents and the Interbasin Exchange, Journal of Physical Oceanography, 38(9), 1965-1978, 10.1175/2008JPO3987.1. Journal Article »
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Title: A 20-Yr Average of the Indonesian Throughflow: Regional Currents and the Interbasin Exchange
Type: Journal Article
Publication: Journal of Physical Oceanography
Author(s): Wijffels, S.E., Meyers, G., and Godfrey, J.S.
Year: 2008
Formatted Citation: Wijffels, S.E., Meyers, G., and Godfrey, J.S., 2008: A 20-Yr Average of the Indonesian Throughflow: Regional Currents and the Interbasin Exchange, Journal of Physical Oceanography, 38(9), 1965-1978, 10.1175/2008JPO3987.1.
Abstract: Twenty years of monthly or more frequent repeat expendable bathythermograph data are used to estimate the mean geostrophic velocity and transport relative to 750 m of the Indonesian Throughflow (ITF) and its partitioning through the major outflow straits into the Indian Ocean. Ekman transports are estimated from satellite and atmospheric reanalysis wind climatologies. A subsurface maximum near 100 m characterizes the geostrophic ITF, but Ekman flows drive a warm near-surface component as well. A subsurface intensified fresh Makassar Jet feeds the Lombok Strait Throughflow ( similar to 2 Sv, 1Sv identical with 106 m3 s-1) and an eastward flow along the Nusa Tenggara island chain [the Nusa Tenggara Current (6 Sv)]. This flow feeds a relatively cold 3.0-Sv flow through the Ombai Strait and Savu Sea. About 4-5 Sv pass through Timor Passage, fed by both the Nusa Tenggara Current and likely warmer and saltier flow from the eastern Banda Sea. The Ombai and Timor Throughflow feature distinctly different shear profiles, Ombai has deep-reaching shear with a subsurface velocity maximum near 150 m and so is cold ( similar to 15.5 degree -17.1 degree C), while Timor Passage has a surface intensified flow and is warm ( similar to 21.6 degree -23 degree C). At the western end of Timor Passage the nascent South Equatorial Current is augmented by recirculation from a strong eastward shallow flow south of the passage. South of the western tip of Java are two mean eastward flows-the very shallow, warm, and fresh South Java Current and a cold salty South Java Undercurrent. These, along with the inflow of the Eastern Gyral Current, recirculate to augment the South Equatorial Current, and greatly increase its salinity compared to that at the outflow passages. The best estimate of the 20-yr-average geostrophic plus Ekman transport is 8.9 plus or minus 1.7 Sv with a transport-weighted temperature of 21.2 degree C and transport-weighted salinity of 34.73 near 110 degree E. The warm temperatures of the flow can be reconciled with the much cooler estimates based on mooring data in Makassar Strait by accounting for an unmeasured barotropic and deep component, and local surface heat fluxes that warm the ITF by 2 degree -4 degree C during its passage through the region.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1175/2008JPO3987.1
Other URLs:
Williams, B.A. and Long, D.G. (2008). Estimation of Hurricane Winds From SeaWinds at Ultrahigh Resolution, IEEE Transactions on Geoscience and Remote Sensing, 46(10), 2924-2935, 10.1109/TGRS.2008.924096. Journal Article »
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Title: Estimation of Hurricane Winds From SeaWinds at Ultrahigh Resolution
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Williams, B.A. and Long, D.G.
Year: 2008
Formatted Citation: Williams, B.A. and Long, D.G., 2008: Estimation of Hurricane Winds From SeaWinds at Ultrahigh Resolution, IEEE Transactions on Geoscience and Remote Sensing, 46(10), 2924-2935, 10.1109/TGRS.2008.924096.
Abstract: Although the SeaWinds scatterometer was not specifically designed to observe tropical cyclones, new high-resolution wind products resolve much of the horizontal structure of these storms. However, these higher resolution products (2.5 km) are inherently noisier than the standard 25-km near-surface wind products. These noise levels combined with rain contamination complicate high-resolution wind estimation-particularly in tropical cyclones. Fortunately, tropical cyclones have structures that can be exploited by using a wind field model. This paper develops a new procedure for hurricane wind field estimation from the SeaWinds instrument at ultrahigh resolution. A simplified hurricane model is developed to provide prior information to be used in maximum a posteriori probability estimation of ocean winds. Using the hurricane model ameliorates the effects of rain and noise and provides useful hurricane parameters such as the eye center location. The model also improves ambiguity selection. The new method reduces the variability of the wind speed and direction estimates, although high wind speeds still tend to be underestimated. The method also greatly improves wind direction estimates in hurricanes-even in rain-contaminated portions of the storm.
Keywords: atmospheric techniques probability rain remote sensing storms wind SeaWinds scatterometer hurricane model hurricane wind estimation ocean winds posteriori probability estimation rain contamination rain effects storms tropic
Mission: |SeaWinds|
URL: https://doi.org/10.1109/TGRS.2008.924096
Other URLs:
Williams, B.A., and Long, D.G. (2008). Rain and Wind Estimation from Seawinds in Hurricanes at Ultra High Resolution, IGARSS 2008 - 2008 IEEE International Geoscience and Remote Sensing Symposium, II-664-II-667, 10.1109/IGARSS.2008.4779080. Conference Paper »
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Title: Rain and Wind Estimation from Seawinds in Hurricanes at Ultra High Resolution
Type: Conference Paper
Publication: IGARSS 2008 - 2008 IEEE International Geoscience and Remote Sensing Symposium
Author(s): Williams, B.A., and Long, D.G.
Year: 2008
Formatted Citation: Williams, B.A., and Long, D.G., 2008: Rain and Wind Estimation from Seawinds in Hurricanes at Ultra High Resolution, IGARSS 2008 - 2008 IEEE International Geoscience and Remote Sensing Symposium, II-664-II-667, 10.1109/IGARSS.2008.4779080.
Abstract: A Bayesian method for estimating wind and rain in hurricanes from SeaWinds at ultra-high resolution is developed. We use a hurricane model to generate prior distributions for the wind speed, wind direction, and rain rate. The rain prior is derived from data from the Tropical Rainfall Measuring Mission Precipitation Radar (TRMMPR). The new method reduces the variability of the standard simultaneous wind and rain estimates while preserving meso-scale detail.
Keywords: Seawinds
Mission:
URL: https://doi.org/10.1109/IGARSS.2008.4779080
Other URLs:
Wu, P., Yamanaka, M.D., and Matsumoto, J. (2008). The Formation of Nocturnal Rainfall Offshore from Convection over Western Kalimantan (Borneo) Island, Journal of the Meteorological Society of Japan, 86, 187-203, 10.2151/jmsj.86A.187. Journal Article »
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Title: The Formation of Nocturnal Rainfall Offshore from Convection over Western Kalimantan (Borneo) Island
Type: Journal Article
Publication: Journal of the Meteorological Society of Japan
Author(s): Wu, P., Yamanaka, M.D., and Matsumoto, J.
Year: 2008
Formatted Citation: Wu, P., Yamanaka, M.D., and Matsumoto, J., 2008: The Formation of Nocturnal Rainfall Offshore from Convection over Western Kalimantan (Borneo) Island, Journal of the Meteorological Society of Japan, 86, 187-203, 10.2151/jmsj.86A.187.
Abstract: This study investigates the diurnal variation of convection over western Kalimantan (Borneo) Island and the adjacent seas through analysis of results from surface meteorological observations, satellite observations of convection and precipitation, and numerical experiments with a mesoscale model. Precipitation measurements from the TRMM satellite indicated that rainfall occurs mostly in the afternoon and evening along the coast of the island, and at night and in the early morning over the plains in the central regions of the island and over the sea adjacent to the coast. Results from surface meteorological observations showed that intense shortwave radiation is observed on the western coast at Siantan on most days, even on days with heavy rain. Consequently, sea breezes are evident in the afternoon, whereas land breezes prevail in the early morning. Occasionally, a strong offshore flow is observed by the QuikSCAT satellite over the sea adjacent to the western coast of the island in the early morning, with calm surface winds on the coastal land. Climate modeling studies for a 1-month period during the region`s rainy season successfully replicated the main features of the observed regional distribution, diurnal variation of surface winds and convection over the western coast of the island and the adjacent seas. The results showed that convections develop across a wide area along the coast of the island at similar times in the late afternoon with the penetration of the sea breeze. The convections cause a rapid drop in temperature in the lower atmosphere, which produces a temperature contrast between the land and the sea, with lower temperatures occurring over the island. In response to the temperature differences, a strong offshore flow occurs over the sea adjacent to the western coast during nighttime, which creates an intensive wind convergence at the low-levels, and initiates convection offshore near the coast at late night and early morning. The results of this study suggest that the strong offshore flow derived principally from convections that develop earlier in the afternoon and evening over the island plays an important role in the formation of the nocturnal rainfall over the sea in the vicinity of western Kalimantan Island.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.2151/jmsj.86A.187
Other URLs:
Xavier, V.F., Chandrasekar, A., Rahman, H., Niyogi, D., and Alapaty, K. (2008). The Effect of Satellite and Conventional Meteorological Data Assimilation on the Mesoscale Modeling of Monsoon Depressions Over India, Meteorology and Atmospheric Physics, 101, 65-92, 10.1007/s00703-008-0314-7. Journal Article »
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Title: The Effect of Satellite and Conventional Meteorological Data Assimilation on the Mesoscale Modeling of Monsoon Depressions Over India
Type: Journal Article
Publication: Meteorology and Atmospheric Physics
Author(s): Xavier, V.F., Chandrasekar, A., Rahman, H., Niyogi, D., and Alapaty, K.
Year: 2008
Formatted Citation: Xavier, V.F., Chandrasekar, A., Rahman, H., Niyogi, D., and Alapaty, K., 2008: The Effect of Satellite and Conventional Meteorological Data Assimilation on the Mesoscale Modeling of Monsoon Depressions Over India, Meteorology and Atmospheric Physics, 101, 65-92, 10.1007/s00703-008-0314-7.
Abstract: The Fifth Generation Mesoscale Model (MM5) is used to study the effect of assimilated satellite and conventional data on the prediction of three monsoon depressions over India using analysis nudging. The satellite data comprised the vertical profiles of temperature and humidity (NOAA-TOVS: - National Oceanic and Atmospheric Administration-TIROS Operational Vertical Sounder, MODIS: - MODerate resolution Imaging Spectroradiometer) and the surface wind vector over the sea (QuikSCAT: - Quick Scatterometer), the conventional meteorological data included the upper-air and surface data from the India Meteorological Department (IMD). Two sets of numerical experiments are performed for each case: the first set, NOFDDA (no nudging), utilizes NCEP reanalysis (for the initial conditions and lateral boundary conditions) in the simulation, the second set, FDDA, employs the satellite and conventional meteorological data for an improved analysis through analysis nudging. Two additional experiments are performed to study the effect of increased vertical and horizontal resolution as well as convective parameterization for one of the depressions for which special fields observations were available. The results from the simulation are compared with each other and with the analysis and observations. The results show that the predicted sea level pressure (SLP), the lower tropospheric cyclonic circulation, and the precipitation of the FDDA simulation reproduced the large-scale structure of the depression as manifested in the NCEP reanalysis. The simulation of SLP using no assimilation high-resolution runs (HRSKF10KM, HRSKF3.3KM) with the Kain-Fritsch cumulus parameterization scheme appeared poor in comparison with the FDDA run, while the no assimilation high-resolution runs (HRSGR10KM, HRSGR3.3KM) with the Grell cumulus scheme provided better results. However, the space correlation and the root mean square (rms) error of SLP for the HRSKF10KM was better than the FDDA, the largest and smallest space correlation for HRSKF10KM, FDDA, and HRSGR10KM were 0.894 and 0.623, 0.663 and 0.195, and 0.733 and 0.338 respectively, the smallest and largest rms error for HRSKF10KM, FDDA and HRSGR10KM were 1.879 and 5.245, 2.308 and 4.242, and 2.055 and 4.909 respectively. The precipitation simulations with the 3.3 km high-resolution, no assimilation runs performed no better than the precipitation simulation with the FDDA run. Thus, a significant finding of this study is that over the Indian monsoon region, the improvements in the simulation using nudging in the FDDA run are of similar magnitude (or better) than the improvements in the simulation due to high-resolution and to cumulus parameterization sensitivity. The improvements in the FDDA run due to analysis nudging were also verified in two more depression cases. The current operational regional models in India do not incorporate the data assimilation of NOAA-TOVS/MODIS and QuikSCAT satellite data, and hence the results of this study are relevant to operational forecasters in India and their ongoing efforts to improve weather forecasting using satellite data sets.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1007/s00703-008-0314-7
Other URLs:
Xie, X. S. and Liu, W. T. and Tang, B. Y. (2008). Spacebased estimation of moisture transport in marine atmosphere using support vector regression, REMOTE SENSING OF ENVIRONMENT, 112(4), 1846-1855, 10.1016/j.rse.2007.09.003. Journal Article »
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Title: Spacebased estimation of moisture transport in marine atmosphere using support vector regression
Type: Journal Article
Publication: REMOTE SENSING OF ENVIRONMENT
Author(s): Xie, X. S. and Liu, W. T. and Tang, B. Y.
Year: 2008
Formatted Citation: Xie, X. S. and Liu, W. T. and Tang, B. Y., 2008: Spacebased estimation of moisture transport in marine atmosphere using support vector regression, REMOTE SENSING OF ENVIRONMENT, 112(4), 1846-1855, 10.1016/j.rse.2007.09.003.
Abstract: An improved algorithm is developed based on support vector regression (SVR) to estimate horizonal water vapor transport integrated through the depth of the atmosphere (Θ,) over the global ocean from observations of surface wind-stress vector by QuikSCAT, cloud drift wind vector derived from the Multi-angle Imaging SpectroRadiometer (MISR) and geostationary satellites, and precipitable water from the Special Sensor Microwave/Imager (SSM/I). The statistical relation is established between the input parameters (the surface wind stress, the 850 mb wind, the precipitable water, time and location) and the target data (Θ, calculated from rawinsondes and reanalysis of numerical weather prediction model). The results are validated with independent daily rawinsonde observations, monthly mean reanalysis data, and through regional water balance. This study clearly demonstrates the improvement of Θ, derived from satellite data using SVR over previous data sets based on linear regression and neural network. The SVR methodology reduces both mean bias and standard deviation compared with rawinsonde observations. It agrees better with observations from synoptic to seasonal time scales, and compare more favorably with the reanalysis data on seasonal variations. Only the SVR result can achieve the water balance over South America. The rationale of the advantage by SVR method and the impact of adding the upper level wind will also be discussed.
Keywords: Moisture transport, Water cycle, Support vector regression, Remote sensing
Mission:
URL: http://airsea-www.jpl.nasa.gov/publication/paper/Xie-etal-2008-rse.pdf
Other URLs:
Xie, X., Chen, K., Yu, W., Hu, W., Zeng, Q., and Fang, Y. (2008). A Study on Geophysical Model Function Modeling with Water Surface Temperature as One of the Input Parameters, International Geoscience and Remote Sensing Symposium (IGARSS), 1(1), I398-I401, 10.1109/IGARSS.2008.4778878. Journal Article »
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Title: A Study on Geophysical Model Function Modeling with Water Surface Temperature as One of the Input Parameters
Type: Journal Article
Publication: International Geoscience and Remote Sensing Symposium (IGARSS)
Author(s): Xie, X., Chen, K., Yu, W., Hu, W., Zeng, Q., and Fang, Y.
Year: 2008
Formatted Citation: Xie, X., Chen, K., Yu, W., Hu, W., Zeng, Q., and Fang, Y., 2008: A Study on Geophysical Model Function Modeling with Water Surface Temperature as One of the Input Parameters, International Geoscience and Remote Sensing Symposium (IGARSS), 1(1), I398-I401, 10.1109/IGARSS.2008.4778878.
Abstract: Geophysical model function is the basis for the wind vector retrieval with scatterometer and a number of models have been developed to operationally retrieve the ocean surface wind in the past three decades. However, none of the operational models ever took the water surface temperature into account in its modeling, which is considered to have some effect on the ocean backscattering, and in turn on the model accuracy. Taking SeaWinds as an example, this paper attempts to develop new geophysical model functions with surface temperature to be taken into account by using its level 2A data and corresponding buoy data. For contrast, two independent models are established for the ocean water and fresh water respectively. The modeling results and analysis indicate that some effect of the surface temperature on backscatter were found for both types of water, but with a larger extent of the temperature effect for fresh water.
Keywords: Seawinds
Mission:
URL: https://doi.org/10.1109/IGARSS.2008.4778878
Other URLs:
Xie, X., Fang, Y., Chen, K., Huang, Z., and Chen, B. (2008). Neural Network-Based Model for Retrieval of the Ocean Surface Wind Vector from SeaWinds Scatterometer Data, Gaojishu Tongxin/Chinese High Technology Letters, 18(2), 184-189.
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Title: Neural Network-Based Model for Retrieval of the Ocean Surface Wind Vector from SeaWinds Scatterometer Data
Type: Journal Article
Publication: Gaojishu Tongxin/Chinese High Technology Letters
Author(s): Xie, X., Fang, Y., Chen, K., Huang, Z., and Chen, B.
Year: 2008
Formatted Citation: Xie, X., Fang, Y., Chen, K., Huang, Z., and Chen, B., 2008: Neural Network-Based Model for Retrieval of the Ocean Surface Wind Vector from SeaWinds Scatterometer Data, Gaojishu Tongxin/Chinese High Technology Letters, 18(2), 184-189.
Abstract: Aiming at the main problems in establishing a neural network model for retrieval of the ocean surface wind vector from SeaWinds data, and in consideration of the SeaWinds scatterometer's geometry observation characteristics, the paper presents a neural network retrieval model and a corresponding algorithm, which are suitable to the conical scanning mode of the scatterometer. The retrieval of the model consists of two steps-the wind direction retrieval and the wind speed retrieval. Two sets of data, Level 2A and corresponding Level 2B, and buoy data were selected to validate the model preliminarily. The experimental results demonstrated the feasibility of the retrieval model. The retrieval efficiency of the model was approximately five times higher than that of the maximum likelihood estimation (MLE) method without obviously reducing the retrieval precision. Thereby, the model provides the possibility for real-time retrieval of ocean surface wind vectors.
Keywords: Seawinds
Mission:
URL:
Other URLs:
Xie, X., W.T. Liu and B. Tang (2008). Spacebased estimation of moisture transport in marine atmosphere using support vector machine, Remote Sensing of Environment, 112, 1845-1855.
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Title: Spacebased estimation of moisture transport in marine atmosphere using support vector machine
Type: Journal Article
Publication: Remote Sensing of Environment
Author(s): Xie, X., W.T. Liu and B. Tang
Year: 2008
Formatted Citation: Xie, X., W.T. Liu and B. Tang, 2008: Spacebased estimation of moisture transport in marine atmosphere using support vector machine, Remote Sensing of Environment, 112, 1845-1855.
Abstract:
Keywords:
Mission:
URL:
Other URLs:
Xie, X., Zeng, Q., Hu, W., Yu, W., Chen, K., and Fang, Y. (2008). Validation of QSCAT-1 Geophysical Model Function Using Seawinds Level 2 and Buoy Data, IGARSS 2008 - 2008 IEEE International Geoscience and Remote Sensing Symposium, 1(1), I339-I342, 10.1109/IGARSS.2008.4778863. Journal Article »
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Title: Validation of QSCAT-1 Geophysical Model Function Using Seawinds Level 2 and Buoy Data
Type: Journal Article
Publication: IGARSS 2008 - 2008 IEEE International Geoscience and Remote Sensing Symposium
Author(s): Xie, X., Zeng, Q., Hu, W., Yu, W., Chen, K., and Fang, Y.
Year: 2008
Formatted Citation: Xie, X., Zeng, Q., Hu, W., Yu, W., Chen, K., and Fang, Y., 2008: Validation of QSCAT-1 Geophysical Model Function Using Seawinds Level 2 and Buoy Data, IGARSS 2008 - 2008 IEEE International Geoscience and Remote Sensing Symposium, 1(1), I339-I342, 10.1109/IGARSS.2008.4778863.
Abstract: Geophysical model function(GMF) is the basis and prerequisite for the ocean surface wind vector retrieval with scatterometers. Among many operational models, the Qscat- 1 model was specifically developed for SeaWinds scatterometer and is being applied to its operational wind retrieval. This paper is to validate the accuracy of the Qscat- 1 model by using some SeaWinds Level 2 data and corresponding buoy data. First, a comparison between L2B and co-located buoy wind speed was made to analyze the systematic bias between them, and then a new geophysical model function was established using the match-ups of the L2A and Buoy data to further valuate the accuracy of the Qscat-1 model. The analytical and modeling results indicate that there may be some systematic error in the Qscat-1 model.
Keywords: Seawinds
Mission:
URL: https://doi.org/10.1109/IGARSS.2008.4778863
Other URLs:
Xu, J., Luo, Y., Zhang, X., and Zhu, R. (2008). China Offshore Wind Energy Resources Assessment with the QuikSCAT Data, Proceedings of the SPIE, 71050B, 10.1117/12.800296. Conference Paper »
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Title: China Offshore Wind Energy Resources Assessment with the QuikSCAT Data
Type: Conference Paper
Publication: Proceedings of the SPIE
Author(s): Xu, J., Luo, Y., Zhang, X., and Zhu, R.
Year: 2008
Formatted Citation: Xu, J., Luo, Y., Zhang, X., and Zhu, R., 2008: China Offshore Wind Energy Resources Assessment with the QuikSCAT Data, Proceedings of the SPIE, 71050B, 10.1117/12.800296.
Abstract: With the data, which were obtained from the SeaWinds scatterometer on board the National Aeronautics and Space Administration (NASA) QuikSCAT satellite (12.5km*12.5km available from 1999 to current daily orbit swath), the China offshore region were studied (105-135E 15-45N). Because swath location is not fixed, interpolation was applied to get a fixed grid with 0.1 resolution. We calculate and analysis China offshore wind resources effective density of wind energy (EDWE) at 10 meters high above the sea level. And find that EDWE is rich in offshore area. The highest EDWE is in Taiwan Strait and North and South of the strait, with the EDWE 600-800W/m2, the next highest is East China Sea and South China Sea. The lowest EDWE is Yellow Sea and Bohai bay, less than 400W/m2. And several other wind energy resource-rich areas are: 1)the north of Bohai Bay, with wind power density more than 800 w/m*m decline to the south, 2)the East China Sea area the power density above 400 w/m*m increase to the southward. Guangdong coastal waters are rich in wind resources energy. 2008 Copyright SPIE - The International Society for Optical Engineering.
Keywords: QuikSCAT, Seawinds
Mission:
URL: https://doi.org/10.1117/12.800296
Other URLs:
Xu, Q., Lin, H., Zheng, Q., Xiu, P., Cheng, Y., and Liu, Y. (2008). Evaluation of ENVISAT ASAR Data for Sea Surface Wind Retrieval in Hong Kong Coastal Waters of China, Acta Oceanologica Sinica, 27(4), 57-62. Journal Article »
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Title: Evaluation of ENVISAT ASAR Data for Sea Surface Wind Retrieval in Hong Kong Coastal Waters of China
Type: Journal Article
Publication: Acta Oceanologica Sinica
Author(s): Xu, Q., Lin, H., Zheng, Q., Xiu, P., Cheng, Y., and Liu, Y.
Year: 2008
Formatted Citation: Xu, Q., Lin, H., Zheng, Q., Xiu, P., Cheng, Y., and Liu, Y., 2008: Evaluation of ENVISAT ASAR Data for Sea Surface Wind Retrieval in Hong Kong Coastal Waters of China, Acta Oceanologica Sinica, 27(4), 57-62.
Abstract: The C-band wind speed retrieval models, CMOD4, CMOD - IFR2, and CMOD5 were applied to retrieval of sea surface wind speeds from ENVISAT (European environmental satellite) ASAR (advanced synthetic aperture radar) data in the coastal waters near Hong Kong during a period from October 2005 to July 2007. The retrieved wind speeds are evaluated by comparing with buoy measurements and the QuikSCAT (quick scatterometer) wind products. The results show that the CMOD4 model gives the best performance at wind speeds lower than 15 m/s. The correlation coefficients with buoy and QuikSCAT winds are 0.781 and 0.896, respectively. The root mean square errors are the same 1.74 m/s. Namely, the CMOD4 model is the best one for sea surface wind speed retrieval from ASAR data in the coastal waters near Hong Kong.
Keywords: QuikSCAT
Mission:
URL: http://aosocean.com/article/id/20080405
Other URLs:
Xu, Y. and Scott, R.B. (2008). Subtleties in Forcing Eddy Resolving Ocean Models with Satellite Wind Data, Ocean Modelling, 20(3), 240-251, 10.1016/j.ocemod.2007.09.003. Journal Article »
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Title: Subtleties in Forcing Eddy Resolving Ocean Models with Satellite Wind Data
Type: Journal Article
Publication: Ocean Modelling
Author(s): Xu, Y. and Scott, R.B.
Year: 2008
Formatted Citation: Xu, Y. and Scott, R.B., 2008: Subtleties in Forcing Eddy Resolving Ocean Models with Satellite Wind Data, Ocean Modelling, 20(3), 240-251, 10.1016/j.ocemod.2007.09.003.
Abstract: Using new global satellite remote sensing data, we show that ignoring the ocean current dependence in the wind stress artificially increases global wind power input to the oceanic general circulation by about 32%, and more than doubles the input in the regions of strong ocean current systems. Scatterometer-derived wind stress naturally accounts for the moving ocean that is not included in traditional wind stress products. However, forcing an ocean model with a scatterometer-derived wind stress cannot actually account for the ocean current effect on the wind power input. The difference between the real and modeled surface eddy fields can reduce the damping associated with the ocean current dependence in wind stress, leading to a positive bias in global wind power input of about 23%. Most of this spurious energy flux goes directly to the fluctuation eddy field and is several times larger than the energy flux to real ocean eddies.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1016/j.ocemod.2007.09.003
Other URLs:
Yan, X.-H., Jo, Y.-H., Jiang, L., Wan, Z., Liu, W.T., Li, Y., Zhan, J., and Du, T. (2008). Impact of the Three Gorges Dam Water Storage on the Yangtze River Outflow into the East China Sea, Geophysical Research Letters, 35(5), L05610, 10.1029/2007GL032908. Journal Article »
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Title: Impact of the Three Gorges Dam Water Storage on the Yangtze River Outflow into the East China Sea
Type: Journal Article
Publication: Geophysical Research Letters
Author(s): Yan, X.-H., Jo, Y.-H., Jiang, L., Wan, Z., Liu, W.T., Li, Y., Zhan, J., and Du, T.
Year: 2008
Formatted Citation: Yan, X.-H., Jo, Y.-H., Jiang, L., Wan, Z., Liu, W.T., Li, Y., Zhan, J., and Du, T., 2008: Impact of the Three Gorges Dam Water Storage on the Yangtze River Outflow into the East China Sea, Geophysical Research Letters, 35(5), L05610, 10.1029/2007GL032908.
Abstract:
Keywords:
Mission:
URL: https://doi.org/10.1029/2007GL032908
Other URLs:
Yang, Y., Ma, J., and Xie, S.-P. (2008). Observations of the Trade-Wind Wakes of Kauai and Oahu, Geophysical Research Letters: Atmospheric Science, 35(4), L04807, 10.1029/2007GL031742. Journal Article »
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Title: Observations of the Trade-Wind Wakes of Kauai and Oahu
Type: Journal Article
Publication: Geophysical Research Letters: Atmospheric Science
Author(s): Yang, Y., Ma, J., and Xie, S.-P.
Year: 2008
Formatted Citation: Yang, Y., Ma, J., and Xie, S.-P., 2008: Observations of the Trade-Wind Wakes of Kauai and Oahu, Geophysical Research Letters: Atmospheric Science, 35(4), L04807, 10.1029/2007GL031742.
Abstract: The Hawaiian islands of Kauai and Oahu stand in the path of the east-northeasterly trade winds, creating wakes in the lee. For the first time, the structure of the wakes and their diurnal cycle were observed on a cruise during 18-20 December 2006. The dynamic wakes, characterized by reduced trades, extend about 1 km in height with strong wind shear at the top. Thermal forcing of these small islands also affects the wake circulations. Sea breezes develop in the afternoon turning the winds into westerly near the shore in the wakes. At night, land breezes advect cool air from the islands, creating a shallow cool layer between the sea surface and a capping inversion. The warming in the wake in the afternoon extends much deeper (1.4 km) than the cool layer (0.5 km) at night. The effect of diurnal changes on cloud formation in the wakes is discussed, and the sharp variations in wind velocity lee of the islands may affect ocean currents, waves and mixing.
Keywords: wake, diurnal cycle, trade winds
Mission:
URL: https://doi.org/10.1029/2007GL031742
Other URLs:
Yu, P., Clausi, D.A., De Abreu, R., and Agnew, T. (2008). Combining AMSR-E and QuikSCAT Image Data to Improve Sea Ice Classification, 2008 IAPR Workshop on Pattern Recognition in Remote Sensing, PRRS 2008, December 7, 2008 - December 7, 1-4, 10.1109/PRRS.2008.4783170. Conference Paper »
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Title: Combining AMSR-E and QuikSCAT Image Data to Improve Sea Ice Classification
Type: Conference Paper
Publication: 2008 IAPR Workshop on Pattern Recognition in Remote Sensing, PRRS 2008, December 7, 2008 - December 7
Author(s): Yu, P., Clausi, D.A., De Abreu, R., and Agnew, T.
Year: 2008
Formatted Citation: Yu, P., Clausi, D.A., De Abreu, R., and Agnew, T., 2008: Combining AMSR-E and QuikSCAT Image Data to Improve Sea Ice Classification, 2008 IAPR Workshop on Pattern Recognition in Remote Sensing, PRRS 2008, December 7, 2008 - December 7, 1-4, 10.1109/PRRS.2008.4783170.
Abstract: The benefits of augmenting AMSR-E image data with QuikSCAT image data for supervised sea ice classification in the Western Arctic region are investigated. Experiments compared the performance of a maximum likelihood classifier when used with the AMSR-E only data set against the combined data and examined the preferred number of features to use as well as the reliability of training data over time. Adding QuikSCAT often improves classifier accuracy in a statistically significant manner and never decreased it significantly when enough features are used. Combining these data sets is beneficial for sea ice mapping. Using all available features is recommended and training data from a specific date remains reliable within 30 days.
Keywords: QuikSCAT
Mission:
URL: https:/doi.org/10.1109/PRRS.2008.4783170
Other URLs:
Yuan, D., Zhu, J., Li, C., and Hu, D. (2008). Cross-Shelf Circulation in the Yellow and East China Seas Indicated by MODIS Satellite Observations, Journal of Marine Systems, 70(1-2), 134-149, 10.1016/j.jmarsys.2007.04.002. Journal Article »
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Title: Cross-Shelf Circulation in the Yellow and East China Seas Indicated by MODIS Satellite Observations
Type: Journal Article
Publication: Journal of Marine Systems
Author(s): Yuan, D., Zhu, J., Li, C., and Hu, D.
Year: 2008
Formatted Citation: Yuan, D., Zhu, J., Li, C., and Hu, D., 2008: Cross-Shelf Circulation in the Yellow and East China Seas Indicated by MODIS Satellite Observations, Journal of Marine Systems, 70(1-2), 134-149, 10.1016/j.jmarsys.2007.04.002.
Abstract: Ocean color and sea surface temperature data from Moderate Resolution Imaging Spectroradiometer (MODIS) onboard the Terra satellite are used to study the cross-shelf circulation and transport of suspended sediments in the Yellow and the East China Seas. The ocean color images show a significant turbid water plume extending in the southeast direction from the Subei coasts of China to the shelf edge south of Cheju during fall-winter, suggesting significant cross-shelf currents in the Yellow Sea/East China Sea in winter. The currents transport suspended sediments from the area of the old Huanghe mouth into the Okinawa Trough. Part of the turbid plume joins the Yellow Sea Warm Current to enter the Yellow Sea trough in winter. The satellite images suggest that the time scales of cross-shelf transport and surface-to-subsurface descending of the suspended sediments are a few weeks. The turbid plume grows in fall, reaches its maximum expansion and intensity in winter-spring, and subsides in late spring. In summer, the plume becomes coastally trapped. Substantial interannual variations of the intensity and coverage of the turbid plume are indicated by the observations. In comparison, the Changjiang Diluted Water in summer only transports a small amount of the Changjiang suspended sediment to the outer shelf south of Cheju, which does not enter the Yellow Sea owing to the weak intrusion of the Yellow Sea Warm Current in summer. The dynamics of the cross-shelf circulation in the Yellow Sea in winter are hypothesized to be associated with (1) the convergence of the Yellow Sea Coastal Current and the Taiwan Warm Current off the Changjiang mouth and (2) the time-dependent forcing of the northerly wind bursts that drives the intrusion of the Yellow Sea Warm Current.
Keywords: Seawinds
Mission:
URL: https://doi.org/10.1016/j.jmarsys.2007.04.002
Other URLs:
Yueh, S.H. (2008). Directional Signals in Windsat Observations of Hurricane Ocean Winds, IEEE Transactions on Geoscience and Remote Sensing, 46(1), 130-136, 10.1109/TGRS.2007.909079. Journal Article »
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Title: Directional Signals in Windsat Observations of Hurricane Ocean Winds
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Yueh, S.H.
Year: 2008
Formatted Citation: Yueh, S.H., 2008: Directional Signals in Windsat Observations of Hurricane Ocean Winds, IEEE Transactions on Geoscience and Remote Sensing, 46(1), 130-136, 10.1109/TGRS.2007.909079.
Abstract: In this paper, wind-direction signals in passive microwave polarimetry for ocean surfaces under hurricane force winds are presented. We performed analysis of Windsat data for several Atlantic hurricanes from 2003 to 2005. The polarimetric third Stokes parameter observations from the Windsat 10-, 18-, and 37-GHz channels were collocated with the ocean-surface winds from the National Oceanic and Atmospheric Administration Hwind analysis. The collocated data were binned as a function of wind speed and wind direction. The 10-GHz data show clear 4-K peak-to-peak directional signals at 50-60-m/s wind speed after correction for atmospheric attenuation. The signals in the 18- and 37-GHz channels were unclear at above 40-m/s wind speeds, probably caused by the impact of clouds and rain. The data were expanded by sinusoidal series of the relative azimuth angles between the Hwind analysis and observation directions. The coefficients of the sinusoidal series suggest decreasing response to wind direction for increasing wind speed, but the 10-GHz data appear to be fairly constant for up to 50-m/s wind speeds.
Keywords: Hurricanes, microwave polarimetry, sea-surface wind
Mission: |WindSat|
URL: https://doi.org/10.1109/TGRS.2007.909079
Other URLs:
Zabolotskikh, E.V., Mitnik, L.M., Bobylev, L.P., and Johannessenn, O.M. (2008). Arctic Polar Algorithms for Atmospheric Water Parameter Retrievals from Satellite Passive Microwave Data, 2008 Microwave Radiometry and Remote Sensing of the Environment - 10th Specialist Meeting, MICRORAD, March 11, 2008 - March 14, 1-4, 10.1109/MICRAD.2008.4579501. Conference Paper »
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Title: Arctic Polar Algorithms for Atmospheric Water Parameter Retrievals from Satellite Passive Microwave Data
Type: Conference Paper
Publication: 2008 Microwave Radiometry and Remote Sensing of the Environment - 10th Specialist Meeting, MICRORAD, March 11, 2008 - March 14
Author(s): Zabolotskikh, E.V., Mitnik, L.M., Bobylev, L.P., and Johannessenn, O.M.
Year: 2008
Formatted Citation: Zabolotskikh, E.V., Mitnik, L.M., Bobylev, L.P., and Johannessenn, O.M., 2008: Arctic Polar Algorithms for Atmospheric Water Parameter Retrievals from Satellite Passive Microwave Data, 2008 Microwave Radiometry and Remote Sensing of the Environment - 10th Specialist Meeting, MICRORAD, March 11, 2008 - March 14, 1-4, 10.1109/MICRAD.2008.4579501.
Abstract: The new algorithms for retrieval of total atmospheric water vapor content (Q) and total cloud liquid water content (W) from satellite microwave radiometer data, applicable for the Arctic Basin. These algorithms are based on the Neural Networks (NNs) regression technique employed for the inversion of a Radiative Transfer Equation (RTE). For the algorithm development the numerical integration of RTE was carried out for the channel characteristics of a Special Sensor Microwave/Imager (SSM/I) and Advanced Microwave Scanning Radiometer (AMSR-E), and brightness temperatures (TB) were simulated for non-precipitating conditions over the open ocean. Sets of sea surface temperatures (Ts), surface winds and radiosonde reports collected by Russian research vessels served as input data for the integration. Only data with Ts less than 15C were selected for algorithm development. Simulated radiometer noise was added to the calculated values of TB. Once developed, using theoretically simulated values of TB, the Q algorithms were then validated both for SSM/I and AMSR-E retrievals using satellite radiometric measurements collocated in space and time with polar station radiosonde data. The resulting SSM retrieval error proved to be 1.1 kg/m2, AMSR-E retrieval error - 0.9 kg/m2. Considered case study was the polar low in the Norwegian Sea occurred 30-31 January 2008. NOAA AVHRR, Terra and Aqua MODIS images, QuikSCAT-retrieved wind fields, Envisat ASAR images as well as weather maps were used as ancillary data to passive microwave retrievals to study this phenomenon.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1109/MICRAD.2008.4579501
Other URLs:
Zapotocny, T.H., Jung, J.A., Le Marshall, J.F., and Treadon, R.E. (2008). A Two-Season Impact Study of Four Satellite Data Types and Rawinsonde Data in the NCEP Global Data Assimilation System, Weather and Forecasting, 23(1), 80-100, 10.1175/2007WAF2007010.1. Journal Article »
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Title: A Two-Season Impact Study of Four Satellite Data Types and Rawinsonde Data in the NCEP Global Data Assimilation System
Type: Journal Article
Publication: Weather and Forecasting
Author(s): Zapotocny, T.H., Jung, J.A., Le Marshall, J.F., and Treadon, R.E.
Year: 2008
Formatted Citation: Zapotocny, T.H., Jung, J.A., Le Marshall, J.F., and Treadon, R.E., 2008: A Two-Season Impact Study of Four Satellite Data Types and Rawinsonde Data in the NCEP Global Data Assimilation System, Weather and Forecasting, 23(1), 80-100, 10.1175/2007WAF2007010.1.
Abstract: Extended-length observing system experiments (OSEs) during two seasons are used to quantify the contributions made to forecast quality by conventional rawinsonde data and four types of remotely sensed sateflite data. The impact is measured by comparing the analysis and forecast results from an assimilation- forecast system using all data types with those excluding a particular observing system. The impact of the particular observing system is assessed by comparing the forecast results over extended periods. For these observing system experiments, forecast results are compared through 168 h for periods covering more than a month during both the summer and winter seasons of each hemisphere. The assimilation-forecast system used for these experiments is the National Centers for Environmental Prediction (NCEP) Global Data Assimilation System (GDAS) and the Global Forecast System (GFS). The case studies chosen consist of periods during January-February 2003 and August-September 2003. During these periods, a T254L64 layer version of NCEP`s global spectral model was used. The control run utilized all data types routinely assimilated in ihe GDAS. The experimental runs individuaily denied data from the Advanced Microwave Sounding Unit (AMSU), the High-Resolution Infrared Radiation Sounder (HIRS), geostationary sateffite atmospheric motion vectors (GEO winds), in situ rawinsondes (raobs), and surface winds derived from the Quick Scatterometer (QuikSCAT). Differences between the control and denial experiment forecasts are accumulated over the two 45-day periods and are analyzed to demonstrate the impact of these data types. Anomaly correlations (ACs), forecast impacts (FIs), and hurricane track forecasts are evaluated for all experimental runs during both seasons. The anomaly correlations used the standard NCEP software suite and are partitioned into subsections covering the polar caps (60-90) and midlatitudes (20-80) of each hemisphere and the tropical region (20N-20S). Anomaly correlations of geopotential heights are shown at several pressure levels in the polar regions and midlatitudes. The root-mean-square error (RMSE) for 850- and 200-hPa wind vector differences are shown for the tropical region. The geographical distributions of forecast impacts on geopotential heights are also examined. The influence these data types have on tropical cyclone track forecasts are shown for both the Atlantic and Pacific basins and again are computed using standard algorithms developed and maintained at NCEP. The results demonstrate a positive impact from all data types with AMSU and rawinsonde data providing the largest anomaly correlation improvements in all zonal regions examined. Smaller forecast improvements are noticed from each of the other data types. In the Atlantic basin, each of the four satellite data types provides nearly equal improvement to the tropical cyclone track forecasts, however, GEO winds provide the largest improvement to track forecasts in the Pacific basin.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1175/2007WAF2007010.1
Other URLs:
Zaugg, E.C. and Long, D.G. (2008). Theory and Application of Motion Compensation for LFM-CW SAR, IEEE Transactions on Geoscience and Remote Sensing, 46(10), 2990-2998, 10.1109/TGRS.2008.921958. Journal Article »
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Title: Theory and Application of Motion Compensation for LFM-CW SAR
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Zaugg, E.C. and Long, D.G.
Year: 2008
Formatted Citation: Zaugg, E.C. and Long, D.G., 2008: Theory and Application of Motion Compensation for LFM-CW SAR, IEEE Transactions on Geoscience and Remote Sensing, 46(10), 2990-2998, 10.1109/TGRS.2008.921958.
Abstract: Small low-cost high-resolution synthetic aperture radar (SAR) systems are made possible by using a linear frequency-modulated continuous-wave (LFM-CW) signal. SAR processing assumes that the sensor is moving in a straight line at a constant speed, but in actuality, an unmanned aerial vehicle (UAV) or airplane will often significantly deviate from this ideal. This nonideal motion can seriously degrade the SAR image quality. In a continuous-wave system, this motion happens during the radar pulse, which means that existing motion compensation techniques that approximate the position as constant over a pulse are limited for LFM-CW SAR. Small aircraft and UAVs are particularly susceptible to atmospheric turbulence, making the need for motion compensation even greater for SARs operating on these platforms. In this paper, the LFM-CW SAR signal model is presented, and processing algorithms are discussed. The effects of nonideal motion on the SAR signal are derived, and new methods for motion correction are developed, which correct for motion during the pulse. These new motion correction algorithms are verified with simulated data and with actual data collected using the Brigham Young University muSAR system.
Keywords: geophysical techniques motion compensation synthetic aperture radar Brigham Young University muSAR system LFM-CW signal model SAR image quality aircraft atmospheric turbulence high-resolution synthetic aperture radar systems linear frequ
Mission:
URL: https://doi.org/10.1109/TGRS.2008.921958
Other URLs:
Zecchetto, S., De Biasio, F., and Trivero, P. (2008). Computation of Wind Direction from SAR Images Without External a Priori Information, 2007 IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2007, June 23, 2007 - June 28, 3277-3280, 10.1109/IGARSS.2007.4423544. Conference Paper »
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Title: Computation of Wind Direction from SAR Images Without External a Priori Information
Type: Conference Paper
Publication: 2007 IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2007, June 23, 2007 - June 28
Author(s): Zecchetto, S., De Biasio, F., and Trivero, P.
Year: 2008
Formatted Citation: Zecchetto, S., De Biasio, F., and Trivero, P., 2008: Computation of Wind Direction from SAR Images Without External a Priori Information, 2007 IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2007, June 23, 2007 - June 28, 3277-3280, 10.1109/IGARSS.2007.4423544.
Abstract: We present here the follow-up of a previously published work [1], where we described a wavelet based method to characterize the sea surface backscatter structures present in the SAR images. The method relies on the ability of the two-dimensional continuous wavelet technique to detect the spatial structure of the marine atmospheric boundary layer and to isolate wind-related cells and features. The analysis of the cells' geometry, moulded by the radiometric characteristics of the sea surface, permits the identification of the wind direction inside the cells and thus the computation of the wind speed through standard algorithms. About twenty SAR images (ERS-2 and ASAR Wide Swath) over the Mediterranean Sea have been analyzed, and the results compared with NSCAT and QuikSCAT satellites wind fields. These images cover a wide range of meteorological conditions, from low (2 m/s) to moderate winds (12 m/s), presenting many kinds of signature, i.e. wind cells, atmospheric gravity waves, convective structures and radiometric flatness. The main difference of this method, with respect to the majority of those already proposed, is that it does not require a-priori information about the wind direction as well as any periodicity of the backscatter structures. The aliased wind directions are estimated from the texture of the SAR reconstructed map, while the dealiasing is possible due to the asymmetries present in the detected backscatter structures. The resulting SAR derived wind fields have been compared with those provided by satellite scatterometers. Results indicate a good score in detecting the wind direction ( 70%). The developed methodology, once tested over an adequate quantity of images to derive statistically reliable results, could be routinely used to enrich SAR images with the wind field, as well as to characterize other backscatter structures displayed by SAR not depending directly on the wind. 2007 IEEE.
Keywords: QuikSCAT,NSCAT
Mission:
URL: https://doi.org/10.1109/IGARSS.2007.4423544
Other URLs:
Zou, J., Lin, M., Pan, D., Chen, Z., and Yang, L. (2008). Wind Retrievals in Typhoons from QuikSCAT Considering Rain Effect, Proceedings of the SPIE, 7105, 10.1117/12.799901. Conference Paper »
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Title: Wind Retrievals in Typhoons from QuikSCAT Considering Rain Effect
Type: Conference Paper
Publication: Proceedings of the SPIE
Author(s): Zou, J., Lin, M., Pan, D., Chen, Z., and Yang, L.
Year: 2008
Formatted Citation: Zou, J., Lin, M., Pan, D., Chen, Z., and Yang, L., 2008: Wind Retrievals in Typhoons from QuikSCAT Considering Rain Effect, Proceedings of the SPIE, 7105, 10.1117/12.799901.
Abstract: By analyzing several collocated QuikSCAT measurements and Special Sensor Microwave Imager (SSM/I) rain rate in typhoons, the evidence of rain influence to wind retrieval is presented. The results show that the present of heavy rain in typhoons will cause large bias in both wind speed and wind direction for QuikSCAT wind retrieval. So that the Holland`s model is applied in the ambiguity clear process to correct the errors in wind direction induced by rain. Also, a radiate transfer function (RTF) and collocated SSM/I rain rate is employed to correct the attenuation and scattering effects of rain. The performance of RTF method is limited due to lack of information of the collocated rain rate and the un-precise of the RTF. As an alternative way to RTF, an interpolation method which just uses the data from QuikSCAT itself is introduced to correct the attenuation and scattering effects of rain. This method is applied to retrieve the wind vector in typhoon Ioke, the result shows that the bias in the wind direction and wind speed induced by rain has both been well corrected, indicating that our correction to the impacts of rain on QuikSCAT wind retrieval in typhoons is effective. 2008 Copyright SPIE - The International Society for Optical Engineering.
Keywords: QuikSCAT
Mission:
URL: https://doi.org/10.1117/12.799901
Other URLs:
Alpers, W., Cheng, C.M., Shao, Y., and Yang, L,M. (2007). Study of Rain Events Over the South China Sea by Synergistic Use of Multi-Sensor Satellite and Ground-Based Meteorological Data, Photogrammetric Engineering and Remote Sensing, 73(3), 267-278, 10.14358/PERS.73.3.267. Journal Article »
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Title: Study of Rain Events Over the South China Sea by Synergistic Use of Multi-Sensor Satellite and Ground-Based Meteorological Data
Type: Journal Article
Publication: Photogrammetric Engineering and Remote Sensing
Author(s): Alpers, W., Cheng, C.M., Shao, Y., and Yang, L,M.
Year: 2007
Formatted Citation: Alpers, W., Cheng, C.M., Shao, Y., and Yang, L,M., 2007: Study of Rain Events Over the South China Sea by Synergistic Use of Multi-Sensor Satellite and Ground-Based Meteorological Data, Photogrammetric Engineering and Remote Sensing, 73(3), 267-278, 10.14358/PERS.73.3.267.
Abstract: Rain cells and rain bands over the South China Sea off the coast a Hong Kong are studied by using multi-sensor satellite and ground-based meteorological data. These include synthetic aperture radar (SAR) images acquired by the Advanced Synthetic Aperture Radar (ASAR) onboard the European ENVISAT satellite, weather radar images from the Hong Kong Observatory (HKO), rain rate data acquired by the Special Sensor Microwave Imager (SSM/I) sensor onboard the F15 satellite of the American Defense Meteorological Satellite Program (DMSP) and the rain sensors onboard the Tropical Rainfall Measurement Mission (TRMM) satellite, cloud image of GOES-9 satellite, sea surface wind maps acquired by the scatterometer onboard the QUIKSCAT satellite, and meteorological data from weather stations in Hong Kong. Three rain events, typical of Hong Kong, are studied. The first event consists of a cluster of rain cells associated with the summer monsoon, the second one of rain cells aligned in a rain bond generated by an upper-air trough, and the third one consists of small rain cells embedded in a cold front. It is shown that ASAR images, which have a resolution of 30 m in the Image Mode (IM) and 150 m resolution in the Wide Swath Mode (WSM), yield much more detailed information on the spatial structure of rain events over the ocean than data obtained from SSSM/I and the rain sensors onboard the TRMM satellite. The precipitation radar (PR) onboard TRMM, which is the rain measuring instrument flown in space with the next best resolution, has a resolution of only 4 km. However, the disadvantage of SAR is that it is sometimes difficult to identify SAR signatures visible on SAR images of the sea surface unambiguously as caused by rain events. By comparing SAR images with simultaneously acquired weather radar images of the Hong Kong Observatory, a better knowledge of radar signatures on SAR images resulting from rain events over the ocean is obtained. This knowledge then helps greatly in detecting rain events on SAR images which are acquired over ocean areas, which are not in the reach of weather radar stations. SAR images containing radar signature of rain events allow a much more detailed study of fine-scale structures of rain events over the World`s ocean, in particular of clusters of rain cells, than any other sensor presently flown in space.
Keywords: SYNTHETIC-APERTURE RADAR, SIR-C/X-SAR, MEASURING MISSION TRMM, FOOTPRINTS, STORMS, WAVES, OCEAN, CELLS
Mission: |SeaWinds|
URL: https://doi.org/10.14358/PERS.73.3.267
Other URLs:
Alvera-Azcarate, A., Barth, A., Beckers, J.M. and Weisberg, R.H. (2007). Multivariate Reconstruction of Missing Data in Sea Surface Temperature, Chlorophyll, and Wind Satellite Fields, J. Geophys. Res. Oceans, 112, C03008, 10.1029/2006JC003660. Journal Article »
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Title: Multivariate Reconstruction of Missing Data in Sea Surface Temperature, Chlorophyll, and Wind Satellite Fields
Type: Journal Article
Publication: J. Geophys. Res. Oceans
Author(s): Alvera-Azcarate, A., Barth, A., Beckers, J.M. and Weisberg, R.H.
Year: 2007
Formatted Citation: Alvera-Azcarate, A., Barth, A., Beckers, J.M. and Weisberg, R.H., 2007: Multivariate Reconstruction of Missing Data in Sea Surface Temperature, Chlorophyll, and Wind Satellite Fields, J. Geophys. Res. Oceans, 112, C03008, 10.1029/2006JC003660.
Abstract: An empirical orthogonal function-based technique called Data Interpolating Empirical Orthogonal Functions ( DINEOF) is used in a multivariate approach to reconstruct missing data. Sea surface temperature ( SST), chlorophyll a concentration, and QuikSCAT winds are used to assess the benefit of a multivariate reconstruction. In particular, the combination of SST plus chlorophyll, SST plus lagged SST plus chlorophyll, and SST plus lagged winds have been studied. To assess the quality of the reconstructions, the reconstructed SST and winds have been compared to in situ data. The combination of SST plus chlorophyll, as well as SST plus lagged SST plus chlorophyll, significantly improves the results obtained by the reconstruction of SST alone. All the experiments correctly represent the SST, and an upwelling/downwelling event in the West Florida Shelf reproduced by the reconstructed data is studied.
Keywords: EMPIRICAL ORTHOGONAL FUNCTIONS, WEST FLORIDA SHELF, DATA SETS, INTERPOLATION, VARIABILITY, CIRCULATION, PACIFIC, COAST
Mission: |SeaWinds|
URL: https://doi.org/10.1029/2006JC003660
Other URLs:
Aoki, K. and Isobe, A. (2007). Application of Finite Volume Coastal Ocean Model to Hindcasting the Wind-Induced Sea-Level Variation in Fukuoka Bay, Journal of Oceanography, 63(2), 333-339, 10.1007/s10872-007-0032-7. Journal Article »
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Title: Application of Finite Volume Coastal Ocean Model to Hindcasting the Wind-Induced Sea-Level Variation in Fukuoka Bay
Type: Journal Article
Publication: Journal of Oceanography
Author(s): Aoki, K. and Isobe, A.
Year: 2007
Formatted Citation: Aoki, K. and Isobe, A., 2007: Application of Finite Volume Coastal Ocean Model to Hindcasting the Wind-Induced Sea-Level Variation in Fukuoka Bay, Journal of Oceanography, 63(2), 333-339, 10.1007/s10872-007-0032-7.
Abstract: The wind-induced sea-level variations at Hakata tidal station in winter are reproduced realistically using a one-way nested model. This nested model is constructed with a structured finite-difference Princeton Ocean Model (POM) for the Tsushima-Korea Straits, and an unstructured Finite Volume Coastal Ocean Model (FVCOM) for Fukuoka Bay divided into triangular-cell grids. The correlation coefficient and root-mean-square error between observed and modeled results are 0.742 and 1.88 [cm], respectively. Moreover, the results show that the nested model with FVCOM is more accurate than the model in which FVCOM is replaced with a high-resolution POM for Fukuoka Bay. This indicates that the nested model constructed with structured and unstructured models works effectively in hindcasting the wind-induced sea-level variations.
Keywords: sea-level variation, one-way nested model, FVCOM, POM, QuikSCAT,
Mission: |SeaWinds|
URL: https://doi.org/10.1007/s10872-007-0032-7
Other URLs:
Atlas, R., Reale, O., Ardizzone, J., Terry, J., Jusem, J.-C., Brin, E., Bungato, D., and Le Marshall, J.F. (2007). Evaluation of WINDSAT Surface Wind Data and its Impact on Ocean Surface Wwind Analyses and Numerical Weather Prediction, 11th Symposium on Integrated Observing and Assimilation Systems for the Atmosphere, Oceans, and Land Surface (IOAS-AOLS). Conference Paper »
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Title: Evaluation of WINDSAT Surface Wind Data and its Impact on Ocean Surface Wwind Analyses and Numerical Weather Prediction
Type: Conference Paper
Publication: 11th Symposium on Integrated Observing and Assimilation Systems for the Atmosphere, Oceans, and Land Surface (IOAS-AOLS)
Author(s): Atlas, R., Reale, O., Ardizzone, J., Terry, J., Jusem, J.-C., Brin, E., Bungato, D., and Le Marshall, J.F.
Year: 2007
Formatted Citation: Atlas, R., Reale, O., Ardizzone, J., Terry, J., Jusem, J.-C., Brin, E., Bungato, D., and Le Marshall, J.F., 2007: Evaluation of WINDSAT Surface Wind Data and its Impact on Ocean Surface Wwind Analyses and Numerical Weather Prediction, 11th Symposium on Integrated Observing and Assimilation Systems for the Atmosphere, Oceans, and Land Surface (IOAS-AOLS).
Abstract:
Keywords:
Mission: |WindSat|
URL: https://ams.confex.com/ams/87ANNUAL/webprogram/Paper119557.html
Other URLs:
Bolaños-Sanchez, R., Sanchez-Arcilla, A., and Cateura, J. (2007). Evaluation of Two Atmospheric Models for Wind-Wave Modelling in the NW Mediterranean, Journal of Marine Systems, 65(1-4), 336-353, 10.1016/j.jmarsys.2005.09.014. Journal Article »
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Title: Evaluation of Two Atmospheric Models for Wind-Wave Modelling in the NW Mediterranean
Type: Journal Article
Publication: Journal of Marine Systems
Author(s): Bolaños-Sanchez, R., Sanchez-Arcilla, A., and Cateura, J.
Year: 2007
Formatted Citation: Bolaños-Sanchez, R., Sanchez-Arcilla, A., and Cateura, J., 2007: Evaluation of Two Atmospheric Models for Wind-Wave Modelling in the NW Mediterranean, Journal of Marine Systems, 65(1-4), 336-353, 10.1016/j.jmarsys.2005.09.014.
Abstract: The NW Mediterranean experiences, as illustrated by the last decade, strong and rapidly varying storms with severe waves and winds. This has motivated a continuous validation of models and the efforts to improve wave and wind predictions. In this paper we use two atmospherics models, MASS (from SMC-Meteorological Office of Catalunya) and ARPEGE (from Meteo-France), to force two third generation wave models: WAM and SWAN. The evaluation and comparison has been carried out for two severe storms registered in November 2001 and March-April 2002. The ARPEGE and MASS models predicted higher 10 m wind speeds than coastal meteorological stations, a fact attributed to local land influences. Regarding the 10 m wind direction, models do not present large differences, although considerable deviations from recorded data were found during some dates. ARPEGE presents less scatter and lower errors than MASS when compared with QuikSCAT data. The 10m wind fields from both atmospheric models were used to force the two selected wave models and analyse the errors and sensitivities when predicting severe wave storms. The wave model simulations show some interesting results, during the storm, the spatial wave pattern using ARPEGE showed a higher maximum, although the values of significant wave height at the buoys were lower than the ones forced by MASS (with both WAM and SWAN). The SWAN simulations show a better agreement in predicting the growing and waning of the storm peaks. The prediction of mean period was improved when using the ARPEGE wind field. However the underestimation by SWAN due to the large energy at high frequencies was evident. Validation of spectral shape predictions showed that it still has considerable error when predicting the full frequency spectra. The storms showed bimodal spectral features which were not always reproduced by wave models and are likely to be responsible for part of the discrepancies.
Keywords: Mediterranean Sea, wave storms, wind modelling, wave modelling, QuikSCAT, WAM, SWAN, TURNING WINDS, PREDICTION, FIELDS, PARAMETERIZATION, VARIABILITY, RESOLUTION, SPECTRUM, CLIMATE, GROWTH, SWELL
Mission: |SeaWinds|
URL: https://doi.org/10.1016/j.jmarsys.2005.09.014
Other URLs:
Bourassa, M.A., Dukhovskoy, D., Morey, S.L., and O'Brien, J.J. (2007). Innovations in Modeling Gulf of Mexico Surface Turbulent Fluxes, Flux News, 3, 9.
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Title: Innovations in Modeling Gulf of Mexico Surface Turbulent Fluxes
Type: Journal Article
Publication: Flux News
Author(s): Bourassa, M.A., Dukhovskoy, D., Morey, S.L., and O'Brien, J.J.
Year: 2007
Formatted Citation: Bourassa, M.A., Dukhovskoy, D., Morey, S.L., and O'Brien, J.J., 2007: Innovations in Modeling Gulf of Mexico Surface Turbulent Fluxes, Flux News, 3, 9.
Abstract:
Keywords: NCOM, scatterometry, Mexico
Mission: |SeaWinds|
URL:
Other URLs:
Chang, C.Y., Carton, J.A., Grodsky, S.A., and Nigam, S. (2007). Seasonal Climate of the Tropical Atlantic Sector in the NCAR Community Climate System Model 3: Error Structure and Probable Causes of Errors, Journal of Climate, 20(6), 1053-1070, 10.1175/JCLI4047.1. Journal Article »
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Title: Seasonal Climate of the Tropical Atlantic Sector in the NCAR Community Climate System Model 3: Error Structure and Probable Causes of Errors
Type: Journal Article
Publication: Journal of Climate
Author(s): Chang, C.Y., Carton, J.A., Grodsky, S.A., and Nigam, S.
Year: 2007
Formatted Citation: Chang, C.Y., Carton, J.A., Grodsky, S.A., and Nigam, S., 2007: Seasonal Climate of the Tropical Atlantic Sector in the NCAR Community Climate System Model 3: Error Structure and Probable Causes of Errors, Journal of Climate, 20(6), 1053-1070, 10.1175/JCLI4047.1.
Abstract: The Community Climate System Model version 3 (CCSM3) has a dipolelike pattern with a cold bias in the northern Tropics and a warm bias in the southeastern Tropics, which is reminiscent of the observed pattern of climate variability in boreal spring. Along the equator, in contrast, in boreal spring CCSM3 exhibits striking westerly winds with easterly winds in the upper troposphere, in turn reminiscent of the observed pattern of climate variability in boreal summer. The westerly winds cause a deepening of the eastern thermocline that keeps the east warm despite enhanced coastal upwelling. Thus, the bias in the seasonal cycle of the coupled model appears to project at least partially onto the spatial patterns of natural climate variability in this sector. Information about the origin of the bias in CCSM3 is deduced from a comparison of CCSM3 with a simulation using specified historical SST to force the Community Atmospheric Model version 3 (CAM3). The patterns of bias in CAM3 resemble those apparent in CCSM3, including the appearance of substantially intensified subtropical bands of sea level pressure (SLP), indicating that the problem may be traced to difficulties in the atmospheric component model. Positive SLP bias also appears in the western tropical region, which may be related to deficient Amazonian precipitation. The positive SLP bias seems to be the cause of the anomalous westerly trade winds in boreal spring, and those in turn appear to be responsible for the anomalous deepening of the thermocline in the southeastern Tropics.
Keywords: SEA-SURFACE TEMPERATURE, INTERTROPICAL CONVERGENCE ZONE, EASTERN EQUATORIAL PACIFIC, ANNUAL CYCLE, ATMOSPHERE MODEL, COUPLED MODEL, OCEAN, VARIABILITY, CCSM3, SENSITIVITY
Mission:
URL: https://doi.org/10.1175/JCLI4047.1
Other URLs:
Chelton, D.B., Schlax, M.G., and Samelson, R.M. (2007). Summertime Coupling Between Sea Surface Temperature and Wind Stress in the California Current System, Journal of Physical Oceanography, 37(3), 495-517, 10.1175/JPO3025.1. Journal Article »
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Title: Summertime Coupling Between Sea Surface Temperature and Wind Stress in the California Current System
Type: Journal Article
Publication: Journal of Physical Oceanography
Author(s): Chelton, D.B., Schlax, M.G., and Samelson, R.M.
Year: 2007
Formatted Citation: Chelton, D.B., Schlax, M.G., and Samelson, R.M., 2007: Summertime Coupling Between Sea Surface Temperature and Wind Stress in the California Current System, Journal of Physical Oceanography, 37(3), 495-517, 10.1175/JPO3025.1.
Abstract: Satellite observations of wind stress and sea surface temperature (SST) are analyzed to investigate oceanatmosphere interaction in the California Current System (CCS). As in regions of strong SST fronts elsewhere in the World Ocean, SST in the CCS region is positively correlated with surface wind stress when SST fronts are strong, which occurs during the summertime in the CCS region. This ocean influence on the atmosphere is apparently due to SST modification of stability and mixing in the atmospheric boundary layer and is most clearly manifest in the derivative wind stress fields: wind stress curl and divergence are linearly related to, respectively, the crosswind and downwind components of the local SST gradient. The dynamic range of the Ekman upwelling velocities associated with the summertime SST-induced perturbations of the wind stress curl is larger than that of the upwelling velocities associated with the mean summertime wind stress curl. This suggests significant feedback effects on the ocean, which likely modify the SST distribution that perturbed the wind stress curl field. The atmosphere and ocean off the west coast of North America must therefore be considered a fully coupled system. It is shown that the observed summertime oceanatmosphere interaction is poorly represented in the NOAA North American Mesoscale Model (formerly called the Eta Model). This is due, at least in part, to the poor resolution and accuracy of the SST boundary condition used in the model. The sparse distribution of meteorological observations available over the CCS for data assimilation may also contribute to the poor model performance.
Keywords: ATMOSPHERIC BOUNDARY-LAYER, NUMERICAL WEATHER PREDICTION, EASTERN TROPICAL PACIFIC, COASTAL UPWELLING JET, CROSS-EQUATORIAL FLOW, NORTHERN CALIFORNIA, MARINE-LAYER, SATELLITE-OBSERVATIONS, CAPE BLANCO, WEST-COAST
Mission:
URL: https://doi.org/10.1175/JPO3025.1
Other URLs:
de Szoeke, S.P., Xie, S.P., Miyama, T., Richards, K.J., and Small, R.J.O. (2007). What Maintains the SST Front North of the Eastern Pacific Equatorial Cold Tongue?, Journal of Climate, 20(11), 2500-2514, 10.1175/JCLI4173.1. Journal Article »
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Title: What Maintains the SST Front North of the Eastern Pacific Equatorial Cold Tongue?
Type: Journal Article
Publication: Journal of Climate
Author(s): de Szoeke, S.P., Xie, S.P., Miyama, T., Richards, K.J., and Small, R.J.O.
Year: 2007
Formatted Citation: de Szoeke, S.P., Xie, S.P., Miyama, T., Richards, K.J., and Small, R.J.O., 2007: What Maintains the SST Front North of the Eastern Pacific Equatorial Cold Tongue?, Journal of Climate, 20(11), 2500-2514, 10.1175/JCLI4173.1.
Abstract: A coupled oceanatmosphere regional model suggests a mechanism for formation of a sharp sea surface temperature (SST) front north of the equator in the eastern Pacific Ocean in boreal summer and fall. Meridional convergence of Ekman transport at 5N is forced by eastward turning of the southeasterly cross-equatorial wind, but the SST front forms considerably south of the maximum Ekman convergence. Geostrophic equatorward flow at 3N in the lower half of the isothermally mixed layer enhances mixed layer convergence. Cold water is upwelled on or south of the equator and is advected poleward by mean mixed layer flow and by eddies. The mixed layer current convergence in the north confines the cold advection, so the SST front stays close to the equator. Warm advection from the north and cold advection from the south strengthen the front. In the Southern Hemisphere, a continuous southwestward current advects cold water far from the upwelling core. The cold tongue is warmed by the net surface flux, which is dominated by solar radiation. Evaporation and net surface cooling are at a maximum just north of the SST front where relatively cool dry air is advected northward over warm SST. The surface heat flux is decomposed into a response to SST alone, and an atmospheric feedback. The atmospheric feedback enhances cooling on the north side of the front by 178 W m ^-2, about half of which is due to enhanced evaporation from cold dry advection, while the other half is due to cloud radiative forcing.
Keywords: SEA-SURFACE TEMPERATURE, ATMOSPHERIC BOUNDARY-LAYER, TROPICAL INSTABILITY WAVES, HEAT-BUDGET, LONG WAVES, PART I, OCEAN, MODEL, CIRCULATION, CLIMATE
Mission:
URL: https://doi.org/10.1175/JCLI4173.1
Other URLs:
Dewitte, B., Cibot, C., Perigaud, C., An, S.I., and Terray, L. (2007). Interaction Between Near-Annual and ENSO Modes in a CGCM Simulation: Role of the Equatorial Background Mean State, Journal of Climate, 20(6), 1035-1052, 10.1175/JCLI4060.1. Journal Article »
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Title: Interaction Between Near-Annual and ENSO Modes in a CGCM Simulation: Role of the Equatorial Background Mean State
Type: Journal Article
Publication: Journal of Climate
Author(s): Dewitte, B., Cibot, C., Perigaud, C., An, S.I., and Terray, L.
Year: 2007
Formatted Citation: Dewitte, B., Cibot, C., Perigaud, C., An, S.I., and Terray, L., 2007: Interaction Between Near-Annual and ENSO Modes in a CGCM Simulation: Role of the Equatorial Background Mean State, Journal of Climate, 20(6), 1035-1052, 10.1175/JCLI4060.1.
Abstract: A 260-yr-long coupled general circulation model (CGCM) simulation is used to investigate the interaction between ENSO mode and near-annual variability and its sensitivity to the equatorial background mean stratification and seasonal cycles. Although the thermocline mean vertical structure of the model favors the high-order baroclinic modes that are associated with the slow time scales of the coupled variability, the simulated ENSO oscillates at a dominant quasi-biennial frequency. Biases of the climatological velocity field are favorable to the dominance of the zonal advective feedback over the thermocline feedback, the model exhibiting an overenergetic westward seasonal zonal current in the central-western equatorial Pacific, and an upwelling rate that is about half the observations. This sets the conditions for the enhancement of a near-annual mode that is observed to oscillate at an 8-month period in the model. Using an intermediate coupled model of the tropical Pacific where the climatological fields are prescribed to the ones derived from the CGCM, it is demonstrated that the quasi-biennial ENSO variability simulated by the CGCM is mostly due to the biases in the climatological currents of the CGCM. These biases favor the dominance of the fast zonal advective feedback over the slow thermocline feedback in the coupled system and enhance a fast coupled basin mode. This fast mode differs from the theoretical Pacific Ocean basin mode in that, besides mean temperature advection by the zonal current anomalies, it is also driven by anomalous temperature advection by the total current. Results suggest that the near-annual mode destabilizes the ENSO mode to produce overenergetic quasi-biennial oscillations in the model. It also contributes to the ENSO asymmetry and the cold bias of the CGCM mean state by nonlinear accumulation of temperature zonal advection, which works toward the cold in the western Pacific more than the warm in the east. It is suggested that the model equilibrium results from the interaction between the ENSO mode, the near-annual mode, and the mean state.
Keywords: NINO SOUTHERN-OSCILLATION, EL-NINO, PACIFIC-OCEAN, DECADAL VARIABILITY, TROPICAL PACIFIC, COUPLED MODEL, INTERDECADAL CHANGES, CIRCULATION, ASYMMETRY, FREQUENCY
Mission:
URL: https://doi.org/10.1175/JCLI4060.1
Other URLs:
Dong, S., Hautala, S.L., and Kelly, K.A. (2007). Interannual Variations in Upper-Ocean Heat Content and Heat Transport Convergence in the Western North Atlantic, Journal of Physical Oceanography, 37(11), 2682-2697, 10.1175/2007JPO3645.1. Journal Article »
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Title: Interannual Variations in Upper-Ocean Heat Content and Heat Transport Convergence in the Western North Atlantic
Type: Journal Article
Publication: Journal of Physical Oceanography
Author(s): Dong, S., Hautala, S.L., and Kelly, K.A.
Year: 2007
Formatted Citation: Dong, S., Hautala, S.L., and Kelly, K.A., 2007: Interannual Variations in Upper-Ocean Heat Content and Heat Transport Convergence in the Western North Atlantic, Journal of Physical Oceanography, 37(11), 2682-2697, 10.1175/2007JPO3645.1.
Abstract: Subsurface temperature data in the western North Atlantic Ocean are analyzed to study the variations in the heat content above a fixed isotherm and contributions from surface heat fluxes and oceanic processes. The study region is chosen based on the data density, its northern boundary shifts with the Gulf Stream position and its southern boundary shifts to contain constant volume. The temperature profiles are objectively mapped to a uniform grid (0.5 latitude and longitude, 10 m in depth, and 3 months in time). The interannual variations in upper-ocean heat content show good agreement with the changes in the sea surface height from the Ocean Topography Experiment (TOPEX)/Poseidon altimeter, both indicate positive anomalies in 1994 and 199899 and negative anomalies in 1996-97. The interannual variations in surface heat fluxes cannot explain the changes in upper-ocean heat storage rate. On the contrary, a positive anomaly in heat released to the atmosphere corresponds to a positive upper-ocean heat content anomaly. The oceanic heat transport, mainly owing to the geostrophic advection, controls the interannual variations in heat storage rate, which suggests that geostrophic advection plays an important role in the airsea heat exchange. The 18C isotherm depth and layer thickness also show good correspondence to the upper-ocean heat content, a deep and thin 18C layer corresponds to a positive heat content anomaly. The oceanic transport in each isotherm layer shows an annual cycle, converging heat in winter, and diverging in summer in a warm layer, it also shows interannual variations with the largest heat convergence occurring in even warmer layers during the period of large ocean-to-atmosphere flux.
Keywords: SEA-SURFACE TEMPERATURE, GULF-STREAM, CLIMATE VARIABILITY, FLUX ANOMALIES, SST ANOMALIES, MODE WATERS, PACIFIC, BUDGET, MECHANISMS, SIMULATION
Mission:
URL: https://doi.org/10.1175/2007JPO3645.1
Other URLs:
Edwards, K.A. and Kelly, K.A. (2007). A Seasonal Heat Budget Across the Extent of the California Current, Journal of Physical Oceanography, 37(3), 518-530, 10.1175/JPO2990.1. Journal Article »
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Title: A Seasonal Heat Budget Across the Extent of the California Current
Type: Journal Article
Publication: Journal of Physical Oceanography
Author(s): Edwards, K.A. and Kelly, K.A.
Year: 2007
Formatted Citation: Edwards, K.A. and Kelly, K.A., 2007: A Seasonal Heat Budget Across the Extent of the California Current, Journal of Physical Oceanography, 37(3), 518-530, 10.1175/JPO2990.1.
Abstract: A seasonal heat budget is based on observations that span the broad California Current (CC) region. Budget terms are estimated from satellite data (oceanic heat advection), repeat ship transects (heat storage rate), and the Comprehensive OceanAtmosphere Data Set (COADS) (surface heat flux). The balance between terms differs with distance from shore. Offshore, a local balance between the heat storage rate and net heat flux (Q0) holds, the latter is dominated by its shortwave component QSW. Shoreward of ~500 km, oceanic heat advection shifts the phase of the heat storage rate to earlier in the year and partially offsets an increase in Q0 due to cloud clearing. During the summer maximum of Q0, the ~500-km-wide CC region loses heat to alongshore geostrophic transport, offshore Ekman transport, and, to a lesser degree, cross-shore geostrophic transport and eddy transport. The advective heat loss is neither uniform in space nor temporal phase, instead, the region of geostrophic and eddy heat loss expands cross shore with the annual widening of the California Current to ~500 km. This expansion begins in spring with the onset of equatorward winds. A region of relatively positive wind stress curl widens at the same gradual rate as the CC, suggesting a coupling mechanism between the two.
Keywords: EDDY KINETIC-ENERGY, NORTH PACIFIC, CURRENT SYSTEM, OCEAN, TRANSPORT, VARIABILITY, CIRCULATION, SALT, MASS, ASSIMILATION
Mission:
URL: https://doi.org/10.1175/JPO2990.1
Other URLs:
Fukumori, I., Menemenlis, D., and Lee, T. (2007). A Near-Uniform Basin-Wide Sea Level Fluctuation of the Mediterranean Sea, Journal of Physical Oceanography, 37(2), 338-358, 10.1175/JPO3016.1. Journal Article »
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Title: A Near-Uniform Basin-Wide Sea Level Fluctuation of the Mediterranean Sea
Type: Journal Article
Publication: Journal of Physical Oceanography
Author(s): Fukumori, I., Menemenlis, D., and Lee, T.
Year: 2007
Formatted Citation: Fukumori, I., Menemenlis, D., and Lee, T., 2007: A Near-Uniform Basin-Wide Sea Level Fluctuation of the Mediterranean Sea, Journal of Physical Oceanography, 37(2), 338-358, 10.1175/JPO3016.1.
Abstract: A new basin-wide oscillation of the Mediterranean Sea is identified and analyzed using sea level observations from the Ocean Topography Experiment (TOPEX)/Poseidon satellite altimeter and a numerical ocean circulation model. More than 50% of the large-scale, nontidal, and non-pressure-driven variance of sea level can be attributed to this oscillation, which is nearly uniform in phase and amplitude across the entire basin. The oscillation has periods ranging from 10 days to several years and has a magnitude as large as 10 cm. The model suggests that the fluctuations are driven by winds at the Strait of Gibraltar and its neighboring region, including the Alboran Sea and a part of the Atlantic Ocean immediately to the west of the strait. Winds in this region force a net mass flux through the Strait of Gibraltar to which the Mediterranean Sea adjusts almost uniformly across its entire basin with depth-independent pressure perturbations. The wind-driven response can be explained in part by wind setup, a near-stationary balance is established between the along-strait wind in this forcing region and the sea level difference between the Mediterranean Sea and the Atlantic Ocean. The amplitude of this basin-wide wind-driven sea level fluctuation is inversely proportional to the setup regions depth but is insensitive to its width including that of Gibraltar Strait. The wind-driven fluctuation is coherent with atmospheric pressure over the basin and contributes to the apparent deviation of the Mediterranean Sea from an inverse barometer response.
Keywords: STRAIT-OF-GIBRALTAR, ATMOSPHERIC-PRESSURE, FLOW-THROUGH, GENERAL-CIRCULATION, PACIFIC-OCEAN, BLACK-SEA, VARIABILITY, EXCHANGE, MODEL, SENSITIVITY
Mission:
URL: https://doi.org/10.1175/JPO3016.1
Other URLs:
Han, W.Q., Yuan, D.L., Liu, W.T., and Halkides, D.J. (2007). Intraseasonal Variability of Indian Ocean Sea Surface Temperature During Boreal Winter: Madden-Julian Oscillation Versus Submonthly Forcing and Processes, Journal of Geophysical Research: Oceans, 112, C04001, 10.1029/2006JC003791. Journal Article »
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Title: Intraseasonal Variability of Indian Ocean Sea Surface Temperature During Boreal Winter: Madden-Julian Oscillation Versus Submonthly Forcing and Processes
Type: Journal Article
Publication: Journal of Geophysical Research: Oceans
Author(s): Han, W.Q., Yuan, D.L., Liu, W.T., and Halkides, D.J.
Year: 2007
Formatted Citation: Han, W.Q., Yuan, D.L., Liu, W.T., and Halkides, D.J., 2007: Intraseasonal Variability of Indian Ocean Sea Surface Temperature During Boreal Winter: Madden-Julian Oscillation Versus Submonthly Forcing and Processes, Journal of Geophysical Research: Oceans, 112, C04001, 10.1029/2006JC003791.
Abstract: [ 1] Intraseasonal variability of Indian Ocean sea surface temperature (SST) during boreal winter is investigated by analyzing available data and a suite of solutions to an ocean general circulation model for 1998 - 2004. This period covers the QuikSCAT and Tropical Rainfall Measuring Mission (TRMM) observations. Impacts of the 30 - 90 day and 10 - 30 day atmospheric intraseasonal oscillations (ISOs) are examined separately, with the former dominated by the Madden-Julian Oscillation (MJO) and the latter dominated by convectively coupled Rossby and Kelvin waves. The maximum variation of intraseasonal SST occurs at 10 degrees S - 2 degrees S in the wintertime Intertropical Convergence Zone (ITCZ), where the mixed layer is thin and intraseasonal wind speed reaches its maximum. The observed maximum warming ( cooling) averaged over ( 60 degrees E - 85 degrees E, 10 degrees S - 3 degrees S) is 1.13 degrees C ( - 0.97 degrees C) for the period of interest, with a standard deviation of 0.39 degrees C in winter. This SST change is forced predominantly by the MJO. While the MJO causes a basin-wide cooling ( warming) in the ITCZ region, submonthly ISOs cause a more complex SST structure that propagates southwestward in the western-central basin and southeastward in the eastern ocean. On both the MJO and submonthly timescales, winds are the deterministic factor for the SST variability. Short-wave radiation generally plays a secondary role, and effects of precipitation are negligible. The dominant role of winds results roughly equally from wind speed and stress forcing. Wind speed affects SST by altering turbulent heat fluxes and entrainment cooling. Wind stress affects SST via several local and remote oceanic processes.
Keywords: GENERAL-CIRCULATION MODELS, TROPICAL WESTERN PACIFIC, 1997-98 EL-NINO, MONSOON RAINFALL, EQUATORIAL WAVES, SUMMER MONSOON, PART I, CONVECTION, LAYER, SCALE
Mission: |SeaWinds|
URL: https://doi.org/10.1029/2006JC003791
Other URLs:
Hristova-Veleva, S.M., Callahan, P.S., Dunbar, R.S., Stiles, B.W., Yueh, S.H., Huddleston, J.N., Hsiao, S.V., Neumann, G., Freilich, M.H., Vanhoff, B.A., Tsai, W.-Y., Gaston, R.W., Rodriguez, E., and Weissman, D.E. (2007). Passive Microwave Rain Retrievals Using a New, Observations-Based, Parameterization of Sub-Satellite Rain Variability, 14th Symposium on Meteorological Observation and Instrumentation, 2007 AMS Meeting. Conference Paper »
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Title: Passive Microwave Rain Retrievals Using a New, Observations-Based, Parameterization of Sub-Satellite Rain Variability
Type: Conference Paper
Publication: 14th Symposium on Meteorological Observation and Instrumentation, 2007 AMS Meeting
Author(s): Hristova-Veleva, S.M., Callahan, P.S., Dunbar, R.S., Stiles, B.W., Yueh, S.H., Huddleston, J.N., Hsiao, S.V., Neumann, G., Freilich, M.H., Vanhoff, B.A., Tsai, W.-Y., Gaston, R.W., Rodriguez, E., and Weissman, D.E.
Year: 2007
Formatted Citation: Hristova-Veleva, S.M., Callahan, P.S., Dunbar, R.S., Stiles, B.W., Yueh, S.H., Huddleston, J.N., Hsiao, S.V., Neumann, G., Freilich, M.H., Vanhoff, B.A., Tsai, W.-Y., Gaston, R.W., Rodriguez, E., and Weissman, D.E., 2007: Passive Microwave Rain Retrievals Using a New, Observations-Based, Parameterization of Sub-Satellite Rain Variability, 14th Symposium on Meteorological Observation and Instrumentation, 2007 AMS Meeting.
Abstract:
Keywords:
Mission:
URL: http://ams.confex.com/ams/87ANNUAL/techprogram/paper_120409.htm
Other URLs:
Hu, A., Meehl, G.A., and Han, W.Q. (2007). Causes of a Fresher, Colder Northern North Atlantic in Late 20th Century in a Coupled Model, Progress in Oceanography, 73(3-4), 384-405, 10.1016/j.pocean.2006.07.008. Journal Article »
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Title: Causes of a Fresher, Colder Northern North Atlantic in Late 20th Century in a Coupled Model
Type: Journal Article
Publication: Progress in Oceanography
Author(s): Hu, A., Meehl, G.A., and Han, W.Q.
Year: 2007
Formatted Citation: Hu, A., Meehl, G.A., and Han, W.Q., 2007: Causes of a Fresher, Colder Northern North Atlantic in Late 20th Century in a Coupled Model, Progress in Oceanography, 73(3-4), 384-405, 10.1016/j.pocean.2006.07.008.
Abstract: Observational evidence indicates that in the northern North Atlantic, especially in the Labrador Sea, almost the whole column of the ocean water is fresher, and colder in late 20th century than in 19501960s. Here we analyze a four-member ensemble of the 20th century simulations from a coupled climate model to examine the possible causes for these observed changes. The model simulations resemble the observed changes in the northern North Atlantic. The simulated results show that a decreased meridional freshwater divergence and an increased meridional heat divergence associated with a weaker thermohaline circulation in the North Atlantic are the primary causes for the freshening and cooling in the northern North Atlantic. The increased precipitation less evaporation tends to enforce the freshening, but the reduced sea ice flux into this region tends to weaken it. On the other hand, the surface warming induced by a higher atmospheric CO2 concentration tends to heat up the northern North Atlantic, but is overcome by the cooling from increased meridional heat divergence.
Keywords: Meridional freshwater transport, Meridional heat transport, Thermohaline circulation
Mission:
URL: https://doi.org/10.1016/j.pocean.2006.07.008
Other URLs:
Hu, A.X., Meehl, G.A., and Han, W.Q. (2007). Role of the Bering Strait in the Thermohaline Circulation and Abrupt Climate Change, Geophysical Research Letters: Climate, 34(L05704), 10.1029/2006GL028906. Journal Article »
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Title: Role of the Bering Strait in the Thermohaline Circulation and Abrupt Climate Change
Type: Journal Article
Publication: Geophysical Research Letters: Climate
Author(s): Hu, A.X., Meehl, G.A., and Han, W.Q.
Year: 2007
Formatted Citation: Hu, A.X., Meehl, G.A., and Han, W.Q., 2007: Role of the Bering Strait in the Thermohaline Circulation and Abrupt Climate Change, Geophysical Research Letters: Climate, 34(L05704), 10.1029/2006GL028906.
Abstract: Here we investigate the role of the Bering Strait (BS) in the thermohaline circulation (THC) response to added freshwater forcing (hosing) in the subpolar North Atlantic, through analyzing simulations of a fully coupled climate model with an open and closed BS. Results show that the THC declines similarly with an open and closed BS during hosing. However, the recovery of the THC is delayed by about a century in the closed BS simulation than in the open BS one after the hosing is off. The closed BS prevents the added freshwater being transported from the Atlantic into the Pacific via the Arctic as in the open BS case. Further, the freshwater supply is elevated significantly after the hosing by exporting the freshwater stored in the Arctic during hosing, as sea ice, back to the North Atlantic. This stabilizes the surface stratification there and suppresses the recovery of the deep convection.
Keywords: Bering Strait, thermohaline circulation, abrupt climate change
Mission:
URL: https://doi.org/10.1029/2006GL028906
Other URLs:
Hudson, D.L., Piepmeier, J.R., and Long, D.G. (2007). Polarization Rotation Correction in Radiometry: An Error Analysis, EEE Transactions on Geoscience and Remote Sensing, 45(10), 3212-3223, 10.1109/TGRS.2007.898438. Journal Article »
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Title: Polarization Rotation Correction in Radiometry: An Error Analysis
Type: Journal Article
Publication: EEE Transactions on Geoscience and Remote Sensing
Author(s): Hudson, D.L., Piepmeier, J.R., and Long, D.G.
Year: 2007
Formatted Citation: Hudson, D.L., Piepmeier, J.R., and Long, D.G., 2007: Polarization Rotation Correction in Radiometry: An Error Analysis, EEE Transactions on Geoscience and Remote Sensing, 45(10), 3212-3223, 10.1109/TGRS.2007.898438.
Abstract: Yueh proposed a method of using the third Stokes parameter TU to correct brightness temperatures such as Tv and Th for polarization rotation. This paper presents an extended error analysis of the estimation of Tv, Th, and TQ equiv Tv - Th by Yueh's method. In order to carry out the analysis, we first develop a forward model of polarization rotation that accounts for the random nature of thermal radiation, receiver noise, and (to first order) calibration. Analytic formulas are then derived for the bias, standard deviation (STD), and root-mean-square error (RMSE) of estimated TQ, Tv, and Th, as functions of scene and radiometer parameters. These formulas are validated through independent calculation via Monte Carlo simulation. Examination of the formulas reveals that: 1) natural TU from planetary surface radiation, of the magnitude expected on Earth at L-band, has a negligible effect on correction for polarization rotation, 2) RMSE is a function of rotation angle Omega, but the value of Omega that minimizes RMSE is not known prior to instrument fabrication, and 3) if residual calibration errors can be sufficiently reduced via postlaunch calibration, then Yueh`s method reduces the error incurred by polarization rotation to negligibility.
Keywords: Faraday effect Monte Carlo methods geophysical techniques mean square error methods microwave measurement polarimetry radiometry remote sensing Faraday effect Monte Carlo simulation Stokes parameter brightness temperature calibrati
Mission:
URL: https://doi.org/10.1109/TGRS.2007.898438
Other URLs:
Illig, S. and Perigaud, C. (2007). Yearly Impact of Submonthly Rain Fluctuations on the Indian Ocean Salinity, Geophysical Research Letters: Oceans, 34(L12609), 10.1029/2007GL029655. Journal Article »
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Title: Yearly Impact of Submonthly Rain Fluctuations on the Indian Ocean Salinity
Type: Journal Article
Publication: Geophysical Research Letters: Oceans
Author(s): Illig, S. and Perigaud, C.
Year: 2007
Formatted Citation: Illig, S. and Perigaud, C., 2007: Yearly Impact of Submonthly Rain Fluctuations on the Indian Ocean Salinity, Geophysical Research Letters: Oceans, 34(L12609), 10.1029/2007GL029655.
Abstract: We investigate the impact of submonthly rain fluctuations on the daily-to-interannual variations of the salinity in the tropical Indian Ocean. A three-year record of daily observed precipitation and wind are used to force an Indian Ocean model in two experiments that differ only by their rain forcing, which is either daily- (Exp_day) or monthly- (Exp_month) averaged. Results show that submonthly precipitations significantly impact the Surface Layer Salinity (SLS) in the northern and eastern Bay of Bengal during the wet season from May to November. In September when the Bay reaches its SLS minimum, the Andaman Sea is saltier by as much as 1.3 psu for Exp_day. The frequency shift between the submonthly rain forcing and the yearly salinity response is due to accumulation in time of nonlinear mechanisms: sudden rain deficits increase the SLS by entraining salty waters from below, whereas rain excesses are inefficient to decrease the salinity of the thick surface layer.
Keywords: Indian Ocean salinity, submonthly TRMM precipitation, weather/climate timescale interactions
Mission:
URL: https://doi.org/10.1029/2007GL029655
Other URLs:
Isobe, A. and Beardsley, R.C. (2007). Atmosphere and Marginal-Sea Interaction Leading to an Interannual Variation in Cold-Air Outbreak Activity Over the Japan sea, Journal of Climate, 20(23), 5707-5714, 10.1175/2007JCLI1779.1. Journal Article »
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Title: Atmosphere and Marginal-Sea Interaction Leading to an Interannual Variation in Cold-Air Outbreak Activity Over the Japan sea
Type: Journal Article
Publication: Journal of Climate
Author(s): Isobe, A. and Beardsley, R.C.
Year: 2007
Formatted Citation: Isobe, A. and Beardsley, R.C., 2007: Atmosphere and Marginal-Sea Interaction Leading to an Interannual Variation in Cold-Air Outbreak Activity Over the Japan sea, Journal of Climate, 20(23), 5707-5714, 10.1175/2007JCLI1779.1.
Abstract: The interannual variation in cold-air outbreak activity over the Japan Sea is investigated using Japan Meteorological Agency buoy 21002 and Quick Scatterometer (QuikSCAT) wind data, Japan Oceanographic Data Center sea surface temperature (SST) data, NCEP-NCAR reanalysis surface wind and sea level pressure (SLP) data, and the winter Arctic Oscillation (AO) index of Thompson and Wallace. Cold-air outbreaks occur during the winter November - March period, and wind data for this season for the 19-winter period 1981 - 2000 were analyzed. Wavelet spectra averaged between 5- and 15-day periods were used to evaluate the intensity of cold-air outbreaks quantitatively. The winter mean wavelet spectra exhibited a clear interannual variation and a significant positive correlation with the AO index, indicating that intensive cold-air outbreaks frequently occur during relatively warm winters caused by a quasi-decadal AO. Based on the SST and SLP data, the low atmospheric surface pressure disturbances tend to develop over the warm East China Sea in warm winters in the positive AO phase. As these low SLP disturbances advance toward the northern Japan islands during the positive AO phase, they intensify more, leading to stronger cold-air outbreaks over the Japan Sea and increased sea surface cooling over the northern Japan Sea.
Keywords: EAST CHINA SEA, ARCTIC OSCILLATION, TEMPERATURE, VARIABILITY, YELLOW, WATER, FLUX
Mission: |SeaWinds|
URL: https://doi.org/10.1175/2007JCLI1779.1
Other URLs:
Juarez, R.I.N., Hodnett, M.G., Fu, R., Goulden, M.L., and von Randow, C. (2007). Control of Dry Season Evapotranspiration Over the Amazonian Forest as Inferred from Observations at a Southern Amazon Forest Site, Journal of Climate, 20(12), 2827-2839, 10.1175/JCLI4184.1. Journal Article »
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Title: Control of Dry Season Evapotranspiration Over the Amazonian Forest as Inferred from Observations at a Southern Amazon Forest Site
Type: Journal Article
Publication: Journal of Climate
Author(s): Juarez, R.I.N., Hodnett, M.G., Fu, R., Goulden, M.L., and von Randow, C.
Year: 2007
Formatted Citation: Juarez, R.I.N., Hodnett, M.G., Fu, R., Goulden, M.L., and von Randow, C., 2007: Control of Dry Season Evapotranspiration Over the Amazonian Forest as Inferred from Observations at a Southern Amazon Forest Site, Journal of Climate, 20(12), 2827-2839, 10.1175/JCLI4184.1.
Abstract: The extent to which soil water storage can support an average dry season evapotranspiration (ET) is investigated using observations from the Rebio Jar site for the period of 2000 to 2002. During the dry season, when total rainfall is less than 100 mm, the soil moisture storage available to root uptake in the top 3-m layer is sufficient to maintain the ET rate, which is equal to or higher than that in the wet season. With a normal or less-than-normal dry season rainfall, more than 75% of the ET is supplied by soil water below 1 m, whereas during a rainier dry season, about 50% of ET is provided by soil water from below 1 m. Soil moisture below 1-m depth is recharged by rainfall during the previous wet season: dry season rainfall rarely infiltrates to this depth. These results suggest that, even near the southern edge of the Amazon forest, seasonal and moderate interannual rainfall deficits can be mitigated by an increase in root uptake from deeper soil. How dry season ET varies geographically within the Amazon and what might control its geographic distribution are examined by comparing in situ observations from 10 sites from different areas of Amazonia reported during the last two decades. Results show that the average dry season ET varies less than 1 mm day^-1 or 30% from the driest to nearly the wettest parts of Amazonia and is largely correlated with the change of surface net radiation of 25% and 30%. Thus the geographic variation of the average dry season ET appears to be mainly determined by the surface radiation.
Keywords: BIOSPHERE-ATMOSPHERE EXPERIMENT, ANEMOMETER (CO)SINE RESPONSE, RAIN-FOREST, TROPICAL FOREST, REGIONAL EVAPOTRANSPIRATION, STOMATAL RESPONSES, CANOPY CONDUCTANCE, CLIMATE ASSESSMENT, FLUX MEASUREMENT, SOIL-MOISTURE
Mission:
URL: https://doi.org/10.1175/JCLI4184.1
Other URLs:
Kara, A.B., Metzger, E.J., and Bourassa, M.A. (2007). Ocean Current and Wave Effects on Wind Stress Drag Coefficient Over the Global Ocean, Geophysical Research Letters, 34(L01604), 10.1029/2006GL027849. Journal Article »
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Title: Ocean Current and Wave Effects on Wind Stress Drag Coefficient Over the Global Ocean
Type: Journal Article
Publication: Geophysical Research Letters
Author(s): Kara, A.B., Metzger, E.J., and Bourassa, M.A.
Year: 2007
Formatted Citation: Kara, A.B., Metzger, E.J., and Bourassa, M.A., 2007: Ocean Current and Wave Effects on Wind Stress Drag Coefficient Over the Global Ocean, Geophysical Research Letters, 34(L01604), 10.1029/2006GL027849.
Abstract: The effects of ocean surface currents and dominant waves on the wind stress drag coefficient (C_D) are examined over the global ocean. Major findings are as follows: (1) the combination of both ocean wave and current speeds can result in reductions in daily C_D (>10%), but the notable impact of the latter is only evident in the tropical Pacific Ocean, (2) the presence of waves generally makes winds weaker and C_D lower almost everywhere over the global ocean, (3) strong ocean currents near the western boundaries (Kuroshio and Gulf Stream) do not substantially influence C_D since the winds and currents are not always aligned, and (4) the change in speed used in bulk flux parameterization also causes large changes in fluxes. Globally, the combined outcome of ocean currents and waves is to reduce C_D by about (2%), but spatial variations (0% to 14%) do exist.
Keywords: wind drag coefficient, ocean current, ocean wave
Mission:
URL: https://doi.org/10.1029/2006GL027849
Other URLs:
Kim, S.B., Lee, T., and Fukumori, I. (2007). Mechanisms Controlling the Interannual Variation of Mixed Layer Temperature Averaged Over the Nino-3 Region, JOURNAL OF CLIMATE, 20(15), 3822-3843, 10.1175/JCLI4206.1. Journal Article »
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Title: Mechanisms Controlling the Interannual Variation of Mixed Layer Temperature Averaged Over the Nino-3 Region
Type: Journal Article
Publication: JOURNAL OF CLIMATE
Author(s): Kim, S.B., Lee, T., and Fukumori, I.
Year: 2007
Formatted Citation: Kim, S.B., Lee, T., and Fukumori, I., 2007: Mechanisms Controlling the Interannual Variation of Mixed Layer Temperature Averaged Over the Nino-3 Region, JOURNAL OF CLIMATE, 20(15), 3822-3843, 10.1175/JCLI4206.1.
Abstract: Processes controlling the interannual variation of mixed layer temperature (MLT) averaged over the Ni???? domain (5N5S, 15090W) are studied using an ocean data assimilation product that covers the period of 19932003. The overall balance is such that surface heat flux opposes the MLT change but horizontal advection and subsurface processes assist the change. Advective tendencies are estimated here as the temperature fluxes through the domains boundaries, with the boundary temperature referenced to the domain-averaged temperature to remove the dependence on temperature scale. This allows the authors to characterize external advective processes that warm or cool the water within the domain as a whole. The zonal advective tendency is caused primarily by large-scale advection of warm-pool water through the western boundary of the domain. The meridional advective tendency is contributed to mostly by Ekman current advecting large-scale temperature anomalies through the southern boundary of the domain. Unlike many previous studies, the subsurface processes that consist of vertical mixing and entrainment are explicitly evaluated. In particular, a rigorous method to estimate entrainment allows an exact budget closure. The vertical mixing across the mixed layer (ML) base has a contribution in phase with the MLT change. The entrainment tendency due to the temporal change in ML depth is negligible compared to other subsurface processes. The entrainment tendency by vertical advection across the ML base is dominated by large-scale changes in upwelling and the temperature of upwelling water. Tropical instability waves (TIWs) result in smaller-scale vertical advection that warms the domain during La Ni????ooling events. However, such a warming tendency is overwhelmed by the cooling tendency associated with the large-scale upwelling by a factor of 2. In summary, all the balance terms are important in the MLT budget except the entrainment due to lateral induction and temporal variation in ML depth. All three advective tendencies are primarily caused by large-scale and low-frequency processes, and they assist the Ni???? MLT change. When the advective tendencies are evaluated by spatially averaging the conventional local advection of temperature, the apparent effects of currents with spatial scales smaller than the domain (such as TIWs) become very important as they redistribute heat within the Ni???? domain. As a result, for example, the averaged zonal advective tendency counteracts rather than assists the Ni???? MLT change. However, such internal redistribution of heat does not represent external processes that control the domain-averaged MLT.
Keywords: EQUATORIAL PACIFIC-OCEAN, TROPICAL INSTABILITY WAVES, SEA-SURFACE TEMPERATURE, 1997-98 EL-NINO, CIRCULATION MODEL, CONCEPTUAL-MODEL, ATLANTIC-OCEAN, HEAT-BUDGET, PART I, VARIABILITY
Mission:
URL: https://doi.org/10.1175/JCLI4206.1
Other URLs:
Kwok, R. (2007). Near Zero Replenishment of the Arctic Multiyear Sea Ice Cover at the End of 2005 Summer, Geophysical Research Letters, 34, L05501, 10.1029/2006GL028737. Journal Article »
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Title: Near Zero Replenishment of the Arctic Multiyear Sea Ice Cover at the End of 2005 Summer
Type: Journal Article
Publication: Geophysical Research Letters
Author(s): Kwok, R.
Year: 2007
Formatted Citation: Kwok, R., 2007: Near Zero Replenishment of the Arctic Multiyear Sea Ice Cover at the End of 2005 Summer, Geophysical Research Letters, 34, L05501, 10.1029/2006GL028737.
Abstract: The remarkably low Arctic multiyear (MY) sea ice coverage following the summer of 2005 is placed in the context of its variability over the past seven years (2000-2006). Annual cycles of MY ice coverage, from QuikSCAT and satellite passive ice motion, show that the replenishment of MY ice area at the end of this summer is near zero (0.1 x 10⁶ km²) compared to the previous five summers of 1.0, 1.2, 0.4, 0.4, and 0.9 x 10⁶ km². This is examined in terms of anomalies in ice export and the record of freezing (F_DD) and melting degree-days (M_DD). The 2005 summer (Jun-Sep) saw the highest Fram Strait ice export (>0.25 x 10(6) km(2)) compared to the 7-year mean of 0.14 x 10⁶ km². This directly explains similar to 40% of the decrease in MY coverage of 0.6 x 10⁶ km² between Jan 2005 and Jan 2006. The cumulative effects of the recent warmer winters and summers, relative to the longer-term record since 1958, explain the balance. For this short record, the combination of spatially averaged F_DD and _MDD anomalies of the preceding year explain similar to 63% of the variance in the replenishment areas.
Keywords: OCEAN
Mission: |SeaWinds|
URL: https://doi.org/10.1029/2006GL028737
Other URLs:
Lambert, B.R. and Long, D.G. (2007). Seasonal and Interannual Variations in Antarctic Backscatter Signature from 1999 to 2006 as Observed by QuikSCAT, Earth Observing Systems XII, 10.1117/12.732455. Conference Paper »
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Title: Seasonal and Interannual Variations in Antarctic Backscatter Signature from 1999 to 2006 as Observed by QuikSCAT
Type: Conference Paper
Publication: Earth Observing Systems XII
Author(s): Lambert, B.R. and Long, D.G.
Year: 2007
Formatted Citation: Lambert, B.R. and Long, D.G., 2007: Seasonal and Interannual Variations in Antarctic Backscatter Signature from 1999 to 2006 as Observed by QuikSCAT, Earth Observing Systems XII, 10.1117/12.732455.
Abstract: Time-series analysis of Antarctic QuikSCAT data reveals several trends. An annual seasonal cycle in which backscatter power increases during the Austral winter and decreases during the Austral summer, is observed over most of the continent, with varying magnitude. Several areas also show a large ( ~ 10dB) decrease in average backscatter during the Austral summer, suggesting melt events. As expected, seasonal variations are strongly dependent on latitude, the southernmost observable portion of the continent is much less seasonably variable than the coasts. Interanual trends show strong long-term trends superimposed on seasonal cycles in much of the continent. Along the coast of most of the continent, backscatter has consistently increased, on the order of 0.5 dB/year, during the seven-year study period. Other regions, mostly in the West-Antarctic interior show the opposite trend, with average backscatter decreasing on the order of 0.5 dB/year.
Keywords:
Mission: |SeaWinds|
URL: https://doi.org/10.1117/12.732455
Other URLs:
Li, W.H., Dickinson, R.E., Fu, R., Niu, G.Y., Yang, Z.L., and Canadell, J.G. (2007). Future Precipitation Changes and Their Implications for Tropical Peatlands, Geophysical Research Letters, 34(L01403), 10.1029/2006GL028364. Journal Article »
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Title: Future Precipitation Changes and Their Implications for Tropical Peatlands
Type: Journal Article
Publication: Geophysical Research Letters
Author(s): Li, W.H., Dickinson, R.E., Fu, R., Niu, G.Y., Yang, Z.L., and Canadell, J.G.
Year: 2007
Formatted Citation: Li, W.H., Dickinson, R.E., Fu, R., Niu, G.Y., Yang, Z.L., and Canadell, J.G., 2007: Future Precipitation Changes and Their Implications for Tropical Peatlands, Geophysical Research Letters, 34(L01403), 10.1029/2006GL028364.
Abstract: Carbon (C) in tropical peatlands over Southeast Asia and Amazonia, if released to the atmosphere, can substantially increase the growth rate of atmospheric carbon dioxide. Over Southeast Asia, where the most extensive tropical peatlands in the world occur, 11 climate models for the IPCC Fourth Assessment show an overall decrease of rainfall in future dry seasons. Over Amazonia, future rainfall changes in dry seasons are highly uncertain, five models predict increased rainfall, and the remaining models predict the opposite. We have further examined the UKMO-HadCM3, GISS-ER, and GFDL-CM2.1 models. Over Southeast Asia, all three models predict similar decreases of rainfall and evaporative fraction, implying an increase of water table depth and surface dryness during the dry season south of the equator. Such changes would potentially switch peat ecosystems from acting as C sinks to C sources. Over Amazonia, the two models with the best simulations of current rainfall produce conflicting results for the future of peat stability.
Keywords: future precipitation changes, tropical peatland
Mission:
URL: https://doi.org/10.1029/2006GL028364
Other URLs:
Liang, X.D., Wang, B., Chan, J.C.L., Duan, Y.H., Wang, D.L., Zeng, Z.H., and Ma, L.M. (2007). Tropical Cyclone Forecasting with Model-Constrained 3D-Var. II: Improved Cyclone Track Forecasting Using AMSU-A, QuikSCAT and Cloud-Drift Wind Data, Quarterly Journal of the Royal Meteorological Society, 133(622), 155-165, 10.1002/qj.10. Journal Article »
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Title: Tropical Cyclone Forecasting with Model-Constrained 3D-Var. II: Improved Cyclone Track Forecasting Using AMSU-A, QuikSCAT and Cloud-Drift Wind Data
Type: Journal Article
Publication: Quarterly Journal of the Royal Meteorological Society
Author(s): Liang, X.D., Wang, B., Chan, J.C.L., Duan, Y.H., Wang, D.L., Zeng, Z.H., and Ma, L.M.
Year: 2007
Formatted Citation: Liang, X.D., Wang, B., Chan, J.C.L., Duan, Y.H., Wang, D.L., Zeng, Z.H., and Ma, L.M., 2007: Tropical Cyclone Forecasting with Model-Constrained 3D-Var. II: Improved Cyclone Track Forecasting Using AMSU-A, QuikSCAT and Cloud-Drift Wind Data, Quarterly Journal of the Royal Meteorological Society, 133(622), 155-165, 10.1002/qj.10.
Abstract: Generally, the three-dimensional variational (3D-Var) data assimilation technique does not impose constraints on the numerical model such as the dynamics and physics, which are used in a 4D-Var technique. On the other hand, adopting the 4D-Var technique requires a large amount of computer resources, which limits its practical application. In Part 1, a 3D-Var method was proposed by minimizing the distance between observations and model variables, and the time tendency of model variables which makes the optimized initial conditions satisfy the constraints of full dynamics and physics in the numerical model. The forward and adjoint models used in this method are the same as those in a 4D-Var method but are only integrated one time step to calculate the time tendency and gradient. Because a numerical model is adopted as weak constraint, this technique is labelled as MC-3DVar. Here the National Center for Atmospheric Research/Penn State Mesoscale Model 5 (MM5) is used. In this paper (Part II), AMSU-A retrieved air temperatures are assimilated into 32 tropical cyclone (TC) cases using this framework. The results show a significant decrease in track forecast errors. Meanwhile, one case-study of assimilating AMSU-A temperature, QuikSCAT sea-level winds, and efoud-drift winds gives dramatic track error decreases. The study shows that the assimilation of these data with MC-3DVar improves TC forecasts, and more satellite data give better performances.
Keywords: satellite data, data assimilation, ATMOSPHERIC MOTION VECTORS, DATA ASSIMILATION SCHEME, SATELLITE-DERIVED WINDS, MICROPHYSICAL RETRIEVAL, PART II, IMPACT, INITIALIZATION, PREDICTION, SIMULATION, ADJOINT
Mission: |SeaWinds|
URL: https://doi.org/10.1002/qj.10
Other URLs:
Liebmann, B., Camargo, S.J., Seth, A., Marengo, J.A., Carvalho, L.M.V., Allured, D., Fu, R., and Vera, C.S. (2007). Onset and End of the Rainy Season in South America in Observations and the ECHAM 4.5 Atmospheric General Circulation Model, Journal of Climate, 20(10), 2037-2050, 10.1175/JCLI4122.1. Journal Article »
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Title: Onset and End of the Rainy Season in South America in Observations and the ECHAM 4.5 Atmospheric General Circulation Model
Type: Journal Article
Publication: Journal of Climate
Author(s): Liebmann, B., Camargo, S.J., Seth, A., Marengo, J.A., Carvalho, L.M.V., Allured, D., Fu, R., and Vera, C.S.
Year: 2007
Formatted Citation: Liebmann, B., Camargo, S.J., Seth, A., Marengo, J.A., Carvalho, L.M.V., Allured, D., Fu, R., and Vera, C.S., 2007: Onset and End of the Rainy Season in South America in Observations and the ECHAM 4.5 Atmospheric General Circulation Model, Journal of Climate, 20(10), 2037-2050, 10.1175/JCLI4122.1.
Abstract: Rainfall in South America as simulated by a 24-ensemble member of the ECHAM 4.5 atmospheric general circulation model is compared and contrasted with observations (in areas in which data are available) for the period 1976-2001. Emphasis is placed on determining the onset and end of the rainy season, from which its length and rain rate are determined. It is shown that over large parts of the domain the onset and ending dates are well simulated by the model, with biases of less than 10 days. There is a tendency for model onset to occur early and ending to occur late, resulting in a simulated rainy season that is on average too long in many areas. The model wet season rain rate also tends to be larger than observed. To estimate the relative importance of errors in wet season length and rain rate in determining biases in the annual total, adjusted totals are computed by substituting both the observed climatological wet season length and rate for those of the model. Problems in the rain rate generally are more important than problems in the length. The wet season length and rain rate also contribute substantially to interannual variations in the annual total. These quantities are almost independent, and it is argued that they are each associated with different mechanisms. The observed onset dates almost always lie within the range of onset of the ensemble members, even in the areas with a large model onset bias. In some areas, though, the model does not perform well. In southern Brazil the model ensemble average onset always occurs in summer, whereas the observations show that winter is often the wettest period. Individual members, however, do occasionally show a winter rainfall peak. In southern Northeast Brazil the model has a more distinct rainy season than is observed. In the northwest Amazon the model annual cycle is shifted relative to that observed, resulting in a model bias. No interannual relationship between model and observed onset dates is expected unless onset in the model and observations has a mutual relationship with SST anomalies. In part of the near-equatorial Amazon, there does exist an interannual relationship between onset dates. Previous studies have shown that in this area there is a relationship between SST anomalies and variations in seasonal total rainfall.
Keywords: BRAZILIAN AMAZON BASIN, TROPICAL ATMOSPHERE, PRECIPITATION, RAINFALL, CLIMATE, VARIABILITY, CONVECTION, REANALYSIS, MONSOON
Mission:
URL: https://doi.org/10.1175/JCLI4122.1
Other URLs:
Liu, W.T., Xie, X.S., and Niiler, P.P. (2007). Ocean-Atmosphere Interaction Over Agulhas Extension Meanders, Journal of Climate, 20(23), 5784-5797, 10.1175/2007JCLI1732.1. Journal Article »
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Title: Ocean-Atmosphere Interaction Over Agulhas Extension Meanders
Type: Journal Article
Publication: Journal of Climate
Author(s): Liu, W.T., Xie, X.S., and Niiler, P.P.
Year: 2007
Formatted Citation: Liu, W.T., Xie, X.S., and Niiler, P.P., 2007: Ocean-Atmosphere Interaction Over Agulhas Extension Meanders, Journal of Climate, 20(23), 5784-5797, 10.1175/2007JCLI1732.1.
Abstract: Many years of high-resolution measurements by a number of space-based sensors and from Lagrangian drifters became available recently and are used to examine the persistent atmospheric imprints of the semipermanent meanders of the Agulhas Extension Current (AEC), where strong surface current and temperature gradients are found. The sea surface temperature (SST) measured by the Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E) and the chlorophyll concentration measured by the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) support the identification of the meanders and related ocean circulation by the drifters. The collocation of high and low magnitudes of equivalent neutral wind (ENW) measured by Quick Scatterometer (QuikSCAT), which is uniquely related to surface stress by definition, illustrates not only the stability dependence of turbulent mixing but also the unique stress measuring capability of the scatterometer. The observed rotation of ENW in opposition to the rotation of the surface current clearly demonstrates that the scatterometer measures stress rather than winds. The clear differences between the distributions of wind and stress and the possible inadequacy of turbulent parameterization affirm the need of surface stress vector measurements, which were not available before the scatterometers. The opposite sign of the stress vorticity to current vorticity implies that the atmosphere spins down the current rotation through momentum transport. Coincident high SST and ENW over the southern extension of the meander enhance evaporation and latent heat flux, which cools the ocean. The atmosphere is found to provide negative feedback to ocean current and temperature gradients. Distribution of ENW convergence implies ascending motion on the downwind side of local SST maxima and descending air on the upwind side and acceleration of surface wind stress over warm water (deceleration over cool water), the convection may escalate the contrast of ENW over warm and cool water set up by the dependence of turbulent mixing on stability, this relation exerts a positive feedback to the ENWSST relation. The temperature sounding measured by the Atmospheric Infrared Sounder (AIRS) is consistent with the spatial coherence between the cloud-top temperature provided by the International Satellite Cloud Climatology Project (ISCCP) and SST. Thus ocean mesoscale SST anomalies associated with the persistent meanders may have a long-term effect well above the midlatitude atmospheric boundary layer, an observation not addressed in the past.
Keywords: SEA-SURFACE TEMPERATURE, TROPICAL INSTABILITY WAVES, EXTRATROPICAL SST ANOMALIES, EASTERN EQUATORIAL PACIFIC, BOUNDARY-LAYER RESPONSE, SATELLITE MEASUREMENTS, SOUTHERN-OCEAN, BULK PARAMETERIZATION, VORTICITY BALANCE, RETURN CURRENT
Mission:
URL: https://doi.org/10.1175/2007JCLI1732.1
Other URLs:
Mears, C.A., Santer, B.D., Wentz, F.J., Taylor, K.E., and Wehner, M.F. (2007). Relationship Between Temperature and Precipitable Water Changes Over Tropical Oceans, Geophysical Research Letters, 34(L24709), 10.1029/2007GL031936. Journal Article »
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Title: Relationship Between Temperature and Precipitable Water Changes Over Tropical Oceans
Type: Journal Article
Publication: Geophysical Research Letters
Author(s): Mears, C.A., Santer, B.D., Wentz, F.J., Taylor, K.E., and Wehner, M.F.
Year: 2007
Formatted Citation: Mears, C.A., Santer, B.D., Wentz, F.J., Taylor, K.E., and Wehner, M.F., 2007: Relationship Between Temperature and Precipitable Water Changes Over Tropical Oceans, Geophysical Research Letters, 34(L24709), 10.1029/2007GL031936.
Abstract: We use observations, climate models and reanalysis output to examine the relationship between changes in temperature and changes in precipitable water. In climate models these variables are highly correlated over the tropical oceans, with a similar scaling ratio for interannual and decadal time scales. This result is consistent with the most recently developed satellite datasets. In contrast, scaling rations based either on an earlier version of the satellite measurements or reanalysis show scaling ratios that are inconsistent with models, and are dependent on time scale. These results demonstrate that climate model output is useful for evaluating differences between divergent observational datasets.
Keywords: climate change, water vapor, temperature
Mission:
URL: https://doi.org/10.1029/2007GL031936
Other URLs:
Menemenlis, D., Fukumori, I., and Lee, T. (2007). Atlantic to Mediterranean Sea Level Difference Driven by Winds Near Gibraltar Strait, Journal of Physical Oceanography, 37(2), 359-376, 10.1175/JPO3015.1. Journal Article »
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Title: Atlantic to Mediterranean Sea Level Difference Driven by Winds Near Gibraltar Strait
Type: Journal Article
Publication: Journal of Physical Oceanography
Author(s): Menemenlis, D., Fukumori, I., and Lee, T.
Year: 2007
Formatted Citation: Menemenlis, D., Fukumori, I., and Lee, T., 2007: Atlantic to Mediterranean Sea Level Difference Driven by Winds Near Gibraltar Strait, Journal of Physical Oceanography, 37(2), 359-376, 10.1175/JPO3015.1.
Abstract: Observations and numerical simulations show that winds near Gibraltar Strait cause an Atlantic Ocean to Mediterranean Sea sea level difference of 20 cm peak to peak with a 3-cm standard deviation for periods of days to years. Theoretical arguments and numerical experiments establish that this wind-driven sea level difference is caused in part by storm surges due to alongshore winds near the North African coastline on the Atlantic side of Gibraltar. The fraction of the Moroccan coastal current offshore of the 284-m isobath is deflected across Gibraltar Strait, west of Camarinal Sill, resulting in a geostrophic surface pressure gradient that contributes to a sea level difference at the stationary limit. The sea level difference is also caused in part by the along-strait wind setup, with a contribution proportional to the along-strait wind stress and to the length of Gibraltar Strait and adjoining regions and inversely proportional to its depth. In the 20360-day band, average transfer coefficients between the AtlanticAlboran sea level difference and surface wind stress at 36N, 6.5W, estimated from barometrically corrected Ocean Topography Experiment (TOPEX)/Poseidon data and NCEPNCAR reanalysis data, are 0.10 ± 0.04 m Pa^-1 with 1 5-day lag and 0.19 ± 0.08 m Pa^-1with 5 4-day lag for the zonal and meridional wind stresses, respectively. This transfer function is consistent with equivalent estimates derived from a 19922003 high-resolution barotropic simulation forced by the NCEPNCAR wind stress. The barotropic simulation explains 29% of the observed AtlanticAlboran sea level difference in the 20360-day band. In turn, the Alboran and Mediterranean mean sea level time series are highly correlated, ρ = 0.7 in the observations and ρ = 0.8 in the barotropic simulation, hence providing a pathway for winds near Gibraltar Strait to affect the mean sea level of the entire Mediterranean.
Keywords: ATMOSPHERIC-PRESSURE, MODEL, CIRCULATION, OCEAN, FLUCTUATIONS, VARIABILITY, TOPOGRAPHY, ALTIMETRY, EXCHANGE, FLOWS
Mission:
URL: https://doi.org/10.1175/JPO3015.1
Other URLs:
Myneni, R.B., Yang, W.Z., Nemani, R.R., Huete, A.R., Dickinson, R.E., Knyazikhin, Y., Didan, K., Fu, R., Juarez, R.I.N., Saatchi, S.S., Hashimoto, H., Ichii, K., Shabanov, N.V., Tan, B., Ratana, P., Privette, J.L., Morisette, J.T., Vermote, E.F., Roy, D.P., Wolfe, R.E., Friedl, M.A., Running, S.W., Votava, P., El-Saleous, N., Devadiga, S., Su, Y., and Salomonson, V.V. (2007). Large Seasonal Swings in Leaf Area of Amazon Rainforests, Proceedings of the National Academy of Sciences of the United States of America, 104(12), 4820-4823, 10.1073/pnas.0611338104. Journal Article »
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Title: Large Seasonal Swings in Leaf Area of Amazon Rainforests
Type: Journal Article
Publication: Proceedings of the National Academy of Sciences of the United States of America
Author(s): Myneni, R.B., Yang, W.Z., Nemani, R.R., Huete, A.R., Dickinson, R.E., Knyazikhin, Y., Didan, K., Fu, R., Juarez, R.I.N., Saatchi, S.S., Hashimoto, H., Ichii, K., Shabanov, N.V., Tan, B., Ratana, P., Privette, J.L., Morisette, J.T., Vermote, E.F., Roy, D.P., Wolfe, R.E., Friedl, M.A., Running, S.W., Votava, P., El-Saleous, N., Devadiga, S., Su, Y., and Salomonson, V.V.
Year: 2007
Formatted Citation: Myneni, R.B., Yang, W.Z., Nemani, R.R., Huete, A.R., Dickinson, R.E., Knyazikhin, Y., Didan, K., Fu, R., Juarez, R.I.N., Saatchi, S.S., Hashimoto, H., Ichii, K., Shabanov, N.V., Tan, B., Ratana, P., Privette, J.L., Morisette, J.T., Vermote, E.F., Roy, D.P., Wolfe, R.E., Friedl, M.A., Running, S.W., Votava, P., El-Saleous, N., Devadiga, S., Su, Y., and Salomonson, V.V., 2007: Large Seasonal Swings in Leaf Area of Amazon Rainforests, Proceedings of the National Academy of Sciences of the United States of America, 104(12), 4820-4823, 10.1073/pnas.0611338104.
Abstract: Despite early speculation to the contrary, all tropical forests studied to date display seasonal variations in the presence of new leaves, flowers, and fruits. Past studies were focused on the timing of phenological events and their cues but not on the accompanying changes in leaf area that regulate vegetationatmosphere exchanges of energy, momentum, and mass. Here we report, from analysis of 5 years of recent satellite data, seasonal swings in green leaf area of ≈,25% in a majority of the Amazon rainforests. This seasonal cycle is timed to the seasonality of solar radiation in a manner that is suggestive of anticipatory and opportunistic patterns of net leaf flushing during the early to mid part of the light-rich dry season and net leaf abscission during the cloudy wet season. These seasonal swings in leaf area may be critical to initiation of the transition from dry to wet season, seasonal carbon balance between photosynthetic gains and respiratory losses, and litterfall nutrient cycling in moist tropical forests.
Keywords:
Mission:
URL: https://doi.org/10.1073/pnas.0611338104
Other URLs:
Nie, C. and Long, D.G. (2007). Simultaneous Wind and Rain Retrieval for ERS, 2007 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `07), 4455-4458, 10.1109/IGARSS.2007.4423844. Conference Paper »
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Title: Simultaneous Wind and Rain Retrieval for ERS
Type: Conference Paper
Publication: 2007 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `07)
Author(s): Nie, C. and Long, D.G.
Year: 2007
Formatted Citation: Nie, C. and Long, D.G., 2007: Simultaneous Wind and Rain Retrieval for ERS, 2007 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `07), 4455-4458, 10.1109/IGARSS.2007.4423844.
Abstract: Using collocated ESCAT, TRMM PR, and ECMWF data, the effects of rain on the ESCAT wind-only retrieval has been evaluated. For high incidence angle measurements, the additional scattering of rain causes estimated wind speeds to appear higher than expected. It is also noted that the selected directions of the rain-corrupted wind vectors generally point along swath in heavy rain, regardless of the true wind. A simultaneous wind/rain retrieval method (SWRR) is developed using a simple wind/rain backscatter model. Validation shows that SWRR method significantly improves the wind vector estimates at high incidence angles in heavy rain cases. It also provides an estimate of the surface rain rate.
Keywords: backscatter data acquisition microwave measurement rain remote sensing wind ECMWF data ERS scatterometer measurement ESCAT data SWRR method TRMM PR data rain backscatter model rain-corrupted wind vectors simultane
Mission:
URL: https://doi.org/10.1109/IGARSS.2007.4423844
Other URLs:
Nie, C. and Long, D.G. (2007). RADARSAT ScanSAR Wind Retrieval under Hurricane Conditions, Earth Observing Systems XII, 66770K, 10.1117/12.732600. Conference Paper »
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Title: RADARSAT ScanSAR Wind Retrieval under Hurricane Conditions
Type: Conference Paper
Publication: Earth Observing Systems XII
Author(s): Nie, C. and Long, D.G.
Year: 2007
Formatted Citation: Nie, C. and Long, D.G., 2007: RADARSAT ScanSAR Wind Retrieval under Hurricane Conditions, Earth Observing Systems XII, 66770K, 10.1117/12.732600.
Abstract: RADARSAT-1 ScanSAR SWA images of Hurricane Katrina are used to retrieve the surface wind vectors over the ocean. Due to the inadequate spatial resolution of the ScanSAR SWA images, the spectrum method cannot be implemented to estimate the wind direction. Instead, collocated H*wind wind directions are used as wind direction estimates. The wind speed is derived from the sigma by inversion of a C-band HH-polarization Geophysical Model Function (GMF), which is derived from C-band VV-polarization GMF using a polarization ratio model. Because existing polarization models don`t fit the ScanSAR SWA data well, a recalibration model is proposed to "recalibrate" the ScanSAR SWA images. The coefficients of the recalibration model are "tuned" using collocated H*wind surface wind fields. To validate the SAR-retrieved wind speed, the mean and the RMS difference between SAR-retrieved and H*wind wind speed estimates are calculated. The mean of difference is small and the RMS for wind speed less than 25 m/s is below 4 m/s, suggesting that the high resolution wind retrieval algorithm can work under hurricane conditions. Except for the influence from rain, the largest errors occur at high wind speed (over 25 m/s), which is mainly due to the saturation of the C-band GMF CMOD5.
Keywords:
Mission:
URL: https://doi.org/10.1117/12.732600
Other URLs:
Nie, C.L. and Long, D.G. (2007). A C-band Wind/Rain Backscatter Model, IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING, 45(3), 621-631, 10.1109/TGRS.2006.888457. Journal Article »
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Title: A C-band Wind/Rain Backscatter Model
Type: Journal Article
Publication: IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
Author(s): Nie, C.L. and Long, D.G.
Year: 2007
Formatted Citation: Nie, C.L. and Long, D.G., 2007: A C-band Wind/Rain Backscatter Model, IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING, 45(3), 621-631, 10.1109/TGRS.2006.888457.
Abstract: With the confirmed evidence of rain surface perturbation in recent studies, the rain effects on C-band scatterometer measurements are reevaluated. By using colocated Tropical Rainfall Measuring Mission Precipitation Radar, ESCAT on European Remote Sensing Satellites, and European Centre for Medium-Range Weather Forecasts data, we evaluate the sensitivity of C-band sigmadeg to rain. We develop a low-order wind/rain backscatter model with inputs of surface rain rate, incidence angle, wind speed, wind direction, and azimuth angle. We demonstrate that the wind/rain backscatter model is accurate enough for describing the total backscatter in raining areas with relatively low variance. We also show that the rain surface perturbation is a dominating factor of the rain-induced backscatter. Using three distinct regimes, we show under what conditions the wind, rain, and both wind and rain can be retrieved from the measurements. We find that the effect of rain has a more significant impact on the measurements at high incidence angles than at low incidence angles
Keywords: Backscatter European Centre for Medium-Range Weather Forecasts (ECMWF) European Remote Sensing (ERS) Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) rain scatterometer surface effects
Mission:
URL: https://doi.org/10.1109/TGRS.2006.888457
Other URLs:
Owen, M.P., Stuart, K.M., and Long, D.G. (2007). Ultra-High-Resolution Near-Coastal Wind Retrieval for QuikSCAT, Coastal Ocean Remote Sensing, 6680, 10.1117/12.732681. Conference Paper »
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Title: Ultra-High-Resolution Near-Coastal Wind Retrieval for QuikSCAT
Type: Conference Paper
Publication: Coastal Ocean Remote Sensing
Author(s): Owen, M.P., Stuart, K.M., and Long, D.G.
Year: 2007
Formatted Citation: Owen, M.P., Stuart, K.M., and Long, D.G., 2007: Ultra-High-Resolution Near-Coastal Wind Retrieval for QuikSCAT, Coastal Ocean Remote Sensing, 6680, 10.1117/12.732681.
Abstract: The SeaWinds on QuikSCAT scatterometer measures near surface ocean winds using radar backscatter values and a geophysical model function. QuikSCAT data is limited in coastal regions due to land contamination of the backscatter measurements. However, wind retrieval in near coastal areas can be successfully accomplished by estimating the amount of land contamination in the backscatter measurements and eliminating measurements which exceed a specified threshold. In order to accurately assess the amount of land contamination in a given measurement, a detailed knowledge of the antenna spatial response is required. The land contribution ratio is used as the contamination metric and is calculated using the spatial response of each QuikSCAT measurement. The land contamination threshold changes during wind retrieval as a function of wind conditions in the local area which allows retrieval closer to the coast as wind speeds increase. To ameliorate processing time the QuikSCAT spatial response is calculated and tabulated prior to wind retrieval. Subjective comparisons to estimated coastal winds show that determining a land contamination threshold using the percent land contribution metric provides accurate wind retrieval up to 25km closer to the coast than current methods. As a result wind speeds can be accurately retrieved as close as 2.5km from the coast.
Keywords:
Mission: |SeaWinds|
URL: https://doi.org/10.1117/12.732681
Other URLs:
Perez-Brunius, P., Lopez, M., Pares-Sierra, A., and Pineda, J. (2007). Comparison of Upwelling Indices Off Baja California Derived From Three Different Wind Data Sources, Journal Article »
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Title: Comparison of Upwelling Indices Off Baja California Derived From Three Different Wind Data Sources
Type: Journal Article
Publication:
Author(s): Perez-Brunius, P., Lopez, M., Pares-Sierra, A., and Pineda, J.
Year: 2007
Formatted Citation: Perez-Brunius, P., Lopez, M., Pares-Sierra, A., and Pineda, J., 2007: Comparison of Upwelling Indices Off Baja California Derived From Three Different Wind Data Sources,
Abstract: We compared the NOAA Southwest Fisheries Science Center`s Environmental Research Division (formerly Pacific Fisheries Environmental Laboratory: PFEL) coastal upwelling indices along the northern Baja California coast with those derived from winds measured by coastal meteorological stations and estimated by the QuikSCAT satellite. With the exception of the PFEL series at 33 degrees N, the three data sets compare reasonably well, having similar typical year patterns, correlations > 0.6, and significant coherences for periods three to five days or longer. By contrast, the seasonal variations, the timing and magnitude of maximum upwelling, and the variability of the PFEL indices at 33 degrees N are significantly different compared to all the other time series, including QuikSCAT at that location. The performance of the QuikSCAT winds close to shore was evaluated using the coastal meteorological station data. Although large root-mean-square (RMS) errors in direction were found for the QuikSCAT winds, both datasets have properties similar to the variance ellipses, and show reasonable coherences for frequencies in the weather band and lower, particularly south of 33 degrees N.
Keywords: STRESS CURL, NORTHERN CALIFORNIA, CURRENT SYSTEM, COASTAL OCEAN, MARINE-LAYER, TIME-SERIES, VARIABILITY, SURVIVAL, ROCKFISH, REGIONS
Mission: |SeaWinds|
URL: http://science.whoi.edu/labs/pinedalab/PDFdocs/Perez_B_2007.pdf
Other URLs:
Perovich, D.K., Nghiem, S.V., Markus, T., and Schweiger, A. (2007). Seasonal Evolution and Interannual Variability of the Local Solar Energy Absorbed by the Arctic Sea Ice-Ocean System, Journal of Geophysical Research: Oceans, 112, C03005, 10.1029/2006JC003558. Journal Article »
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Title: Seasonal Evolution and Interannual Variability of the Local Solar Energy Absorbed by the Arctic Sea Ice-Ocean System
Type: Journal Article
Publication: Journal of Geophysical Research: Oceans
Author(s): Perovich, D.K., Nghiem, S.V., Markus, T., and Schweiger, A.
Year: 2007
Formatted Citation: Perovich, D.K., Nghiem, S.V., Markus, T., and Schweiger, A., 2007: Seasonal Evolution and Interannual Variability of the Local Solar Energy Absorbed by the Arctic Sea Ice-Ocean System, Journal of Geophysical Research: Oceans, 112, C03005, 10.1029/2006JC003558.
Abstract: The melt season of the Arctic sea ice cover is greatly affected by the partitioning of the incident solar radiation between reflection to the atmosphere and absorption in the ice and ocean. This partitioning exhibits a strong seasonal cycle and significant interannual variability. Data in the period 1998, 2000-2004 were analyzed in this study. Observations made during the 1997-1998 SHEBA (Surface HEat Budget of the Arctic Ocean) field experiment showed a strong seasonal dependence of the partitioning, dominated by a five-phase albedo evolution. QuikSCAT scatterometer data from the SHEBA region in 1999-2004 were used to further investigate solar partitioning in summer. The time series of scatterometer data were used to determine the onset of melt and the beginning of freezeup. This information was combined with SSM/I-derived ice concentration, TOVS-based estimates of incident solar irradiance, and SHEBA results to estimate the amount of solar energy absorbed in the ice-ocean system for these years. The average total solar energy absorbed in the ice-ocean system from April through September was 900 MJ m(-2). There was considerable interannual variability, with a range of 826 to 1044 MJ m(-2). The total amount of solar energy absorbed by the ice and ocean was strongly related to the date of melt onset, but only weakly related to the total duration of the melt season or the onset of freezeup. The timing of melt onset is significant because the incident solar energy is large and a change at this time propagates through the entire melt season, affecting the albedo every day throughout melt and freezeup.
Keywords: POLARIMETRIC SIGNATURES, SURFACE CONDITIONS, ALBEDO, COVER, SATELLITE, SUMMER, BUDGET, SHEBA, FLUX, PARAMETERIZATIONS
Mission: |SeaWinds|
URL: https://doi.org/10.1029/2006JC003558
Other URLs:
Pun, I.F., Lin, I.I., Wu, C.R., Ko, D.H., and Liu, W.T. (2007). Validation and Application of Altimetry-Derived Upper Ocean Thermal Structure in the Western North Pacific Ocean for Typhoon-Intensity forecast, IEEE Transactions on Geoscience and Remote Sensing, 45(6, Pt.1), 1616-1630, 10.1109/TGRS.2007.895950. Journal Article »
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Title: Validation and Application of Altimetry-Derived Upper Ocean Thermal Structure in the Western North Pacific Ocean for Typhoon-Intensity forecast
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Pun, I.F., Lin, I.I., Wu, C.R., Ko, D.H., and Liu, W.T.
Year: 2007
Formatted Citation: Pun, I.F., Lin, I.I., Wu, C.R., Ko, D.H., and Liu, W.T., 2007: Validation and Application of Altimetry-Derived Upper Ocean Thermal Structure in the Western North Pacific Ocean for Typhoon-Intensity forecast, IEEE Transactions on Geoscience and Remote Sensing, 45(6, Pt.1), 1616-1630, 10.1109/TGRS.2007.895950.
Abstract: This paper uses more than 5000 colocated and near-coincident in-situ profiles from the National Oceanic and Atmospheric Administration/Global Temperature and Salinity Profile Program database spanning over the period from 2002 to 2005 to systematically validate the satellite-altimetry-derived upper ocean thermal structure in the western North Pacific ocean as such ocean thermal structure information is critical in typhoon-intensity change. It is found that this satellite-derived information is applicable in the central and the southwestern North Pacific (covering 122-170degE, 9-25degN) but not in the northern part (130-170degE, 25-40degN). However, since > 80% of the typhoons are found to intensify in the central and southern part, this regional dependence should not pose a serious constraint in studying typhoon intensification. Further comparison with the U.S. Naval Research Laboratory's North Pacific Ocean Nowcast/Forecast System (NPACNFS) hydrodynamic ocean model shows similar regional applicability, but NPACNFS is found to have a general underestimation in the upper ocean thermal structure and causes a large underestimation of the tropical cyclone heat potential (TCHP) by up to 60 kJ/cm2. After validation, the derived upper ocean thermal profiles are used to study the intensity change of supertyphoon Dianmu (2004). It is found that two upper ocean parameters, i.e., a typhoon`s self-induced cooling and the during-typhoon TCHP, are the most sensitive parameters (with R ~0.7) to the 6-h intensity change of Dianmu during the study period covering Dianmu's rapid intensification to category 5 and its subsequent decay to category 4. This paper suggests the usefulness of satellite-based upper ocean thermal information in future research and operation that is related to typhoon-intensity change in the western North Pacific
Keywords: Altimetry typhoon upper ocean thermal structure
Mission:
URL: https://doi.org/10.1109/TGRS.2007.895950
Other URLs:
Reynolds, R.W., Smith, T.M., Liu, C., Chelton, D.B., Casey, K.S., and Schlax, M.G. (2007). Daily High-Resolution Blended Analyses for Sea Surface Temperature, Journal of Physical Oceanography, 20(22), 5473-5496, 10.1175/2007JCLI1824.1. Journal Article »
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Title: Daily High-Resolution Blended Analyses for Sea Surface Temperature
Type: Journal Article
Publication: Journal of Physical Oceanography
Author(s): Reynolds, R.W., Smith, T.M., Liu, C., Chelton, D.B., Casey, K.S., and Schlax, M.G.
Year: 2007
Formatted Citation: Reynolds, R.W., Smith, T.M., Liu, C., Chelton, D.B., Casey, K.S., and Schlax, M.G., 2007: Daily High-Resolution Blended Analyses for Sea Surface Temperature, Journal of Physical Oceanography, 20(22), 5473-5496, 10.1175/2007JCLI1824.1.
Abstract: Two new high-resolution sea surface temperature (SST) analysis products have been developed using optimum interpolation (OI). The analyses have a spatial grid resolution of 0.25° and a temporal resolution of 1 day. One product uses the Advanced Very High Resolution Radiometer (AVHRR) infrared satellite SST data. The other uses AVHRR and Advanced Microwave Scanning Radiometer (AMSR) on the NASA Earth Observing System satellite SST data. Both products also use in situ data from ships and buoys and include a large-scale adjustment of satellite biases with respect to the in situ data. Because of AMSRï¿½s near-all-weather coverage, there is an increase in OI signal variance when AMSR is added to AVHRR. Thus, two products are needed to avoid an analysis variance jump when AMSR became available in June 2002. For both products, the results show improved spatial and temporal resolution compared to previous weekly 1° OI analyses. The AVHRR-only product uses Pathfinder AVHRR data (currently available from January 1985 to December 2005) and operational AVHRR data for 2006 onward. Pathfinder AVHRR was chosen over operational AVHRR, when available, because Pathfinder agrees better with the in situ data. The AMSR–AVHRR product begins with the start of AMSR data in June 2002. In this product, the primary AVHRR contribution is in regions near land where AMSR is not available. However, in cloud-free regions, use of both infrared and microwave instruments can reduce systematic biases because their error characteristics are independent.
Keywords: SST, diurnal, wind
Mission:
URL: https://doi.org/10.1175/2007JCLI1824.1
Other URLs:
Romero-Centeno, R., Zavala-Hidalgo, J., and Raga, G.B. (2007). Midsummer Gap Winds and Low-Level Circulation Over the Eastern Tropical Pacific, Journal of Climate, 20(15), 3768-3784, 10.1175/JCLI4220.1. Journal Article »
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Title: Midsummer Gap Winds and Low-Level Circulation Over the Eastern Tropical Pacific
Type: Journal Article
Publication: Journal of Climate
Author(s): Romero-Centeno, R., Zavala-Hidalgo, J., and Raga, G.B.
Year: 2007
Formatted Citation: Romero-Centeno, R., Zavala-Hidalgo, J., and Raga, G.B., 2007: Midsummer Gap Winds and Low-Level Circulation Over the Eastern Tropical Pacific, Journal of Climate, 20(15), 3768-3784, 10.1175/JCLI4220.1.
Abstract: The low-level seasonal and intraseasonal wind variability over the northeastern tropical Pacific (NETP), its relationship with other variables, and the connection with large- and middle-scale atmospheric patterns are analyzed using a suite of datasets. Quick Scatterometer (QuikSCAT) wind data show that the low-level circulation over the NETP is mainly affected by the northerly trades, the southerly trades, and the wind jets crossing through the Tehuantepec, Papagayo, and Panama mountain gaps. The seasonal and intraseasonal evolution of these wind systems determines the circulation patterns over the NETP, showing predominant easterly winds in winter and early spring and wind direction reversals in summer over the central region of the NETP. During summer, when southerly trades are the strongest and reach their maximum northward penetration, weak westerlies are observed in June, easterlies in July-August, despite that strong southerlies tend to turn eastward, and again westerlies in September-October. This circulation pattern appears to be related to the Tehuantepec and Papagayo jets, which slightly strengthen during midsummer favored by the westward elongation and intensification of the Azores-Bermuda high (ABH). This ABH evolution induces an across-gap pressure gradient over the Isthmus of Tehuantepec favoring the generation of the jet and a meridional sea level pressure (SLP) gradient in the western Caribbean that favors the funneling of the trade winds through the Papagayo gap. The SLP pattern causing the gap winds in winter is different than in midsummer, being the southeastward intrusion of high pressure systems coming from the northwest, the main cause of the large meridional SLP gradients in Tehuantepec and the western Caribbean. The westward low-level circulation observed over the central-eastern region of the NETP during midsummer induces westward moisture fluxes in the lower layers of the atmosphere, displaces convergence areas away from the coasts, and confines the relatively strong convergence in the easternmost NETP to the south of the area of influence of the wind jets and associated easterlies, contributing to the development of the midsummer drought observed in southern Mexico and Central America.
Keywords: GULF-OF-TEHUANTEPEC, CENTRAL-AMERICA, SATELLITE-OBSERVATIONS, INTERANNUAL VARIABILITY, BIMODAL DISTRIBUTION, SURFACE WINDS, WARM POOL, OCEAN, MEXICO, DIVERGENCE
Mission: |SeaWinds|
URL: https://doi.org/10.1175/JCLI4220.1
Other URLs:
Sampe, T. and Xie, S.-P. (2007). Mapping High Sea Winds from Space: A Global Climatology, Bulletin of the American Meteorological Society, 88(12), 1965-1978, 10.1175/BAMS-88-12-1965. Journal Article »
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Title: Mapping High Sea Winds from Space: A Global Climatology
Type: Journal Article
Publication: Bulletin of the American Meteorological Society
Author(s): Sampe, T. and Xie, S.-P.
Year: 2007
Formatted Citation: Sampe, T. and Xie, S.-P., 2007: Mapping High Sea Winds from Space: A Global Climatology, Bulletin of the American Meteorological Society, 88(12), 1965-1978, 10.1175/BAMS-88-12-1965.
Abstract: High winds at sea are feared by sailors, but their distribution is poorly known because ships have avoided them as much as possible. The accumulation of spaceborne scatterometer measurements now allows a global mapping of high winds over the ocean. Seven years of Quick Scatterometer (QuikSCAT) data gathered since July 1999 show that high-wind events, defined as wind speeds greater than 20 m s(-1) (strong gale and higher on the Beaufort scale), mostly happen in winter. Over coastal regions, land orography is the major cause of high winds, forcing wind jets of various types. Over the open ocean, high winds tend to be collocated with the extratropical storm tracks, along which migratory low and high pressure systems travel eastward. In comparison, tropical cyclones do not leave a strong signature in the climatology of high-wind occurrence except in the western Pacific east of Taiwan. In the extratropics, sea surface temperature (SST) fronts and their meanders significantly change the frequency of high-wind events. For example, high winds occur twice as often (or more) over the warmer than the colder flank of the Gulf Stream, and over the poleward than equatorward meanders of the Antarctic Circumpolar Current. The collocation of frequent high winds and SST frontal zones is not a mere coincidence because SST gradients anchor storm tracks, which in turn sustain the surface westerlies against friction with lateral heat and momentum flux. Both the high mean speed and large variance of wind increase the probability of high winds. Implications for navigation safety and oceanographic and climate research are discussed.
Keywords: EASTERN EQUATORIAL PACIFIC, HEMISPHERE STORM TRACKS, GREENLAND TIP JET, SURFACE-TEMPERATURE, SOUTHERN-HEMISPHERE, SATELLITE-OBSERVATIONS, WEATHER PREDICTION, OCEANIC FRONTS, GULF-STREAM, QUIKSCAT
Mission: |SeaWinds|
URL: https://doi.org/10.1175/BAMS-88-12-1965
Other URLs:
Santer, B.D., Mears, C., Wentz, F.J., Taylor, K.E., Gleckler, P.J., Wigley, T.M.L., Barnett, T.P., Boyle, J.S., Bruggemann, W., Gillett, N.P., Klein, S.A., Meehl, G.A., Nozawa, T., Pierce, D.W., Stott, P.A., Washington, W.M., and Wehner, M.F. (2007). Identification of Human-Induced Changes in Atmospheric Moisture Content, Proceedings of the National Academy of Sciences of the United States of America, 104(39), 15248-15253, 10.1073/pnas.0702872104. Journal Article »
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Title: Identification of Human-Induced Changes in Atmospheric Moisture Content
Type: Journal Article
Publication: Proceedings of the National Academy of Sciences of the United States of America
Author(s): Santer, B.D., Mears, C., Wentz, F.J., Taylor, K.E., Gleckler, P.J., Wigley, T.M.L., Barnett, T.P., Boyle, J.S., Bruggemann, W., Gillett, N.P., Klein, S.A., Meehl, G.A., Nozawa, T., Pierce, D.W., Stott, P.A., Washington, W.M., and Wehner, M.F.
Year: 2007
Formatted Citation: Santer, B.D., Mears, C., Wentz, F.J., Taylor, K.E., Gleckler, P.J., Wigley, T.M.L., Barnett, T.P., Boyle, J.S., Bruggemann, W., Gillett, N.P., Klein, S.A., Meehl, G.A., Nozawa, T., Pierce, D.W., Stott, P.A., Washington, W.M., and Wehner, M.F., 2007: Identification of Human-Induced Changes in Atmospheric Moisture Content, Proceedings of the National Academy of Sciences of the United States of America, 104(39), 15248-15253, 10.1073/pnas.0702872104.
Abstract: Data from the satellite-based Special Sensor Microwave Imager (SSM/I) show that the total atmospheric moisture content over oceans has increased by 0.41 kg/m2 per decade since 1988. Results from current climate models indicate that water vapor increases of this magnitude cannot be explained by climate noise alone. In a formal detection and attribution analysis using the pooled results from 22 different climate models, the simulated fingerprint pattern of anthropogenically caused changes in water vapor is identifiable with high statistical confidence in the SSM/I data. Experiments in which forcing factors are varied individually suggest that this fingerprint match is primarily due to human-caused increases in greenhouse gases and not to solar forcing or recovery from the eruption of Mount Pinatubo. Our findings provide preliminary evidence of an emerging anthropogenic signal in the moisture content of earth's atmosphere.
Keywords: climate change , climate modeling , detection and attribution , water vapor
Mission:
URL: https://doi.org/10.1073/pnas.0702872104
Other URLs:
Satheesan, K., Sarkar, A., Parekh, A., Kumar, M.R.R., and Kuroda, Y. (2007). Comparison of Wind Data from QuikSCAT and Buoys in the Indian Ocean, International Journal of Remote Sensing, 28(10), 2375-2382, 10.1080/01431160701236803. Journal Article »
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Title: Comparison of Wind Data from QuikSCAT and Buoys in the Indian Ocean
Type: Journal Article
Publication: International Journal of Remote Sensing
Author(s): Satheesan, K., Sarkar, A., Parekh, A., Kumar, M.R.R., and Kuroda, Y.
Year: 2007
Formatted Citation: Satheesan, K., Sarkar, A., Parekh, A., Kumar, M.R.R., and Kuroda, Y., 2007: Comparison of Wind Data from QuikSCAT and Buoys in the Indian Ocean, International Journal of Remote Sensing, 28(10), 2375-2382, 10.1080/01431160701236803.
Abstract: The performance of QuikSCAT-derived wind vectors is evaluated using in-situ data from moored buoys over the Indian Ocean. The results show that the mean differences for wind speed and wind direction are 0.37 ms-1 and 5.8 degrees, root mean square deviations are 1.57ms(-1) and 44.1 degrees and corresponding coefficients of correlation are 0.87 and 0.75, respectively. The matching between in-situ and satellite estimates seems to be better in the North Indian Ocean than in the Equatorial Indian Ocean. The effects of sea surface temperature and air-sea temperature difference on wind residuals were also investigated. In general, QuikSCAT is found to overestimate the winds. It is speculated that low wind speed during rain-free conditions and high wind speed, normally associated with rain, may be the reason for the less accurate estimation of the wind vector from QuikSCAT over the Indian Ocean.
Keywords: ATMOSPHERIC STABILITY, SURFACE WINDS, SPEED, DEPENDENCE, VECTORS, WAVE
Mission: |SeaWinds|
URL: https://doi.org/10.1080/01431160701236803
Other URLs:
Sharma, R., Sarkar, A., Agarwal, N., Kumar, R., and Basu, S. (2007). A New Technique for Forecasting Surface Wind Field from Scatterometer Observations: A Case Study for the Arabian Sea, IEEE Transactions on Geoscience and Remote Sensing, 45(3), 613-620, 10.1109/TGRS.2006.888093. Journal Article »
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Title: A New Technique for Forecasting Surface Wind Field from Scatterometer Observations: A Case Study for the Arabian Sea
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Sharma, R., Sarkar, A., Agarwal, N., Kumar, R., and Basu, S.
Year: 2007
Formatted Citation: Sharma, R., Sarkar, A., Agarwal, N., Kumar, R., and Basu, S., 2007: A New Technique for Forecasting Surface Wind Field from Scatterometer Observations: A Case Study for the Arabian Sea, IEEE Transactions on Geoscience and Remote Sensing, 45(3), 613-620, 10.1109/TGRS.2006.888093.
Abstract: The possibility of predicting ocean-surface wind field a few days ahead from satellite scatterometer observations in the Arabian Sea has been explored in this paper. The prediction technique is based on a combination of empirical orthogonal function (EOF) analysis and genetic algorithm (GA). The space-time distributed satellite data (zonal or meridional wind field) have been decomposed into a set of spatial eigenmodes ranked by their temporal variance. The associated temporal amplitude functions have been used by the GA for carrying out forecasts with lead times varying from one to five days. The GA finds the analytical equations that best describe the behavior of the different temporal amplitude functions in the EOF decomposition. Later, the predicted wind field has been generated as a linear combination of the dominant spatial modes weighted by the corresponding predicted amplitudes. The technique has been tested using independent validation data sets. It has been further tested by comparing the forecast fields with buoy data. The performance of GA is comparable to that of persistence forecast for the first two days of forecast, while it is better than that of persistence for three- to five-day-ahead forecasts.
Keywords: Arabian Sea, empirical orthogonal function (EOF) analysis, forecasting ocean-surface wind, genetic algorithm (GA), QuikSCAT scatterometer, CHAOTIC TIME-SERIES, GENETIC ALGORITHMS, HUMIDITY PROFILES, NEURAL-NETWORKS, OSCILLATIONS, VARIABILITY, MONSOON, OCE
Mission: |SeaWinds|
URL: https://doi.org/10.1109/TGRS.2006.888093
Other URLs:
Small, R.J.O., de Szoeke, S.P., and Xie, S.-P. (2007). The Central American Mid-Summer Drought: Regional Aspects and Large Scale Forcing, Journal of Climate, 20(19), 4853-4873, 10.1175/JCLI4261.1. Journal Article »
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Title: The Central American Mid-Summer Drought: Regional Aspects and Large Scale Forcing
Type: Journal Article
Publication: Journal of Climate
Author(s): Small, R.J.O., de Szoeke, S.P., and Xie, S.-P.
Year: 2007
Formatted Citation: Small, R.J.O., de Szoeke, S.P., and Xie, S.-P., 2007: The Central American Mid-Summer Drought: Regional Aspects and Large Scale Forcing, Journal of Climate, 20(19), 4853-4873, 10.1175/JCLI4261.1.
Abstract: The midsummer drought (MSD) is a diminution in rainfall experienced during the middle of the rainy season in southern Mexico and Central America, as well as in the adjacent Caribbean, Gulf of Mexico, and eastern Pacific seas. The aim of this paper is to describe the regional characteristics of the MSD and to propose some possible forcing mechanisms. Satellite and in situ data are used to form a composite of the evolution of a typical MSD, which highlights its coincidence with a low-level anticyclone centered over the Gulf of Mexico and associated easterly flow across Central America. The diurnal cycle of precipitation over the region is reduced in amplitude during midsummer. The MSD is also coincident with heavy precipitation over the Sierra Madre Occidental (part of the North American monsoon). Reanalysis data are used to show that the divergence of the anomalous low-level flow during the MSD is the main factor governing the variations in precipitation. A linear baroclinic model is used to show that the seasonal progression of the Pacific intertropical convergence zone (ITCZ), which moves northward following warm sea surface temperature (SST) during the early summer, and of the Atlantic subtropical high, which moves westward, are the most important remote factors that contribute toward the low-level easterly flow and divergence during the MSD. The circulation associated with the MSD precipitation deficit helps to maintain the deficit by reinforcing the low-level anticyclonic flow over the Gulf of Mexico. Surface heating over land also plays a role: a large thermal low over the northern United States in early summer is accompanied by enhanced subsidence over the North Atlantic. This thermal low is seen to decrease considerably in midsummer, allowing the high pressure anomalies in the Atlantic and Pacific Oceans to extend into the Gulf of Mexico. These anomalies are maintained until late summer, when an increase in rainfall from the surge in Atlantic tropical depressions induces anomalous surface cyclonic flow with westerlies fluxing moisture from the Pacific ITCZ toward Central America.
Keywords: Pacific Ocean , North Pacific , Atlantic Ocean , North Atlantic , Northwest Atlantic , North American Atlantic , Reanalysis , Composite analysis , Caribbean Sea , Northeast Pacific , Gulf of Mexico , Central America , mechanism , Composite analysis , line
Mission:
URL: https://doi.org/10.1175/JCLI4261.1
Other URLs:
Soisuvarn, S., Jelenak, Z., and Jones, W.L. (2007). An Ocean Surface Wind Vector Model Function for a Spaceborne Microwave Radiometer, IEEE Transactions on Geoscience and Remote Sensing, 45(10), 3119-3130, 10.1109/TGRS.2007.895418. Journal Article »
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Title: An Ocean Surface Wind Vector Model Function for a Spaceborne Microwave Radiometer
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Soisuvarn, S., Jelenak, Z., and Jones, W.L.
Year: 2007
Formatted Citation: Soisuvarn, S., Jelenak, Z., and Jones, W.L., 2007: An Ocean Surface Wind Vector Model Function for a Spaceborne Microwave Radiometer, IEEE Transactions on Geoscience and Remote Sensing, 45(10), 3119-3130, 10.1109/TGRS.2007.895418.
Abstract: Surface wind vector measurements over the oceans are vital for scientists and forecasters to understand the Earth's global weather and climate. In the last two decades, operational measurements of global ocean wind speeds were obtained from passive microwave radiometers (Special Sensor Microwave/ Imagers), and over this period, full ocean surface wind vector data were obtained from several National Aeronautics and Space Administration and European Space Agency scatterometry missions. However, since SeaSat-A in 1978, there have not been other combined active and passive wind measurements on the same satellite until the launch of Japan Aerospace Exploration Agency's Advanced Earth Observing Satellite-II in 2002. This mission provided a unique data set of coincident measurements between the SeaWinds scatterometer and the Advanced Microwave Scanning Radiometer (AMSR). The AMSR instrument measured linearly polarized brightness temperatures (TB) over the ocean. Although these measurements contained wind direction information, the overlying atmospheric influence obscured this signal and made wind direction retrievals not feasible. However, for radiometer channels between 10 and 37 GHz, a certain linear combination of vertical and horizontal brightness temperatures causes the atmospheric dependence to cancel and surface parameters such as wind speed and direction and sea surface temperature to dominate the resulting signal. In this paper, an empirical relationship between AMSR T-B's (specifically A center dot T-BV - T-BH) and surface wind vectors (inferred from SeaWinds` retrievals) is established for three microwave frequencies: 10, 18, and 37 GHz. This newly developed wind vector model function for microwave radiometers can serve as a basis for wind vector retrievals either separately or in combination with active scatterometer measurements.
Keywords: active and passive microwave, microwave radiometry, ocean surface wind vector, scatterometry, SATELLITE
Mission: |SeaWinds|
URL: https://doi.org/10.1109/TGRS.2007.895418
Other URLs:
Soloviev, A., Donelan, M., Graber, H., Haus, B., and Schlussel, P. (2007). An Approach to Estimation of Near-Surface Turbulence and CO2 Transfer Velocity from Remote Sensing Data, Journal of Marine Systems, 66(1-4), 182-194, 10.1016/j.jmarsys.2006.03.023. Journal Article »
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Title: An Approach to Estimation of Near-Surface Turbulence and CO2 Transfer Velocity from Remote Sensing Data
Type: Journal Article
Publication: Journal of Marine Systems
Author(s): Soloviev, A., Donelan, M., Graber, H., Haus, B., and Schlussel, P.
Year: 2007
Formatted Citation: Soloviev, A., Donelan, M., Graber, H., Haus, B., and Schlussel, P., 2007: An Approach to Estimation of Near-Surface Turbulence and CO2 Transfer Velocity from Remote Sensing Data, Journal of Marine Systems, 66(1-4), 182-194, 10.1016/j.jmarsys.2006.03.023.
Abstract: The air-sea CO2 exchange is primarily determined by the boundary-layer processes in the near-surface layer of the ocean since it is a water-side limited gas. As a consequence, the interfacial component of the CO2 transfer velocity can be linked to parameters of turbulence in the near-surface layer of the ocean. The development of remote sensing techniques provides a possibility to quantify the dissipation of the turbulent kinetic energy in the near-surface layer of the ocean and the air-sea CO2 transfer velocity on a global scale. In this work, the dissipation rate of the turbulent kinetic energy in the near-surface layer of the ocean and its patchiness has been linked to the air-sea CO2 transfer velocity with a boundary-layer type model. Field observations of upper ocean turbulence, laboratory studies, and the direct CO2 flux measurements are used to validate the model. The model is then forced with the TOPEX POSEIDON wind speed and significant wave height to demonstrate its applicability for estimating the distribution of the near-surface turbulence dissipation rate and gas transfer velocity for an extended (decadal) time period. A future version of this remote sensing algorithm will incorporate directional wind/wave data being available from QUIKSCAT, a now-cast wave model, and satellite heat fluxes. The inclusion of microwave imagery from the Special Sensor Microwave Imager (SSM/I) and the Synthetic Aperture Radar (SAR) will provide additional information on the fractional whitecap coverage and sea surface turbulence patchiness.
Keywords: air-water inter-face, turbulence, remote sensing, boundary-layers, LATENT-HEAT FLUX, SEA GAS TRANSFER, WAVE-ENHANCED TURBULENCE, WIND-SPEED, UPPER-OCEAN, COOL SKIN, EXCHANGE, LAYER, BREAKING, PARAMETERIZATION
Mission: |SeaWinds|
URL: https://doi.org/10.1016/j.jmarsys.2006.03.023
Other URLs:
Stephen, H. and Long, D.G. (2007). Spatial and Temporal Behavior of Microwave Backscatter Directional Modulation Over the Saharan Ergs, IEEE Transactions on Geoscience and Remote Sensing, 45(5), 1164-1173, 10.1109/TGRS.2007.892584. Journal Article »
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Title: Spatial and Temporal Behavior of Microwave Backscatter Directional Modulation Over the Saharan Ergs
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Stephen, H. and Long, D.G.
Year: 2007
Formatted Citation: Stephen, H. and Long, D.G., 2007: Spatial and Temporal Behavior of Microwave Backscatter Directional Modulation Over the Saharan Ergs, IEEE Transactions on Geoscience and Remote Sensing, 45(5), 1164-1173, 10.1109/TGRS.2007.892584.
Abstract: Radar backscatter (sigmadeg) from ergs is modulated with view direction [incidence (thetas) and azimuth (phi) angles], where the modulation characteristics reflect the surface geometry. sigmadeg also varies spatially and reflects the spatial inhomogeneity of the sand surface. We use sigmadeg measurements at different thetas and phi angles from the NASA, European Remote Sensing satellite, and SeaWinds scatterometers to understand the relationship between wind and erg bedforms. A model incorporating the sigmadeg phi-modulation and spatial inhomogeneity is proposed. Surface slope variations are related to the sigmadeg spatial inhomogeneity. We compare the backscatter model results with numerically predicted wind direction data provided by the European Centre for Medium-Range Weather Forecasts (ECMWF) over the erg surfaces. We use the maxima of the phi-modulation at thetas=33deg to infer the orientation of the dominant slip-sides on the sand surface. These orientations are consistent with the ECMWF wind directions spatially and temporally.
Keywords: Desert European Centre for Medium-Range Weather Forecasts (ECMWF) European RemoteSensing Satellite Scatterometer (ESCAT) NASA Scatterometer (NSCAT) SeaWinds Scatterometer dunes ergs winds
Mission: |SeaWinds|
URL: https://doi.org/10.1109/TGRS.2007.892584
Other URLs:
Taguchi, B., Xie, S.P., Schneider, N., Nonaka, M., Sasaki, H., and Sasai, Y. (2007). Decadal Variability of the Kuroshio Extension: Observations and an Eddy-Resolving Model Hindcast, Journal of Climate, 20(11), 2357-2377, 10.1175/JCLI4142.1. Journal Article »
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Title: Decadal Variability of the Kuroshio Extension: Observations and an Eddy-Resolving Model Hindcast
Type: Journal Article
Publication: Journal of Climate
Author(s): Taguchi, B., Xie, S.P., Schneider, N., Nonaka, M., Sasaki, H., and Sasai, Y.
Year: 2007
Formatted Citation: Taguchi, B., Xie, S.P., Schneider, N., Nonaka, M., Sasaki, H., and Sasai, Y., 2007: Decadal Variability of the Kuroshio Extension: Observations and an Eddy-Resolving Model Hindcast, Journal of Climate, 20(11), 2357-2377, 10.1175/JCLI4142.1.
Abstract: Low-frequency variability of the Kuroshio Extension (KE) is studied using observations and a multidecadal (19502003) hindcast by a high-resolution (0.1), eddy-resolving, global ocean general circulation model for the Earth Simulator (OFES). In both the OFES hindcast and satellite altimeter observations, low-frequency sea surface height (SSH) variability in the North Pacific is high near the KE front. An empirical orthogonal function (EOF) analysis indicates that much of the SSH variability in the western North Pacific east of Japan is explained by two modes with meridional structures tightly trapped along the KE front. The first mode represents a southward shift and to a lesser degree, an acceleration of the KE jet associated with the 1976/77 shift in basin-scale winds. The second mode reflects quasi-decadal variations in the intensity of the KE jet. Both the spatial structure and time series of these modes derived from the hindcast are in close agreement with observations. A linear Rossby wave model forced by observed wind successfully reproduces the time series of the leading OFES modes but fails to explain why their meridional structure is concentrated on the KE front and inconsistent with the broadscale wind forcing. Further analysis suggests that KE variability may be decomposed into broad- and frontal-scale components in the meridional directionthe former following the linear Rossby wave solution and the latter closely resembling ocean intrinsic modes derived from an OFES run forced by climatological winds. The following scenario is suggested for low-frequency KE variability: basin-scale wind variability excites broadscale Rossby waves, which propagate westward, triggering intrinsic modes of the KE jet and reorganizing SSH variability in space.
Keywords: SEA-SURFACE TEMPERATURE, OCEAN-ATMOSPHERE INTERACTION, LARGE-SCALE VARIABILITY, NORTH PACIFIC-OCEAN, WIND-DRIVEN, INTERDECADAL VARIABILITY, CLIMATE VARIABILITY, OYASHIO EXTENSION, DOUBLE-GYRE, HEAT-FLUX
Mission:
URL: https://doi.org/10.1175/JCLI4142.1
Other URLs:
Tziperman, E. and Yu, L.S. (2007). Quantifying the Dependence of Westerly Wind Bursts on the Large-Scale Tropical Pacific SST, Journal of Climate, 20(12), 2760-2768, 10.1175/JCLI4138a.1. Journal Article »
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Title: Quantifying the Dependence of Westerly Wind Bursts on the Large-Scale Tropical Pacific SST
Type: Journal Article
Publication: Journal of Climate
Author(s): Tziperman, E. and Yu, L.S.
Year: 2007
Formatted Citation: Tziperman, E. and Yu, L.S., 2007: Quantifying the Dependence of Westerly Wind Bursts on the Large-Scale Tropical Pacific SST, Journal of Climate, 20(12), 2760-2768, 10.1175/JCLI4138a.1.
Abstract: The correlation between parameters characterizing observed westerly wind bursts (WWBs) in the equatorial Pacific and the large-scale SST is analyzed using singular value decomposition. The WWB parameters include the amplitude, location, scale, and probability of occurrence for a given SST distribution rather than the wind stress itself. This approach therefore allows for a nonlinear relationship between the SST and the wind signal of the WWBs. It is found that about half of the variance of the WWB parameters is explained by only two large-scale SST modes. The first mode represents a developed El Niño event, while the second mode represents the seasonal cycle. More specifically, the central longitude of WWBs, their longitudinal extent, and their probability seem to be determined to a significant degree by the ENSO-driven signal. The amplitude of the WWBs is found to be strongly influenced by the phase of the seasonal cycle. It is concluded that the WWBs, while partially stochastic, seem an inherent part of the large-scale deterministic ENSO dynamics. Implications for ENSO predictability and prediction are discussed.
Keywords: SURFACE TEMPERATURE ANOMALIES, 1997-98 EL-NINO, SOUTHERN OSCILLATION, EQUATORIAL PACIFIC, SEASONAL CYCLE, COUPLED MODEL, ENSO, VARIABILITY, CONVECTION, CLIMATE
Mission:
URL: https://doi.org/10.1175/JCLI4138a.1
Other URLs:
Wang, H. and Fu, R. (2007). The Influence of Amazon Rainfall on the Atlantic ITCZ Through Convectively Coupled Kelvin waves, Journal of Climate, 20(7), 1188-1201, 10.1175/JCLI4061.1. Journal Article »
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Title: The Influence of Amazon Rainfall on the Atlantic ITCZ Through Convectively Coupled Kelvin waves
Type: Journal Article
Publication: Journal of Climate
Author(s): Wang, H. and Fu, R.
Year: 2007
Formatted Citation: Wang, H. and Fu, R., 2007: The Influence of Amazon Rainfall on the Atlantic ITCZ Through Convectively Coupled Kelvin waves, Journal of Climate, 20(7), 1188-1201, 10.1175/JCLI4061.1.
Abstract: Using outgoing longwave radiation (OLR) and Tropical Rainfall Measuring Mission (TRMM) daily rain-rate data, systematic changes in intensity and location of the Atlantic intertropical convergence zone (ITCZ) were detected along the equator during boreal spring. It is found that the changes in convection over the tropical Atlantic may be induced by deep convection in equatorial South America. Lagged regression analyses demonstrate that the anomalies of convection developed over the land propagate eastward across the Atlantic and then into Africa. The eastward-propagating disturbances appear to be convectively coupled Kelvin waves with a period of 6-7.5 days and a phase speed of around 15 m s(-1). These waves modulate the intensity and location of the convection in the tropical Atlantic and result in a zonal variation of the Atlantic ITCZ on synoptic time scales. The convectively coupled Kelvin wave has substantial signals in both the lower and upper troposphere. Both a reanalysis dataset and the Quick Scatterometer (QuikSCAT) ocean surface wind are used to characterize the Kelvin wave. This study suggests that synoptic-scale variation of the Atlantic ITCZ may be linked to precipitation anomalies in South America through the convectively coupled Kelvin wave. The results imply that the changes of Amazon convection could contribute to the large variability of the tropical Atlantic ITCZ observed during boreal spring.
Keywords: SEA-SURFACE TEMPERATURE, SYNOPTIC-SCALE DISTURBANCES, GENERAL-CIRCULATION MODEL, EASTERN PACIFIC ITCZ, TROPICAL ATLANTIC, NORTHEAST BRAZIL, CLIMATE VARIABILITY, EQUATORIAL WAVES, ANNUAL CYCLE, DECADAL VARIABILITY
Mission: |SeaWinds|
URL: https://doi.org/10.1175/JCLI4061.1
Other URLs:
Wentz, F.J., Ricciardulli, L., Hilburn, K., and Mears, C. (2007). How Much More Rain Will Global Warming Bring?, Science, 317(5835), 233-235, 10.1126/science.1140746. Journal Article »
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Title: How Much More Rain Will Global Warming Bring?
Type: Journal Article
Publication: Science
Author(s): Wentz, F.J., Ricciardulli, L., Hilburn, K., and Mears, C.
Year: 2007
Formatted Citation: Wentz, F.J., Ricciardulli, L., Hilburn, K., and Mears, C., 2007: How Much More Rain Will Global Warming Bring?, Science, 317(5835), 233-235, 10.1126/science.1140746.
Abstract: Climate models and satellite observations both indicate that the total amount of water in the atmosphere will increase at a rate of 7% per kelvin of surface warming. However, the climate models predict that global precipitation will increase at a much slower rate of 1 to 3% per kelvin. A recent analysis of satellite observations does not support this prediction of a muted response of precipitation to global warming. Rather, the observations suggest that precipitation and total atmospheric water have increased at about the same rate over the past two decades.
Keywords: MODEL INTERCOMPARISON PROJECT, HYDROLOGICAL CYCLE, CLIMATE, TEMPERATURE, SENSITIVITY
Mission:
URL: https://doi.org/10.1126/science.1140746
Other URLs:
Williams, B.L. and Long, D.G. (2007). Hurricane Wind Field Estimation from SeaWinds at Ultra High Resolution, 2007 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `07), 1075-1078, 10.1109/IGARSS.2007.4422987. Conference Paper »
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Title: Hurricane Wind Field Estimation from SeaWinds at Ultra High Resolution
Type: Conference Paper
Publication: 2007 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `07)
Author(s): Williams, B.L. and Long, D.G.
Year: 2007
Formatted Citation: Williams, B.L. and Long, D.G., 2007: Hurricane Wind Field Estimation from SeaWinds at Ultra High Resolution, 2007 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `07), 1075-1078, 10.1109/IGARSS.2007.4422987.
Abstract: Although SeaWinds was not originally designed to observe tropical cyclones, new higher resolution products resolve much of the horizontal structure of these storms. However, these higher resolution products (reported at 2.5 km) are inherently noisier than the standard 25 km products and the high rain rates often associated with hurricanes corrupt the wind estimates. Fortunately, these storms have structure which can be exploited using a model. This paper develops a new procedure for hurricane wind field estimation from the SeaWinds instrument at ultra high resolution. We develop a simplified hurricane model to provide prior information to be used in maximum a posteriori probability (MAP) wind estimation. Using the hurricane model ameliorates the effects of rain and noise on the scatterometer measurements and directly provides useful hurricane parameters such as the eye center location and intensity.
Keywords: storms weather forecasting wind SeaWinds hurricane wind field estimation maximum aposteriori probability tropical cyclones
Mission: |SeaWinds|
URL: https://doi.org/10.1109/IGARSS.2007.4422987
Other URLs:
Wu, Q. and Bowman, K.P. (2007). Multiyear Satellite Observations of the Atmospheric Response to Atlantic Tropical Instability Waves, Journal of Geophysical Research: Atmospheres, 112, D19104, 10.1029/2007JD008627. Journal Article »
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Title: Multiyear Satellite Observations of the Atmospheric Response to Atlantic Tropical Instability Waves
Type: Journal Article
Publication: Journal of Geophysical Research: Atmospheres
Author(s): Wu, Q. and Bowman, K.P.
Year: 2007
Formatted Citation: Wu, Q. and Bowman, K.P., 2007: Multiyear Satellite Observations of the Atmospheric Response to Atlantic Tropical Instability Waves, Journal of Geophysical Research: Atmospheres, 112, D19104, 10.1029/2007JD008627.
Abstract: [1] High-resolution satellite measurements from the Tropical Rainfall Measuring Mission (TRMM), Quick Scatterometer (QuikSCAT), and Special Sensor Microwave Imager (SSM/I) are used to study the variability of sea surface temperature (SST), surface wind velocity, water vapor, cloud liquid water, and precipitation associated with westward moving tropical instability waves (TIWs) in the Atlantic Ocean from 1998 to 2005. Coherent ocean-atmosphere patterns are shown during these 8 years. Southeasterly trades strengthen and water vapor increases over warm SST anomalies associated with TIWs. The opposite is true over cold TIW SST anomalies. The cloud liquid water and rain response to the SSTs follows a similar pattern, appearing generally downstream of SST anomalies in the central tropical Atlantic. The atmospheric response to the TIW SST anomalies extends north of the TIW active region, suggesting a remote response to the TIWs. The atmospheric response to the Atlantic TIWs also exhibits interannual variations. In 1999, owing to the southward movement of the Atlantic Intertropical Convergence Zone (ITCZ), the rainfall response to the TIW SST anomalies is much larger than in other years. When the Atlantic ITCZ moves south, it is more susceptible to TIW influence.
Keywords: SEA-SURFACE TEMPERATURE, EASTERN EQUATORIAL PACIFIC, LONG WAVES, OCEAN, VARIABILITY, ENSO, OSCILLATION, GRADIENTS, QUIKSCAT, REMOTE
Mission: |SeaWinds|
URL: https://doi.org/10.1029/2007JD008627
Other URLs:
Xie, Q., Wu, X., Yuan, W., Wang, D., and Xie, S.-P. (2007). Life Cycle of Intraseasonal Oscillation of Summer SST in the Western South China Sea, Acta Oceanologica Sinica, 26(3), 1-8. Journal Article »
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Title: Life Cycle of Intraseasonal Oscillation of Summer SST in the Western South China Sea
Type: Journal Article
Publication: Acta Oceanologica Sinica
Author(s): Xie, Q., Wu, X., Yuan, W., Wang, D., and Xie, S.-P.
Year: 2007
Formatted Citation: Xie, Q., Wu, X., Yuan, W., Wang, D., and Xie, S.-P., 2007: Life Cycle of Intraseasonal Oscillation of Summer SST in the Western South China Sea, Acta Oceanologica Sinica, 26(3), 1-8.
Abstract: Intraseasonal oscillation (ISO, times-cales of 30～,90 d) of summer sea surface temperature (SST) in the western South China Sea is studied using harmonic and empirical orthogonal function analyses of microwave observations by the tropical rainfall measuring mission satellite. Each summer from May to September, two or three ISO events occur off South Vietnam, with a typical period of approximately 50 d. The life cycle of these events from the initiation to decay of SST anomalies is described.
Keywords:
Mission:
URL: https://www.researchgate.net/publication/289327721_Life_cycle_of_intraseasonal_oscillation_of_summer_SST_in_the_western_South_China_Sea
Other URLs:
Xie, S.-P., Chang, C.-S., Xie, Q., and Wang, D. (2007). Intraseasonal Variability in the Summer South China Sea: The Wind Jet, Cold Filament, and Recirculations, Journal of Geophysical Research: Oceans, 112(C10), C10008, 10.1029/2007JC004238. Journal Article »
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Title: Intraseasonal Variability in the Summer South China Sea: The Wind Jet, Cold Filament, and Recirculations
Type: Journal Article
Publication: Journal of Geophysical Research: Oceans
Author(s): Xie, S.-P., Chang, C.-S., Xie, Q., and Wang, D.
Year: 2007
Formatted Citation: Xie, S.-P., Chang, C.-S., Xie, Q., and Wang, D., 2007: Intraseasonal Variability in the Summer South China Sea: The Wind Jet, Cold Filament, and Recirculations, Journal of Geophysical Research: Oceans, 112(C10), C10008, 10.1029/2007JC004238.
Abstract: A recent study shows that the blockage of the southwest monsoon by the mountain range on the east coast of Indochina triggers a chain of ocean-atmospheric response, including a wind jet and cold filament in the South China Sea (SCS). We extend this climatological analysis by using higher temporal resolution (weekly) to study intraseasonal variability in summer. Our analysis shows that the development of the wind jet and cold filament is not a smooth seasonal process but consists of several intraseasonal events each year at about 45-day intervals. In a typical intraseasonal event, the wind jet intensifies to above 12 m/s, followed in a week by the development of a cold filament advected by an offshore jet east of South Vietnam on the boundary of a double gyre circulation in the ocean. The double gyre circulation itself also strengthens in response to the intraseasonal wind event via Rossby wave adjustment, reaching the maximum strength in 2 to 3 weeks. The intraseasonal cold filaments appear to influence the surface wind, reducing the local wind speed because of the increased static stability in the near-surface atmosphere. To first order, the above sequence of events may be viewed as the SCS response to atmospheric intraseasonal wind pulses, which are part of the planetary-scale boreal summer intraseasonal oscillation characterized by the northeastward propagation of atmospheric deep convection. The intraseasonal anomalies of sea surface temperature and precipitation are in phase over the SCS, suggesting an oceanic feedback onto the atmosphere. As wind variations are now being routinely monitored by satellite, the lags of 1-3 weeks in oceanic response offer useful predictability that may be exploited.
Keywords: intraseasonal variability, South China Sea, cold filament
Mission:
URL: https://doi.org/10.1029/2007JC004238
Other URLs:
Xie, S.-P., Miyama, T., Wang, Y., Xu, H., de Szoeke, S.P., Small, R.J.O., Richards, K.J., Mochizuki, T., and Awaji, T. (2007). A Regional Ocean-Atmosphere Model for Eastern Pacific Climate: Toward Reducing Tropical Biases, Journal of Climate, 20(8), 1504-1522, 10.1175/JCLI4080.1. Journal Article »
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Title: A Regional Ocean-Atmosphere Model for Eastern Pacific Climate: Toward Reducing Tropical Biases
Type: Journal Article
Publication: Journal of Climate
Author(s): Xie, S.-P., Miyama, T., Wang, Y., Xu, H., de Szoeke, S.P., Small, R.J.O., Richards, K.J., Mochizuki, T., and Awaji, T.
Year: 2007
Formatted Citation: Xie, S.-P., Miyama, T., Wang, Y., Xu, H., de Szoeke, S.P., Small, R.J.O., Richards, K.J., Mochizuki, T., and Awaji, T., 2007: A Regional Ocean-Atmosphere Model for Eastern Pacific Climate: Toward Reducing Tropical Biases, Journal of Climate, 20(8), 1504-1522, 10.1175/JCLI4080.1.
Abstract: The tropical Pacific Ocean is a climatically important region, home to El Niño and the Southern Oscillation. The simulation of its climate remains a challenge for global coupled oceanatmosphere models, which suffer large biases especially in reproducing the observed meridional asymmetry across the equator in sea surface temperature (SST) and rainfall. A basin ocean general circulation model is coupled with a full-physics regional atmospheric model to study eastern Pacific climate processes. The regional oceanatmosphere model (ROAM) reproduces salient features of eastern Pacific climate, including a northward-displaced intertropical convergence zone (ITCZ) collocated with a zonal band of high SST, a low-cloud deck in the southeastern tropical Pacific, the equatorial cold tongue, and its annual cycle. The simulated low-cloud deck experiences significant seasonal variations in vertical structure and cloudiness, cloud becomes decoupled and separated from the surface mixed layer by a stable layer in March when the ocean warms up, leading to a reduction in cloudiness. The interaction of low cloud and SST is an important internal feedback for the climatic asymmetry between the Northern and Southern Hemispheres. In an experiment where the cloud radiative effect is turned off, this climatic asymmetry weakens substantially, with the ITCZ migrating back and forth across the equator following the sun. In another experiment where tropical North Atlantic SST is lowered by 2Csay, in response to a slow-down of the Atlantic thermohaline circulation as during the Younger Dryasthe equatorial Pacific SST decreases by up to 3C in JanuaryApril but changes much less in other seasons, resulting in a weakened equatorial annual cycle. The relatively high resolution (0.5) of the ROAM enables it to capture mesoscale features, such as tropical instability waves, Central American gap winds, and a thermocline dome off Costa Rica. The implications for tropical biases and paleoclimate research are discussed.
Keywords: SEA-SURFACE TEMPERATURE, BOUNDARY-LAYER CLOUDS, CROSS-EQUATORIAL FLOW, INSTABILITY WAVES, SOUTHEAST PACIFIC, PART I, ANNUAL CYCLE, THERMOHALINE CIRCULATION, INTERANNUAL VARIABILITY, NUMERICAL-SIMULATION
Mission:
URL: https://doi.org/10.1175/JCLI4080.1
Other URLs:
Yang, J., Liu, Q., Xie, S.-P., Liu, Z., and Wu, L. (2007). Impact of the Indian Ocean SST Basin Mode on the Asian Summer Monsoon, Geophysical Research Letters: Climate, 34(2), L02708, 10.1029/2006GL028571. Journal Article »
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Title: Impact of the Indian Ocean SST Basin Mode on the Asian Summer Monsoon
Type: Journal Article
Publication: Geophysical Research Letters: Climate
Author(s): Yang, J., Liu, Q., Xie, S.-P., Liu, Z., and Wu, L.
Year: 2007
Formatted Citation: Yang, J., Liu, Q., Xie, S.-P., Liu, Z., and Wu, L., 2007: Impact of the Indian Ocean SST Basin Mode on the Asian Summer Monsoon, Geophysical Research Letters: Climate, 34(2), L02708, 10.1029/2006GL028571.
Abstract: Following an El Nino event, a basin-wide warming takes place over the tropical Indian Ocean, peaks in late boreal winter and early spring, and persists through boreal summer. Our observational analysis suggests that this Indian Ocean warming induces robust climatic anomalies in the summer Indo-West Pacific region, prolonging the El Ni???? influence after tropical East Pacific sea surface temperature has returned to normal. In response to the Indian Ocean warming, precipitation increases over most of the basin, forcing a Matsuno-Gill pattern in the upper troposphere with a strengthened South Asian high. Near the ground, the southwest monsoon intensifies over the Arabian Sea and weakens over the South China and Philippine Seas. An anomalous anticyclonic circulation forms over the subtropical Northwest Pacific, collocated with negative precipitation anomalies. All these anomaly patterns are reproduced in a coupled model simulation initialized with a warming in the tropical Indian Ocean mixed layer, indicating that the Indian Ocean warming is not just a passive response to El Nino but important for summer climate variability in the Indo-West Pacific region. The implications for seasonal prediction are discussed.
Keywords: Indian Ocean, basin mode, Asian summer monsoon
Mission:
URL: https://doi.org/10.1029/2006GL028571
Other URLs:
Yin, X., Wang, Z., Liu, Y., and Xu, Y. (2007). Ocean Response to Typhoon Ketsana Traveling Over the Northwest Pacific and a Numerical Model Approach, Geophysical Research Letters: Oceans, 34(21), L21606, 10.1029/2007GL031477. Journal Article »
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Title: Ocean Response to Typhoon Ketsana Traveling Over the Northwest Pacific and a Numerical Model Approach
Type: Journal Article
Publication: Geophysical Research Letters: Oceans
Author(s): Yin, X., Wang, Z., Liu, Y., and Xu, Y.
Year: 2007
Formatted Citation: Yin, X., Wang, Z., Liu, Y., and Xu, Y., 2007: Ocean Response to Typhoon Ketsana Traveling Over the Northwest Pacific and a Numerical Model Approach, Geophysical Research Letters: Oceans, 34(21), L21606, 10.1029/2007GL031477.
Abstract: Recent satellite data of sea surface temperature and chlorophyll- a concentration are presented in investigating the ocean response to Typhoon Ketsana traveling over the Northwest Pacific in October 2003. A significant characteristic is that the surface chlorophyll- a concentration triggered by the typhoon increased 10 times on average during its five- day stay. Characteristics of ocean response to the typhoon are simulated by the Regional Oceanic Modeling System ( ROMS). The simulations indicate that when QuikSCAT wind data are used to force the ROMS, the model outputs of sea surface temperature, chlorophyll- a concentration in cold pool are underestimated compared with satellite data. However, more accurate wind data under strong wind and heavy rain condition can be derived from the angular momentum model. When those wind data are used to force the ROMS, the model output fits the satellite data much better. At last, it is confirmed that the Regional Oceanic Modeling System with strong wind data from the angular momentum model of wind and moderate wind data from QuikSCAT can correctly simulate both the biochemical and physical responses of the ocean to Typhoon Ketsana traveling over the Northwest Pacific.
Keywords: TROPICAL CYCLONE, HURRICANE, WIND, TEMPERATURE, PROPAGATION, SURFACE, SYSTEM, FLUX
Mission: |SeaWinds|
URL: https://doi.org/10.1029/2007GL031477
Other URLs:
Yu, H., Fu, R., Dickinson, R.E., Zhang, Y., Chen, M., and Wang, H. (2007). Interannual Variability of Smoke and Warm Cloud Relationships in the Amazon as Inferred from MODIS Retrievals, Remote Sensing of Environment, 111(4), 435-449, 10.1016/j.rse.2007.04.003. Journal Article »
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Title: Interannual Variability of Smoke and Warm Cloud Relationships in the Amazon as Inferred from MODIS Retrievals
Type: Journal Article
Publication: Remote Sensing of Environment
Author(s): Yu, H., Fu, R., Dickinson, R.E., Zhang, Y., Chen, M., and Wang, H.
Year: 2007
Formatted Citation: Yu, H., Fu, R., Dickinson, R.E., Zhang, Y., Chen, M., and Wang, H., 2007: Interannual Variability of Smoke and Warm Cloud Relationships in the Amazon as Inferred from MODIS Retrievals, Remote Sensing of Environment, 111(4), 435-449, 10.1016/j.rse.2007.04.003.
Abstract: Aerosol and cloud data from the MODerate resolution Imaging Spectroradiometer (MODIS) onboard the Earth Observing System (EOS) Aqua are used to investigate interannual variability of smoke and warm cloud relationships during the dry-to-wet transition season (AugustOctober) over the Amazon for two years and its association with meteorological conditions. In one year (2003), smoke aerosols are associated with an increase of cloud fraction and a decrease of cloud effective radius. These effects amplify the cooling at the surface and at the top of the atmosphere (TOA) caused by the aerosol extinction. However, in another year (2002) the cloud fraction decreases with increasing aerosol optical depth. Such a decrease of cloud fraction could offset the effect of increased reflection of solar radiation by the aerosols both at the surface and at TOA. The changes in radiative fluxes between these years would contribute to interannual changes of surface energy fluxes and radiative balance at the top of the atmosphere and influence variability of the wet season onset in the basin. In 2003, the atmosphere was more humid and less stable. These conditions may be relatively favorable for the activation of aerosol particles into cloud condensation nuclei and hence cloud droplets. In 2002, the clouds were less extensive and thinner in a relatively dry atmosphere and presumably dissipated more easily. This study suggests that the aerosol-cloud relation can be influenced by atmospheric structure and convective motions, in addition to changes in aerosols properties. An adequate characterization of aerosol-cloud relationship would require a longer time series of data that includes a variety of climate conditions. The caveat of this analysis is that differences in aerosol absorption and its vertical distribution may have contributed to the observed interannual change of smoke-cloud relationship but could not be determined due to lack of adequate measurements.
Keywords: Aerosols, Cloud, Satellite remote sensing
Mission:
URL: https://doi.org/10.1016/j.rse.2007.04.003
Other URLs:
Yu, L.S. (2007). Global Variations in Oceanic Evaporation (1958-2005): The Role of the Changing Wind Speed, Journal of Climate, 20(21), 5376-5390, 10.1175/2007JCLI1714.1. Journal Article »
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Title: Global Variations in Oceanic Evaporation (1958-2005): The Role of the Changing Wind Speed
Type: Journal Article
Publication: Journal of Climate
Author(s): Yu, L.S.
Year: 2007
Formatted Citation: Yu, L.S., 2007: Global Variations in Oceanic Evaporation (1958-2005): The Role of the Changing Wind Speed, Journal of Climate, 20(21), 5376-5390, 10.1175/2007JCLI1714.1.
Abstract: Global estimates of oceanic evaporation (Evp) from 1958 to 2005 have been recently developed by the Objectively Analyzed Air-Sea Fluxes (OAFlux) project at the Woods Hole Oceanographic Institution (WHOI). The nearly 50-yr time series shows that the decadal change of the global oceanic evaporation ( Evp) is marked by a distinct transition from a downward trend to an upward trend around 1977-78. Since the transition, the global oceanic Evp has been up about 11 cm yr(-1) (similar to 10%), from a low at 103 cm yr(-1) in 1977 to a peak at 114 cm yr(-1) in 2003. The increase in Evp was most dramatic during the 1990s. The uncertainty of the estimates is about +/- 2.74 cm yr(-1). By utilizing the newly developed datasets of Evp and related air-sea variables, the study investigated the cause of the decadal change in oceanic Evp. The decadal differences between the 1990s and the 1970s indicates that the increase of Evp in the 1990s occurred over a global scale and had spatially coherent structures. Larger Evp is most pronounced in two key regions-one is the paths of the global western boundary currents and their extensions, and the other is the tropical Indo- Pacific warm water pools. It is also found that Evp was enlarged primarily during the hemispheric wintertime (defined as the mean of December-February for the northern oceans and June-August for the southern oceans). Despite the dominant upward tendency over the global basins, a slight reduction in Evp appeared in such regions as the subtropical centers of the Evp maxima as well as the eastern equatorial Pacific and Atlantic cold tongues. An empirical orthogonal function (EOF) analysis was performed for the yearly winter-mean time series of Evp and the related air-sea variables [i.e., wind speed ( U) and air-sea humidity differences (dq)]. The analysis suggested a dominant role of the wind forcing in the decadal change of both Evp and dq. It is hypothesized that wind impacts Evp in two ways. The first way is direct: the greater wind speed induces more evaporation by carrying water vapor away from the evaporating surface to allow the air-sea humidity gradients to be reestablished at a faster pace. The second way is indirect: the enhanced surface wind strengthens the wind-driven subtropical gyre, which in turn drives a greater heat transport by the western boundary currents, warms up SST along the paths of the currents and extensions, and causes more evaporation by enlarging the air-sea humidity gradients. The EOF analysis performed for the time series of the global annual-mean Evp fields showed that the first three EOF modes account for nearly 50% of the total variance. The mode 1 variability represents the upward trend in Evp after 1978 and is attributable to the increased U, and the mode 2 variability explains much of the downward trend in Evp before 1978 and is correlated to the global dq variability. The EOF mode 3 of Evp captures the interannual variability of Evp on time scales of the El Ni (n) over tildeo-Southern Oscillation, with the center of action over the eastern equatorial Pacific.
Keywords: SEA-SURFACE TEMPERATURE, ATLANTIC-OCEAN, NORTH PACIFIC, BULK PARAMETERIZATION, WATER-VAPOR, HEAT-FLUX, VARIABILITY, LATENT, TRENDS, OSCILLATION
Mission:
URL: https://doi.org/10.1175/2007JCLI1714.1
Other URLs:
Yu, L.S. and Weller, R.A. (2007). Objectively Analyzed Air-Sea Heat Fluxes for the Global Ice-Free Oceans (1981-2005), Bulletin of the American Meteorological Society, 88(4), 527-539, 10.1175/BAMS-88-4-527. Journal Article »
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Title: Objectively Analyzed Air-Sea Heat Fluxes for the Global Ice-Free Oceans (1981-2005)
Type: Journal Article
Publication: Bulletin of the American Meteorological Society
Author(s): Yu, L.S. and Weller, R.A.
Year: 2007
Formatted Citation: Yu, L.S. and Weller, R.A., 2007: Objectively Analyzed Air-Sea Heat Fluxes for the Global Ice-Free Oceans (1981-2005), Bulletin of the American Meteorological Society, 88(4), 527-539, 10.1175/BAMS-88-4-527.
Abstract: A 25-yr (19812005) time series of daily latent and sensible heat fluxes over the global ice-free oceans has been produced by synthesizing surface meteorology obtained from satellite remote sensing and atmospheric model reanalyses outputs. The project, named Objectively Analyzed AirSea Fluxes (OAFlux), was developed from an initial study of the Atlantic Ocean that demonstrated that such data synthesis improves daily flux estimates over the basin scale. This paper introduces the 25-yr heat flux analysis and documents variability of the global ocean heat flux fields on seasonal, interannual, decadal, and longer time scales suggested by the new dataset. The study showed that, among all the climate signals investigated, the most striking is a long-term increase in latent heat flux that dominates the data record. The globally averaged latent heat flux increased by roughly 9 W m−,2 between the low in 1981 and the peak in 2002, which amounted to about a 10% increase in the mean value over the 25-yr period. Positive linear trends appeared on a global scale, and were most significant over the tropical Indian and western Pacific warm pool and the boundary current regions. The increase in latent heat flux was in concert with the rise of sea surface temperature, suggesting a response of the atmosphere to oceanic forcing.
Keywords: SURFACE TEMPERATURE, ATLANTIC-OCEAN, WATER-VAPOR, BULK PARAMETERIZATION, EQUATORIAL PACIFIC, NORTHERN OCEANS, DATA SETS, IN-SITU, LATENT, MODEL
Mission:
URL: https://doi.org/10.1175/BAMS-88-4-527
Other URLs:
Yu, L.S., Jin, X.Z., and Weller, R.A. (2007). Annual, Seasonal, and Interannual Variability of Air-Sea Heat Fluxes in the Indian Ocean, Journal of Climate, 20(13), 3190-3209, 10.1175/JCLI4163.1. Journal Article »
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Title: Annual, Seasonal, and Interannual Variability of Air-Sea Heat Fluxes in the Indian Ocean
Type: Journal Article
Publication: Journal of Climate
Author(s): Yu, L.S., Jin, X.Z., and Weller, R.A.
Year: 2007
Formatted Citation: Yu, L.S., Jin, X.Z., and Weller, R.A., 2007: Annual, Seasonal, and Interannual Variability of Air-Sea Heat Fluxes in the Indian Ocean, Journal of Climate, 20(13), 3190-3209, 10.1175/JCLI4163.1.
Abstract: This study investigated the accuracy and physical representation of airsea surface heat flux estimates for the Indian Ocean on annual, seasonal, and interannual time scales. Six heat flux products were analyzed, including the newly developed latent and sensible heat fluxes from the Objectively Analyzed AirSea Heat Fluxes (OAFlux) project and net shortwave and longwave radiation results from the International Satellite Cloud Climatology Project (ISCCP), the heat flux analysis from the Southampton Oceanography Centre (SOC), the National Centers for Environmental Prediction reanalysis 1 (NCEP1) and reanalysis-2 (NCEP2) datasets, and the European Centre for Medium-Range Weather Forecasts operational (ECMWF-OP) and 40-yr Re-Analysis (ERA-40) products. This paper presents the analysis of the six products in depicting the mean, the seasonal cycle, and the interannual variability of the net heat flux into the ocean. Two time series of in situ flux measurements, one taken from a 1-yr Arabian Sea Experiment field program and the other from a 1-month Joint AirSea Monsoon Interaction Experiment (JASMINE) field program in the Bay of Bengal were used to evaluate the statistical properties of the flux products over the measurement periods. The consistency between the six products on seasonal and interannual time scales was investigated using a standard deviation analysis and a physically based correlation analysis. The study has three findings. First of all, large differences exist in the mean value of the six heat flux products. Part of the differences may be attributable to the bias in the numerical weather prediction (NWP) models that underestimates the net heat flux into the Indian Ocean. Along the JASMINE ship tracks, the four NWP modeled mean fluxes all have a sign opposite to the observations, with NCEP1 being underestimated by 53 W m−,2 (the least biased) and ECMWF-OP by 108 W m−,2 (the most biased). At the Arabian Sea buoy site, the NWP mean fluxes also have an underestimation bias, with the smallest bias of 26 W m−,2 (ERA-40) and the largest bias of 69 W m−,2 (NCEP1). On the other hand, the OAFlux+ISCCP has the best comparison at both measurement sites. Second, the bias effect changes with the time scale. Despite the fact that the mean is biased significantly, there is no major bias in the seasonal cycle of all the products except for ECMWF-OP. The latter does not have a fixed mean due to the frequent updates of the model platform. Finally, among the four products (OAFlux+ISCCP, ERA-40, NCEP1, and NCEP2) that can be used for studying interannual variability, OAFlux+ISCCP and ERA-40 Qnet have good consistency as judged from both statistical and physical measures. NCEP1 shows broad agreement with the two products, with varying details. By comparison, NCEP2 is the least representative of the Qnet variabilities over the basin scale.
Keywords: ATMOSPHERE RESPONSE EXPERIMENT, BULK PARAMETERIZATION, SURFACE METEOROLOGY, EQUATORIAL PACIFIC, TROPICAL OCEAN, TURBULENT HEAT, ATLANTIC-OCEAN, NCEP-NCAR, IN-SITU, MODEL
Mission:
URL: https://doi.org/10.1175/JCLI4163.1
Other URLs:
Yuan, D., Han, W., and Hu, D. (2007). Anti-Cyclonic Eddies Northwest of Luzon in Summer-Fall Observed by Satellite Altimeters, Geophysical Research Letters: Oceans, 34(13), L13610C, 10.1029/2007GL029401. Journal Article »
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Title: Anti-Cyclonic Eddies Northwest of Luzon in Summer-Fall Observed by Satellite Altimeters
Type: Journal Article
Publication: Geophysical Research Letters: Oceans
Author(s): Yuan, D., Han, W., and Hu, D.
Year: 2007
Formatted Citation: Yuan, D., Han, W., and Hu, D., 2007: Anti-Cyclonic Eddies Northwest of Luzon in Summer-Fall Observed by Satellite Altimeters, Geophysical Research Letters: Oceans, 34(13), L13610C, 10.1029/2007GL029401.
Abstract: Anti-cyclonic eddies northwest of Luzon of the Philippines in summer-fall are identified in the merged data products of satellite altimeters of Topex/Poseidon, Jason-1 and European Research Satellites. The generation and propagation of the anti-cyclonic eddies, which are confirmed by satellite ocean color data, are found to be a seasonal phenomenon that is phase-locked to the onset of the southwesterly monsoon and the relaxation of the cyclonic wind curl in the northeastern South China Sea. The eddies originate from northwest of Luzon in summer, move across the northeastern South China Sea to reach the China continental slope in fall, and propagate southwestward along the continental slope in fallwinter, inducing shelfbreak current variations in the western South China Sea in fallwinter. The anti-cyclonic eddy discovered by Li et al. (1998) in the northern South China Sea is found to originate from northwest of Luzon and carry primarily the South China Sea waters. It does not appear to be an eddy shed from the Kuroshio in the Luzon Strait area as alluded by Li et al. (1998) and others.
Keywords: anti-cyclonic eddy, South China Sea, seasonal cycle
Mission:
URL: https://doi.org/10.1029/2007GL029401
Other URLs:
Zlotnicki, V., Wahr, J., Fukumori, I., and Song, Y.T. (2007). Antarctic Circumpolar Current Transport Variability During 2003-05 from GRACE, Journal of Physical Oceanography, 37(2), 230-244, 10.1175/JPO3009.1. Journal Article »
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Title: Antarctic Circumpolar Current Transport Variability During 2003-05 from GRACE
Type: Journal Article
Publication: Journal of Physical Oceanography
Author(s): Zlotnicki, V., Wahr, J., Fukumori, I., and Song, Y.T.
Year: 2007
Formatted Citation: Zlotnicki, V., Wahr, J., Fukumori, I., and Song, Y.T., 2007: Antarctic Circumpolar Current Transport Variability During 2003-05 from GRACE, Journal of Physical Oceanography, 37(2), 230-244, 10.1175/JPO3009.1.
Abstract: Gravity Recovery and Climate Experiment ( GRACE) gravity data spanning January 2003 - November 2005 are used as proxies for ocean bottom pressure ( BP) averaged over 1 month, spherical Gaussian caps 500 km in radius, and along paths bracketing the Antarctic Circumpolar Current`s various fronts. The GRACE BP signals are compared with those derived from the Estimating the Circulation and Climate of the Ocean ( ECCO) ocean modeling - assimilation system, and to a non-Boussinesq version of the Regional Ocean Model System ( ROMS). The discrepancy found between GRACE and the models is 1.7 cm(H2O) ( 1 cm(H2O) similar to 1 hPa), slightly lower than the 1.9 cm(H2O) estimated by the authors independently from propagation of GRACE errors. The northern signals are weak and uncorrelated among basins. The southern signals are strong, with a common seasonality. The seasonal cycle GRACE data observed in the Pacific and Indian Ocean sectors of the ACC are consistent, with annual and semiannual amplitudes of 3.6 and 0.6 cm(H2O) ( 1.1 and 0.6 cm(H2O) with ECCO), the average over the full southern path peaks ( stronger ACC) in the southern winter, on days of year 197 and 97 for the annual and semiannual components, respectively, the Atlantic Ocean annual peak is 20 days earlier. An approximate conversion factor of 3.1 Sv ( Sv equivalent to 106 m(3) s(-1)) of barotropic transport variability per cm(H2O) of BP change is estimated. Wind stress data time series from the Quick Scatterometer ( QuikSCAT), averaged monthly, zonally, and over the latitude band 40 degrees - 65 degrees S, are also constructed and subsampled at the same months as with the GRACE data. The annual and semiannual harmonics of the wind stress peak on days 198 and 82, respectively. A decreasing trend over the 3 yr is observed in the three data types.
Keywords: BOTTOM PRESSURE MEASUREMENTS, GLOBAL OCEAN CIRCULATION, TIME-VARIABLE GRAVITY, DRAKE PASSAGE, CLIMATE EXPERIMENT, ANNULAR MODE, SEA-LEVEL, WIND, SURFACE, EARTH
Mission: |SeaWinds|
URL: https://doi.org/10.1175/JPO3009.1
Other URLs:
Zou, Q., He, Y., Perrie, W., and Vachon, P.W. (2007). Wind-Vector Estimation for RADARSAT-1 SAR Images: Validation of Wind-Direction Estimates Based Upon Geometry Diversity, IEEE Geoscience and Remote Sensing Letters, 4(1), 176-180, 10.1109/LGRS.2006.885886. Journal Article »
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Title: Wind-Vector Estimation for RADARSAT-1 SAR Images: Validation of Wind-Direction Estimates Based Upon Geometry Diversity
Type: Journal Article
Publication: IEEE Geoscience and Remote Sensing Letters
Author(s): Zou, Q., He, Y., Perrie, W., and Vachon, P.W.
Year: 2007
Formatted Citation: Zou, Q., He, Y., Perrie, W., and Vachon, P.W., 2007: Wind-Vector Estimation for RADARSAT-1 SAR Images: Validation of Wind-Direction Estimates Based Upon Geometry Diversity, IEEE Geoscience and Remote Sensing Letters, 4(1), 176-180, 10.1109/LGRS.2006.885886.
Abstract: In this letter, a new wind-vector algorithm is presented that uses radar backscatter sigma(0) measurements at two adjacent subscenes of RADARSAT-1 synthetic aperture radar (SAR) images, with each subscene having slightly different geometry. Resultant wind vectors are validated using in situ buoy measurements and compared with wind vectors determined from a hybrid wind-retrieval model using wind directions determined by spectral analysis of wind-induced image streaks and observed by colocated QuikSCAT measurements. The hybrid wind-retrieval model consists of CMOD-IFR2 [applicable to C-band vertical-vertical (W) polarization] and a C-band copolarization ratio according to Kirchhoff scattering. The new algorithm displays improved skill in wind-vector estimation for RADARSAT-1 SAR data when compared to conventional wind-retrieval methodology. In addition, unlike conventional methods, the present method is applicable to RADARSAT-1 images both with and without visible streaks. However, this method requires ancillary data such as buoy measurements to resolve the ambiguity in retrieved wind direction.
Keywords: air-sea interaction, RADARSAT, synthetic aperture radar (SAR), wind-vector retrieval, BOUNDARY-LAYER, INVERSION, ALGORITHM, RETRIEVAL
Mission: |SeaWinds|
URL: https://doi.org/10.1109/LGRS.2006.885886
Other URLs:
Adams, I.S., Hennon, C.C., Jones, L., and Ahmad, K.A. (2006). Evaluation of Hurricane Ocean Vector Winds from WindSat, IEEE Transactions on Geoscience and Remote Sensing, 44(3), 656-667, 10.1109/TGRS.2005.862506. Journal Article »
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Title: Evaluation of Hurricane Ocean Vector Winds from WindSat
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Adams, I.S., Hennon, C.C., Jones, L., and Ahmad, K.A.
Year: 2006
Formatted Citation: Adams, I.S., Hennon, C.C., Jones, L., and Ahmad, K.A., 2006: Evaluation of Hurricane Ocean Vector Winds from WindSat, IEEE Transactions on Geoscience and Remote Sensing, 44(3), 656-667, 10.1109/TGRS.2005.862506.
Abstract: The ability to accurately measure ocean surface wind vectors from space in all weather conditions is important in many scientific and operational usages. One highly desirable application of satellite-based wind vector retrievals is to provide realistic estimates of tropical cyclone intensity for hurricane monitoring. Historically, the extreme environmental conditions in tropical cyclones (TCs) have been a challenge to traditional space-based wind vector sensing provided by microwave scatterometers. With the advent of passive microwave polarimetry, an alternate tool for estimating surface wind conditions in the TC has become available. This paper evaluates the WindSat polarimetric radiometer`s ability to accurately sense winds within TCs. Three anecdotal cases studies are presented from the 2003 Atlantic Hurricane season. Independent surface wind estimates from aircraft flights and other platforms are used to provide surface wind fields for comparison to WindSat retrievals. Results of a subjective comparison of wind flow patterns are presented as well as quantitative statistics for point location comparisons of wind speed and direction.
Keywords: hurricane, ocean vector wind, passive microwave, polarimetry, tropical cyclone (TC), WindSat, SSM/I, RADIOMETERS, FIELDS, SPEED, HRD
Mission: |WindSat|
URL: https://doi.org/10.1109/TGRS.2005.862506
Other URLs:
Allen, J.R., and Long, D.G. (2006). Microwave Observations of Daily Antarctic Sea-Ice Edge Expansion and Contraction Rates, IEEE Geoscience and Remote Sensing Letters, 3(1), 54-58, 10.1109/LGRS.2005.856710. Journal Article »
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Title: Microwave Observations of Daily Antarctic Sea-Ice Edge Expansion and Contraction Rates
Type: Journal Article
Publication: IEEE Geoscience and Remote Sensing Letters
Author(s): Allen, J.R., and Long, D.G.
Year: 2006
Formatted Citation: Allen, J.R., and Long, D.G., 2006: Microwave Observations of Daily Antarctic Sea-Ice Edge Expansion and Contraction Rates, IEEE Geoscience and Remote Sensing Letters, 3(1), 54-58, 10.1109/LGRS.2005.856710.
Abstract: Algorithms for estimating sea-ice extent from remotely sensed microwave sensor data can benefit from knowledge of the a priori distribution of the daily expansion and contraction of the sea-ice pack. To estimate the probability distribution of daily Antarctic sea-ice extent change, two independent sea-ice datasets are analyzed: sea-ice extent derived from the QuikSCAT scatterometer and ice concentration estimates from the Special Sensor Microwave/Imager. The daily sea-ice advance and retreat is tracked over a four-year period. The distribution of the daily sea-ice advance/retreat from each sensor is similar and is approximately double-exponential. Daily ice-pack statistics are presented.
Keywords: SeaWinds, QuikSCAT, special sensor microwave/imager (SSMI), sea ice, VARIABILITY, MODEL
Mission: |SeaWinds|
URL: https://doi.org/10.1109/LGRS.2005.856710
Other URLs:
Ashcraft, I.S., and Long, D.G. (2006). Comparison of Methods for Melt Detection Over Greenland Using Active and Passive Microwave Measurements, International Journal of Remote Sensing, 27(12), 2469-2488, 10.1080/01431160500534465. Journal Article »
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Title: Comparison of Methods for Melt Detection Over Greenland Using Active and Passive Microwave Measurements
Type: Journal Article
Publication: International Journal of Remote Sensing
Author(s): Ashcraft, I.S., and Long, D.G.
Year: 2006
Formatted Citation: Ashcraft, I.S., and Long, D.G., 2006: Comparison of Methods for Melt Detection Over Greenland Using Active and Passive Microwave Measurements, International Journal of Remote Sensing, 27(12), 2469-2488, 10.1080/01431160500534465.
Abstract: Microwave measurements have been used in various studies to detect melt based on their sensitivity to liquid water present in snow. To contrast different melt detection methods used with different sensors, six different melt detection method/sensor combinations are compared using data for the summer of 2000. The sensors include the Special Spectral Microwave Imager (SSM/I), SeaWinds on QuikSCAT (QSCAT), and the European Remote Sensing (ERS) Advanced Microwave Instrument (AMI) in scatterometer mode. Existing melt detection methods are compared with melt detection based on a simple physical model. The model relates the moisture content and depth of a surface melt layer of wet snow to a single channel melt detection threshold. The model can be applied to both active and passive sensors and improves the consistency between brightness temperature (Tb ) and normalized radar backscatter (T_b) based detection of melt. Model-based melt estimates from different sensors are highly correlated and do not exhibit the unnatural phenomenon observed with previous methods. Relative merits and limitations of the various methods are discussed.
Keywords: Aerial Photography - Geography (See also Remote Sensing), Environmental Sciences, Remote Sensing
Mission: |SeaWinds|
URL: https://doi.org/10.1080/01431160500534465
Other URLs:
Ashcraft, I.S., and Long, D.G. (2006). Relating Microwave Backscatter Azimuth Modulation to Surface Properties of the Greenland Ice Sheet, Journal of Glaciology, 52(177), 257-266, 10.3189/172756506781828764. Journal Article »
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Title: Relating Microwave Backscatter Azimuth Modulation to Surface Properties of the Greenland Ice Sheet
Type: Journal Article
Publication: Journal of Glaciology
Author(s): Ashcraft, I.S., and Long, D.G.
Year: 2006
Formatted Citation: Ashcraft, I.S., and Long, D.G., 2006: Relating Microwave Backscatter Azimuth Modulation to Surface Properties of the Greenland Ice Sheet, Journal of Glaciology, 52(177), 257-266, 10.3189/172756506781828764.
Abstract: Azimuth dependence of a normalized radar cross-section (σº) over the Greenland ice sheet is modeled with a simple surface scattering model. The model assumes that azimuth anisotropy in surface roughness at scales of 3-300 m is the primary mechanism driving the modulation. To evaluate the contribution of azimuth anisotropy in surface roughness to the radar backscatter, the model is compared to models based on isotropic surface roughness. The models are inverted to estimate snow surface properties using σº, measurements from the C-band European Remote-sensing Satellite advanced microwave instrument in scatterometer mode. Results indicate that the largest mesoscale rms surface slopes are found in the lower portions of the dry snow zone. Estimates of the preferential direction in surface roughness are highly correlated with katabatic wind fields over Greenland, which is consistent with wind-formed sastrugi as the dominant mechanism causing azimuth modulation of σº. The maximum improvement of the azimuth modulation surface model compared to its isotropic counterparts occurs in the lower regions of the dry snow zone where the azimuth variability of σº is the largest. In regions with azimuth modulation over 1 dB, the mean root-mean-square error estimate of the azimuth-dependent surface scattering model is 0.46 dB compared with 0.70 dB for similar models using isotropic roughness.
Keywords: SCATTEROMETER DATA, ACCUMULATION, ANTARCTICA, SATELLITE, WINDS
Mission:
URL: https://doi.org/10.3189/172756506781828764
Other URLs:
Caruso, M.J., Gawarkiewicz, G.G., and Beardsley, R.C. (2006). Interannual Variability of the Kuroshio Intrusion in the South China Sea, Journal of Oceanography, 62(4), 559-575, 10.1007/s10872-006-0076-0. Journal Article »
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Title: Interannual Variability of the Kuroshio Intrusion in the South China Sea
Type: Journal Article
Publication: Journal of Oceanography
Author(s): Caruso, M.J., Gawarkiewicz, G.G., and Beardsley, R.C.
Year: 2006
Formatted Citation: Caruso, M.J., Gawarkiewicz, G.G., and Beardsley, R.C., 2006: Interannual Variability of the Kuroshio Intrusion in the South China Sea, Journal of Oceanography, 62(4), 559-575, 10.1007/s10872-006-0076-0.
Abstract: The interannual variability of intrusions of the Kuroshio into the South China Sea (SCS) is investigated using satellite remote sensing data supported by in-situ measurements. The mesoscale circulation of the SCS is predominantly wind-forced by the northeast winter and southwest summer monsoons. Although the region has been studied extensively, considerable uncertainty remains about the annual and interannual mesoscale nature of the circulation. The frequency and characteristics of Kuroshio intrusions and their effect on circulation patterns in the northeast SCS are also not well understood. Satellite observations of Sea Surface Temperature (SST) from the Tropical Rainfall Measuring Mission (TRMM) and the Advanced Very High Resolution Radiometer (AVHRR) and Sea Surface Height Anomalies (SSHA) from TOPEX/ Poseidon for the period 1997-2005 are used here to analyze the annual and interannual variability in Kuroshio intrusions and their effects on the region. Analysis of SST and SSHA shows the formation and characteristics of intrusions vary considerably each year. Typically, the intrusion occurs in the central region of Luzon Strait and results in an anticyclonic circulation in the northeastern SCS. However, in some years, the intrusion is located in the northern portion of Luzon Strait and a cyclonic intrusion results. Wind stress and wind stress curl derived from the National Aeronautics and Space Administration (NASA) QuikSCAT satellite scatterometer are used to evaluate the relationship between wind stress or wind stress curl and the presence of winter Kuroshio intrusions into the SCS.
Keywords: Kuroshio intrusion - sea surface temperature - sea surface height anomalies - South China Sea - interannual variability
Mission:
URL: https://doi.org/10.1007/s10872-006-0076-0
Other URLs:
Chang, P., Yamagata, T., Schopf, P., Behera, S.K., Carton, J., Keesler, W.S., Meyers, G., Qu, T., Schott, F., Shetye, S., and Xie, S.P. (2006). Climate Fluctuations of Tropical Coupled Systems - The Role of Ocean Dynamics, Journal of Climate, 19(20), 5122-5174, 10.1175/JCLI3903.1. Journal Article »
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Title: Climate Fluctuations of Tropical Coupled Systems - The Role of Ocean Dynamics
Type: Journal Article
Publication: Journal of Climate
Author(s): Chang, P., Yamagata, T., Schopf, P., Behera, S.K., Carton, J., Keesler, W.S., Meyers, G., Qu, T., Schott, F., Shetye, S., and Xie, S.P.
Year: 2006
Formatted Citation: Chang, P., Yamagata, T., Schopf, P., Behera, S.K., Carton, J., Keesler, W.S., Meyers, G., Qu, T., Schott, F., Shetye, S., and Xie, S.P., 2006: Climate Fluctuations of Tropical Coupled Systems - The Role of Ocean Dynamics, Journal of Climate, 19(20), 5122-5174, 10.1175/JCLI3903.1.
Abstract: The tropical oceans have long been recognized as the most important region for large-scale oceanatmosphere interactions, giving rise to coupled climate variations on several time scales. During the Tropical Ocean Global Atmosphere (TOGA) decade, the focus of much tropical ocean research was on understanding El Niño-related processes and on development of tropical ocean models capable of simulating and predicting El Niño. These studies led to an appreciation of the vital role the ocean plays in providing the memory for predicting El Niño and thus making seasonal climate prediction feasible. With the end of TOGA and the beginning of Climate Variability and Prediction (CLIVAR), the scope of climate variability and predictability studies has expanded from the tropical Pacific and ENSO-centric basis to the global domain. In this paper the progress that has been made in tropical ocean climate studies during the early years of CLIVAR is discussed. The discussion is divided geographically into three tropical ocean basins with an emphasis on the dynamical processes that are most relevant to the coupling between the atmosphere and oceans. For the tropical Pacific, the continuing effort to improve understanding of large- and small-scale dynamics for the purpose of extending the skill of ENSO prediction is assessed. This paper then goes beyond the time and space scales of El Niño and discusses recent research activities on the fundamental issue of the processes maintaining the tropical thermocline. This includes the study of subtropical cells (STCs) and ventilated thermocline processes, which are potentially important to the understanding of the low-frequency modulation of El Niño. For the tropical Atlantic, the dominant oceanic processes that interact with regional atmospheric feedbacks are examined as well as the remote influence from both the Pacific El Niño and extratropical climate fluctuations giving rise to multiple patterns of variability distinguished by season and location. The potential impact of Atlantic thermohaline circulation on tropical Atlantic variability (TAV) is also discussed. For the tropical Indian Ocean, local and remote mechanisms governing low-frequency sea surface temperature variations are examined. After reviewing the recent rapid progress in the understanding of coupled dynamics in the region, this study focuses on the active role of ocean dynamics in a seasonally locked eastwest internal mode of variability, known as the Indian Ocean dipole (IOD). Influences of the IOD on climatic conditions in Asia, Australia, East Africa, and Europe are discussed. While the attempt throughout is to give a comprehensive overview of what is known about the role of the tropical oceans in climate, the fact of the matter is that much remains to be understood and explained. The complex nature of the tropical coupled phenomena and the interaction among them argue strongly for coordinated and sustained observations, as well as additional careful modeling investigations in order to further advance the current understanding of the role of tropical oceans in climate.
Keywords: SEA-SURFACE TEMPERATURE, NINO-SOUTHERN-OSCILLATION, EQUATORIAL ATLANTIC-OCEAN, GENERAL-CIRCULATION MODEL, PACIFIC DECADAL VARIABILITY, MERIDIONAL OVERTURNING CIRCULATION, INTERTROPICAL CONVERGENCE ZONE, INTRASEASONAL KELVIN WAVES, MADDEN-JULIAN OSCILLATIO
Mission:
URL: https://doi.org/10.1175/JCLI3903.1
Other URLs:
Chelton, D.B., Freilich, M.H., Sienkiewicz, J.M., and Von Ahn, J.M. (2006). On the Use of QuikSCAT Scatterometer Measurements of Surface Winds for Marine Weather Prediction, Monthly Weather Review, 134(8), 2055-2071, 10.1175/MWR3179.1. Journal Article »
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Title: On the Use of QuikSCAT Scatterometer Measurements of Surface Winds for Marine Weather Prediction
Type: Journal Article
Publication: Monthly Weather Review
Author(s): Chelton, D.B., Freilich, M.H., Sienkiewicz, J.M., and Von Ahn, J.M.
Year: 2006
Formatted Citation: Chelton, D.B., Freilich, M.H., Sienkiewicz, J.M., and Von Ahn, J.M., 2006: On the Use of QuikSCAT Scatterometer Measurements of Surface Winds for Marine Weather Prediction, Monthly Weather Review, 134(8), 2055-2071, 10.1175/MWR3179.1.
Abstract: The value of Quick Scatterometer (QuikSCAT) measurements of 10-m ocean vector winds for marine weather prediction is investigated from two Northern Hemisphere case studies. The first of these focuses on an intense cyclone with hurricane-force winds that occurred over the extratropical western North Pacific on 10 January 2005. The second is a 17 February 2005 example that is typical of sea surface temperature influence on low-level winds in moderate wind conditions in the vicinity of the Gulf Stream in the western North Atlantic. In both cases, the analyses of 10-m winds from the NCEP and ECMWF global numerical weather prediction models considerably underestimated the spatial variability of the wind field on scales smaller than 1000 km compared with the structure determined from QuikSCAT observations. The NCEP and ECMWF models both assimilate QuikSCAT observations. While the accuracies of the 10-m wind analyses from these models measurably improved after implementation of the QuikSCAT data assimilation, the information content in the QuikSCAT data is underutilized by the numerical models. QuikSCAT data are available in near - real time in the NOAA/NCEP Advanced Weather Interactive Processing System (N-AWIPS) and are used extensively in manual analyses of surface winds. The high resolution of the QuikSCAT data is routinely utilized by forecasters at the NOAA/NCEP Ocean Prediction Center, Tropical Prediction Center, and other NOAA weather forecast offices to improve the accuracies of wind warnings in marine forecasts.
Keywords: SATELLITE MEASUREMENTS, ASSIMILATION SYSTEM, TROPICAL CYCLONES, OPERATIONAL ECMWF, TEMPERATURE, IMPACT, PACIFIC, RAIN, STRESS, FIELDS
Mission: |SeaWinds|
URL: https://doi.org/10.1175/MWR3179.1
Other URLs:
Chhak, K.C., Moore, A.M., Milliff, R.F., Branstator, G., Holland, W.R., and Fisher, M. (2006). Stochastic Forcing of the North Atlantic Wind-Driven Ocean Circulation. Part II: An Analysis of the Dynamical Ocean Response Using Generalized Stability Theory , Journal of Physical Oceanography, 36(3), 316-334, 10.1175/JPO2853.1. Journal Article »
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Title: Stochastic Forcing of the North Atlantic Wind-Driven Ocean Circulation. Part II: An Analysis of the Dynamical Ocean Response Using Generalized Stability Theory
Type: Journal Article
Publication: Journal of Physical Oceanography
Author(s): Chhak, K.C., Moore, A.M., Milliff, R.F., Branstator, G., Holland, W.R., and Fisher, M.
Year: 2006
Formatted Citation: Chhak, K.C., Moore, A.M., Milliff, R.F., Branstator, G., Holland, W.R., and Fisher, M., 2006: Stochastic Forcing of the North Atlantic Wind-Driven Ocean Circulation. Part II: An Analysis of the Dynamical Ocean Response Using Generalized Stability Theory , Journal of Physical Oceanography, 36(3), 316-334, 10.1175/JPO2853.1.
Abstract: As discussed in Part I of this study, the magnitude of the stochastic component of wind stress forcing is comparable to that of the seasonal cycle and thus will likely have a significant influence on the ocean circulation. By forcing a quasigeostrophic model of the North Atlantic Ocean circulation with stochastic wind stress curl data from the NCAR CCM3, it was found in Part I that much of the stochastically induced variability in the ocean circulation is confined to the western boundary region and some major topographic features even though the stochastic forcing is basinwide. This can be attributed to effects of bathymetry and vorticity gradients in the basic state on the system eigenmodes. Using generalized stability theory (GST), it was found in Part I that transient growth due to the linear interference of nonnormal eigenmodes enhances the stochastically induced variance. In the present study, the GST analysis of Part I is extended and it is found that the patterns of wind stress curl that are most effective for inducing variability in the model have their largest projection on the most nonnormal eigenmodes of the system. These eigenmodes are confined primarily to the western boundary region and are composed of long Rossby wave packets that are Doppler shifted by the Gulf Stream to have eastward group velocity. Linear interference of these eigenmodes yields transient growth of stochastically induced perturbations, and it is this process that maintains the variance of the stochastically induced circulations. Analysis of the large-scale circulation also reveals that the system possesses a large number of degrees of freedom, which has significant implications for ocean prediction. Sensitivity studies show that the results and conclusions of this study are insensitive and robust to variations in model parameters and model configuration.
Keywords: Atlantic Ocean , North Atlantic , ocean basins , localization , Stability theory , Eigenmode , Wind effect , stochastic processes , Forcing , Quasi geostrophic approximation , digital simulation , ocean-atmosphere interaction , Drift current , ocean curre
Mission:
URL: https://doi.org/10.1175/JPO2853.1
Other URLs:
Chhak, K.C., Moore, A.M., Milliff, R.F., Branstator, G., Holland, W.R., and Fisher, M. (2006). Stochastic Forcing of the North Atlantic Wind-Driven Ocean Circulation. Part I: A Diagnostic Analysis of the Ocean Response to Stochastic Forcing, Journal of Physical Oceanography, 36(3), 300-315, 10.1175/JPO2852.1. Journal Article »
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Title: Stochastic Forcing of the North Atlantic Wind-Driven Ocean Circulation. Part I: A Diagnostic Analysis of the Ocean Response to Stochastic Forcing
Type: Journal Article
Publication: Journal of Physical Oceanography
Author(s): Chhak, K.C., Moore, A.M., Milliff, R.F., Branstator, G., Holland, W.R., and Fisher, M.
Year: 2006
Formatted Citation: Chhak, K.C., Moore, A.M., Milliff, R.F., Branstator, G., Holland, W.R., and Fisher, M., 2006: Stochastic Forcing of the North Atlantic Wind-Driven Ocean Circulation. Part I: A Diagnostic Analysis of the Ocean Response to Stochastic Forcing, Journal of Physical Oceanography, 36(3), 300-315, 10.1175/JPO2852.1.
Abstract: At midlatitudes, the magnitude of stochastic wind stress forcing due to atmospheric weather is comparable to that associated with the seasonal cycle. Stochastic forcing is therefore likely to have a significant influence on the ocean circulation. In this work, the influence of the stochastic component of the wind stress forcing on the large-scale, wind-driven circulation of the North Atlantic Ocean is examined. To this end, a quasigeostrophic model of the North Atlantic was forced with estimates of the stochastic component of wind stress curl obtained from the NCAR Community Climate Model. Analysis reveals that much of the stochastically induced variability in the ocean circulation occurs in the vicinity of the western boundary and some major bathymetric features. Thus, the response is localized even though the stochastic forcing occurs over most of the ocean basin. Using the ideas of generalized stability theory, the stochastically induced response in the ocean circulation can be interpreted as a linear interference of the nonorthogonal eigenmodes of the system. This linear interference process yields transient growth of stochastically induced perturbations. By examining the model pseudospectra, it is seen that the nonnormal nature of the system enhances the transient growth of perturbation enstrophy and therefore elevates and maintains the variance of the stochastically induced circulations in the aforementioned regions. The primary causes of nonnormality in the enstrophy norm are bathymetry and the western boundary current circulation.
Keywords: Atlantic Ocean , North Atlantic , localization , Western boundary current , bathymetry , Enstrophy , Quasi geostrophic approximation , digital simulation , ocean-atmosphere interaction , stochastic processes , Forcing , ocean basins , Drift current , ocea
Mission:
URL: https://doi.org/10.1175/JPO2852.1
Other URLs:
Collins, W.D., Bitz, C.M., Blackmon, M.L., Bonan, G.B., Bretherton, C.S., Carton, J.A., Chang, P., Doney, S.C., Hack, J.J., Henderson, T.B., Kiehl, J.T., Large, W.G., McKenna, D.S., Santer, B.D., and Smith, R.D. (2006). The Community Climate System Model version 3 (CCSM3), Journal of Climate, 19(11), 2122-2143, 10.1175/JCLI3761.1. Journal Article »
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Title: The Community Climate System Model version 3 (CCSM3)
Type: Journal Article
Publication: Journal of Climate
Author(s): Collins, W.D., Bitz, C.M., Blackmon, M.L., Bonan, G.B., Bretherton, C.S., Carton, J.A., Chang, P., Doney, S.C., Hack, J.J., Henderson, T.B., Kiehl, J.T., Large, W.G., McKenna, D.S., Santer, B.D., and Smith, R.D.
Year: 2006
Formatted Citation: Collins, W.D., Bitz, C.M., Blackmon, M.L., Bonan, G.B., Bretherton, C.S., Carton, J.A., Chang, P., Doney, S.C., Hack, J.J., Henderson, T.B., Kiehl, J.T., Large, W.G., McKenna, D.S., Santer, B.D., and Smith, R.D., 2006: The Community Climate System Model version 3 (CCSM3), Journal of Climate, 19(11), 2122-2143, 10.1175/JCLI3761.1.
Abstract: The Community Climate System Model version 3 (CCSM3) has recently been developed and released to the climate community. CCSM3 is a coupled climate model with components representing the atmosphere, ocean, sea ice, and land surface connected by a flux coupler. CCSM3 is designed to produce realistic simulations over a wide range of spatial resolutions, enabling inexpensive simulations lasting several millennia or detailed studies of continental-scale dynamics, variability, and climate change. This paper will show results from the configuration used for climate-change simulations with a T85 grid for the atmosphere and land and a grid with approximately 1° resolution for the ocean and sea ice. The new system incorporates several significant improvements in the physical parameterizations. The enhancements in the model physics are designed to reduce or eliminate several systematic biases in the mean climate produced by previous editions of CCSM. These include new treatments of cloud processes, aerosol radiative forcing, land-atmosphere fluxes, ocean mixed layer processes, and sea ice dynamics. There are significant improvements in the sea ice thickness, polar radiation budgets, tropical sea surface temperatures, and cloud radiative effects. CCSM3 can produce stable climate simulations of millennial duration without ad hoc adjustments to the fluxes exchanged among the component models. Nonetheless, there are still systematic biases in the ocean-atmosphere fluxes in coastal regions west of continents, the spectrum of ENSO variability, the spatial distribution of precipitation in the tropical oceans, and continental precipitation and surface air temperatures. Work is under way to extend CCSM to a more accurate and comprehensive model of the earth's climate system.
Keywords:
Mission:
URL: https://doi.org/10.1175/JCLI3761.1
Other URLs:
de Szoeke, S.P., Wang, Y.Q., Xie, S.P., and Miyama, T. (2006). Effect of Shallow Cumulus Convection on the Eastern Pacific Climate in a Coupled Model, Geophysical Research Letters, 33(17), 10.1029/2006GL026715. Journal Article »
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Title: Effect of Shallow Cumulus Convection on the Eastern Pacific Climate in a Coupled Model
Type: Journal Article
Publication: Geophysical Research Letters
Author(s): de Szoeke, S.P., Wang, Y.Q., Xie, S.P., and Miyama, T.
Year: 2006
Formatted Citation: de Szoeke, S.P., Wang, Y.Q., Xie, S.P., and Miyama, T., 2006: Effect of Shallow Cumulus Convection on the Eastern Pacific Climate in a Coupled Model, Geophysical Research Letters, 33(17), 10.1029/2006GL026715.
Abstract: Shallow cumulus convection evaporates stratocumulus clouds in the atmospheric boundary layer. The effect of shallow convection on the large-scale climate of the eastern tropical Pacific is investigated with a coupled ocean-atmosphere model by disabling the shallow convection parameterization (noSC). Without shallow convection, the stratiform cloud fraction increases and surface solar radiation decreases. The sea surface temperature (SST) cools on average by 2^oC. The cooling in noSC is larger under the low cloud deck south of the equator than north of the equator, resulting in an increase in the climatic meridional asymmetry. In the control run an ITCZ forms south of the equator in March-April. In noSC the SST is at most 24^oC south of the equator and an ITCZ does not form. The perennial northern-hemisphere ITCZ in noSC is accompanied by year-round southerlies of at least ~3 m s^-1 on the equator, considerably reducing the seasonal cycle of equatorial SST.
Keywords: BOUNDARY-LAYER CLOUDS, SOUTHEAST PACIFIC, TROPICAL PACIFIC, ANNUAL CYCLE, PART II, SIMULATIONS, PARAMETERIZATION, STRATOCUMULUS, ATMOSPHERE, TRANSITION
Mission:
URL: https://doi.org/10.1029/2006GL026715
Other URLs:
deCastro, M., Dale, A.W., Gomez-Gesteira, M., Prego, R. and Alvarez, I. (2006). Hydrographic and Atmospheric Analysis of an Autumnal Upwelling Event in the Ria of Vigo (NW Iberian Peninsula), Estuarine, Coastal and Shelf Science, 68(3-4), 529-537, 10.1016/j.ecss.2006.03.004. Journal Article »
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Title: Hydrographic and Atmospheric Analysis of an Autumnal Upwelling Event in the Ria of Vigo (NW Iberian Peninsula)
Type: Journal Article
Publication: Estuarine, Coastal and Shelf Science
Author(s): deCastro, M., Dale, A.W., Gomez-Gesteira, M., Prego, R. and Alvarez, I.
Year: 2006
Formatted Citation: deCastro, M., Dale, A.W., Gomez-Gesteira, M., Prego, R. and Alvarez, I., 2006: Hydrographic and Atmospheric Analysis of an Autumnal Upwelling Event in the Ria of Vigo (NW Iberian Peninsula), Estuarine, Coastal and Shelf Science, 68(3-4), 529-537, 10.1016/j.ecss.2006.03.004.
Abstract: An autumnal upwelling event was observed in the Ria of Vigo (NW Iberian Peninsula) on 15th November 2001. This event was analyzed by means of thermohaline variables measured at CTD stations located in the study area, satellite sea surface temperature and wind data provided by QuikSCAT. Salinity and temperature distributions revealed that the upwelled water mass was Eastern North Atlantic Central Water (ENACW), typically observed during summer upwelling events. However, previous to the upwelling event, the characteristic autumnal body of water was recorded on 31st October 2001. Subsequent sea surface temperature and upwelling index corroborated the presence of an autumnal upwelling event of approximately 15 days duration. The probability of upwelling-favorable winds (from 1999 to 2004) was lower during autumn-winter than during spring-summer, although they may occur at any time of the year. Probabilities of similar to 45% were calculated for February and November, with the highest probability (65%) corresponding to July.
Keywords: autumnal upwelling, ENACW, thermohaline variables, wind, SST, Galician coast, Iberian Peninsula, QuikSCAT, SARDINE SARDINA-PILCHARDUS, EASTERN NORTH-ATLANTIC, THERMOHALINE PROPERTIES, WESTERN IBERIA, PONTEVEDRA RIA, ECOSYSTEM RIA, WATER MASSES, NE ATLANTI
Mission: |SeaWinds|
URL: https://doi.org/10.1016/j.ecss.2006.03.004
Other URLs:
Esteban-Fernandez, D., Carswell, J.R., Frasier, S.J., Chang, P. S., Black, P.G., and Marks, F.D. (2006). Dual Polarized C- and Ku-band Ocean Backscatter Response to Hurricane Force Winds, Journal of Geophysical Research, 111(C8), 10.1029/2005JC003048. Journal Article »
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Title: Dual Polarized C- and Ku-band Ocean Backscatter Response to Hurricane Force Winds
Type: Journal Article
Publication: Journal of Geophysical Research
Author(s): Esteban-Fernandez, D., Carswell, J.R., Frasier, S.J., Chang, P. S., Black, P.G., and Marks, F.D.
Year: 2006
Formatted Citation: Esteban-Fernandez, D., Carswell, J.R., Frasier, S.J., Chang, P. S., Black, P.G., and Marks, F.D., 2006: Dual Polarized C- and Ku-band Ocean Backscatter Response to Hurricane Force Winds, Journal of Geophysical Research, 111(C8), 10.1029/2005JC003048.
Abstract: Airborne ocean backscatter measurements at C- and Ku-band wavelengths and H and V polarizations at multiple incidence angles obtained in moderate to very high wind speed conditions (25-65 m s^-1) during missions through several tropical cyclones are presented. These measurements clearly show that the normalized radar cross sections (NRCS) response stops increasing at hurricane-force winds for both frequency bands and polarizations except for high incidence angles at C-band and H polarization. The results also show the mean NRCS departing from a power law behavior for all the presented frequency bands, polarizations, and incidence angles, suggesting a reduction in the drag coefficient. The overall flattening of the azimuthal response of the NRCS is also very apparent in all cases. A new set of geophysical model functions (GMFs) at C- and Ku-band are developed from these direct ocean backscatter observations for ocean surface winds ranging from 25 to 65 m s^-1. The developed GMFs provide a much more accurate characterization of the NRCS versus wind speed and direction, and their implementation in operational retrieval algorithms from satellite-based scatterometer observations would result in better wind fields. The differences between these measurements and other currently available GMFs, such as QuikSCAT, NSCAT2, CMOD4, and CMOD5, are reported. The implementation of these GMFs in retrieval algorithms will result in better wind fields from satellite-based scatterometers measurements.
Keywords: ocean backscatter, tropical cyclones, scatterometry
Mission: |NSCAT|
URL: https://doi.org/10.1029/2005JC003048
Other URLs:
Feng, H., Vandemark, D., Quilfen, Y., Chapron, B. and Beckley, B. (2006). Assessment of Wind-Forcing Impact on a Global Wind-Wave Model Using the TOPEX Altimeter, Ocean Engineering, 33(11-12), 1431-1461, 10.1016/j.oceaneng.2005.10.015. Journal Article »
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Title: Assessment of Wind-Forcing Impact on a Global Wind-Wave Model Using the TOPEX Altimeter
Type: Journal Article
Publication: Ocean Engineering
Author(s): Feng, H., Vandemark, D., Quilfen, Y., Chapron, B. and Beckley, B.
Year: 2006
Formatted Citation: Feng, H., Vandemark, D., Quilfen, Y., Chapron, B. and Beckley, B., 2006: Assessment of Wind-Forcing Impact on a Global Wind-Wave Model Using the TOPEX Altimeter, Ocean Engineering, 33(11-12), 1431-1461, 10.1016/j.oceaneng.2005.10.015.
Abstract: The study presents assessment of an operational wave model (Wavewatch III), focusing upon the model sensitivity to wind-forcing products. Four wind fields are used to drive the model, including the NCEP/NCAR reanalysis and three other products that assimilate various satellite wind measurements having high spatial resolution, including the QuikSCAT scatterometer. Three wave field statistics: significant wave height, mean zero-crossing wave period, and mean square slope are compared with collocated TOPEX altimeter derivatives to gauge the relative skill of differing wind-forced model runs, as well as to demonstrate an extended use of the altimeter beyond simply supplying wave height for wave model validation and assimilation. Results suggest that model output is critically sensitive to choice of the wind field product. Higher spatial resolution in the wind fields does lead to improved agreement for the higher-order wave statistics.
Keywords: wave modeling, altimeter, scatterometer, wind forcing, sea state bias, SEA-STATE BIAS, SCATTEROMETER WINDS, SATELLITE DATA, IN-SITU, VARIABILITY, SENSITIVITY, SPECTRA, LEVEL, SLOPE, SPEED
Mission: |SeaWinds|
URL: https://doi.org/10.1016/j.oceaneng.2005.10.015
Other URLs:
Foster, R.C., Vianey, F., Drobinski, P., and Carlotti, P. (2006). Near-Surface Coherent Structures and the Vertical Momentum Flux in a Large-Eddy Simulation of the Neutrally-Stratified Boundary Layer, Boundary-Layer Meteorology, 120(2), 229-255, 10.1007/s10546-006-9054-8. Journal Article »
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Title: Near-Surface Coherent Structures and the Vertical Momentum Flux in a Large-Eddy Simulation of the Neutrally-Stratified Boundary Layer
Type: Journal Article
Publication: Boundary-Layer Meteorology
Author(s): Foster, R.C., Vianey, F., Drobinski, P., and Carlotti, P.
Year: 2006
Formatted Citation: Foster, R.C., Vianey, F., Drobinski, P., and Carlotti, P., 2006: Near-Surface Coherent Structures and the Vertical Momentum Flux in a Large-Eddy Simulation of the Neutrally-Stratified Boundary Layer, Boundary-Layer Meteorology, 120(2), 229-255, 10.1007/s10546-006-9054-8.
Abstract: The near-surface flow of a well-resolved large-eddy simulation of the neutrally-stratified planetary boundary layer is used to explore the relationships between coherent structures and the vertical momentum flux. The near-surface flow is characterized by transient streaks, which are alternating bands of relatively higher and lower speed flow that form parallel to the mean shear direction in the lower part of the boundary layer. Although individual streaks are transient, the overall flow is in a quasi-equilibrium state in which the streaks form, grow, decay and regenerate over lifetimes on the order of tens of minutes. Coupled with the streaky flow is an overturning circulation with alternating bands of updrafts and downdrafts approximately centered on the streaks. The surface stress is dominated by upward ejections of slower moving near-surface air and downward sweeps of higher speed air from higher in the boundary layer. Conditional sampling of the ejection and sweep events shows that they are compact, coherent structures and are intimately related to the streaks: ejections (sweeps) preferentially form in the updrafts (downdrafts) of the three-dimensional streak flow. Hence, consistent with other recent studies, we propose that the streak motion plays an important role in the maintenance of the surface stress by establishing the preferential conditions for the ejections and sweeps that dominate the surface stress. The velocity fluctuation spectra in the model near the surface have a k −,1 spectral slope over an intermediate range of wavenumbers. This behaviour is consistent with recent theoretical predictions that attempt to evaluate the effects of organized flow, such as near-surface streaks, on the variance spectra.
Keywords: Atmospheric surface layer - Ejections - Large-eddy simulation - Streaks - Sweeps - Turbulence
Mission:
URL: https://doi.org/10.1007/s10546-006-9054-8
Other URLs:
Fu, G., Guo, J.T., Xie, S.P., Duane, Y.H., and Zhang, M.G. (2006). Analysis and High-Resolution Modeling of a Dense Sea Fog Event Over the Yellow Sea, Atmospheric Research, 81(4), 293-303, 10.1016/j.atmosres.2006.01.005. Journal Article »
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Title: Analysis and High-Resolution Modeling of a Dense Sea Fog Event Over the Yellow Sea
Type: Journal Article
Publication: Atmospheric Research
Author(s): Fu, G., Guo, J.T., Xie, S.P., Duane, Y.H., and Zhang, M.G.
Year: 2006
Formatted Citation: Fu, G., Guo, J.T., Xie, S.P., Duane, Y.H., and Zhang, M.G., 2006: Analysis and High-Resolution Modeling of a Dense Sea Fog Event Over the Yellow Sea, Atmospheric Research, 81(4), 293-303, 10.1016/j.atmosres.2006.01.005.
Abstract: A ubiquitous feature of the Yellow Sea (YS) is the frequent occurrence of the sea fog in spring and summer season. An extremely dense sea fog event was observed around the Shandong Peninsula in the morning of 11 April 2004. This fog patch, with a spatial scale of several hundreds kilometers and lasted about 20 h, reduced the horizontal visibility to be less than 20 m in some locations, and caused a series of traffic collisions and 12 injuries on the coastal stretch of a major highway. In this paper, almost all available observational data, including Geostationary Operational Environmental Satellite (GOES)-9 visible satellite imagery, objectively reanalyzed data of final run analysis (FNL) issued by the National Center for Environmental Prediction (NCEP) and the sounding data of Qingdao and Dalian, as well as the latest 4.4 version of Regional Atmospheric Modeling System (RAMS) model, were employed to investigate this sea fog case. Its evolutionary process and the environmental conditions that led to the fog formation were examined by using GOES-9 visible satellite imagery and sounding observations. In order to better understand the fog formation mechanism, a high-resolution RAMS modeling of 4 km ?4 km was designed. The modeling was initialized and validated by FNL data. A 30-h modeling that started from 18 UTC 10 April 2004 reproduced the main characteristics of this fog event. The simulated lower horizontal visibility area agreed reasonably well with the sea fog region identified from the satellite imagery. Advection cooling effect seemed to play a significant role for the fog formation.
Keywords: Sea fog, Visible satellite imagery, Horizontal visibility, High-resolution modeling
Mission:
URL: https://doi.org/10.1016/j.atmosres.2006.01.005
Other URLs:
Gierach, M.M., Bourassa, M.A., Cunningham, P., and O'Brien, J.J. (2006). Vorticity-Based Detection of Tropical Cyclogenesis, Journal of Applied Meteorology and Climatology, 46(8), 1214-1229, 10.1175/JAM2522.1. Journal Article »
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Title: Vorticity-Based Detection of Tropical Cyclogenesis
Type: Journal Article
Publication: Journal of Applied Meteorology and Climatology
Author(s): Gierach, M.M., Bourassa, M.A., Cunningham, P., and O'Brien, J.J.
Year: 2006
Formatted Citation: Gierach, M.M., Bourassa, M.A., Cunningham, P., and O'Brien, J.J., 2006: Vorticity-Based Detection of Tropical Cyclogenesis, Journal of Applied Meteorology and Climatology, 46(8), 1214-1229, 10.1175/JAM2522.1.
Abstract:
Keywords: QSCAT, Tropical, Cyclones, GOES
Mission: |SeaWinds|
URL: https://doi.org/10.1175/JAM2522.1
Other URLs:
Grodsky, S.A., Carton, J.A., and Bingham, F.M. (2006). Low Frequency Variation of Sea Surface Salinity in the Tropical Atlantic, Geophysical Research Letters, 33(14), 10.1029/2006GL026426. Journal Article »
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Title: Low Frequency Variation of Sea Surface Salinity in the Tropical Atlantic
Type: Journal Article
Publication: Geophysical Research Letters
Author(s): Grodsky, S.A., Carton, J.A., and Bingham, F.M.
Year: 2006
Formatted Citation: Grodsky, S.A., Carton, J.A., and Bingham, F.M., 2006: Low Frequency Variation of Sea Surface Salinity in the Tropical Atlantic, Geophysical Research Letters, 33(14), 10.1029/2006GL026426.
Abstract: Examination of the observational record suggests that the near-surface waters in the tropical Atlantic underwent a major salinification during the twenty-five year period 1960-1985 at a rate of 0.1 psu/decade. A reversal of this trend has occurred during the most recent decade. While year-to-year changes in salinity are related to precipitation, we attribute decadal changes in salinity at least in part to low frequency changes of winds in the deep tropics and their role in altering both upwelling and possibly, evaporation rates.
Keywords: INTERANNUAL VARIATIONS, UPPER LAYER, OCEAN, REANALYSIS, PROJECT, BUDGET
Mission:
URL: https://doi.org/10.1029/2006GL026426
Other URLs:
Halkides, D.J., Han, W.Q., and Webster, P.J. (2006). Effects of the Seasonal Cycle on the Development and Termination of the Indian Ocean Zonal Dipole Mode, Journal of Geophysical Research: Oceans, 111(C12), 10.1029/2005JC003247. Journal Article »
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Title: Effects of the Seasonal Cycle on the Development and Termination of the Indian Ocean Zonal Dipole Mode
Type: Journal Article
Publication: Journal of Geophysical Research: Oceans
Author(s): Halkides, D.J., Han, W.Q., and Webster, P.J.
Year: 2006
Formatted Citation: Halkides, D.J., Han, W.Q., and Webster, P.J., 2006: Effects of the Seasonal Cycle on the Development and Termination of the Indian Ocean Zonal Dipole Mode, Journal of Geophysical Research: Oceans, 111(C12), 10.1029/2005JC003247.
Abstract: Effects of the seasonal cycles of atmospheric surface forcings on the development and termination of the Indian Ocean Zonal Dipole Mode (IOZDM) are studied using a nonlinear, 4-1/2 layer ocean model partially coupled to an advective atmospheric mixed layer model in which sea surface temperature (SST) feeds back only to air temperature and specific humidity. A series of experiments are performed for the period of 1984-1998 to isolate processes. The results indicate the seasonal cycle of atmospheric forcing aids development and decay of cold SST anomalies (SSTA) in the eastern basin associated with strong, positive dipole events. During the strong IOZDM years of 1994 and 1997, seasonal southeasterlies associated with the Asian summer monsoon reinforce coastal upwelling associated with the IOZDM near Sumatra-Java in boreal summer and fall, assisting initiation and increasing the peak amplitudes of these events. However, near the equator, fall equatorial westerlies deepen the thermocline in the eastern basin, reducing the cold SSTA in the eastern equatorial region and near Sumatra and Java. This contributes to the early termination of the 1994 IOZDM. In boreal winter the monsoon wind reversal reduces coastal upwelling along Sumatra and Java, further contributing to IOZDM termination. Moreover, the seasonal equatorial westerlies during fall and the monsoon wind reversal during winter counter southeasterly wind anomalies associated with the IOZDM in the eastern antinode region, reducing the total wind speed, weakening entrainment cooling and surface turbulent heat loss and thus further assisting IOZDM termination.
Keywords: IOZDM, seasonal cycle, termination
Mission:
URL: https://doi.org/10.1029/2005JC003247
Other URLs:
Halterman, R.R., and Long, D.G. (2006). A Comparison of Hurricane Eye Determine Using Standard and Ultra-High Resolution QuikSCAT Winds, 2006 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `06), 4117-4120, 10.1109/IGARSS.2006.1060. Conference Paper »
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Title: A Comparison of Hurricane Eye Determine Using Standard and Ultra-High Resolution QuikSCAT Winds
Type: Conference Paper
Publication: 2006 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `06)
Author(s): Halterman, R.R., and Long, D.G.
Year: 2006
Formatted Citation: Halterman, R.R., and Long, D.G., 2006: A Comparison of Hurricane Eye Determine Using Standard and Ultra-High Resolution QuikSCAT Winds, 2006 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `06), 4117-4120, 10.1109/IGARSS.2006.1060.
Abstract:
Keywords:
Mission: |SeaWinds|
URL: https://doi.org/10.1109/IGARSS.2006.1060
Other URLs:
Han, W., Shinoda, T., Fu, L.-L., and McCreary, J.P. (2006). Impact of Atmospheric Intraseasonal Oscillations on the Indian Ocean Dipole During the 1990s, Journal of Physical Oceanography, 36(4), 670-690, 10.1175/JPO2892.1. Journal Article »
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Title: Impact of Atmospheric Intraseasonal Oscillations on the Indian Ocean Dipole During the 1990s
Type: Journal Article
Publication: Journal of Physical Oceanography
Author(s): Han, W., Shinoda, T., Fu, L.-L., and McCreary, J.P.
Year: 2006
Formatted Citation: Han, W., Shinoda, T., Fu, L.-L., and McCreary, J.P., 2006: Impact of Atmospheric Intraseasonal Oscillations on the Indian Ocean Dipole During the 1990s, Journal of Physical Oceanography, 36(4), 670-690, 10.1175/JPO2892.1.
Abstract: Effects of atmospheric intraseasonal oscillations (ISOs) on the Indian Ocean zonal dipole mode (IOZDM) are investigated by analyzing available observations and a suite of solutions to an ocean general circulation model, namely, the Hybrid Coordinate Ocean Model (HYCOM). Data and model solutions for the period 1991-2000 are analyzed, a period that includes two strong IOZDM events, during 1994 and 1997, and a weak one, in 1991. Both the data analysis and model results suggest that atmospheric ISOs play a significant role in causing irregularity of the two strong IOZDM events and the premature termination of the weak one. Of particular interest is a basinwide, wind-driven oceanic resonance with a period near 90 days, involving the propagation of equatorial Kelvin and first-meridional-mode Rossby waves across the basin. Before the onset of the strong 1997 dipole, wind variability had significant power near 90 days, and the resonance was strongly excited. Associated with the resonance was a deepened thermocline in the eastern basin during August and early September, which reduced the upwelling in the eastern antinode region of the IOZDM, thereby delaying the reversal of the equatorial zonal SST gradient - an important indicator of a strong IOZDM - by over a month. A similar deepened thermocline in the eastern basin also contributed to the premature termination of the weak 1991 dipole. During the 1994 IOZDM, the winds had little power near 90 days, and the resonant mode was not prominent. The ISOs influenced the IOZDM through both surface fluxes and thermocline variability. They enhanced warming in the western antinode region during October, the peak phase of the IOZDM, intensifying its strength. During November, strong winds significantly cooled the western and central basin through upwelling and surface fluxes, cooling SST there and contributing to the early and quick termination of the 1994 event.
Keywords:
Mission:
URL: https://doi.org/10.1175/JPO2892.1
Other URLs:
Han, W.Q., Liu, W.T., and Lin, J.L. (2006). Impact of Atmospheric Submonthly Oscillations on Sea Surface Temperature of the Tropical Indian Ocean, Geophysical Research Letters, 33(L03609), L03609, 10.1029/2005GL025082. Journal Article »
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Title: Impact of Atmospheric Submonthly Oscillations on Sea Surface Temperature of the Tropical Indian Ocean
Type: Journal Article
Publication: Geophysical Research Letters
Author(s): Han, W.Q., Liu, W.T., and Lin, J.L.
Year: 2006
Formatted Citation: Han, W.Q., Liu, W.T., and Lin, J.L., 2006: Impact of Atmospheric Submonthly Oscillations on Sea Surface Temperature of the Tropical Indian Ocean, Geophysical Research Letters, 33(L03609), L03609, 10.1029/2005GL025082.
Abstract: Impacts of atmospheric intraseasonal oscillations (ISOs) at submonthly periods (10-30 days) on Indian Ocean sea surface temperature (SST) are studied using satellite observed outgoing long wave radiation, QuikSCAT winds, SST and an ocean general circulation model for the period of 1999-2004. The results suggest that submonthly ISOs can cause significant 10-30 day SST changes throughout the equatorial basin and northern Bay of Bengal, with an amplitude of as large as 0.5 degrees C and standard deviation of exceeding 0.2 degrees C for a 4-year record. Impact of the submonthly ISO associated with the Indian summer monsoon is separately examined. It is associated with basin-scale SST evolution with distinct spatial structures. The SST variation results mainly from submonthly wind forcing, which causes changes in oceanic processes and surface turbulent heat fluxes. Radiative fluxes can also have large influences in some regions for some ISO events.
Keywords: INTRASEASONAL VARIABILITY, MONSOON, FLUXES, MODE, CIRCULATION, CONVECTION
Mission: |SeaWinds|
URL: https://doi.org/10.1029/2005GL025082
Other URLs:
Han, W.Q., Meehl, G.A., and Hu, A.X. (2006). Interpretation of Tropical Thermocline Cooling in the Indian and Pacific Oceans During Recent Decades, Geophysical Research Letters, 33(23), 10.1029/2006GL027982. Journal Article »
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Title: Interpretation of Tropical Thermocline Cooling in the Indian and Pacific Oceans During Recent Decades
Type: Journal Article
Publication: Geophysical Research Letters
Author(s): Han, W.Q., Meehl, G.A., and Hu, A.X.
Year: 2006
Formatted Citation: Han, W.Q., Meehl, G.A., and Hu, A.X., 2006: Interpretation of Tropical Thermocline Cooling in the Indian and Pacific Oceans During Recent Decades, Geophysical Research Letters, 33(23), 10.1029/2006GL027982.
Abstract: A warming trend has been detected in the world's oceans in recent decades. The basin-averaged warming, however, shows a complex vertical structure in the Indian and Pacific oceans. Warming in the upper ocean-with maxima near the surface- accompanies a strong cooling in the upper thermocline. Analysis of observed data and model solutions from this study reveals that the complex structure is confined mainly to the tropics. While increased greenhouse gases act to warm up the upper ocean by increasing downward surface heat fluxes, anomalous winds in the tropics cause upward Ekman pumping velocity and shoal the thermocline, resulting in an upper-thermocline cooling. This cooling process is well demonstrated by a simple model based on the ventilated thermocline theory. The study has important implications for climate change and fisheries.
Keywords: OVERTURNING CIRCULATION, VENTILATED THERMOCLINE, CLIMATE SYSTEM, WORLDS OCEANS, VARIABILITY, MODEL, EXCHANGE
Mission:
URL: https://doi.org/10.1029/2006GL027982
Other URLs:
Hicks, D.R., and Long, D.G. (2006). Diurnal Melt Detection on Arctic Sea Ice Using Tandem QuikSCAT and SeaWinds Data, 2006 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `06), 4112-4114, 10.1109/IGARSS.2006.1054. Conference Paper »
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Title: Diurnal Melt Detection on Arctic Sea Ice Using Tandem QuikSCAT and SeaWinds Data
Type: Conference Paper
Publication: 2006 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `06)
Author(s): Hicks, D.R., and Long, D.G.
Year: 2006
Formatted Citation: Hicks, D.R., and Long, D.G., 2006: Diurnal Melt Detection on Arctic Sea Ice Using Tandem QuikSCAT and SeaWinds Data, 2006 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `06), 4112-4114, 10.1109/IGARSS.2006.1054.
Abstract:
Keywords:
Mission: |SeaWinds|
URL: https://doi.org/10.1109/IGARSS.2006.1054
Other URLs:
Hilburn, K.A., Wentz, F.J., Smith, D.K., and Ashcroft, P.D. (2006). Correcting Active Scatterometer Data for the Effects of Rain Using Passive Radiometer Data, Journal of Applied Meteorology and Climatology, 45(3), 382-398, 10.1175/JAM2357.1. Journal Article »
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Title: Correcting Active Scatterometer Data for the Effects of Rain Using Passive Radiometer Data
Type: Journal Article
Publication: Journal of Applied Meteorology and Climatology
Author(s): Hilburn, K.A., Wentz, F.J., Smith, D.K., and Ashcroft, P.D.
Year: 2006
Formatted Citation: Hilburn, K.A., Wentz, F.J., Smith, D.K., and Ashcroft, P.D., 2006: Correcting Active Scatterometer Data for the Effects of Rain Using Passive Radiometer Data, Journal of Applied Meteorology and Climatology, 45(3), 382-398, 10.1175/JAM2357.1.
Abstract: A model for the effects of rain on scatterometer data is proposed. Data from the Advanced Microwave Scanning Radiometer (AMSR) and the SeaWinds scatterometer, both on the Midori-II satellite, are used. The model includes three basic rain effects: attenuation, rain roughening of the sea surface, and volumetric backscatter. Attenuation is calculated directly from the radiometer data and beam filling is explicitly addressed. The model simultaneously solves for both the rain roughening and volumetric backscatter. Fitting the coefficients of the model requires an estimate of the radar cross section because of wind roughening, and NCEP Global Data Assimilation System (GDAS) wind vectors are used for this purpose. Both the derived rain roughening and volumetric backscatter are similar to results in published work, but the values are slightly smaller, especially for vertical polarization. Drop size distribution variability is accounted for by formulating the radar equation in terms of the parameters of the radiative transfer equation and using additional radiometric information. Explicit inclusion of vertical profile variability results in an underdetermined problem, but it is implicitly included in fitting the model to the data. The correction makes large improvements in wind speeds and modest improvements in wind directions. Wind statistics and specific examples are shown to illustrate the nature of the improvements. The correction is limited, however, by measurement mismatch issues and the nonlinear nature of the wind retrieval.
Keywords: OCEAN ALGORITHM, RADAR, SCATTERING, IMPACT, CELL
Mission: |SeaWinds|
URL: https://doi.org/10.1175/JAM2357.1
Other URLs:
Hite, M.M., Bourassa, M.A., and O'Brien, J.J. (2006). Objective Detection of Atlantic Tropical Disturbances, 14th Conference on Interactions of the Sea and Atmosphere.
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Title: Objective Detection of Atlantic Tropical Disturbances
Type: Conference Paper
Publication: 14th Conference on Interactions of the Sea and Atmosphere
Author(s): Hite, M.M., Bourassa, M.A., and O'Brien, J.J.
Year: 2006
Formatted Citation: Hite, M.M., Bourassa, M.A., and O'Brien, J.J., 2006: Objective Detection of Atlantic Tropical Disturbances, 14th Conference on Interactions of the Sea and Atmosphere.
Abstract:
Keywords: QSCAT, scatterometer, disturbance, rain
Mission: |SeaWinds|
URL:
Other URLs:
Hudson, D.L., Piepmeier, J., and Long, D.G. (2006). Polarization Rotation Correction in Radiometry: An Extended Error Analysis, 2006 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `06), 2305-2308, 10.1109/IGARSS.2006.596. Conference Paper »
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Title: Polarization Rotation Correction in Radiometry: An Extended Error Analysis
Type: Conference Paper
Publication: 2006 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `06)
Author(s): Hudson, D.L., Piepmeier, J., and Long, D.G.
Year: 2006
Formatted Citation: Hudson, D.L., Piepmeier, J., and Long, D.G., 2006: Polarization Rotation Correction in Radiometry: An Extended Error Analysis, 2006 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `06), 2305-2308, 10.1109/IGARSS.2006.596.
Abstract:
Keywords:
Mission:
URL: https://doi.org/10.1109/IGARSS.2006.596
Other URLs:
Kobashi, F., Mitsudera, H., and Xie, S.P. (2006). Three Subtropical Fronts in the North Pacific: Observational Evidence for Mode Water-Induced Subsurface Frontogenesis, Journal of Geophysical Research: Oceans, 111(C9), 10.1029/2006JC003479. Journal Article »
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Title: Three Subtropical Fronts in the North Pacific: Observational Evidence for Mode Water-Induced Subsurface Frontogenesis
Type: Journal Article
Publication: Journal of Geophysical Research: Oceans
Author(s): Kobashi, F., Mitsudera, H., and Xie, S.P.
Year: 2006
Formatted Citation: Kobashi, F., Mitsudera, H., and Xie, S.P., 2006: Three Subtropical Fronts in the North Pacific: Observational Evidence for Mode Water-Induced Subsurface Frontogenesis, Journal of Geophysical Research: Oceans, 111(C9), 10.1029/2006JC003479.
Abstract: Subsurface fronts in the subtropical North Pacific were investigated by constructing a high-resolution temperature climatology. Three distinct subtropical fronts (STFs) are identified, which are the southern, northern and eastern STFs according to their relative geographical locations. The southern STF extends along 19-21N west of the dateline, while the northern and eastern STFs appear along 21-24N and 26N in the western and central subtropical gyre, respectively. Our analysis showed that each of these STFs is associated with large negative meridional potential vorticity (PV) gradient in the thermocline below the front. The northern STF is located on the southern edge of the Kuroshio recirculation, where the negative PV gradient occurs within a narrow density range and is maintained by the low PV core of the subtropical mode water (STMW). On the other hand, the negative PV gradient at the eastern and southern STFs spans over a wide density range. The eastern STF forms near the center axis of the subtropical gyre, north of which the upper and lower portions of the central mode water (CMW) converge, forming a thick low PV pool that maintains the negative PV gradient on the front. Similarly, at the southern STF, the negative PV gradient is due to a low PV pool to the north, with the southernmost portion of the STMW stacked above the upper CMW advected from the central subtropical gyre. It is concluded that the mode waters are essential for the North Pacific STFs.
Keywords: subtropical front, mode water
Mission:
URL: https://doi.org/10.1029/2006JC003479
Other URLs:
Kunz, L.B., and Long, D.G. (2006). Melt Detection in Antarctic Ice Shelves Using Scatterometers and Microwave Radiometers, IEEE Transactions on Geoscience and Remote Sensing, 44(9), 2461-2469, 10.1109/TGRS.2006.874138. Journal Article »
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Title: Melt Detection in Antarctic Ice Shelves Using Scatterometers and Microwave Radiometers
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Kunz, L.B., and Long, D.G.
Year: 2006
Formatted Citation: Kunz, L.B., and Long, D.G., 2006: Melt Detection in Antarctic Ice Shelves Using Scatterometers and Microwave Radiometers, IEEE Transactions on Geoscience and Remote Sensing, 44(9), 2461-2469, 10.1109/TGRS.2006.874138.
Abstract: Ku-band dual-polarization radar backscatter measurements from the SeaWinds-on-QuikSCAT scatterometer are used to determine periods of surface freeze and melt in the Antarctic ice shelves. The normalized horizontal-polarization radar backscatter (sigma^o) and backscatter polarization ratio are used in maximum-likelihood estimation of the ice state. This method is used to infer the daily ice-surface conditions for 25 study locations located on the Ronne, Ross, Larsen, Amery, Shackleton, and other ice shelves. The temporal and spatial variations of the radar response are observed for various neighborhood sizes surrounding each given location during the study period. Criteria for determining the dates of melt onset and freeze-up for each Austral summer are presented. Validation of the ice-state and melt-onset date estimates is performed by analyzing the corresponding brightness temperature (T_b) measurements from Special Sensor Microwave/Imager (SSM/I) radiometers. QuikSCAT sigma^o measurements from 1999 to 2003 are analyzed and found to be effective in determining periods of melt in Antarctic ice sheets at high temporal and spatial resolutions. These estimates can be used in studies of the climatic effects of the seasonal and interannual melting of the Antarctic ice sheets.
Keywords: Antarctic QuikSCAT SeaWinds Special Sensor Microwave/Imager (SSM/I) ice ice shelves melt onset refreeze
Mission: |SeaWinds|
URL: https://doi.org/10.1109/TGRS.2006.874138
Other URLs:
Kwok, R., Cunningham, G.F., Zwally, H.J., and Yi, D. (2006). ICESat Over Arctic Sea Ice: Interpretation of Altimetric and Reflectivity Profiles, Journal of Geophysical Research: Oceans, 111, C06006, 10.1029/2005JC003175. Journal Article »
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Title: ICESat Over Arctic Sea Ice: Interpretation of Altimetric and Reflectivity Profiles
Type: Journal Article
Publication: Journal of Geophysical Research: Oceans
Author(s): Kwok, R., Cunningham, G.F., Zwally, H.J., and Yi, D.
Year: 2006
Formatted Citation: Kwok, R., Cunningham, G.F., Zwally, H.J., and Yi, D., 2006: ICESat Over Arctic Sea Ice: Interpretation of Altimetric and Reflectivity Profiles, Journal of Geophysical Research: Oceans, 111, C06006, 10.1029/2005JC003175.
Abstract: We provide an assessment of the ICESat altimeter for studying the Arctic Ocean and examine the magnitude of the large- and small-scale expressions of geophysical processes embedded in the elevation profiles. This analysis includes data from six surveys. At the large scale the response of the ice-covered ocean to atmospheric loading is near ideal (i.e., approximately -1 cm/hPa). After removal of the inverted barometer effects and best available geoid the elevation signal is still dominated by unresolved geoid residuals (similar to 0.4 m) that can be seen in the similarity of the remaining spatial patterns. Seasonal differences in elevations over multiyear ice are consistent with snow depth climatology, the broad differential spatial patterns are indicative of interannual differences in multiyear ice coverage associated with advection. Patterns in the derived surface roughness fields correspond to the seasonal and perennial ice zones seen in QuikSCAT data. At the small scale, near-coincident RADARSAT imagery provides a spatial context for understanding the signature of the observed elevations, waveforms, and reflectivity, in particular, those associated with thin ice, open water, multiyear ice, and ridges. The precision of the elevation estimates measured over relatively flat sea ice, identified in synthetic aperture radar (SAR) imagery, is similar to 2 cm. The unambiguous identification of ridged areas in coupled ICESat/RADARSAT analysis could be used to enhance the utility of SAR imagery for examining ridge distributions. Over a 20 day period we monitored the evolution of the reflectivity of a newly opened lead. The steep increase in reflectivity due to snow coverage suggests that dips in ICESat reflectivity are likely areas of thin ice and could serve as a basis for selection of tie points for use as sea level reference. Identification of these tie points is crucial for accurate estimation of sea ice freeboard.
Keywords: OCEAN, SAR, MODEL
Mission: |SeaWinds|
URL: https://doi.org/10.1029/2005JC003175
Other URLs:
Lambert, B., and Long, D.G. (2006). A Large-Scale Ku-Band Backscatter Model of the East-Antarctic Megadune Fields, 2006 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `06), 3832-3834, 10.1109/IGARSS.2006.982. Conference Paper »
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Title: A Large-Scale Ku-Band Backscatter Model of the East-Antarctic Megadune Fields
Type: Conference Paper
Publication: 2006 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `06)
Author(s): Lambert, B., and Long, D.G.
Year: 2006
Formatted Citation: Lambert, B., and Long, D.G., 2006: A Large-Scale Ku-Band Backscatter Model of the East-Antarctic Megadune Fields, 2006 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `06), 3832-3834, 10.1109/IGARSS.2006.982.
Abstract:
Keywords:
Mission:
URL: https://doi.org/10.1109/IGARSS.2006.982
Other URLs:
Li, L., Gaiser, P., Twarog, E., Long, D.G., and Albert, M. (2006). WindSat Polarimetric View of Greenland, 2006 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `06), 3807-3810, 10.1109/IGARSS.2006.980. Conference Paper »
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Title: WindSat Polarimetric View of Greenland
Type: Conference Paper
Publication: 2006 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `06)
Author(s): Li, L., Gaiser, P., Twarog, E., Long, D.G., and Albert, M.
Year: 2006
Formatted Citation: Li, L., Gaiser, P., Twarog, E., Long, D.G., and Albert, M., 2006: WindSat Polarimetric View of Greenland, 2006 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `06), 3807-3810, 10.1109/IGARSS.2006.980.
Abstract:
Keywords:
Mission: |WindSat|
URL: https://doi.org/10.1109/IGARSS.2006.980
Other URLs:
Lin, X.P., Xie, S.P., Chen, X.P., and Xu, L.L. (2006). A Well-Mixed Warm Water Column in the Central Bohai Sea in Summer: Effects of Tidal and Surface Wave Mixing, Journal of Geophysical Research: Oceans, 111(C11017), 10.1029/2006JC003504. Journal Article »
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Title: A Well-Mixed Warm Water Column in the Central Bohai Sea in Summer: Effects of Tidal and Surface Wave Mixing
Type: Journal Article
Publication: Journal of Geophysical Research: Oceans
Author(s): Lin, X.P., Xie, S.P., Chen, X.P., and Xu, L.L.
Year: 2006
Formatted Citation: Lin, X.P., Xie, S.P., Chen, X.P., and Xu, L.L., 2006: A Well-Mixed Warm Water Column in the Central Bohai Sea in Summer: Effects of Tidal and Surface Wave Mixing, Journal of Geophysical Research: Oceans, 111(C11017), 10.1029/2006JC003504.
Abstract: A well-mixed water column is observed over a 20 m ridge in the central Bohai Sea, surrounded by stratified water of much colder temperatures. We use a three-dimensional model to investigate its formation mechanisms. The results show that both tidal and surface wave mixing are important for homogenizing the water column, the former reaching 10 m above the bottom and the latter penetrating 10 m beneath the sea surface. The ridge enhances the intensity and vertical extent of tidal mixing, allowing it to connect with the downward penetration of wave mixing. Removing either the bathymetric ridge or wave mixing fails to reproduce this well-mixed water column. The inclusion of the surface wave mixing warms the bottom water by 56C in both the warm water column and surrounding cold water. Wave mixing displays a maximum in the central Bohai Sea basin, which is confirmed by satellite altimeter data and a wave model simulation.
Keywords: Bohai Sea, warm water column, wave mixing
Mission:
URL: https://doi.org/10.1029/2006JC003504
Other URLs:
Liu, W.T., Xie, X., Tang, W., and Zlotnicki, V. (2006). Spacebased Observations of Oceanic Influence on the Annual Variation of South American Water Balance, Geophysical Research Letters, 33(L08710), L08710, 10.1029/2006GL025683. Journal Article »
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Title: Spacebased Observations of Oceanic Influence on the Annual Variation of South American Water Balance
Type: Journal Article
Publication: Geophysical Research Letters
Author(s): Liu, W.T., Xie, X., Tang, W., and Zlotnicki, V.
Year: 2006
Formatted Citation: Liu, W.T., Xie, X., Tang, W., and Zlotnicki, V., 2006: Spacebased Observations of Oceanic Influence on the Annual Variation of South American Water Balance, Geophysical Research Letters, 33(L08710), L08710, 10.1029/2006GL025683.
Abstract: The mass change of South America (SA) continent measured by the Gravity Recovery and Climate Experiment (GRACE) imposes a constraint on the uncertainties in estimating the annual variation of rainfall measured by Tropical Rain Measuring Mission (TRMM) and ocean moisture influx derived from QuikSCAT data. The approximate balance of the mass change rate with the moisture influx less climatological river discharge, in agreement with the conservation principle, bolsters not only the credibility of the spacebased measurements, but supports the characterization of ocean's influence on the annual variation of continental water balance. The annual variation of rainfall is found to be in phase with the mass change rate in the Amazon and the La Plata basins, and the moisture advection across relevant segments of the Pacific and Atlantic coasts agrees with the annual cycle of rainfall in the two basins and the Andes mountains.
Keywords: water cycle, rainfall annual cycle, remote sensing, ocean moisture influx, andes mountains
Mission: |SeaWinds|
URL: https://doi.org/10.1029/2006GL025683
Other URLs:
Long, D.G. (2006). Ultra High Resolution Rain Retrieval from QuikSCAT Data, 2006 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `06), 4113-4116, 10.1109/IGARSS.2006.1059. Conference Paper »
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Title: Ultra High Resolution Rain Retrieval from QuikSCAT Data
Type: Conference Paper
Publication: 2006 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `06)
Author(s): Long, D.G.
Year: 2006
Formatted Citation: Long, D.G., 2006: Ultra High Resolution Rain Retrieval from QuikSCAT Data, 2006 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `06), 4113-4116, 10.1109/IGARSS.2006.1059.
Abstract:
Keywords:
Mission: |SeaWinds|
URL: https://doi.org/10.1109/IGARSS.2006.1059
Other URLs:
Luger, H., Wanninkhof, R., Wallace, D.W.R., and Kortzinger, A. (2006). CO₂ Fluxes in the Subtropical and Subarctic North Atlantic Based on Measurements from a Volunteer Observing Ship, Journal of Geophysical Research: Oceans, 111(C6), C06024, 10.1029/2005JC003101. Journal Article »
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Title: CO₂ Fluxes in the Subtropical and Subarctic North Atlantic Based on Measurements from a Volunteer Observing Ship
Type: Journal Article
Publication: Journal of Geophysical Research: Oceans
Author(s): Luger, H., Wanninkhof, R., Wallace, D.W.R., and Kortzinger, A.
Year: 2006
Formatted Citation: Luger, H., Wanninkhof, R., Wallace, D.W.R., and Kortzinger, A., 2006: CO₂ Fluxes in the Subtropical and Subarctic North Atlantic Based on Measurements from a Volunteer Observing Ship, Journal of Geophysical Research: Oceans, 111(C6), C06024, 10.1029/2005JC003101.
Abstract: Surface seawater pCO₂ and related parameters were measured at high frequency onboard the volunteer observing ship M/V Falstaff in the North Atlantic Ocean between 36 degrees and 52 degrees N. Over 90,000 data points were used to produce monthly CO2 fluxes for 2002/2003. The air-sea CO2 fluxes calculated by two different averaging schemes were compared. The first approach used gas transfer velocity determined from wind speed retrieved at the location of the ship and called colocated winds, while for the second approach a monthly averaged gas transfer velocity was calculated from the wind for each grid pixel including the variability in wind. The colocated wind speeds determined during the time of passage do not capture the monthly wind speed variability of the grid resulting in fluxes that were 47% lower than fluxes using the monthly averaged wind products. The Falstaff COsub>2 fluxes were in good agreement with a climatology using averaged winds. Over the entire region they differed by 2 - 5%, depending on the time-dependent correction scheme to account for the atmospheric in increase in pCOsub>2. However, locally the flux differences between the ship measurements and the climatology were greater, especially in regions north of 45 degrees N, like the eastern sector. A comparison of two wind speed products showed that the annual COsub>2 sink is 4% less when using 6 hourly NCEP/NCAR wind speeds compared to the QuikSCAT wind speed data.
Keywords: GAS-EXCHANGE, WIND-SPEED, OCEAN, CARBON
Mission: |SeaWinds|
URL: https://doi.org/10.1029/2005JC003101
Other URLs:
Luis, A.J., Isoguchi, O. and Kawamura, H. (2006). Characteristic Patterns of QuikScat-Based Wind Stress and Turbulent Heat Flux in the Tropical Indian Ocean, Remote Sensing of Environment, 103(4), 398-407, 10.1016/j.rse.2006.04.002. Journal Article »
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Title: Characteristic Patterns of QuikScat-Based Wind Stress and Turbulent Heat Flux in the Tropical Indian Ocean
Type: Journal Article
Publication: Remote Sensing of Environment
Author(s): Luis, A.J., Isoguchi, O. and Kawamura, H.
Year: 2006
Formatted Citation: Luis, A.J., Isoguchi, O. and Kawamura, H., 2006: Characteristic Patterns of QuikScat-Based Wind Stress and Turbulent Heat Flux in the Tropical Indian Ocean, Remote Sensing of Environment, 103(4), 398-407, 10.1016/j.rse.2006.04.002.
Abstract: Using QuikScat-based vector wind data for 1999-2003, surface wind stress and turbulent heat (Q) have been mapped for the tropical Indian Ocean (10) to understand their seasonal variability. During July wind stress is enhanced by similar to 70% in the Arabian Sea compared to that during January. The Arabian Sea experiences a large Q loss (150-200 W/m(2)) during the summer and winter monsoons, which is nearly 1.3 times of that in the Bay of Bengal. The southeasterlies are strengthened during the southern hemisphere winter. Empirical Orthogonal Function analysis captures different phases of monsoon-induced variability in wind stress and Q, ranging from seasonal to high-frequency perturbations. Coherency between time coefficients of EOF-1 for wind stress and Q suggests that former leads the latter with a temporal lag of 20-40 days for period > 322 days. At high frequencies (< 21 days) Q leads wind stress with a temporal lag of 2 days. Possible explanation for wind stress leading Q over an annual time scale is offered based on the marine atmospheric boundary layer physics and pre-conditioned ocean surface, while on shorter time scales (21 days) ocean thermodynamics through mixed layer processes cause Q to lead wind stress.
Keywords: monsoon, air-sea heat fluxes, QuikScat, marine atmospheric boundary layer processes, Empirical Orthogonal Analysis, tropical Indian Ocean, SEA-SURFACE TEMPERATURE, ARABIAN SEA, SUMMER MONSOON, SOUTHWEST MONSOON, MOISTURE BUDGET, VARIABILITY, CLIMATOLOGY,
Mission: |SeaWinds|
URL: http://dx.doi.org/10.1016/j.rse.2006.04.002
Other URLs:
Maloney, E.D., and Chelton, D.B. (2006). An Assessment of the Sea Surface Temperature Influence on Surface Wind Stress in Numerical Weather Prediction and Climate Models, Journal of Climate, 19(12), 2743-2762, 10.1175/JCLI3728.1. Journal Article »
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Title: An Assessment of the Sea Surface Temperature Influence on Surface Wind Stress in Numerical Weather Prediction and Climate Models
Type: Journal Article
Publication: Journal of Climate
Author(s): Maloney, E.D., and Chelton, D.B.
Year: 2006
Formatted Citation: Maloney, E.D., and Chelton, D.B., 2006: An Assessment of the Sea Surface Temperature Influence on Surface Wind Stress in Numerical Weather Prediction and Climate Models, Journal of Climate, 19(12), 2743-2762, 10.1175/JCLI3728.1.
Abstract: The ability of six climate models to capture the observed coupling between SST and surface wind stress in the vicinity of strong midlatitude SST fronts is analyzed. The analysis emphasizes air?sea interactions associated with ocean meanders in the eastward extensions of major western boundary current systems such as the Gulf Stream, Kuroshio, and Agulhas Current. Satellite observations of wind stress from the SeaWinds scatterometer on NASA's Quick Scatterometer and SST from the Advanced Microwave Scanning Radiometer clearly indicate the influence of SST on surface wind stress on scales smaller than about 30° longitude × 10° latitude. Spatially high-pass-filtered SST and wind stress variations are linearly related, with higher SST associated with higher wind stress. The influence of SST on wind stress is also clearly identifiable in the ECMWF operational forecast model, having a grid resolution of 0.35° × 0.35° (T511). However, the coupling coefficient between wind stress and SST, as indicated by the slope of the linear least squares fit, is only half as strong as for satellite observations. The ability to simulate realistic air-sea interactions is present to varying degrees in the coupled climate models examined. The Model for Interdisciplinary Research on Climate 3.2 (MIROC3.2) high-resolution version (HIRES) (1.1° × 1.1°, T106) and the NCAR Community Climate System Model 3.0 (1.4° × 1.4°, T85) are the highest-resolution models considered and produce the most realistic air-sea coupling associated with midlatitude current systems. Coupling coefficients between SST and wind stress in MIROC3.2_HIRES and the NCAR model are at least comparable to those in the ECMWF operational model. The spatial scales of midlatitude SST variations and SST-induced wind perturbations in MIROC3.2_HIRES are comparable to those of satellite observations. The spatial scales of SST variability in the NCAR model are larger than those in the ECMWF model and satellite observations, and hence the spatial scales of SST-induced perturbations in the wind fields are larger. It is found that the ability of climate models to simulate air?sea interactions degrades with decreasing grid resolution. SST anomalies in the GFDL Climate Model 2.0 (CM2.0) (2.0° × 2.5°), Met Office Third Hadley Centre Coupled Ocean?Atmosphere General Circulation Model (HadCM3) (2.5° × 3.8°), and MIROC3.2 medium-resolution version (MEDRES) (2.8° × 2.8°, T42) have larger spatial scales and are more geographically confined than in the higher-resolution models. The GISS Model E20/Russell (4.0° × 5.0°) is unable to resolve the midlatitude ocean eddies that produce prominent air?sea interaction. Notably, MIROC3.2_MEDRES exhibits much weaker coupling between wind stress and SST than does the higher vertical and horizontal resolution version of the same model. GFDL CM2.0 and Met Office HadCM3 exhibit a linear relationship between SST and wind stress. However, coupling coefficients for the Met Office model are significantly weaker than in the GFDL and higher-resolution models. In addition to model grid resolution (both vertical and horizontal), deficiencies in the parameterization of boundary layer processes may be responsible for some of these differences in air-sea coupling between models and observations.
Keywords: EASTERN EQUATORIAL PACIFIC, ATMOSPHERIC BOUNDARY-LAYER, TROPICAL INSTABILITY WAVES, AGULHAS RETURN CURRENT, INTERANNUAL VARIABILITY, SATELLITE-OBSERVATIONS, ATLANTIC-OCEAN, SST VARIATIONS, NORTH PACIFIC, COLD-TONGUE
Mission: |SeaWinds|
URL: https://doi.org/10.1175/JCLI3728.1
Other URLs:
Mandal, A., Mohanty, U.C., and Das, A.K. (2006). Impact of Satellite Derived Wind in Mesoscale Simulation of Orissa Super Cyclone, Indian Journal of Marine Sciences, 35(2), 161-173. Journal Article »
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Title: Impact of Satellite Derived Wind in Mesoscale Simulation of Orissa Super Cyclone
Type: Journal Article
Publication: Indian Journal of Marine Sciences
Author(s): Mandal, A., Mohanty, U.C., and Das, A.K.
Year: 2006
Formatted Citation: Mandal, A., Mohanty, U.C., and Das, A.K., 2006: Impact of Satellite Derived Wind in Mesoscale Simulation of Orissa Super Cyclone, Indian Journal of Marine Sciences, 35(2), 161-173.
Abstract: Prediction of track and intensity of tropical cyclones is one of the most challenging problems in numerical weather prediction (NWP). Providing reasonably accurate initial condition to tropical cyclone forecast models has always been a problem to numerical weather forecasters. Recent advancements in spatial resolution and radiometric sensitivity have significantly improved the accuracy and density of satellite derived wind. The objective of the present study is to examine the impact of satellite derived winds in improving model initial condition and hence in mesoscale simulation of cyclonic storm. In this study, PSU/NCAR mesoscale model MM5 is used to produce 5-day simulation of the super cyclone that crossed Orissa coast on 29 October 1999. Winds derived from QSCAT, SSM/I, MSMR and METEOSAT-5 satellites are used in preparation of high-resolution reanalysis (HRR) and improving model initial condition. The strength of the southwesterly wind (over ocean) converging to the storm is found to be stronger both in the HRR and improved model initial condition compared to that in the NCEP/NCAR reanalysis. The strength of the cyclonic vortex is also better represented in the HRR and improved model initial condition. Improvement in model initial condition has resulted in consistent and significant improvement (35% in average) in prediction of the track of the storm.
Keywords: cyclone, mesoscale, satellite derived wind, high-resolution reanalysis, super cyclone, Orissa cyclone, HURRICANE TRACK, DROPWINDSONDE OBSERVATIONS, FORECASTS, ASSIMILATION, INFORMATION, MODEL, PARAMETERIZATION, PREDICTION, SYSTEM, CLOUD
Mission: |SeaWinds|
URL: https://www.researchgate.net/publication/228663858_Impact_of_satellite_derived_wind_in_mesoscale_simulation_of_Orissa_super_cyclone
Other URLs:
Miyama, T., McCreary, J.P., Sengupta, D. and Senan, R. (2006). Dynamics of Biweekly Oscillations in the Equatorial Indian Ocean, Journal of Physical Oceanography, 36(5), 827-846, 10.1175/JPO2897.1. Journal Article »
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Title: Dynamics of Biweekly Oscillations in the Equatorial Indian Ocean
Type: Journal Article
Publication: Journal of Physical Oceanography
Author(s): Miyama, T., McCreary, J.P., Sengupta, D. and Senan, R.
Year: 2006
Formatted Citation: Miyama, T., McCreary, J.P., Sengupta, D. and Senan, R., 2006: Dynamics of Biweekly Oscillations in the Equatorial Indian Ocean, Journal of Physical Oceanography, 36(5), 827-846, 10.1175/JPO2897.1.
Abstract: Variability of the wind field over the equatorial Indian Ocean is spread throughout the intraseasonal (10 - 60 day) band. In contrast, variability of the near-surface nu field in the eastern, equatorial ocean is concentrated at biweekly frequencies and is largely composed of Yanai waves. The excitation of this biweekly variability is investigated using an oceanic GCM and both analytic and numerical versions of a linear, continuously stratified (LCS) model in which solutions are represented as expansions in baroclinic modes. Solutions are forced by Quick Scatterometer (QuikSCAT) winds ( the model control runs) and by idealized winds having the form of a propagating wave with frequency sigma and wavenumber k(w). The GCM and LCS control runs are remarkably similar in the biweekly band, indicating that the dynamics of biweekly variability are fundamentally linear and wind driven. The biweekly response is composed of local (nonradiating) and remote ( Yanai wave) parts, with the former spread roughly uniformly along the equator and the latter strengthening to the east. Test runs to the numerical models separately forced by the tau(x) and tau(y) components of the QuikSCAT winds demonstrate that both forcings contribute to the biweekly signal, the response forced by tau(y) being somewhat stronger. Without mixing, the analytic spectrum for Yanai waves forced by idealized winds has a narrowband ( resonant) response for each baroclinic mode: Spectral peaks occur whenever the wavenumber of the Yanai wave for mode n is sufficiently close to kw and they shift from biweekly to lower frequencies with increasing modenumber n. With mixing, the higher-order modes are damped so that the largest ocean response is restricted to Yanai waves in the biweekly band. Thus, in the LCS model, resonance and mixing act together to account for the ocean`s favoring the biweekly band. Because of the GCM's complexity, it cannot be confirmed that vertical mixing also damps its higher-order modes, other possible processes are nonlinear interactions with near-surface currents, and the model's low vertical resolution below the thermocline. Test runs to the LCS model show that Yanai waves from several modes superpose to form a beam (wave packet) that carries energy downward as well as eastward. Reflections of such beams from the near- surface pycnocline and bottom act to maintain near- surface energy levels, accounting for the eastward intensification of the near- surface, equatorial nu field in the control runs.
Keywords: KELVIN WAVE, VARIABILITY, CIRCULATION, MONSOON, TRANSPORTS, CURRENTS, MODEL
Mission: |SeaWinds|
URL: https://doi.org/10.1175/JPO2897.1
Other URLs:
Morey, S.L., Baig, S.R., Bourassa, M.A., Dukhovskoy, D.S., and O'Brien, J.J. (2006). Remote Forcing Contribution to Storm-Induced Sea Level Rise During Hurricane Dennis, Geophysical Research Letters, 33(19), 10.1029/2006GL027021. Journal Article »
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Title: Remote Forcing Contribution to Storm-Induced Sea Level Rise During Hurricane Dennis
Type: Journal Article
Publication: Geophysical Research Letters
Author(s): Morey, S.L., Baig, S.R., Bourassa, M.A., Dukhovskoy, D.S., and O'Brien, J.J.
Year: 2006
Formatted Citation: Morey, S.L., Baig, S.R., Bourassa, M.A., Dukhovskoy, D.S., and O'Brien, J.J., 2006: Remote Forcing Contribution to Storm-Induced Sea Level Rise During Hurricane Dennis, Geophysical Research Letters, 33(19), 10.1029/2006GL027021.
Abstract: Numerical model experiments are conducted to address the previously unexplained anomalously high storm surge along the Florida coast of Apalachee Bay during Hurricane Dennis (2005). The 23 m surge observed during this storm cannot be obviously explained by the relatively weak local winds over this bay 275 km east of the storm center. Realistic and idealized numerical experiments demonstrate that the along-shore winds to the east of the storm center built a high sea level anomaly along the coast which traveled northward to Apalachee Bay as a topographic Rossby wave. The wave was amplified as the storm moved nearly parallel to the shelf and at comparable speed to the wave phase speed. These results suggest that enlarging the domain of the storm surge forecasting models can improve the surge forecast for a storm moving along a similar track, and have now been applied to operational use.
Keywords: QSCAT, hurricane, Dennis, surge
Mission: |WindSat|
URL: https://doi.org/10.1029/2006GL027021
Other URLs:
Morey, S.L., Bourassa, M.A., Dukhovksoy, D.S., and O'Brien, J.J. (2006). Modeling the Impacts of Remote Forcing on Hurricane Storm Surge, Research Activities in Atmospheric and Ocean Modeling. Report »
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Title: Modeling the Impacts of Remote Forcing on Hurricane Storm Surge
Type: Report
Publication: Research Activities in Atmospheric and Ocean Modeling
Author(s): Morey, S.L., Bourassa, M.A., Dukhovksoy, D.S., and O'Brien, J.J.
Year: 2006
Formatted Citation: Morey, S.L., Bourassa, M.A., Dukhovksoy, D.S., and O'Brien, J.J., 2006: Modeling the Impacts of Remote Forcing on Hurricane Storm Surge, Research Activities in Atmospheric and Ocean Modeling.
Abstract:
Keywords: Modeling the impacts of remote forcing on hurricane storm surge
Mission: |SeaWinds|
URL: http://www.coaps.fsu.edu/~morey/GoM/moreyWGNE06.pdf
Other URLs:
Morey, S.L., Bourassa, M.A., Dukhovskoy, D.S., and O'Brien, J.J. (2006). Modeling Studies of the Upper Ocean Response to a Tropical Storm, Ocean Dynamics, 56(5-6), 594-606, 10.1007/s10236-006-0085-y. Journal Article »
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Title: Modeling Studies of the Upper Ocean Response to a Tropical Storm
Type: Journal Article
Publication: Ocean Dynamics
Author(s): Morey, S.L., Bourassa, M.A., Dukhovskoy, D.S., and O'Brien, J.J.
Year: 2006
Formatted Citation: Morey, S.L., Bourassa, M.A., Dukhovskoy, D.S., and O'Brien, J.J., 2006: Modeling Studies of the Upper Ocean Response to a Tropical Storm, Ocean Dynamics, 56(5-6), 594-606, 10.1007/s10236-006-0085-y.
Abstract: A coupled ocean and boundary layer flux numerical modeling system is used to study the upper ocean response to surface heat and momentum fluxes associated with a major hurricane, namely, Hurricane Dennis (July 2005) in the Gulf of Mexico. A suite of experiments is run using this modeling system, constructed by coupling a Navy Coastal Ocean Model simulation of the Gulf of Mexico to an atmospheric flux model. The modeling system is forced by wind fields produced from satellite scatterometer and atmospheric model wind data, and by numerical weather prediction air temperature data. The experiments are initialized from a data assimilative hindcast model run and then forced by surface fluxes with no assimilation for the time during which Hurricane Dennis impacted the region. Four experiments are run to aid in the analysis: one is forced by heat and momentum fluxes, one by only momentum fluxes, one by only heat fluxes, and one with no surface forcing. An equation describing the change in the upper ocean hurricane heat potential due to the storm is developed. Analysis of the model results show that surface heat fluxes are primarily responsible for widespread reduction (0.5-1.5C) of sea surface temperature over the inner West Florida Shelf 100-300 km away from the storm center. Momentum fluxes are responsible for stronger surface cooling (2C) near the center of the storm. The upper ocean heat loss near the storm center of more than 200 MJ/m2 is primarily due to the vertical flux of thermal energy between the surface layer and deep ocean. Heat loss to the atmosphere during the storms passage is approximately 100-150 MJ/m2. The upper ocean cooling is enhanced where the preexisting mixed layer is shallow, e.g., within a cyclonic circulation feature, although the heat flux to the atmosphere in these locations is markedly reduced.
Keywords: tropical cyclone, numerical modeling
Mission: |SeaWinds|
URL: https://doi.org/10.1007/s10236-006-0085-y
Other URLs:
Nie, C., and Long, D.G. (2006). The Effect of Rain on ERS Scatterometer Measurements, International Geoscience and Remote Sensing Symposium, 4119-4121, 10.1109/IGARSS.2006.1056. Conference Paper »
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Title: The Effect of Rain on ERS Scatterometer Measurements
Type: Conference Paper
Publication: International Geoscience and Remote Sensing Symposium
Author(s): Nie, C., and Long, D.G.
Year: 2006
Formatted Citation: Nie, C., and Long, D.G., 2006: The Effect of Rain on ERS Scatterometer Measurements, International Geoscience and Remote Sensing Symposium, 4119-4121, 10.1109/IGARSS.2006.1056.
Abstract:
Keywords:
Mission:
URL: https://doi.org/10.1109/IGARSS.2006.1056
Other URLs:
Okumura, Y., and Xie, S.P. (2006). Some Overlooked Features of Tropical Atlantic Climate Leading to a New Niño-Like Phenomenon, Journal of Climate, 19(22), 5859-5874, 10.1175/JCLI3928.1. Journal Article »
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Title: Some Overlooked Features of Tropical Atlantic Climate Leading to a New Niño-Like Phenomenon
Type: Journal Article
Publication: Journal of Climate
Author(s): Okumura, Y., and Xie, S.P.
Year: 2006
Formatted Citation: Okumura, Y., and Xie, S.P., 2006: Some Overlooked Features of Tropical Atlantic Climate Leading to a New Niño-Like Phenomenon, Journal of Climate, 19(22), 5859-5874, 10.1175/JCLI3928.1.
Abstract: The Atlantic Niño, an equatorial zonal mode akin to the Pacific El Niño Southern Oscillation (ENSO), is phase-locked to boreal summer when the equatorial easterly winds intensify and the thermocline shoals in the Gulf of Guinea. A suite of satellite and in situ observations reveals a new mode of tropical Atlantic variability that displays many characteristics of the zonal mode but instead peaks in November-December (ND). This new mode is found to be statistically independent from both the Atlantic Niño in the preceding summer and the Pacific ENSO. The origin of this ND zonal mode lies in an overlooked aspect of the seasonal cycle in the equatorial Atlantic. In November the equatorial easterly winds intensify for the second time, increasing upwelling and lifting the thermocline in the Gulf of Guinea. An analysis of high-resolution climatological data shows that these dynamical changes induce a noticeable SST cooling in the central equatorial Atlantic. The shoaling thermocline and increased upwelling enhance the SST sensitivity to surface wind changes, reinvigorating equatorial ocean-atmosphere interaction. The resultant ocean-atmospheric anomalies are organized into patterns that give rise to positive mutual feedback as Bjerknes envisioned for the Pacific ENSO. This ND zonal mode significantly affects interannual rainfall variability in coastal Congo-Angola during its early rainy season. It tends to further evolve into a meridional mode in the following March-April, affecting precipitation in northeast Brazil. Thus it offers potential predictability for climate over the Atlantic sector in early boreal winter, a season for which local oceanatmosphere variability was otherwise poorly understood.
Keywords: SEA-SURFACE TEMPERATURE, NORTHEAST BRAZIL RAINFALL, EL-NINO, EQUATORIAL ATLANTIC, ANNUAL CYCLE, SOUTHERN-OSCILLATION, SEASONAL CYCLE, COUPLED MODEL, WARM EVENTS, OCEAN
Mission:
URL: https://doi.org/10.1175/JCLI3928.1
Other URLs:
Park, K.A., Kim, K., Cornillon, P.C., and Chung, J.Y. (2006). Relationship Between Satellite-Observed Cold Water Along the Primorye Coast and Sea Ice in the East Sea (the Sea of Japan), Geophysical Research Letters, 33, L10602, 10.1029/2005GL025611. Journal Article »
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Title: Relationship Between Satellite-Observed Cold Water Along the Primorye Coast and Sea Ice in the East Sea (the Sea of Japan)
Type: Journal Article
Publication: Geophysical Research Letters
Author(s): Park, K.A., Kim, K., Cornillon, P.C., and Chung, J.Y.
Year: 2006
Formatted Citation: Park, K.A., Kim, K., Cornillon, P.C., and Chung, J.Y., 2006: Relationship Between Satellite-Observed Cold Water Along the Primorye Coast and Sea Ice in the East Sea (the Sea of Japan), Geophysical Research Letters, 33, L10602, 10.1029/2005GL025611.
Abstract: The relationship between cold surface water along the Primorye coast and sea ice in the Tatar Strait of the northern East Sea ( the Sea of Japan) is examined by analyzing sea surface temperatures (SST) from NOAA/AVHRR, sea ice concentrations from SSM/I, wind vectors from QuikSCAT, and position data from satellite-tracked drifting buoys. Relatively low SSTs along the Primorye coast in spring and early summer are attributed to sea ice melted water advected to the southwest as the Liman Cold Current (LCC). Monthly to year-to-year variations of SSTs along the Primorye coast in spring and early summer are negatively correlated with those of the sea ice concentration in the Tatar Strait during the previous winter. Translational speeds from the surface drifter and SST anomalies demonstrate that the LCC significantly varies by 2-18 km/day both in space and time.
Keywords: TATARSKIY STRAIT
Mission: |SeaWinds|
URL: https://doi.org/10.1029/2005GL025611
Other URLs:
Petersen, W.A., Fu, R., Chen, M.X., and Blakeslee, R. (2006). Intraseasonal Forcing of Convection and Lightning Activity in the Southern Amazon as a Function of Cross-Equatorial Flow, Journal of Climate, 19(13), 3180-3196, 10.1175/JCLI3788.1. Journal Article »
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Title: Intraseasonal Forcing of Convection and Lightning Activity in the Southern Amazon as a Function of Cross-Equatorial Flow
Type: Journal Article
Publication: Journal of Climate
Author(s): Petersen, W.A., Fu, R., Chen, M.X., and Blakeslee, R.
Year: 2006
Formatted Citation: Petersen, W.A., Fu, R., Chen, M.X., and Blakeslee, R., 2006: Intraseasonal Forcing of Convection and Lightning Activity in the Southern Amazon as a Function of Cross-Equatorial Flow, Journal of Climate, 19(13), 3180-3196, 10.1175/JCLI3788.1.
Abstract: This study focuses on modulation of lightning and convective vertical structure in the southern Amazon as a function of the South American monsoon V index (VI). Four wet seasons (December-March 1998-2001) of Tropical Rainfall Measuring Mission (TRMM) Lightning Imaging Sensor (LIS) and Precipitation Radar (PR) data are examined together with two wet seasons (2000-01) of ground-based Brazilian Lightning Detection Network (BLDN) data. These observations are composited by VI phase (northerly or southerly) for a region of the southern Amazon and discussed relative to VI-regime environmental characteristics such as thermodynamic instability and wind shear. Relative comparisons of VI-regime convective properties reveal 1) slightly larger (20%-25%) PR pixel-mean rainfall during periods of northerly VI due to increased stratiform precipitation, 2) a factor of 2 or more increase in lightning flash density and the lightning diurnal cycle amplitude during periods of southerly VI, 3) a factor of 1.52 increase in the conditional probability of any PR radar reflectivity pixel exceeding 30 dBZ above the -10C level during periods of southerly VI, and 4) an associated factor of 2 or more increase in southerly VI pixel-mean ice water path, with the ice water path being highly correlated to trends in lightning activity. During periods of southerly VI, convection occurs in an environment of increased thermodynamic instability, weak southeasterly low-level, and deep upper-tropospheric easterly wind shear. During periods of northerly VI, low-level westerly shear opposes stronger deep tropospheric easterly shear in a relatively moist environment of weaker thermodynamic instability, consistent with the occurrence of more widespread stratiform precipitation. The composite results of this study point to 1) regime differences in convective forcing that alter the prevalence of ice processes and, by inference, the vertical profile of latent heating and 2) the utility of lightning observations in delineating convective regime changes.
Keywords: TROPOSPHERIC WATER-VAPOR, TRMM PRECIPITATION RADAR, VERTICAL VELOCITY, DIURNAL CYCLE, SQUALL LINES, CLOUD, VARIABILITY, AMERICA, WET, REFLECTIVITY
Mission:
URL: https://doi.org/10.1175/JCLI3788.1
Other URLs:
Quilfen, Y., Tournadre, J., and Chapron, B. (2006). Altimeter Dual-Frequency Observations of Surface Winds, Waves, and Rain Rate in Tropical Cyclone Isabel, Journal of Geophysical Research: Oceans, 111(C1), C01004, 10.1029/2005JC003068. Journal Article »
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Title: Altimeter Dual-Frequency Observations of Surface Winds, Waves, and Rain Rate in Tropical Cyclone Isabel
Type: Journal Article
Publication: Journal of Geophysical Research: Oceans
Author(s): Quilfen, Y., Tournadre, J., and Chapron, B.
Year: 2006
Formatted Citation: Quilfen, Y., Tournadre, J., and Chapron, B., 2006: Altimeter Dual-Frequency Observations of Surface Winds, Waves, and Rain Rate in Tropical Cyclone Isabel, Journal of Geophysical Research: Oceans, 111(C1), C01004, 10.1029/2005JC003068.
Abstract: Extreme weather events such as tropical cyclones are difficult to observe with conventional means. Satellite-based observations provide essential measurements of key parameters governing tropical cyclones. They are critical for short-term forecasting. Radiometers onboard the Defense Meteorological Satellite Program satellite series, WindSat and Tropical Rainfall Measuring Mission satellites, scatterometers onboard the ERS, ADEOS, and QuikScat satellites offer unprecedented synoptic observations of surface wind and atmospheric liquid water content, revealing the storm structures with good accuracy. However, satellite estimates do not provide direct measurements of geophysical parameters and can suffer from limitations linked to the sensors characteristics, such as the signal wavelength and polarization or the measurement incidence angle. For example, measurements at Ku band are strongly affected by rain. Still, each observing system can offer specific information that can be combined with the others. In particular, we highlight the capabilities of dual-frequency altimeter to provide very high resolution measurements of rain rate, surface wind speed, and wave characteristics. A method is proposed to obtain continuous along-track 5 km resolution measurements of these parameters in the tropical cyclone Isabel. The results shows that dual-frequency altimeters can provide useful information to complement and validate the operational fields provided by the atmospheric numerical models and by NOAA observing systems.
Keywords: altimeter cyclone observation
Mission: |SeaWinds|WindSat|
URL: https://doi.org/10.1029/2005JC003068
Other URLs:
Risien, C.M., and Chelton, D.B. (2006). A Satellite-Derived Climatology of Global Ocean Winds, Remote Sensing of Environment, 105(3), 221-236, 10.1016/j.rse.2006.06.017. Journal Article »
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Title: A Satellite-Derived Climatology of Global Ocean Winds
Type: Journal Article
Publication: Remote Sensing of Environment
Author(s): Risien, C.M., and Chelton, D.B.
Year: 2006
Formatted Citation: Risien, C.M., and Chelton, D.B., 2006: A Satellite-Derived Climatology of Global Ocean Winds, Remote Sensing of Environment, 105(3), 221-236, 10.1016/j.rse.2006.06.017.
Abstract: An interactive Climatology of Global Ocean Winds (COGOW) is presented based on 5 years (August 1999July 2004) of QuikSCAT satellite measurements of wind speed and direction 10 m above the sea surface. This climatology provides the first high spatial resolution, observationally based, online atlas of ocean winds. Users can retrieve climatological wind maps and wind statistics, both in tabular and graphical form, from the COGOW web-based atlas. The global coverage of these data provides highly accurate information about the wind statistics in regions of the world ocean that are sparsely sampled by ships and buoys. A case study of the recovery of the vessel Ehime Maru off the Hawaiian Island of Oahu is presented to demonstrate the usage and value of COGOW. Evidence of airsea interactions, one of many wind phenomena visible within COGOW, is discussed to further familiarize users with COGOW. Finally, the utility of COGOW with regard to various operational and research communities is summarized.
Keywords: Climatology, Global ocean winds, QuikSCAT scatterometer
Mission:
URL: https://doi.org/10.1016/j.rse.2006.06.017
Other URLs:
Saji, N.H., Xie, S.P., and Tam, C.Y. (2006). Satellite Observations of Intense Intraseasonal Cooling Events in the Tropical South Indian Ocean, Geophysical Research Letters, 33(L14704), 10.1029/2006GL026525. Journal Article »
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Title: Satellite Observations of Intense Intraseasonal Cooling Events in the Tropical South Indian Ocean
Type: Journal Article
Publication: Geophysical Research Letters
Author(s): Saji, N.H., Xie, S.P., and Tam, C.Y.
Year: 2006
Formatted Citation: Saji, N.H., Xie, S.P., and Tam, C.Y., 2006: Satellite Observations of Intense Intraseasonal Cooling Events in the Tropical South Indian Ocean, Geophysical Research Letters, 33(L14704), 10.1029/2006GL026525.
Abstract: Intense intraseasonal cooling events in the tropical south Indian Ocean are examined using eight years of TRMM observations. These events occur almost every year during austral summer when the intertropical convergence zone is displaced south of the equator and roughly collocated with a thermocline ridge. Composite maps of SST, OLR and surface winds, based on eleven cooling events with SST exceeding 1C, suggest that reduced solar radiation, enhanced evaporation and possibly strong entrainment over the thermocline ridge all play a role in the SST cooling. OLR and covariability in SST exhibit latitudinal variations in spectrum. A distinct southern mode around 10S5S exhibits a peak in coherence-squared at a period of 65 days. In contrast, an equatorially symmetric mode has a coherence-squared peak at 35 days. This may hint at a possible feedback onto the atmosphere from strong intraseasonal SST variability over the south Indian Ocean.
Keywords: SEA-SURFACE TEMPERATURE, MADDEN-JULIAN OSCILLATION, WESTERN PACIFIC, VARIABILITY, ATMOSPHERE, MECHANISMS, SUMMER, FLUXES
Mission:
URL: https://doi.org/10.1029/2006GL026525
Other URLs:
Saji, N.H., Xie, S.P., and Yamagata, T. (2006). Tropical Indian Ocean Variability in the IPCC Twentieth-Century Climate Simulations, Journal of Climate, 19(17), 4397-4417, 10.1175/JCLI3847.1. Journal Article »
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Title: Tropical Indian Ocean Variability in the IPCC Twentieth-Century Climate Simulations
Type: Journal Article
Publication: Journal of Climate
Author(s): Saji, N.H., Xie, S.P., and Yamagata, T.
Year: 2006
Formatted Citation: Saji, N.H., Xie, S.P., and Yamagata, T., 2006: Tropical Indian Ocean Variability in the IPCC Twentieth-Century Climate Simulations, Journal of Climate, 19(17), 4397-4417, 10.1175/JCLI3847.1.
Abstract: The twentieth-century simulations using by 17 coupled oceanatmosphere general circulation models (CGCMs) submitted to the Intergovernmental Panel on Climate Changes Fourth Assessment Report (IPCC AR4) are evaluated for their skill in reproducing the observed modes of Indian Ocean (IO) climate variability. Most models successfully capture the IOs delayed, basinwide warming response a few months after El Niño Southern Oscillation (ENSO) peaks in the Pacific. ENSOs oceanic teleconnection into the IO, by coastal waves through the Indonesian archipelago, is poorly simulated in these models, with significant shifts in the turning latitude of radiating Rossby waves. In observations, ENSO forces, by the atmospheric bridge mechanism, strong ocean Rossby waves that induce anomalies of SST, atmospheric convection, and tropical cyclones in a thermocline dome over the southwestern tropical IO. While the southwestern IO thermocline dome is simulated in nearly all of the models, this ocean Rossby wave response to ENSO is present only in a few of the models examined, suggesting difficulties in simulating ENSOs teleconnection in surface wind. A majority of the models display an equatorial zonal mode of the Bjerknes feedback with spatial structures and seasonality similar to the Indian Ocean dipole (IOD) in observations. This success appears to be due to their skills in simulating the mean state of the equatorial IO. Corroborating the role of the Bjerknes feedback in the IOD, the thermocline depth, SST, precipitation, and zonal wind are mutually positively correlated in these models, as in observations. The IODENSO correlation during boreal fall ranges from −,0.43 to 0.74 in the different models, suggesting that ENSO is one, but not the only, trigger for the IOD.
Keywords: SEA-SURFACE TEMPERATURE, DIPOLE MODE EVENTS, GENERAL-CIRCULATION MODEL, COUPLED GCM, EL-NINO, INTERANNUAL VARIABILITY, INDONESIAN THROUGHFLOW, SOUTHERN-OSCILLATION, RAINFALL ANOMALIES, ATMOSPHERIC BRIDGE
Mission:
URL: https://doi.org/10.1175/JCLI3847.1
Other URLs:
Samelson, R.M., Skyllingstad, E.D., Chelton, D.B., Esbensen, S.K., O'Neill, L.W., and Thum, N. (2006). On the Coupling of Wind Stress and Sea Surface Temperature, Journal of Climate, 19(8), 1557-1566, 10.1175/JCLI3682.1. Journal Article »
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Title: On the Coupling of Wind Stress and Sea Surface Temperature
Type: Journal Article
Publication: Journal of Climate
Author(s): Samelson, R.M., Skyllingstad, E.D., Chelton, D.B., Esbensen, S.K., O'Neill, L.W., and Thum, N.
Year: 2006
Formatted Citation: Samelson, R.M., Skyllingstad, E.D., Chelton, D.B., Esbensen, S.K., O'Neill, L.W., and Thum, N., 2006: On the Coupling of Wind Stress and Sea Surface Temperature, Journal of Climate, 19(8), 1557-1566, 10.1175/JCLI3682.1.
Abstract: A simple quasi-equilibrium analytical model is used to explore hypotheses related to observed spatial correlations between sea surface temperatures and wind stress on horizontal scales of 50500 km. It is argued that a plausible contributor to the observed correlations is the approximate linear relationship between the surface wind stress and stress boundary layer depth under conditions in which the stress boundary layer has come into approximate equilibrium with steady free-atmospheric forcing. Warmer sea surface temperature is associated with deeper boundary layers and stronger wind stress, while colder temperature is associated with shallower boundary layers and weaker wind stress. Two interpretations of a previous hypothesis involving the downward mixing of horizontal momentum are discussed, and it is argued that neither is appropriate for the warm-to-cold transition or quasi-equilibrium conditions, while one may be appropriate for the cold-to-warm transition. Solutions of a turbulent large-eddy simulation numerical model illustrate some of the processes represented in the analytical model. A dimensionless ratio γ,τ,A is introduced to measure the relative influence of lateral momentum advection and local surface stress on the boundary layer wind profile. It is argued that when γ,τ,A < 1, and under conditions in which the thermodynamically induced lateral pressure gradients are small, the boundary layer depth effect will dominate lateral advection and control the surface stress.
Keywords: TROPICAL INSTABILITY WAVES, ATMOSPHERIC BOUNDARY-LAYER, EASTERN EQUATORIAL PACIFIC, LARGE-EDDY SIMULATION, SATELLITE MEASUREMENTS, NUMERICAL-SIMULATION, SST VARIATIONS, GULF-STREAM, OCEAN, FLOW
Mission:
URL: https://doi.org/10.1175/JCLI3682.1
Other URLs:
Sasaki, H., and Nonaka, M. (2006). Far-Reaching Hawaiian Lee Countercurrent Driven by Wind-Stress Curl Induced by Warm SST Band Along the Current, Geophysical Research Letters, 33, L13602, 10.1029/2006GL026540. Journal Article »
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Title: Far-Reaching Hawaiian Lee Countercurrent Driven by Wind-Stress Curl Induced by Warm SST Band Along the Current
Type: Journal Article
Publication: Geophysical Research Letters
Author(s): Sasaki, H., and Nonaka, M.
Year: 2006
Formatted Citation: Sasaki, H., and Nonaka, M., 2006: Far-Reaching Hawaiian Lee Countercurrent Driven by Wind-Stress Curl Induced by Warm SST Band Along the Current, Geophysical Research Letters, 33, L13602, 10.1029/2006GL026540.
Abstract: Two eddy-resolving ocean simulations are carried out to study local air-sea interaction associated with the Hawaiian Lee Countercurrent (HLCC), one forced by the QuikSCAT satellite wind field (QSCAT run) and the other by the NCEP/NCAR reanalysis (NCEP run). The simulated HLCC in the QSCAT run extends west-southwestward from the Hawaiian Islands much farther than that in the NCEP run. We attribute this difference to difference in the wind fields. In the QSCAT wind field, there exist band-like structures of positive and negative wind stress curls induced by warm sea surface temperature band associated with the HLCC, however, these features are not apparent in the reanalysis wind field. The QSCAT run provides a good example of local two-way air-sea interactions in association with the HLCC. Furthermore, interannual variations are suggested in both the simulated HLCC and wind fields over the HLCC.
Keywords: ISLANDS, MODEL
Mission: |SeaWinds|
URL: https://doi.org/10.1029/2006GL026540
Other URLs:
Shen, B.-W., Atlas, R., Chern, J.-D., Reale, O., Lin, S.-J., Lee, T., and Chang, J. (2006). The 0.125 Degree Finite-Volume General Circulation Model on the NASA Columbia Supercomputer: Preliminary Simulations of Mesoscale Vortices, Geophysical Research Letters, 33(5), L05801, 10.1029/2005GL024594. Journal Article »
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Title: The 0.125 Degree Finite-Volume General Circulation Model on the NASA Columbia Supercomputer: Preliminary Simulations of Mesoscale Vortices
Type: Journal Article
Publication: Geophysical Research Letters
Author(s): Shen, B.-W., Atlas, R., Chern, J.-D., Reale, O., Lin, S.-J., Lee, T., and Chang, J.
Year: 2006
Formatted Citation: Shen, B.-W., Atlas, R., Chern, J.-D., Reale, O., Lin, S.-J., Lee, T., and Chang, J., 2006: The 0.125 Degree Finite-Volume General Circulation Model on the NASA Columbia Supercomputer: Preliminary Simulations of Mesoscale Vortices, Geophysical Research Letters, 33(5), L05801, 10.1029/2005GL024594.
Abstract: The NASA Columbia supercomputer was ranked second on the TOP500 List in November, 2004. Such a quantum jump in computing power provides unprecedented opportunities to conduct ultra-high resolution simulations with the finite-volume General Circulation Model (fvGCM). During 2004, the model was run in realtime experimentally at 0.25 degree resolution producing remarkable hurricane forecasts (Atlas et al., 2005). In 2005, the horizontal resolution was further doubled, which makes the fvGCM comparable to the first mesoscale resolving General Circulation Model at the Earth Simulator Center (Ohfuchi et al., 2004). Nine 5-day 0.125 degree simulations of three hurricanes in 2004 are presented first for model validation. Then it is shown how the model can simulate the formation of the Catalina eddies and Hawaiian lee vortices, which are generated by the interaction of the synoptic-scale flow with surface forcing, and have never been reproduced in a GCM before.
Keywords: Atmospheric Processes: Global climate models , Atmospheric Processes: Mesoscale meteorology, Atmospheric Processes: Regional modeling, Atmospheric Processes: Tropical meteorology
Mission:
URL: https://doi.org/10.1029/2005GL024594
Other URLs:
Shen, B.-W., Atlas, R., Reale, O., Lin, S.-J., Chern, J.-D., Chang, J., Henze, C., and Li, J.-L. (2006). Hurricane Forecasts with a Global Mesoscale-Resolving Model: Preliminary Results with Hurricane Katrina (2005), Geophysical Research Letters, 33(13), L13813, 10.1029/2006GL026143. Journal Article »
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Title: Hurricane Forecasts with a Global Mesoscale-Resolving Model: Preliminary Results with Hurricane Katrina (2005)
Type: Journal Article
Publication: Geophysical Research Letters
Author(s): Shen, B.-W., Atlas, R., Reale, O., Lin, S.-J., Chern, J.-D., Chang, J., Henze, C., and Li, J.-L.
Year: 2006
Formatted Citation: Shen, B.-W., Atlas, R., Reale, O., Lin, S.-J., Chern, J.-D., Chang, J., Henze, C., and Li, J.-L., 2006: Hurricane Forecasts with a Global Mesoscale-Resolving Model: Preliminary Results with Hurricane Katrina (2005), Geophysical Research Letters, 33(13), L13813, 10.1029/2006GL026143.
Abstract: It is known that General Circulation Models (GCMs) have insufficient resolution to accurately simulate hurricane near-eye structure and intensity. The increasing capabilities of high-end computers have changed this. The mesoscale-resolving finite-volume GCM (fvGCM) has been experimentally deployed on the NASA Columbia supercomputer, and its performance is evaluated in this study by choosing hurricane Katrina as an example. In late August 2005, Katrina underwent two stages of rapid intensification, and became the sixth most intense hurricane in the Atlantic. Six 5-day simulations of Katrina at both 0.25 and 0.125 show comparable track forecasts but the 0.125 runs provide much better intensity forecasts, producing the center pressure with errors of only 12 hPa. In the runs examined in this study, the 0.125 simulates better near-eye wind distributions and a more realistic average intensification rate. To contribute to the ongoing research on the effects of disabling convection parameterization (CP), we present promising results by comparing 0.125 runs with disabled CPs against runs with enabled CPs.
Keywords: Atmospheric Processes: Mesoscale meteorology, Atmospheric Processes: Global climate models , Atmospheric Processes: Regional modeling, Atmospheric Processes: Tropical meteorology
Mission:
URL: https://doi.org/10.1029/2006GL026143
Other URLs:
Simon, B., Rahman, S.H., and Joshi, P.C. (2006). Conditions Leading to the Onset of the Indian Monsoon: A Satellite Perspective, Meteorology and Atmospheric Physics, 93(3-4), 201-210, 10.1007/s00703-005-0155-6. Journal Article »
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Title: Conditions Leading to the Onset of the Indian Monsoon: A Satellite Perspective
Type: Journal Article
Publication: Meteorology and Atmospheric Physics
Author(s): Simon, B., Rahman, S.H., and Joshi, P.C.
Year: 2006
Formatted Citation: Simon, B., Rahman, S.H., and Joshi, P.C., 2006: Conditions Leading to the Onset of the Indian Monsoon: A Satellite Perspective, Meteorology and Atmospheric Physics, 93(3-4), 201-210, 10.1007/s00703-005-0155-6.
Abstract: The summer monsoon onset-2004 over the Kerala Coast (Southern tip of the Indian Peninsula) was monitored in real-time, using the Tropical Rainfall Measuring Mission (TRMM)/TMI derived total precipitable water vapor, wind speed and sea surface temperature (SST), National Centre for Environmental Prediction (NCEP) and QuikScat wind data. The 2004 onset was of a gradual type, with an early start (24 May), followed by slow growth to full strength (10 June). Hence, the unambiguous forecasting of such onsets becomes very difficult. The water vapor build up over the western Arabian Sea is one of the necessary conditions that gives us a lead time of two and half weeks for the onset of monsoon. The strength of the Hadley cell (monitored using NCEP meridional wind), which is associated with a large convective heat source is also used as a predictive parameter with a lead-time of two weeks. The other dynamical conditions considered are the early May propagation of the Madden Julian Oscillation (MJO) followed by a second MJO, which began in the Western Indian Ocean (WIO) and the kinetic energy over the South East Arabian Sea, with an early start around 24 May (50 m(2)/s(2)) and strengthening around 10 June (80 m2/s2). The setting of large-scale monsoon current using various satellite derived parameters and the distinct features for the year 2004 have been delineated.
Keywords: SEA-SURFACE TEMPERATURE, SOUTH-WEST MONSOON, SUMMER MONSOON, VARIABILITY, FEATURES, KERALA, OCEAN, WINDS
Mission: |SeaWinds|
URL: https://doi.org/10.1007/s00703-005-0155-6
Other URLs:
Tokinaga, H., Tanimoto, Y., Nonaka, M., Taguchi, B., Fukamachi, T., Xie, S.-P., Nakamura, H., Watanabe, T., and Yasuda, I. (2006). Atmospheric Sounding Over the Winter Kuroshio Extension: Effect of Surface Stability on Atmospheric Boundary Layer Structure, Geophysical Research Letters, 33(4), L04703, 10.1029/2005GL025102. Journal Article »
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Title: Atmospheric Sounding Over the Winter Kuroshio Extension: Effect of Surface Stability on Atmospheric Boundary Layer Structure
Type: Journal Article
Publication: Geophysical Research Letters
Author(s): Tokinaga, H., Tanimoto, Y., Nonaka, M., Taguchi, B., Fukamachi, T., Xie, S.-P., Nakamura, H., Watanabe, T., and Yasuda, I.
Year: 2006
Formatted Citation: Tokinaga, H., Tanimoto, Y., Nonaka, M., Taguchi, B., Fukamachi, T., Xie, S.-P., Nakamura, H., Watanabe, T., and Yasuda, I., 2006: Atmospheric Sounding Over the Winter Kuroshio Extension: Effect of Surface Stability on Atmospheric Boundary Layer Structure, Geophysical Research Letters, 33(4), L04703, 10.1029/2005GL025102.
Abstract: Shipboard radiosonde surveys were conducted during the 2003-04 winter east of Japan to study atmospheric boundary layer (ABL) structure over the Kuroshio Extension. ABL displayed large variations in vertical structure, most of which are attributable to changes in atmospheric surface stability. Where the surface atmosphere was unstable (neutral) as measured by the sea-air temperature difference, surface turbulent heat flux increased (decreased) and a mixed-layer developed (undeveloped) with weakened (intensified) vertical wind shear. A linear regression analysis indicates that ABL height tends to increase by 1km as the sea-air temperature difference increases by 7°C or surface turbulent heat flux by 500 Wm^-2. While meridional thermal advection by weather disturbances seems to cause much of atmospheric stability variability during the 43-day surveys, the strong sensitivity of vertical mixing and wind shear to stability is consistent with the observed in-phase co-variability of SST and surface wind from satellite on monthly and longer timescales.
Keywords: * Atmospheric Processes: Boundary layer processes * Atmospheric Processes: Ocean/atmosphere interactions * Oceanography: General: Marine meteorology
Mission:
URL: https://doi.org/10.1029/2005GL025102
Other URLs:
Tveter, F.T. (2006). Assimilating Ambiguous QuikScat Scatterometer Observations in HIRLAM 3-D-Var at the Norwegian Meteorological Institute, Tellus A: Dynamic Meteorology and Oceanography, 58(1), 59-68, 10.1111/j.1600-0870.2006.00155.x. Journal Article »
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Title: Assimilating Ambiguous QuikScat Scatterometer Observations in HIRLAM 3-D-Var at the Norwegian Meteorological Institute
Type: Journal Article
Publication: Tellus A: Dynamic Meteorology and Oceanography
Author(s): Tveter, F.T.
Year: 2006
Formatted Citation: Tveter, F.T., 2006: Assimilating Ambiguous QuikScat Scatterometer Observations in HIRLAM 3-D-Var at the Norwegian Meteorological Institute, Tellus A: Dynamic Meteorology and Oceanography, 58(1), 59-68, 10.1111/j.1600-0870.2006.00155.x.
Abstract: The Norwegian Meteorological Institute has implemented ambiguous QuikScat observations in the HIRLAM three-dimensional variational data assimilation system, by approximating the method that will achieve the best mean squared error verification results according to the Bayesian decision theory. A four-month long impact study of this implementation during the 2003/2004 winter showed that assimilating QuikScat observations had a small positive effect on the average mean sea level pressure forecasting skill.
Keywords: NUMERICAL WEATHER PREDICTION, QUALITY-CONTROL, IMPACT, WINDS
Mission: |SeaWinds|
URL: https://doi.org/10.1111/j.1600-0870.2006.00155.x
Other URLs:
Walker, N.P., Partington, K.C., Van Woert, M.L., and Street, T.L.T. (2006). Arctic Sea Ice Type and Concentration Mapping Using Passive and Active Microwave Sensors, IEEE Transactions on Geoscience and Remote Sensing, 44(12), 3574-3584, 10.1109/TGRS.2006.881116. Journal Article »
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Title: Arctic Sea Ice Type and Concentration Mapping Using Passive and Active Microwave Sensors
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Walker, N.P., Partington, K.C., Van Woert, M.L., and Street, T.L.T.
Year: 2006
Formatted Citation: Walker, N.P., Partington, K.C., Van Woert, M.L., and Street, T.L.T., 2006: Arctic Sea Ice Type and Concentration Mapping Using Passive and Active Microwave Sensors, IEEE Transactions on Geoscience and Remote Sensing, 44(12), 3574-3584, 10.1109/TGRS.2006.881116.
Abstract: The mapping of ice type concentrations in the Arctic is important for commercial operations and for climate-related research. Algorithms based on moderate-resolution passive microwave sensors for mapping first-year ice and multiyear ice concentrations suffer from a number of known problems. In this paper, it has been shown that QuikSCAT scatterometer data can add complimentary information to that available from passive microwave, which can assist in separating different ice classes. Specifically, we identify a class of ice that exhibits a passive microwave signature which is characteristic of first-year ice, but has a scatterometer signature which is typical of multiyear ice. We track the evolution. and distribution of this new ice class throughout the Arctic during the winter season of 2003-2004 and compare the results against the U.S. National Ice Center (NIC) ice charts. It has been found that the new ice class is predominantly multiyear ice and is especially prevalent in the Fram Strait and the high Arctic regions north of the islands Franz Josef Land and Severnaya Zemlya. A simple algorithm has been proposed that enables a passive microwave-based partial ice concentration algorithm (for example, the NT algorithm based on Special Sensor Microwave/Imager data) to be adapted using QuikSCAT seatterometer data, so that the new ice class is corrected from the first-year ice class to the multiyear ice category. The algorithm performance is measured against the NIC ice charts. We provide a discussion regarding the possible physical causes of the effects that have been observed and described.
Keywords: active microwave, ice concentration, passive microwave, QuikSCAT, scatterometer, sea ice, Special Sensor Microwave/Imager (SSM/I), synergy, SCATTEROMETER DATA
Mission: |SeaWinds|
URL: https://doi.org/10.1109/TGRS.2006.881116
Other URLs:
Wang, H., Fu, R., Schemm, J.K., Tang, W., and Liu, W.T. (2006). Prediction of South American Low-Level Jet Using QuikSCAT Ocean Surface Wind, International Journal of Remote Sensing, 29(21), 6117-6172, 10.1080/01431160802175512. Journal Article »
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Title: Prediction of South American Low-Level Jet Using QuikSCAT Ocean Surface Wind
Type: Journal Article
Publication: International Journal of Remote Sensing
Author(s): Wang, H., Fu, R., Schemm, J.K., Tang, W., and Liu, W.T.
Year: 2006
Formatted Citation: Wang, H., Fu, R., Schemm, J.K., Tang, W., and Liu, W.T., 2006: Prediction of South American Low-Level Jet Using QuikSCAT Ocean Surface Wind, International Journal of Remote Sensing, 29(21), 6117-6172, 10.1080/01431160802175512.
Abstract:
Keywords:
Mission:
URL: https://doi.org/10.1080/01431160802175512
Other URLs:
Weissman, D., Hristova-Veleva, S., and Callahan, P. (2006). SeaWinds Scatterometer Wind Vector Retrievals Within Hurricanes Using AMSR and NEXRAD to Perform Corrections for Precipitation Effects, 2006 IEEE Geoscience and Remote Sensing Symposium, (IGARSS 2006), 10.1109/IGARSS.2006.912. Conference Paper »
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Title: SeaWinds Scatterometer Wind Vector Retrievals Within Hurricanes Using AMSR and NEXRAD to Perform Corrections for Precipitation Effects
Type: Conference Paper
Publication: 2006 IEEE Geoscience and Remote Sensing Symposium, (IGARSS 2006)
Author(s): Weissman, D., Hristova-Veleva, S., and Callahan, P.
Year: 2006
Formatted Citation: Weissman, D., Hristova-Veleva, S., and Callahan, P., 2006: SeaWinds Scatterometer Wind Vector Retrievals Within Hurricanes Using AMSR and NEXRAD to Perform Corrections for Precipitation Effects, 2006 IEEE Geoscience and Remote Sensing Symposium, (IGARSS 2006), 10.1109/IGARSS.2006.912.
Abstract:
Keywords:
Mission: |SeaWinds|
URL: https://doi.org/10.1109/IGARSS.2006.912
Other URLs:
Weissman, D.E., and Bourassa, M.A. (2006). Corrections to Scatterometer Wind Vectors, MTS-IEEE OCEANS 2006 Symposium, 10.1109/OCEANS.2006.307003. Conference Paper »
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Title: Corrections to Scatterometer Wind Vectors
Type: Conference Paper
Publication: MTS-IEEE OCEANS 2006 Symposium
Author(s): Weissman, D.E., and Bourassa, M.A.
Year: 2006
Formatted Citation: Weissman, D.E., and Bourassa, M.A., 2006: Corrections to Scatterometer Wind Vectors, MTS-IEEE OCEANS 2006 Symposium, 10.1109/OCEANS.2006.307003.
Abstract: Scatterometer wind measurements in Hurricanes have excellent potential for studying ocean forcing and the forecasting of coastal storm surges and flooding potential. These observations have the advantages of wide coverage, high resolution and accuracy. However, significant errors can occur when rain causes attenuation and backscatter of the Scatterometer`s microwave pencil-beam. For most of the rain conditions existing in Hurricanes, the signal returned to the satellite is larger than that reflected by the sea surface resulting in erroneously high estimates of the wind speed. One consequence can be large errors in estimates of the coastal storm surge. This study shows how NEXRAD measurements of the rain within each Scatterometer cell can be used, with a physically based electromagnetics model, to correct the affected radar cross section data. Hurricane Dennis made landfall in the Gulf of Mexico on July 10, 2005, not far from the Florida/Alabama border. There was a serious impact on the Apalachee Bay and Cedar Key region because of a anomalously high storm surge. Heavy precipitation affected the ability of the QuikSCAT Scatterometer to accurately predict this phenomena. The precipitation in this storm was continuously monitored by the NWS Tallahassee NEXRAD (S-band) radar. The mode of this instrument is to collect radar reflectivity data using conical scans at a sequence of elevations, resulting in a 3-D volume with 2 km spatial scales. This example studies herein underscores the necessity of correcting the Scatterometer`s normalized radar cross section (NRCS) measurements to remove the excess backscatter and attenuation provided by rain areas that exist within the 25-by-35 km antenna footprint. High resolution NWS-NEXRAD techniques are especially useful because of the wide variability of the rain intensity, both horizontally and vertically across each Scatterometer footprint and along the incident beam
Keywords: radar cross-sections rain storms weather forecasting wind 3D volume AD 2005 07 10 Apalachee Bay Cedar Key region Florida-Alabama border Gulf of Mexico Hurricane Dennis NEXRAD NRCS measurements NWS Tallahassee NEXRAD (S-
Mission: |SeaWinds|
URL: https://doi.org/10.1109/OCEANS.2006.307003
Other URLs:
Weissman, D.E., Hristova-Veleva, S., and Callahan, P. (2006). SeaWinds Scatterometer Wind Vector Retrievals for Hurricane Claudette Using AMSR and NEXRAD To Perform Corrections for Precipitation Effects: Comparison of AMSR and NEXRAD Retrievals of Rain, MTS-IEEE OCEANS 2006 Symposium, 10.1109/OCEANS.2006.307002. Conference Paper »
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Title: SeaWinds Scatterometer Wind Vector Retrievals for Hurricane Claudette Using AMSR and NEXRAD To Perform Corrections for Precipitation Effects: Comparison of AMSR and NEXRAD Retrievals of Rain
Type: Conference Paper
Publication: MTS-IEEE OCEANS 2006 Symposium
Author(s): Weissman, D.E., Hristova-Veleva, S., and Callahan, P.
Year: 2006
Formatted Citation: Weissman, D.E., Hristova-Veleva, S., and Callahan, P., 2006: SeaWinds Scatterometer Wind Vector Retrievals for Hurricane Claudette Using AMSR and NEXRAD To Perform Corrections for Precipitation Effects: Comparison of AMSR and NEXRAD Retrievals of Rain, MTS-IEEE OCEANS 2006 Symposium, 10.1109/OCEANS.2006.307002.
Abstract: The estimation of sea surface winds near and within hurricanes, with the spatial coverage of a satellite radar (scatterometer), is an important objective for public safety. It is also a significant technical challenge when intense rain is present in the scatterometer Field-Of-View (FOV). The presence of rain affects the measured Ku-band normalized radar cross section (NRCS or SIGMA_0) in three ways: rain, cloud and vapor in the atmosphere attenuate the scatterometer signal, rain backscatter augments the signal that comes from the ocean surface, finally, rain hitting the ocean surface induces surface roughening ("splash") that also augments the wind-related signal from the ocean surface. Scatterometer wind retrievals assume that variations in the the measured SIGMA_0 are solely caused by variations in the wind-induced ocean surface roughening. Hence, any rain-related effects have to be accounted for before the scatterometer measurements in rain can be used to estimate the near-surface wind velocity. The MIDORI-II mission, during 2003, carried five earth-observing sensors including the SeaWinds scatterometer and the Advanced Microwave Scanning Radiometer (AMSR). The latter`s six frequency brightness temperatures are collected to derive atmospheric water-related parameters and to measure the sea surface temperature. Since its coverage was closely coincident and collocated with the scatterometer, it provided the opportunity to obtain the precipitation measurements necessary to estimate the attenuation, volume backscatter and surface roughening by the raindrops within the scatterometer beam. Corrections to the scatterometer measurements of ocean surface winds can be pursued with either empirical or physical modeling. While both methods rely on the AMSR-based geophysical retrievals, they differ in how the information is used. The empirical method compares the observed sigmaO to the NCEP-model-wind-inferred SIGMA_0 to estimate the rain corrections (attenuation and backsca- tter that combines the rain backscatter and the "splash") as function of the AMSR-derived geophysical parameters. The physical method estimates the three rain effects separately using parametrized relationships between total liquid water, rain rate, surface roughening, volume attenuation and rain backscatter. As such, the physical method does not take into account the NCEP model winds and the produced corrections are more directly related to the AMSR-derived geophysical parameters. The AMSR was designed to measure atmospheric water-related parameters on a spatial scale comparable to the SeaWinds scatterometer (~25km). Optimal estimates of the volume backscatter and attenuation require a knowledge of the three dimensional distribution of reflectivity on a smaller scale comparable to that of the precipitation. Studies selected near the US coastline enable the much higher resolution NEXRAD reflectivity measurements to help evaluate, understand, and improve the AMSR estimates and to conduct research into the effects of different beam geometries and nonuniform beamfilling of precipitation within the field-of-view of the AMSR and the scatterometer
Keywords: atmospheric humidity clouds ocean temperature oceanography radar cross-sections rain remote sensing by radar storms wind 3D distribution AD 2003 AMSR Advanced Microwave Scanning Radiometer Field-Of-View Ku-band MIDORI-II
Mission: |SeaWinds|
URL: https://doi.org/10.1109/OCEANS.2006.307002
Other URLs:
Weissman, D.E., Morey, S.L., and Bourassa, M.A. (2006). Estimation of Storm Surge During Hurricane Dennis Using QuikSCAT Derived Winds, with Rain Correction, OCEAN SCIENCES MTG, American Geophysical Union.
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Title: Estimation of Storm Surge During Hurricane Dennis Using QuikSCAT Derived Winds, with Rain Correction
Type: Conference Paper
Publication: OCEAN SCIENCES MTG, American Geophysical Union
Author(s): Weissman, D.E., Morey, S.L., and Bourassa, M.A.
Year: 2006
Formatted Citation: Weissman, D.E., Morey, S.L., and Bourassa, M.A., 2006: Estimation of Storm Surge During Hurricane Dennis Using QuikSCAT Derived Winds, with Rain Correction, OCEAN SCIENCES MTG, American Geophysical Union.
Abstract: Scatterometer wind measurements, because of their wide coverage, high resolution and accuracy, have excellent potential for studying ocean forcing and the forecasting of coastal storm surges. Significant errors can occur when rain causes attenuation and backscatter of the scatterometer`s microwave pencil-beam. For most of the rain conditions existing in Hurricanes, the signal returned to the satellite is larger than that reflected by the sea surface resulting in erroneously high estimates of the wind speed. The consequence can be exaggerated estimates of the coastal storm surge. This project shows how NEXRAD measurements of the rain within each Scatterometer cell can be used, with a physically based electromagnetics model, to correct the affected radar cross section data. Hurricane Dennis made landfall in the Gulf of Mexico on July 10, 2005, not far from the northwest coast of Florida. This study combined the QuikSCAT Scatterometer derived predictions, NCEP winds, a hybrid wind model with in-situ tidal and wind measurements near the Cedar Key region north of Tampa. An ocean circulation model was forced by wind stresses derived separately from QSCAT winds, NCEP winds, a hybrid of the two and the NOAA HWind data product to estimate the storm surge in the northeastern Gulf. Only the model forced by the Hwind product produced a sea level rise at Cedar Key in good agreement with the local tide gauge measurements. This is because the wind product derived from the Hwind fields had sufficiently low offshore winds at the outer reaches of the storm to prevent a sea level run out along the coast, and was in good agreement with the NOAA-NDBC C-MAN instrumented anemometer. The other wind products had excessively strong offshore winds at Cedar Key leading to a modeled 1 meter drop in the sea level, that disagreed with observations. This example underscores the necessity of correcting the Scatterometer normalized radar cross section (NRCS) measurements to remove the excess backscatter and attenuation provided by rain areas that exist within the 25-by-35 km antenna footprint. High resolution NWS-NEXRAD techniques are especially useful because of the wide variability of the rain intensity, both horizontally and vertically across each Scatterometer footprint and along the incident beam. The method utilizes simultaneous, collocated measurements of the S-Band rain-reflectivity in the atmosphere. These three-dimensional data are combined with models of the electromagnetic processes associated with propagation and scattering, to remove the effects of volumetric rain (backscatter and attenuation). A Scatterometer wind retrieval algorithm recalculates the surface wind vectors and stresses using the corrected NRCS. For this event, these modified wind estimates were a significant improvement from the original data products, but are still too large to give close agreement with the ground information. This technique is being developed to study additional aspects and implications of these initial results.
Keywords:
Mission: |SeaWinds|
URL:
Other URLs:
Williams, B.L., and Long, D.G. (2006). An Improved High Resolution Wind Ambiguity Removal Procedure for SeaWinds, 2006 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `06), 2643-2646, 10.1109/IGARSS.2006.682. Conference Paper »
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Title: An Improved High Resolution Wind Ambiguity Removal Procedure for SeaWinds
Type: Conference Paper
Publication: 2006 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `06)
Author(s): Williams, B.L., and Long, D.G.
Year: 2006
Formatted Citation: Williams, B.L., and Long, D.G., 2006: An Improved High Resolution Wind Ambiguity Removal Procedure for SeaWinds, 2006 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `06), 2643-2646, 10.1109/IGARSS.2006.682.
Abstract:
Keywords:
Mission: |SeaWinds|
URL: https://doi.org/10.1109/IGARSS.2006.682
Other URLs:
Wyatt, L.R., Green, J.J., Middleditch, A., Moorhead, M.D., Howarth, J., Holt, M., and Keogh, S. (2006). Operational Wave, Current, and Wind Measurements with the Pisces HF Radar, IEEE Journal of Oceanic Engineering, 31(4), 819-834, 10.1109/JOE.2006.888378. Journal Article »
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Title: Operational Wave, Current, and Wind Measurements with the Pisces HF Radar
Type: Journal Article
Publication: IEEE Journal of Oceanic Engineering
Author(s): Wyatt, L.R., Green, J.J., Middleditch, A., Moorhead, M.D., Howarth, J., Holt, M., and Keogh, S.
Year: 2006
Formatted Citation: Wyatt, L.R., Green, J.J., Middleditch, A., Moorhead, M.D., Howarth, J., Holt, M., and Keogh, S., 2006: Operational Wave, Current, and Wind Measurements with the Pisces HF Radar, IEEE Journal of Oceanic Engineering, 31(4), 819-834, 10.1109/JOE.2006.888378.
Abstract: This paper presents results of a trial of a Pisces HF radar system aimed at assessing its use as a component of a wave-monitoring network being installed around the coasts of England and Wales. The radar system has been operating since December 2003 and the trial continued to June 2005. The data have been processed in near-real time and displayed on a website. Radar measurements of the directional spectrum and derived parameters are compared with those measured with a directional waverider and with products from the Met Office, United Kingdom, operational wave model. Radar measurements of currents and winds are also compared with Met Office model products and, in the case of winds, with the QuikSCAT scatterometer. Statistics on data availability and accuracy are presented. The results demonstrate that useful availability and accuracy in wave and wind parameters are obtained above a waveheight threshold of 2 in and at ranges up to 120 km at the radar operating frequencies (7-10 MHz) used. Waveheight measurements above about 1 m can be made with reasonable accuracy (e.g., mean difference of 2.5% during January-February 2004). Period and direction parameters in low seas are often contaminated by noise in the radar signal. The comparisons provide some evidence of wave model limitations in offshore wind and swell conditions.
Keywords: directional waverider buoy, HF radar, model, ocean wave measurement, QuikSCAT, surface current, tide, wind, HIGH-FREQUENCY RADAR, OCEAN SURFACE, INTEGRAL INVERSION, NONLINEAR-THEORY, DOPPLER SPECTRA, GRAVITY-WAVES, SEA-ECHO, EXTRACTION, BACKSCATTER, PARAM
Mission: |SeaWinds|
URL: https://doi.org/10.1109/JOE.2006.888378
Other URLs:
Xie, S.P., Xu, H.M., Saji, N.H., Wang, Y.Q., and Liu, W.T. (2006). Role of Narrow Mountains in Large-Scale Organization of Asian Monsoon Convection, Journal of Climate, 19(14), 3420-3429, 10.1175/JCLI3777.1. Journal Article »
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Title: Role of Narrow Mountains in Large-Scale Organization of Asian Monsoon Convection
Type: Journal Article
Publication: Journal of Climate
Author(s): Xie, S.P., Xu, H.M., Saji, N.H., Wang, Y.Q., and Liu, W.T.
Year: 2006
Formatted Citation: Xie, S.P., Xu, H.M., Saji, N.H., Wang, Y.Q., and Liu, W.T., 2006: Role of Narrow Mountains in Large-Scale Organization of Asian Monsoon Convection, Journal of Climate, 19(14), 3420-3429, 10.1175/JCLI3777.1.
Abstract: The Asian summer monsoon is organized into distinct convection centers, but the mechanism for this organization is not well understood. Analysis of new satellite observations reveals that narrow mountain ranges are an important organizing agent anchoring monsoon convection centers on the windward side. The Bay of Bengal convection, in particular, features the heaviest precipitation on its eastern coast because of orographic lifting as the southwest monsoon impinges on the coastal mountains of Myanmar (also known as Burma). This is in contrast to the widely held view that this convection is centered over the open ocean as implied by coarse-resolution datasets, a view that would require an entirely different explanation for its formation. Narrow in width and modest in height (≤,1 km), these mountains are hardly mentioned in conceptual depictions of the large-scale monsoon and poorly represented in global climate models. The numerical simulations of this study show that orographic rainbands are not a local phenomenon but exert far-reaching effects on the continental-scale monsoon. The realization that these overlooked geographical features are an important element of the Asian monsoon has important implications for studying the monsoon in the past, present, and future.
Keywords: SUMMER MONSOON, GHAT MOUNTAINS, PRECIPITATION, OCEAN, SIMULATION, MODEL, VARIABILITY, CIRCULATION, DYNAMICS, PACIFIC
Mission:
URL: https://doi.org/10.1175/JCLI3777.1
Other URLs:
Yan, X.H., Jo, Y.H., Liu, W.T., and He, M.X. (2006). A New Study of the Mediterranean Outflow, Air-Sea Interactions, and Meddies Using Multisensor Data, Journal of Physical Oceanography, 36(4), 691-710, 10.1175/JPO2873.1. Journal Article »
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Title: A New Study of the Mediterranean Outflow, Air-Sea Interactions, and Meddies Using Multisensor Data
Type: Journal Article
Publication: Journal of Physical Oceanography
Author(s): Yan, X.H., Jo, Y.H., Liu, W.T., and He, M.X.
Year: 2006
Formatted Citation: Yan, X.H., Jo, Y.H., Liu, W.T., and He, M.X., 2006: A New Study of the Mediterranean Outflow, Air-Sea Interactions, and Meddies Using Multisensor Data, Journal of Physical Oceanography, 36(4), 691-710, 10.1175/JPO2873.1.
Abstract: Previous studies of the Mediterranean Sea outflow and meddies (O&M) were limited by the poor spatial and temporal resolution of conventional in situ observations as well as the confinement of satellite observations to the oceans surface. Accordingly, little is known about the formation and transport of meddies and the spatial and temporal variation of O&M trajectories, which are located, on average, at a depth of 1000 m. However, a new remote sensing method has been developed by the authors to observe and study the O&M through unique approaches in satellite multisensor data integration analyses. Satellite altimeter, scatterometer, infrared satellite imagery, and XBT data were used to detect and calculate the trajectories and the relative transport of the O&M (January 1993December 2002). Two experiments [covering 199395: A Mediterranean Undercurrent Seeding Experiment (AMUSE) and Structures des Echanges MerAtmosph?, Propri?s des H?rog?it?Oc?iques: Recherche Exp?mentale (SEMAPHORE)] and XBT temperature measurements were used to directly validate the method presented herein. The monthly mean features derived from floats and XBTs for multiple meddies and the results of the presented method were significantly correlated based on a statistical chi-square test. In addition, the complex singular value decomposition method was used to identify the propagating features and their phase speeds. It was found that saltier water from the Mediterranean Sea was transported into the North Atlantic Ocean over the Strait of Gibraltar in boreal spring and summer relative to boreal autumn and winter. Streamfunctions using altimetry, and timefrequency energy distributions using the HilbertHuang transform, were computed to evaluate the meddy interactions with the sea surface variation. Since the O&M play a significant role in carrying salty water from the Mediterranean Sea into the Atlantic, such new knowledge about their trajectories, transport, and life histories is important to the understanding of their mixing and interaction with North Atlantic water. This may lead to a better understanding of the global ocean circulation and global climate change.
Keywords: MIXED-LAYER DEPTH, SINGULAR-VALUE DECOMPOSITION, SURFACE TEMPERATURE, NORTH-ATLANTIC, SEMAPHORE EXPERIMENT, COUPLED PATTERNS, ANALYTICAL MODEL, CANARY BASIN, AZORES FRONT, SALT LENS
Mission:
URL: https://doi.org/10.1175/JPO2873.1
Other URLs:
Yu, L.S. and Jin, X.Z., and Weller, R.A. (2006). Role of Net Surface Heat Flux in Seasonal Variations of Sea Surface Temperature in the Tropical Atlantic Ocean, Journal of Climate, 19(23), 6153-6169, 10.1175/JCLI3970.1. Journal Article »
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Title: Role of Net Surface Heat Flux in Seasonal Variations of Sea Surface Temperature in the Tropical Atlantic Ocean
Type: Journal Article
Publication: Journal of Climate
Author(s): Yu, L.S. and Jin, X.Z., and Weller, R.A.
Year: 2006
Formatted Citation: Yu, L.S. and Jin, X.Z., and Weller, R.A., 2006: Role of Net Surface Heat Flux in Seasonal Variations of Sea Surface Temperature in the Tropical Atlantic Ocean, Journal of Climate, 19(23), 6153-6169, 10.1175/JCLI3970.1.
Abstract: The present study used a new net surface heat flux (Qnet) product obtained from the Objective Analyzed AirSea Fluxes (OAFlux) project and the International Satellite Cloud Climatology Project (ISCCP) to examine two specific issuesone is to which degree Qnet controls seasonal variations of sea surface temperature (SST) in the tropical Atlantic Ocean (20S20N, east of 60W), and the other is whether the physical relation can serve as a measure to evaluate the physical representation of a heat flux product. To better address the two issues, the study included the analysis of three additional heat flux products: the Southampton Oceanographic Centre (SOC) heat flux analysis based on ship reports, and the model fluxes from the National Centers for Environmental PredictionNational Center for Atmospheric Research (NCEPNCAR) reanalysis and the 40-yr European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERA-40). The study also uses the monthly subsurface temperature fields from the World Ocean Atlas to help analyze the seasonal changes of the mixed layer depth (hMLD). The study showed that the tropical Atlantic sector could be divided into two regimes based on the influence level of Qnet. SST variability poleward of 5S and 10N is dominated by the annual cycle of Qnet. In these regions the warming (cooling) of the sea surface is highly correlated with the increased (decreased) Qnet confined in a relatively shallow (deep) hMLD. The seasonal evolution of SST variability is well predicted by simply relating the local Qnet with a variable hMLD. On the other hand, the influence of Qnet diminishes in the deep Tropics within 5S and 10N and ocean dynamic processes play a dominant role. The dynamics-induced changes in SST are most evident along the two belts, one of which is located on the equator and the other off the equator at about 3N in the west, which tilts to about 10N near the northwestern African coast. The study also showed that if the degree of consistency between the correlation relationships of Qnet, hMLD, and SST variability serves as a measure of the quality of the Qnet product, then the Qnet from OAFlux + ISCCP and ERA-40 are most physically representative, followed by SOC. The NCEPNCAR Qnet is least representative. It should be noted that the Qnet from OAFlux + ISCCP and ERA-40 have a quite different annual mean pattern. OAFlux + ISCCP agrees with SOC in that the tropical Atlantic sector gains heat from the atmosphere on the annual mean basis, where the ERA-40 and the NCEPNCAR model reanalyses indicate that positive Qnet occurs only in the narrow equatorial band and in the eastern portion of the tropical basin. Nevertheless, seasonal variances of the Qnet from OAFlux + ISCCP and ERA-40 are very similar once the respective mean is removed, which explains why the two agree with each other in accounting for the seasonal variability of SST. In summary, the study suggests that an accurate estimation of surface heat flux is crucially important for understanding and predicting SST fluctuations in the tropical Atlantic Ocean. It also suggests that future emphasis on improving the surface heat flux estimation should be placed more on reducing the mean bias.
Keywords: NORTH EQUATORIAL COUNTERCURRENT, SUBSURFACE THERMAL STRUCTURE, ANNUAL CYCLE, MIXED-LAYER, IN-SITU, VARIABILITY, PACIFIC, MODEL, CLIMATE, RETROFLECTION
Mission:
URL: https://doi.org/10.1175/JCLI3970.1
Other URLs:
Yuan, D.L., Han, W.Q., and Hu, D.X. (2006). Surface Kuroshio Path in the Luzon Strait Area Derived from Satellite Remote Sensing Data, Journal of Geophysical Research: Oceans, 111(C11007), 10.1029/2005JC003412. Journal Article »
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Title: Surface Kuroshio Path in the Luzon Strait Area Derived from Satellite Remote Sensing Data
Type: Journal Article
Publication: Journal of Geophysical Research: Oceans
Author(s): Yuan, D.L., Han, W.Q., and Hu, D.X.
Year: 2006
Formatted Citation: Yuan, D.L., Han, W.Q., and Hu, D.X., 2006: Surface Kuroshio Path in the Luzon Strait Area Derived from Satellite Remote Sensing Data, Journal of Geophysical Research: Oceans, 111(C11007), 10.1029/2005JC003412.
Abstract: Satellite ocean color, sea surface temperature, and altimeter data are used to study the surface Kuroshio path in the Luzon Strait area. The results suggest that the dominant path of surface Kuroshio intrusion in winter is a direct route from northeast of Luzon to southwest of Taiwan and then westward along the continental slope of northern South China Sea. Anticyclonic intrusions of the Kuroshio in the Luzon Strait area are observed during less than 30% of the time on average and in all four seasons of the year. Winter is the most favorable season for the formation of the anticyclonic intrusions. However, the Kuroshio is observed to deviate from the dominant path during only a little over one third of the wintertime on average. The loop currents of the Kuroshio, which feature prominent inflow-outflow currents in the Luzon Strait during the anticyclonic intrusions, are observed only occasionally, with more episodes in summer than in winter. The observation of more frequent loop currents of the Kuroshio in summer than in winter is a revision to the existing conclusion. These results demonstrate that the anticyclonic intrusion of the Kuroshio is a transient phenomenon rather than a persistent circulation pattern in the Luzon Strait area as suggested by some of the existing numerical model simulations. The growth and decay of the anticyclonic intrusions of the Kuroshio are closely related to the passages and evolution of mesoscale eddies in the Luzon Strait area. Each anticyclonic intrusion event lasts for a few weeks. Its termination sometimes results in a detached anticyclonic eddy propagating to the western basin along the continental slope of the northern South China Sea.
Keywords: surface Kuroshio, Luzon Strait, satellite remote sensing
Mission:
URL: https://doi.org/10.1029/2005JC003412
Other URLs:
Zheng, Q., Lai, R.J., Huang, N.E., Pan, J., Yuan, Y., and Liu, W.T. (2006). Observation of Ocean Current Response to 1998 Hurricane Georges in the Gulf of Mexico, Acta Oceanologica Sinica, 25(1), 1-14. Journal Article »
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Title: Observation of Ocean Current Response to 1998 Hurricane Georges in the Gulf of Mexico
Type: Journal Article
Publication: Acta Oceanologica Sinica
Author(s): Zheng, Q., Lai, R.J., Huang, N.E., Pan, J., Yuan, Y., and Liu, W.T.
Year: 2006
Formatted Citation: Zheng, Q., Lai, R.J., Huang, N.E., Pan, J., Yuan, Y., and Liu, W.T., 2006: Observation of Ocean Current Response to 1998 Hurricane Georges in the Gulf of Mexico, Acta Oceanologica Sinica, 25(1), 1-14.
Abstract: The ocean current response to a hurricane on the shelf-break is examined. The study area is the DeSoto Canyon in the northeast Gulf of Mexico, and the event is the passage of 1998 Hurricane Georges with a maximum wind speed of 49 m/s. The data sets used for analysis consist of the mooring data taken by the Field Program of the DeSoto Canyon Eddy Intrusion Study, and simultaneous winds observed by NOAA (National Oceanic and Atmospheric Administration) Moored Buoy 42040. Time-depth ocean current energy density images derived from the observed data show that the ocean currents respond almost immediately to the hurricane with important differences on and offthe shelf. On the shelf, in the shallow water of 100 m, the disturbance penetrates rapidly downward to the bottom and forms two energy peaks, the major peak is located in the mixed layer and the secondary one in the lower layer. The response dissipates quickly after external forcing disappears. Off the shelf, in the deep water, the major disturbance energy seems to be trapped in the mixed layer with a trailing oscillation, although the disturbance signals may still be observed at the depths of 500 and 1 290 m. Vertical dispersion analysis reveals that the near-initial wave packet generated off the shelf consists of two modes. One is a barotropic wave mode characterized by a fast decay rate of velocity amplitude of 0.020 s-1, and the other is baroclinic wave mode characterized by a slow decay rate of 0.006 9 s-1. The band-pass-filtering and empirical function techniques are employed to the frequency analysis. The results indicate that all frequencies shift above the local inertial frequency. On the shelf, the average frequency is 1.04fin the mixed layer, close to the diagnosed frequency of the first baroclinic mode, and the average frequency increases to 1.07fin the thermocline.Off the shelf, all frequencies are a little smaller than the diagnosed frequency of the first mode. The average frequency decreases from 1.035fin the mixed layer to 1.02fin the thermocline, implying a trend for the shift in frequency of the oscillations towards f with the depth.
Keywords:
Mission:
URL: https://www.researchgate.net/publication/285854126_Observation_of_ocean_current_response_to_1998_Hurricane_Georges_in_the_Gulf_of_Mexico
Other URLs:
Allen, J.R., and Long, D.G. (2005). An Analysis of SeaWinds-Based Rain Retrieval in Severe Weather Events, IEEE Transactions on Geoscience and Remote Sensing, 43(12), 2870-2878, 10.1109/TGRS.2005.858431. Journal Article »
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Title: An Analysis of SeaWinds-Based Rain Retrieval in Severe Weather Events
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Allen, J.R., and Long, D.G.
Year: 2005
Formatted Citation: Allen, J.R., and Long, D.G., 2005: An Analysis of SeaWinds-Based Rain Retrieval in Severe Weather Events, IEEE Transactions on Geoscience and Remote Sensing, 43(12), 2870-2878, 10.1109/TGRS.2005.858431.
Abstract: The Ku-band SeaWinds scatterometer estimates near-surface ocean wind vectors by relating measured backscatter to a geophysical model function for the near-surface vector wind. The conventional wind retrieval algorithm does not explicitly account for SeaWinds` sensitivity to rain, resulting in rain-caused wind retrieval error. A new retrieval method, termed simultaneous wind/rain retrieval, that estimates both wind and rain from rain-contaminated measurements has been previously proposed and validated with Tropical Rain Measuring Mission data. Here, the accuracy of rains retrieved by the new method is validated through comparison with the Next Generation Weather Radar (NEXRAD) in coastal storm events. The rains detected by both sensors are comparable, though SeaWinds-estimated rains exhibit greater variability. The performance of simultaneous wind/rain retrieval in flagging excessively rain-contaminated winds is discussed and compared to existing methods. A new rain-only retrieval algorithm for use in rain-backscatter-dominated areas is proposed and tested. A simple noise model for SeaWinds rain estimates is developed, and Monte Carlo simulation is employed to verify the model. The model shows that SeaWinds rain estimates have a standard deviation of 2.5 mm/h, which is higher than the NEXRAD measurements. Thresholding SeaWinds rain estimates at 2 mm/h yields a better rain flag than current rain flag algorithms.
Keywords: WIND, ACCURACY, Next Generation Weather Radar (NEXRAD), QuikSCAT, rain, scatterometer, SeaWinds, simultaneous wind/rain retrieval, wind
Mission: |SeaWinds|
URL: https://doi.org/10.1109/TGRS.2005.858431
Other URLs:
Anderson, H.S., and Long, D.G. (2005). Sea Ice Mapping Method for SeaWinds, IEEE Transactions on Geoscience and Remote Sensing, 43(3), 647-657, 10.1109/TGRS.2004.842017. Journal Article »
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Title: Sea Ice Mapping Method for SeaWinds
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Anderson, H.S., and Long, D.G.
Year: 2005
Formatted Citation: Anderson, H.S., and Long, D.G., 2005: Sea Ice Mapping Method for SeaWinds, IEEE Transactions on Geoscience and Remote Sensing, 43(3), 647-657, 10.1109/TGRS.2004.842017.
Abstract: A sea ice mapping algorithm for SeaWinds is developed that incorporates statistical and spatial a priori information in a modified maximum a posteriori (MAP) framework. Spatial a priori data are incorporated in the loss terms of a Bayes risk formulation. Conditional distributions and priors for sea ice and ocean statistics are represented as empirical histograms that are forced to conform to a set of expected histograms via principal component filtering. Tuning parameters for the algorithm allow adjustments in the algorithm`s performance. Results of the algorithm exhibit high correlation with the Remund-Long sea ice mapping algorithm for SeaWinds and the Special Sensor Microwave/Imager National Aeronautics and Space Administration Team 30% ice edge, and are verified with RADARSAT-1 ScanSAR imagery. The resulting sea ice maps exhibit high edge detail, preserve polynyas and ice bodies disjoint from the primary ice sheet, and thus are suitable for use with wind retrieval and sea ice studies. Principles employed in the algorithm may be of interest in other classification studies.
Keywords: SCATTEROMETER DATA, Bayes method, maximum a posteriori (MAP), principal components, QuikSCAT, scatterometer, sea ice extent, SeaWinds
Mission: |SeaWinds|
URL: https://doi.org/10.1109/TGRS.2004.842017
Other URLs:
Arguez, A., Bourassa, M.A., and O'Brien, J.J. (2005). Detection of the MJO Signal from QuikSCAT, Journal of Atmospheric and Oceanic Technology, 22(12), 1885-1894, 10.1175/JTECH1822.1. Journal Article »
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Title: Detection of the MJO Signal from QuikSCAT
Type: Journal Article
Publication: Journal of Atmospheric and Oceanic Technology
Author(s): Arguez, A., Bourassa, M.A., and O'Brien, J.J.
Year: 2005
Formatted Citation: Arguez, A., Bourassa, M.A., and O'Brien, J.J., 2005: Detection of the MJO Signal from QuikSCAT, Journal of Atmospheric and Oceanic Technology, 22(12), 1885-1894, 10.1175/JTECH1822.1.
Abstract: Wind data from the SeaWinds instrument on NASA's Quick Scatterometer (QuikSCAT) satellite are investigated to ascertain how well the surface manifestation of the Madden–Julian oscillation (MJO) can be resolved. The MJO signal is detected in nonfiltered gridded data using extended EOF analysis of the zonal wind field, overshadowed by annual, semiannual, and monsoon-related modes. After bandpass filtering with Lanczos weights, MJO signals are clearly detected in several kinematic quantities, including the zonal wind speed, the zonal pseudostress, and the velocity potential. Extraction of the MJO using QuikSCAT winds compares favorably with extraction using NCEP Reanalysis 2, except that the QuikSCAT signal appears to be more robust. In addition, an alternative bandpass-filtering technique using variable filter weights near time series endpoints is presented. The method uses least squares minimization to match newly created frequency response functions in edge zones as closely as possible to the predetermined frequency response function of interior points. This method stands in contrast to the common practice of simply discarding those endpoints where a convolution cannot be computed.
Keywords: QuikSCAT, MJO, Filtering, Extended EOF, Scatterometer
Mission: |SeaWinds|
URL: https://doi.org/10.1175/JTECH1822.1
Other URLs:
Ashcraft, I.S., and Long, D.G. (2005). Observation and Characterization of Radar Backscatter Over Greenland, IEEE Transactions on Geoscience and Remote Sensing, 43(2), 225-237, 10.1109/TGRS.2004.841484. Journal Article »
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Title: Observation and Characterization of Radar Backscatter Over Greenland
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Ashcraft, I.S., and Long, D.G.
Year: 2005
Formatted Citation: Ashcraft, I.S., and Long, D.G., 2005: Observation and Characterization of Radar Backscatter Over Greenland, IEEE Transactions on Geoscience and Remote Sensing, 43(2), 225-237, 10.1109/TGRS.2004.841484.
Abstract: Characterization of the microwave signature of the Greenland snow surface enables delineation of the different snow facies and is a tool for tracking the effects of climate change. A new empirical observation model is introduced that uses a limited number of parameters to characterize the snow surface based on the dependence of radar backscatter on incidence angle, azimuth angle, spatial gradient, and temporal rate of change. The individual model parameters are discussed in depth with examples using data from the NASA Scatterometer (NSCAT) and from the C-band European Remote Sensing (ERS) satellite Advanced Microwave Instrument in scatterometer mode. The contribution of each model term to the overall accuracy of the model is evaluated. The relative contributions of the modeled dependencies vary by region. Two studies illustrating applications of the model are included. First, interannual changes over the Greenland ice sheet are investigated using nine years of ERS data. Surface changes are observed as anomalies in the /spl sigma//spl deg/ model parameters. Second, intraannual variations of the surface are investigated. These changes are observed in the average backscatter normalized to a given observation geometry. The results indicate that the model can be used to obtain a more complete understanding of multiyear change and to obtain low-variance high temporal resolution observations of intraannual changes. The model may be applied for increased accuracy in scatterometer, synthetic aperture radar (SAR), and wide-angle SAR studies.
Keywords: backscatter hydrological techniques microwave measurement remote sensing by radar snow spaceborne radar synthetic aperture radar terrain mapping
Mission: |NSCAT|
URL: https://doi.org/10.1109/TGRS.2004.841484
Other URLs:
Atlas, R., Hou, A.Y., and Oreste, R. (2005). Application of SeaWinds Scatterometer and TMI-SSM/I Rain Rates to Hurricane Analysis and Forecasting, Journal of Photogrammetry and Remote Sensing, 59(4), 233-243, 10.1016/j.isprsjprs.2005.02.007. Journal Article »
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Title: Application of SeaWinds Scatterometer and TMI-SSM/I Rain Rates to Hurricane Analysis and Forecasting
Type: Journal Article
Publication: Journal of Photogrammetry and Remote Sensing
Author(s): Atlas, R., Hou, A.Y., and Oreste, R.
Year: 2005
Formatted Citation: Atlas, R., Hou, A.Y., and Oreste, R., 2005: Application of SeaWinds Scatterometer and TMI-SSM/I Rain Rates to Hurricane Analysis and Forecasting, Journal of Photogrammetry and Remote Sensing, 59(4), 233-243, 10.1016/j.isprsjprs.2005.02.007.
Abstract: Results provided by two different assimilation methodologies involving data from passive and active space-borne microwave instruments are presented. The impact of the precipitation estimates produced by the TRMM Microwave Imager (TMI) and Special Sensor Microwave/Imager (SSM/I) in a previously developed 1D variational continuous assimilation algorithm for assimilating tropical rainfall is shown on two hurricane cases. Results on the impact of the SeaWinds scatterometer on the intensity and track forecast of a mid-Atlantic hurricane are also presented. This work is the outcome of a collaborative effort between NASA and NOAA and indicates the substantial improvement in tropical cyclone forecasting that can result from the assimilation of space-based data in global atmospheric models.
Keywords: Scatterometer, TMI-SSM/I, Hurricane prediction, Microwave remote sensing applications
Mission: |SeaWinds|
URL: https://doi.org/10.1016/j.isprsjprs.2005.02.007
Other URLs:
Atlas, R., Reale, O., Shen, B.-W., Lin, S.-J., Chern, J.-D., Putman, W., Lee, T., Yeh, K.-S., Bosilovich, M., and Radakovich, J. (2005). Hurricane Forecasting with the High-Resolution NASA Finite Volume General Circulation Model, Geophysical Research Letters, 32(3), L03807, 10.1029/2004GL021513. Journal Article »
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Title: Hurricane Forecasting with the High-Resolution NASA Finite Volume General Circulation Model
Type: Journal Article
Publication: Geophysical Research Letters
Author(s): Atlas, R., Reale, O., Shen, B.-W., Lin, S.-J., Chern, J.-D., Putman, W., Lee, T., Yeh, K.-S., Bosilovich, M., and Radakovich, J.
Year: 2005
Formatted Citation: Atlas, R., Reale, O., Shen, B.-W., Lin, S.-J., Chern, J.-D., Putman, W., Lee, T., Yeh, K.-S., Bosilovich, M., and Radakovich, J., 2005: Hurricane Forecasting with the High-Resolution NASA Finite Volume General Circulation Model, Geophysical Research Letters, 32(3), L03807, 10.1029/2004GL021513.
Abstract: A high-resolution finite volume general circulation model (fvGCM), resulting from a development effort of more than ten years, is now being run operationally at the NASA Goddard Space Flight Center and Ames Research Center. The model is based on a finite volume dynamical core with terrain-following Lagrangian control volume discretization and performs efficiently on massive parallel architectures. The computational efficiency allows simulations at a resolution of a quarter of a degree, which is double the resolution currently adopted by most global models in operational weather centers. Such fine global resolution brings us closer to overcoming a fundamental barrier in global atmospheric modeling for both weather and climate, because tropical cyclones can be more realistically represented. In this work, preliminary results are shown. Fifteen simulations of four Atlantic tropical cyclones in 2002 and 2004, chosen because of varied difficulties presented to numerical weather forecasting, are performed. The fvGCM produces very good forecasts of these tropical systems, adequately resolving problems like erratic track, abrupt recurvature, intense extratropical transition, multiple landfall and reintensification, and interaction among vortices.
Keywords: Atmospheric Processes: Tropical meteorology, Atmospheric Processes: Synoptic-scale meteorology, Atmospheric Processes: Mesoscale meteorology, Atmospheric Processes: Global climate models
Mission:
URL: https://doi.org/10.1029/2004GL021513
Other URLs:
Chelton D.B. (2005). The Impact of SST Specification on ECMWF Surface Wind Stress Fields in the Eastern Tropical Pacific, Journal of Climate, 18(4), 530-550, 10.1175/JCLI-3275.1. Journal Article »
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Title: The Impact of SST Specification on ECMWF Surface Wind Stress Fields in the Eastern Tropical Pacific
Type: Journal Article
Publication: Journal of Climate
Author(s): Chelton D.B.
Year: 2005
Formatted Citation: Chelton D.B., 2005: The Impact of SST Specification on ECMWF Surface Wind Stress Fields in the Eastern Tropical Pacific, Journal of Climate, 18(4), 530-550, 10.1175/JCLI-3275.1.
Abstract: The impact of SST specification on low-level winds in the operational ECMWF numerical weather prediction model is investigated in the eastern tropical Pacific from comparisons of ECMWF wind stress fields with QuikSCAT satellite scatterometer observations of wind stress during the AugustDecember cold seasons of 2000 and 2001. These two time periods bracket the 9 May 2001 change from the Reynolds SST analyses to the Real-Time Global SST (RTG_SST) analyses as the ocean boundary condition in the ECMWF model. The oceanatmosphere interaction in the eastern tropical Pacific that is clearly evident in QuikSCAT wind stress divergence and curl fields is also evident in the ECMWF winds, but is more than twice as strong in the 2001 cold season as in the 2000 cold season, due primarily to the improved spatial and temporal resolution of the RTG_SST analyses compared with the Reynolds SST analyses. While a significant improvement compared with 2000, the response of the 2001 ECMWF wind stress field to SST is only about half as strong as the coupling inferred from QuikSCAT data and satellite observations of SST from the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI). It is concluded that the underrepresentation of the oceanatmosphere coupling is attributable partly to underrepresentation of SST gradients in the RTG_SST fields and partly to inadequacies of the ECWMF model. The latter may be due to errors in the parameterization of boundary layer processes or to insufficient horizontal or vertical resolution in the model.
Keywords: ATMOSPHERIC BOUNDARY-LAYER, INSTABILITY WAVES, EQUATORIAL PACIFIC, SATELLITE MEASUREMENTS, TEMPERATURE-GRADIENTS, MEASURING MISSION, AGULHAS CURRENT, IN-SITU, OCEAN, FRONT
Mission: |SeaWinds|
URL: https://doi.org/10.1175/JCLI-3275.1
Other URLs:
Chelton, D.B., and Freilich, M.H. (2005). Scatterometer-Based Assessment of 10-m Wind Analyses from the Operational ECMWF and NCEP Numerical Weather Prediction Models, Monthly Weather Review, 133(2), 409-429, 10.1175/MWR-2861.1. Journal Article »
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Title: Scatterometer-Based Assessment of 10-m Wind Analyses from the Operational ECMWF and NCEP Numerical Weather Prediction Models
Type: Journal Article
Publication: Monthly Weather Review
Author(s): Chelton, D.B., and Freilich, M.H.
Year: 2005
Formatted Citation: Chelton, D.B., and Freilich, M.H., 2005: Scatterometer-Based Assessment of 10-m Wind Analyses from the Operational ECMWF and NCEP Numerical Weather Prediction Models, Monthly Weather Review, 133(2), 409-429, 10.1175/MWR-2861.1.
Abstract: Wind measurements by the National Aeronautics and Space Administration (NASA) scatterometer (NSCAT) and the SeaWinds scatterometer on the NASA QuikSCAT satellite are compared with buoy observations to establish that the accuracies of both scatterometers are essentially the same. The scatterometer measurement errors are best characterized in terms of random component errors, which are about 0.75 and 1.5 m s^-1) for the along-wind and crosswind components, respectively. The NSCAT and QuikSCAT datasets provide a consistent baseline from which recent changes in the accuracies of 10-m wind analyses from the European Centre for Medium-Range Weather Forecasts (ECMWF) and the U.S. National Centers for Environmental Prediction (NCEP) operational numerical weather prediction (NWP) models are assessed from consideration of three time periods: September 1996-June 1997, August 1999-July 2000, and February 2002-January 2003. These correspond, respectively, to the 9.5-month duration of the NSCAT mission, the first 12 months of the QuikSCAT mission, and the first year after both ECMWF and NCEP began assimilating QuikSCAT observations. There were large improvements in the accuracies of both NWP models between the 1997 and 2000 time periods. Though modest in comparison, there were further improvements in 2002, at least partly attributable to the assimilation of QuikSCAT observations in both models. There is no evidence of bias in the 10-m wind speeds in the NCEP model. The 10-m wind speeds in the ECMWF model, however, are shown to be biased low by about 0.4 m s^-1. While it is difficult to eliminate systematic errors this small, a bias of 0.4 in s^-1 corresponds to a typical wind stress bias of more than 10%. This wind stress bias increases to nearly 20% if atmospheric stability effects are not taken into account. Biases of these magnitudes will result in significant systematic errors in ocean general circulation models that are forced by ECMWF winds.
Keywords: KU-BAND, SATELLITE-OBSERVATIONS, STRESS VECTOR, OCEAN WINDS, RAIN, SEAWINDS, WAVES, NSCAT, RETRIEVALS, MAGNITUDE,
Mission: |NSCAT|SeaWinds|
URL: https://doi.org/10.1175/MWR-2861.1
Other URLs:
Chelton, D.B., and Wentz, F.J. (2005). Global Microwave Satellite Observations of Sea Surface Temperature for Numerical Weather Prediction and Climate Research, Bulletin of the American Meteorological Society, 86(8), 1097-1115, 10.1175/BAMS-86-8-1097. Journal Article »
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Title: Global Microwave Satellite Observations of Sea Surface Temperature for Numerical Weather Prediction and Climate Research
Type: Journal Article
Publication: Bulletin of the American Meteorological Society
Author(s): Chelton, D.B., and Wentz, F.J.
Year: 2005
Formatted Citation: Chelton, D.B., and Wentz, F.J., 2005: Global Microwave Satellite Observations of Sea Surface Temperature for Numerical Weather Prediction and Climate Research, Bulletin of the American Meteorological Society, 86(8), 1097-1115, 10.1175/BAMS-86-8-1097.
Abstract: Obtaining global sea surface temperature (SST) fields for the ocean boundary condition in numerical weather prediction (NWP) models and for climate research has long been problematic. Historically, such fields have been constructed by a blendig of in situ observations from ships and buoys and satellite infrared observations from the Advanced Vey High Resolution Radiometer (AVHRR) that has been operational on NOAA satellites since November 1981. The resolution of these global SST fields is limited by the sparse coverage of in situ observation in many areas of the World Ocean and cloud contamination of AVHRR observations, which can exceed 75% over the subpolar oceans. As clouds and aerosols are essential transparent to microwave radiation, satellite microwave observation can grealty improve the sampling and resolution of global SST fields. The Advance Microwave Scanning Radiometer on the NASA Earth Observation System (EOS) Aqua satellite (AMST-E) is providing the first hihly accurate and global satellite microwave observations of SST. The potentail for AMSR-E observation to improved the sampling, resolution, and accuracy of SST fields for NWP and climate research is demonstrated from example SST fields and from an investigation of the sensitivity of NWP models to specification of the SST boundary conditio of the SST boundary condition.
Keywords:
Mission:
URL: https://doi.org/10.1175/BAMS-86-8-1097
Other URLs:
Esteban-Fernandez, D.E., Kerr, E.A., Castells, A., Carswell, J.R., Frasier, S.J., Chang, P.S., Black, P.G., and Marks, F.D. (2005). IWRAP: The Imaging Wind and Rain Airborne Profiler for Remote Sensing of the Ocean and the Atmospheric Boundary Layer Within Tropical Cyclones, IEEE Transactions on Geoscience and Remote Sensing, 43(8), 1775-1787, 10.1109/TGRS.2005.851640. Journal Article »
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Title: IWRAP: The Imaging Wind and Rain Airborne Profiler for Remote Sensing of the Ocean and the Atmospheric Boundary Layer Within Tropical Cyclones
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Esteban-Fernandez, D.E., Kerr, E.A., Castells, A., Carswell, J.R., Frasier, S.J., Chang, P.S., Black, P.G., and Marks, F.D.
Year: 2005
Formatted Citation: Esteban-Fernandez, D.E., Kerr, E.A., Castells, A., Carswell, J.R., Frasier, S.J., Chang, P.S., Black, P.G., and Marks, F.D., 2005: IWRAP: The Imaging Wind and Rain Airborne Profiler for Remote Sensing of the Ocean and the Atmospheric Boundary Layer Within Tropical Cyclones, IEEE Transactions on Geoscience and Remote Sensing, 43(8), 1775-1787, 10.1109/TGRS.2005.851640.
Abstract: The Imaging Wind and Rain Airborne Profiler (IWRAP) is the first high-resolution dual-band airborne Doppler radar designed to study the inner core of tcyclones (TCs). IWRAP is operated from a National Oceanic and Atmospheric Administration WP-3D aircraft during missions through TCs and severe ocean storms. The system is designed to provide high-resolution dual-polarized G and Ku-band reflectivity and Doppler velocity profiles of the atmospheric boundary layer (ABL) within the inner core precipitation bands of TCs and to study the effects precipitation has on ocean wind scatterometry as it applies to TCs. IWRAP implements a very unique measurement strategy, it profiles simultaneously at four separate incidence angles (approximately 30 degrees, 35 degrees, 40 degrees, and 50 degrees) while conically scanning at 60 rpm. A summary of the principles of operation and the design of the instrument is given, followed by examples of IWRAPs unique imaging capability. To our knowledge, these examples include the highest resolution measurements of the ABL winds in a hurricane ever obtained.
Keywords: HURRICANE ANDREW LANDFALL, GENERATED WAVES, SOUTH FLORIDA, ROSSBY-WAVES, MODEL, SCATTEROMETRY, FIELDS, atmospheric boundary layer (ABL), cyclone, ocean remote sensing, precipitation, scatterometry
Mission:
URL: https://doi.org/10.1109/TGRS.2005.851640
Other URLs:
Evans D.L., Alpers W., Cazenave A., Elachi C., Farr T., Glackin D., Holt B., Jones L., Liu W.T., McCandless W., Menard Y., Moore R., and Njoku E. (2005). Seasat - A 25-Year Legacy of Success, Remote Sensing of Environment, 94(3), 384-404, 10.1016/j.rse.2004.09.011. Journal Article »
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Title: Seasat - A 25-Year Legacy of Success
Type: Journal Article
Publication: Remote Sensing of Environment
Author(s): Evans D.L., Alpers W., Cazenave A., Elachi C., Farr T., Glackin D., Holt B., Jones L., Liu W.T., McCandless W., Menard Y., Moore R., and Njoku E.
Year: 2005
Formatted Citation: Evans D.L., Alpers W., Cazenave A., Elachi C., Farr T., Glackin D., Holt B., Jones L., Liu W.T., McCandless W., Menard Y., Moore R., and Njoku E., 2005: Seasat - A 25-Year Legacy of Success, Remote Sensing of Environment, 94(3), 384-404, 10.1016/j.rse.2004.09.011.
Abstract: Thousands of scientific publications and dozens of textbooks include data from instruments derived from NASA's Seasat. The Seasat mission was launched on June 26, 1978, on an Atlas-Agena rocket from Vandenberg Air Force Base. It was the first Earth-orbiting satellite to carry four complementary microwave experimentsthe Radar Altimeter (ALT) to measure ocean surface topography by measuring spacecraft altitude above the ocean surface, the Seasat-A Satellite Scatterometer (SASS), to measure wind speed and direction over the ocean, the Scanning Multichannel Microwave Radiometer (SMMR) to measure surface wind speed, ocean surface temperature, atmospheric water vapor content, rain rate, and ice coverage, and the Synthetic Aperture Radar (SAR), to image the ocean surface, polar ice caps, and coastal regions. While originally designed for remote sensing of the Earth's oceans, the legacy of Seasat has had a profound impact in many other areas including solid earth science, hydrology, ecology and planetary science.
Keywords: Seasat, Scanning Multichannel Microwave Radiometer, Synthetic Aperture Radar
Mission:
URL: https://doi.org/10.1016/j.rse.2004.09.011
Other URLs:
Kelly, K.A., Dickinson, S., and Johnson, G.C. (2005). Comparisons of Scatterometer and TAO Winds Reveal Time-Varying Surface Currents for the Tropical Pacific Ocean, Journal of Atmospheric and Oceanic Technology, 22(6), 735-745, 10.1175/JTECH1738.1. Journal Article »
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Title: Comparisons of Scatterometer and TAO Winds Reveal Time-Varying Surface Currents for the Tropical Pacific Ocean
Type: Journal Article
Publication: Journal of Atmospheric and Oceanic Technology
Author(s): Kelly, K.A., Dickinson, S., and Johnson, G.C.
Year: 2005
Formatted Citation: Kelly, K.A., Dickinson, S., and Johnson, G.C., 2005: Comparisons of Scatterometer and TAO Winds Reveal Time-Varying Surface Currents for the Tropical Pacific Ocean, Journal of Atmospheric and Oceanic Technology, 22(6), 735-745, 10.1175/JTECH1738.1.
Abstract: The differences between Tropical Atmosphere Ocean (TAO) anemometer and QuikSCAT scatterometer winds are analyzed over a period of 3 yr. Systematic differences are expected owing to ocean currents because the anemometer measures absolute air motion, whereas a radar measures the motion of the air relative to the ocean. Monthly averaged collocated wind differences (CWDs) are compared with available near-surface current data at 15-m depth from drifters, at 25-m depth from acoustic Doppler current profilers (ADCPs), and at 10-m depth from current meters and with geostrophic currents at the surface from the TOPEX/Poseidon radar altimeter. Because direct current observations are so sparse, comparisons are also made with climatological currents from these same sources. Zonal CWDs are in good agreement with the zonal current observations, particularly from 2 degrees S to 2 degrees N where there are strong currents and a robust seasonal cycle, with the altimeter-derived anomalous currents giving the best match. At higher latitudes there is qualitative agreement at buoys with relatively large currents. The overall variance of the zonal component of the CWDs is reduced by approximately 25% by subtracting an estimate of the zonal currents. The meridional CWDs are nearly as large as the zonal CWDs but are unpredictable. The mean CWDs show a robust divergence pattern about the equator, which is suggestive of Ekman currents, but with unexpectedly large magnitudes. Coefficients for estimating climatological zonal surface currents from the altimeter at the TAO buoys are tabulated: the amplitudes and phases for the annual and semiannual harmonics, and a linear regression against the Southern Oscillation index, are combined with the mean from the drifter currents. Examples are shown of the application of these estimators to data from SeaWinds on the Midori satellite. These estimators are also useful for deriving air-sea fluxes from TAO winds.
Keywords: MODEL, HEAT,
Mission: |SeaWinds|
URL: https://doi.org/10.1175/JTECH1738.1
Other URLs:
Kunz, L.B., Long, D.G. (2005). Calibrating Seawinds and QuikSCAT Scatterometers Using Natural Land Targets, IEEE Geoscience and Remote Sensing Letters, 2(2), 182-186, 10.1109/LGRS.2004.842468. Journal Article »
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Title: Calibrating Seawinds and QuikSCAT Scatterometers Using Natural Land Targets
Type: Journal Article
Publication: IEEE Geoscience and Remote Sensing Letters
Author(s): Kunz, L.B., Long, D.G.
Year: 2005
Formatted Citation: Kunz, L.B., Long, D.G., 2005: Calibrating Seawinds and QuikSCAT Scatterometers Using Natural Land Targets, IEEE Geoscience and Remote Sensing Letters, 2(2), 182-186, 10.1109/LGRS.2004.842468.
Abstract: The SeaWinds-on-QuikSCAT (QuikSCAT) and SeaWinds-on-ADEOS-2 (SeaWinds) scatterometers measure the normalized radar backscatter (sigma degrees) of the earth`s surface. These identical radar sensors are on different spaceborne platforms in similar orbits. QuikSCAT and SeaWinds data are used to infer near-surface wind vectors, polar sea-ice extent, polar-ice melt events, etc. In order to verify the relative calibration of these sensors, a simple cross calibration based on land backscatter measurements is performed. A first-order polynomial model is used to remove the incidence angle dependence of sigma degrees for selected regions of the Amazon rainforest and the Sahara Desert. It is shown that the two sensors are well-calibrated to each other and require no bias corrections. Additionally, evidence of a diurnal cycle in the Amazon rainforest backscatter is given.
Keywords: RADAR, Amazon forest, calibration, QuikSCAT, radar cross section, SeaWinds
Mission: |SeaWinds|
URL: https://doi.org/10.1109/LGRS.2004.842468
Other URLs:
Lee, T., and Liu, W.T. (2005). Effects of High-Frequency Wind Sampling on Simulated Mixed Layer Depth and Upper Ocean Temperature, Journal of Geophysical Research, 110(C05002), 10.1029/2004JC002746. Journal Article »
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Title: Effects of High-Frequency Wind Sampling on Simulated Mixed Layer Depth and Upper Ocean Temperature
Type: Journal Article
Publication: Journal of Geophysical Research
Author(s): Lee, T., and Liu, W.T.
Year: 2005
Formatted Citation: Lee, T., and Liu, W.T., 2005: Effects of High-Frequency Wind Sampling on Simulated Mixed Layer Depth and Upper Ocean Temperature, Journal of Geophysical Research, 110(C05002), 10.1029/2004JC002746.
Abstract: Effects of high-frequency wind sampling on a near-global ocean model are studied by forcing the model with a 12 hourly averaged wind product and its 24 hourly subsamples in separate experiments. The differences in mixed layer depth and sea surface temperature resulting from these experiments are examined, and the underlying physical processes are investigated. The 24 hourly subsampling not only reduces the high-frequency variability of the wind but also affects the annual mean wind because of aliasing. While the former effect largely impacts mid- to high-latitude oceans, the latter primarily affects tropical and coastal oceans. At mid- to high-latitude regions the subsampled wind results in a shallower mixed layer and higher sea surface temperature because of reduced vertical mixing associated with weaker high-frequency wind. In tropical and coastal regions, however, the change in upper ocean structure due to the wind subsampling is primarily caused by the difference in advection resulting from aliased annual mean wind, which varies with the subsampling time. The results of the study indicate a need for more frequent sampling of satellite wind measurement and have implications for data assimilation in terms of identifying the nature of model errors.
Keywords: errors , Data assimilation , Wind satellite , advection , Mixing , mixing , High latitude , Variability , experimental studies , Forcing , Ocean model , world ocean , Sea surface temperature , depth , Mixed layer , sampling , winds , high frequency
Mission:
URL: https://doi.org/10.1029/2004JC002746
Other URLs:
Morey, S.L., Bourassa, M.A., Dukhovskoy, D., and O'Brien, J.J. (2005). Modelling the Oceanic Response to Air-Sea Fluxes Associated with a Tropical Storm, Research Activities in Atmospheric and Ocean Modeling, Report No. 35, Edite. Report »
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Title: Modelling the Oceanic Response to Air-Sea Fluxes Associated with a Tropical Storm
Type: Report
Publication: Research Activities in Atmospheric and Ocean Modeling
Author(s): Morey, S.L., Bourassa, M.A., Dukhovskoy, D., and O'Brien, J.J.
Year: 2005
Formatted Citation: Morey, S.L., Bourassa, M.A., Dukhovskoy, D., and O'Brien, J.J., 2005: Modelling the Oceanic Response to Air-Sea Fluxes Associated with a Tropical Storm, Research Activities in Atmospheric and Ocean Modeling, Report No. 35, Edite.
Abstract:
Keywords: Cyclone, flux
Mission:
URL: https://www.wcrp-climate.org/WGNE/BlueBook/2005/individual-articles/08_Morey_Steven_L._moreyWGNE05.pdf
Other URLs:
O'Neill, L.W., Chelton, D.B., and Esbensen, S.K. (2005). High-Resolution Satellite Measurements of the Atmospheric Boundary Layer Response to SST Variations Along the Agulhas Return Current, Journal of Climate, 18(14), 2706-2723, 10.1175/JCLI3415.1. Journal Article »
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Title: High-Resolution Satellite Measurements of the Atmospheric Boundary Layer Response to SST Variations Along the Agulhas Return Current
Type: Journal Article
Publication: Journal of Climate
Author(s): O'Neill, L.W., Chelton, D.B., and Esbensen, S.K.
Year: 2005
Formatted Citation: O'Neill, L.W., Chelton, D.B., and Esbensen, S.K., 2005: High-Resolution Satellite Measurements of the Atmospheric Boundary Layer Response to SST Variations Along the Agulhas Return Current, Journal of Climate, 18(14), 2706-2723, 10.1175/JCLI3415.1.
Abstract: The marine atmospheric boundary layer (MABL) response to sea surface temperature (SST) perturbations with wavelengths shorter than 30 degrees longitude by 10 degrees latitude along the Agulhas Return Current (ARC) is described from the first year of SST and cloud liquid water (CLW) measurements from the Advanced Microwave Scanning Radiometer (AMSR) on the Earth Observing System (EOS) Aqua satellite and surface wind stress measurements from the QuikSCAT scatterometer. AMSR measurements of SST at a resolution of 58 km considerably improves upon a previous analysis that used the Reynolds SST analyses, which underestimate the short-scale SST gradient magnitude over the ARC region by more than a factor of 5. The AMSR SST data thus provide the first quantitatively accurate depiction of the SST-induced MABL response along the ARC. Warm (cold) SST perturbations produce positive (negative) wind stress magnitude perturbations, leading to short-scale perturbations in the wind stress curl and divergence fields that are linearly related to the crosswind and downwind components of the SST gradient, respectively. The magnitudes of the curl and divergence responses vary seasonally and spatially with a response nearly twice as strong during the winter than during the summer along a zonal band between 40 degrees and 50 degrees S. These seasonal variations closely correspond to seasonal and spatial variability of large-scale MABL stability and surface sensible heat flux estimated from NCEP reanalysis fields. SST-induced deepening of the MABL over warm water is evident in AMSR measurements of CLW. Typical annual mean differences in cloud thickness between cold and warm SST perturbations are estimated to be about 300 m.
Keywords: SEA-SURFACE TEMPERATURE, TROPICAL INSTABILITY WAVES, EASTERN EQUATORIAL PACIFIC, GULF-STREAM, WIND STRESS, THERMAL FRONT, NORTH WALL, OCEAN, VARIABILITY, GRADIENTS
Mission: |SeaWinds|
URL: https://doi.org/10.1175/JCLI3415.1
Other URLs:
Small, R.J., Xie, S.-P., and Hafner, J. (2005). Satellite Observations of Mesoscale Ocean Features and Co-propagating Atmospheric Surface Fields in the Tropical Belt, Journal of Geophysical Research, 110, C02021, 10.1029/2004JC002598. Journal Article »
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Title: Satellite Observations of Mesoscale Ocean Features and Co-propagating Atmospheric Surface Fields in the Tropical Belt
Type: Journal Article
Publication: Journal of Geophysical Research
Author(s): Small, R.J., Xie, S.-P., and Hafner, J.
Year: 2005
Formatted Citation: Small, R.J., Xie, S.-P., and Hafner, J., 2005: Satellite Observations of Mesoscale Ocean Features and Co-propagating Atmospheric Surface Fields in the Tropical Belt, Journal of Geophysical Research, 110, C02021, 10.1029/2004JC002598.
Abstract: Recent studies of air-sea interaction using satellite data have shown a high positive correlation between wind speed and sea surface temperature (SST) over mesoscale ocean features in certain frontal regions. The aim of this study is to determine to what extent mesoscale ocean dynamics modifies the surface wind speed over the global tropics between 40°S and 40°N. Cross-spectral and linear regression methods are used to identify robust relationships between ocean and atmospheric variables. The ocean dynamical features, measured by their sea surface height anomaly (SSHA), affect SST in a manner consistent with advection of the mean temperature gradient by anomalous currents. The response varies from 0.2°C of SST per cm of SSHA near the equator to 0.05°C cm?1 at higher latitudes. A remarkably consistent in-phase relationship between SST and wind speed is found over the complete domain. Wind speed response varied from 0.5 to 1.5 ms^-1 per °C of SST change. This in-phase response of wind speed is consistent with previous studies suggesting that the SST variations cause changes in the vertical exchange of momentum and in the pressure gradient, which alter the wind speed.
Keywords: * air-sea interaction * mesoscale eddies * satellite observations
Mission:
URL: https://doi.org/10.1029/2004JC002598
Other URLs:
Stephen, H., and Long, D.G. (2005). Modeling Microwave Emissions of Erg Surfaces in the Sahara Desert, IEEE Transactions on Geoscience and Remote Sensing, 43(12), 2822-2830, 10.1109/TGRS.2005.857899. Journal Article »
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Title: Modeling Microwave Emissions of Erg Surfaces in the Sahara Desert
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Stephen, H., and Long, D.G.
Year: 2005
Formatted Citation: Stephen, H., and Long, D.G., 2005: Modeling Microwave Emissions of Erg Surfaces in the Sahara Desert, IEEE Transactions on Geoscience and Remote Sensing, 43(12), 2822-2830, 10.1109/TGRS.2005.857899.
Abstract: Sand seas (ergs) of the Sahara are the most dynamic parts of the desert. Aeolian erosion, transportation, and deposition continue to reshape the surface of the ergs. The large-scale features (dunes) of these bedforms reflect the characteristics of the sand and the long-term wind. Radiometric emissions from the ergs have strong dependence on the surface geometry. We model the erg surface as composed of tilted rough facets. Each facet is characterized by a tilt distribution dependent upon the surface roughness of the facet. The radiometric temperature (T/sub b/) of ergs is then the weighted sum of the T/sub b/ from all the facets. We use dual-polarization T/sub b/ measurements at 19 and 37 GHz from the Special Sensor Microwave Imager aboard the Defense Meteorological Satellite Program and the Tropical Rainfall Measuring Mission Microwave Imager to analyze the radiometric response of erg surfaces and compare them to the model results. The azimuth angle (/spl phi/) modulation of T/sub b/ is caused by the surface geometrical characteristics. It is found that longitudinal and transverse dune fields are differentiable based on their polarization difference (/spl Delta/T/sub b/) /spl phi/-modulation, which reflects type and orientation of dune facets. /spl Delta/T/sub b/ measurements at 19 and 37 GHz provide consistent results. The magnitude of /spl Delta/T/sub b/ at 37 GHz is lower than at 19 GHz due to higher attenuation. The analysis of /spl Delta/T/sub b/ over dry sand provides a unique insight into radiometric emission over ergs.
Keywords: Azimuth angle modulation Special Sensor Microwave Imager (SSM/I) Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) ergs microwave emission polarization difference radiometric temperature sand dunes
Mission:
URL: https://doi.org/10.1109/TGRS.2005.857899
Other URLs:
Stephen, H., Long, D.G. (2005). Microwave Backscatter Modeling of Erg Surfaces in the Sahara Desert, IEEE Transactions on Geoscience and Remote Sensing, 43(2), 238-247, 10.1109/TGRS.2004.840646. Journal Article »
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Title: Microwave Backscatter Modeling of Erg Surfaces in the Sahara Desert
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Stephen, H., Long, D.G.
Year: 2005
Formatted Citation: Stephen, H., Long, D.G., 2005: Microwave Backscatter Modeling of Erg Surfaces in the Sahara Desert, IEEE Transactions on Geoscience and Remote Sensing, 43(2), 238-247, 10.1109/TGRS.2004.840646.
Abstract: The Sahara desert includes large expanses of sand dunes called ergs. These dunes are formed and constantly reshaped by prevailing winds. Previous study shows that Saharan ergs exhibit significant radar backscatter (sigmadegrees) modulation with azimuth angle (phi). We use alphadegrees measurements observed at various incidence angles and phi from the NASA Scatterometer (NSCAT), the SeaWinds scatterometer, the ERS scatterometer (ESCAT), and the Tropical Rainfall Measuring Mission's Precipitation Radar to model the sigmadegrees response from sand dunes. Observations reveal a characteristic relationship between the backscatter modulation and the dune type, i.e., the number and orientation of the dune slopes. Sand dunes are modeled as a composite of tilted rough facets, which are characterized by a probability distribution of tilt with a mean value, and small ripples on the facet surface. The small ripples are modeled as cosinusoidal surface waves that contribute to the return signal at Bragg angles only. Longitudinal and transverse dunes are modeled with rough facets having Gaussian tilt distributions. The model results in a sigmadegrees response similar to NSCAT and ESCAT observations over areas of known dune types in the Sahara. The response is high at look angles equal to the mean tilts of the rough facets and is lower elsewhere. This analysis provides a unique insight into scattering by large-scale sand bedforms.
Keywords: SCATTEROMETER DATA, SEA-ICE, SATELLITE, backscatter, Erg, ERS Scatterometer (ESCAT), NASA Scatterometer (NSCAT), sand dune, sand sheet, Sea Winds scatterometer (QSCAT), Tropical Rainfall Measuring Mission Precipitation Radar (TRMM-PR)
Mission: |NSCAT|SeaWinds|
URL: https://doi.org/10.1109/TGRS.2004.840646
Other URLs:
Tokinaga, H., Tanimoto, Y., and Xie, S.-P. (2005). SST-Induced Surface Wind Variations Over the Brazil-Malvinas Confluence: Satellite and In Situ Observations, Journal of Climate, 18(17), 3471-3482, 10.1175/JCLI3485.1. Journal Article »
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Title: SST-Induced Surface Wind Variations Over the Brazil-Malvinas Confluence: Satellite and In Situ Observations
Type: Journal Article
Publication: Journal of Climate
Author(s): Tokinaga, H., Tanimoto, Y., and Xie, S.-P.
Year: 2005
Formatted Citation: Tokinaga, H., Tanimoto, Y., and Xie, S.-P., 2005: SST-Induced Surface Wind Variations Over the Brazil-Malvinas Confluence: Satellite and In Situ Observations, Journal of Climate, 18(17), 3471-3482, 10.1175/JCLI3485.1.
Abstract: The confluence of the Brazil-Malvinas Currents maintains strong sea surface temperature (SST) fronts in the midlatitude southwestern Atlantic year-round. SST effects on near-surface stability and surface wind variations are examined in this region using satellite and in situ datasets. Satellite observations show strong (weak) surface wind speeds over the warm Brazil (cold Malvinas) Current. A novel feature of this study is the construction of a high-resolution surface meteorological dataset that is based on historical ship observations. Analysis of this new in situ dataset reveals an increased (reduced) sea-air temperature difference over the Brazil (Malvinas) Current, indicating destabilization (stabilization) in the atmospheric boundary layer. These results are consistent with the SST-induced vertical mixing mechanism for wind adjustment. The SST effect on the near-surface atmosphere is observed both in the climatology and on interannual time scales in the Brazil-Malvinas confluence. Along a zonal SST front at 49°S northeast of the Malvinas/Falkland Islands, there is a collocated line of surface wind divergence, with moderate convergence to the north. Vertical mixing does not explain this divergence pattern because the prevailing surface winds are westerly, blowing in parallel with the front. An additional mechanism is proposed for boundary layer wind adjustment.
Keywords: Atlantic Ocean , Equatorial Atlantic , Atlantic Ocean , South Atlantic , Space remote sensing , troposphere , Malvinas Current , Brazil Current , Southwest Atlantic , Local wind , Atmospheric stability , stabilization , Satellite observation , Measurement
Mission:
URL: https://doi.org/10.1175/JCLI3485.1
Other URLs:
Torsekar, V., Kasparis, T., Jones, W.L., Ahmad, K., and Long, D.G. (2005). Oceanic Rain Identification Using Multifractal Analysis of QuikSCAT Sigma-0, Proceedings of OCEANS 2005 MTS/IEEE, 2656-2663, 10.1109/OCEANS.2005.1640174. Conference Paper »
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Title: Oceanic Rain Identification Using Multifractal Analysis of QuikSCAT Sigma-0
Type: Conference Paper
Publication: Proceedings of OCEANS 2005 MTS/IEEE
Author(s): Torsekar, V., Kasparis, T., Jones, W.L., Ahmad, K., and Long, D.G.
Year: 2005
Formatted Citation: Torsekar, V., Kasparis, T., Jones, W.L., Ahmad, K., and Long, D.G., 2005: Oceanic Rain Identification Using Multifractal Analysis of QuikSCAT Sigma-0, Proceedings of OCEANS 2005 MTS/IEEE, 2656-2663, 10.1109/OCEANS.2005.1640174.
Abstract: The presence of rain over oceans interferes with the measurement of sea surface wind speed and direction from the Sea Winds scatterometer, and as a result, in rain regions wind measurements contain biases. In past research at the Central Florida Remote Sensing Lab, it has been observed that rain has multifractal behavior. In this paper we present an algorithm to detect the presence of rain so that rain regions are flagged. The forward and aft views of the high resolution horizontal polarization backscatter are used for the extraction of textural information with the help of multifractals. A negated multifractal exponent is computed to discriminate between wind and rain. Pixels with exponent value above a threshold are classified as rain pixels and those that do not meet the threshold are further examined with the help of correlation of the multifractal exponent within a predefined neighborhood of individual pixels. It was observed that the rain has less correlation within a neighborhood compared to wind. This property is utilized for reactivation of the pixels that fall below a certain threshold of correlation. An adaptive multifractal exponent and threshold is used, as we deal with a wide range of latitudes. Validation results are presented through comparison with the Tropical Rainfall Measurement Mission Microwave Imager (TMI) 2A12 rain retrieval product for one day. The results show that the algorithm is effective in identifying rain pixels. Some algorithm deficiencies in high wind speed regions are also discussed. Comparisons with other proposed approaches are also presented.
Keywords: artificial satellites atmospheric techniques fractals oceanographic techniques rain remote sensing wind Central Florida Remote Sensing Lab QuikSCAT Sigma-0 Sea Winds scatterometer Tropical Rainfall Measurement Mission Mi
Mission: |SeaWinds|
URL: https://doi.org/10.1109/OCEANS.2005.1640174
Other URLs:
Weissman, D.E., and Bourassa, M.A. (2005). Corrections to Scatterometer Wind Vectors from the Effects of Rain, Using High Resolution NEXRAD Radar Collocations, Proceedings of OCEANS 2005 MTS/IEEE, 3, 10.1109/OCEANS.2005.1640054. Conference Paper »
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Title: Corrections to Scatterometer Wind Vectors from the Effects of Rain, Using High Resolution NEXRAD Radar Collocations
Type: Conference Paper
Publication: Proceedings of OCEANS 2005 MTS/IEEE
Author(s): Weissman, D.E., and Bourassa, M.A.
Year: 2005
Formatted Citation: Weissman, D.E., and Bourassa, M.A., 2005: Corrections to Scatterometer Wind Vectors from the Effects of Rain, Using High Resolution NEXRAD Radar Collocations, Proceedings of OCEANS 2005 MTS/IEEE, 3, 10.1109/OCEANS.2005.1640054.
Abstract: Rain in the atmosphere and impacts on the ocean surface lead to erroneous observations of the K/sub u-/band normalized radar cross section (NRCS) for the ocean surface, which is collected by orbiting Scatterometers. Rain can cause large errors in satellite-based estimates of the sea surface wind speed and direction derived from the affected data, depending on the surface wind speed and the rainrate. Rain within the radar beam results in attenuation and additive volume backscatter to the satellite. In order to correct each NRCS using a physically based electromagnetic model, the 3-D rain reflectivity must be measured throughout the satellite's K/sub u-/band beam with high resolution, and be nearly simultaneous with the satellite. Using satellite observations within the range of the NWS NEXRAD radars, these S-band data provide 2 km horizontal resolution and comparable vertical resolution, within 4 minutes of the satellite overpass. The correction technique also includes removal of the augmented surface roughness due to rain impacts. The surface wind vectors are then recalculated using the corrected NRCS, with the same wind-retrieval algorithm as that is used to produce the SeaWinds data product. Case studies will be presented that show the improved wind vector estimates over a significant area in several coastal regions, (the U.S. East Coast and the Gulf of Mexico), when comparing the corrected winds with the NCEP winds and buoy measurements.
Keywords: artificial satellites backscatter ocean waves oceanographic regions oceanographic techniques rain remote sensing by radar wind 4 mins K/sub u/ band NEXRAD radar collocations electromagnetic model normalized radar cross section
Mission: |SeaWinds|
URL: https://doi.org/10.1109/OCEANS.2005.1640054
Other URLs:
Weissman, D.E., Apgar, G., Tongue, J.S., and Bourassa, M.A. (2005). Corrections to the SeaWinds Scatterometer Wind Vectors by Removing Rain Effects, Bulletin of the American Meteorological Society, 86, 621-622.
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Title: Corrections to the SeaWinds Scatterometer Wind Vectors by Removing Rain Effects
Type: Journal Article
Publication: Bulletin of the American Meteorological Society
Author(s): Weissman, D.E., Apgar, G., Tongue, J.S., and Bourassa, M.A.
Year: 2005
Formatted Citation: Weissman, D.E., Apgar, G., Tongue, J.S., and Bourassa, M.A., 2005: Corrections to the SeaWinds Scatterometer Wind Vectors by Removing Rain Effects, Bulletin of the American Meteorological Society, 86, 621-622.
Abstract:
Keywords: Scatterometer, wind speed, rain
Mission:
URL:
Other URLs:
Xie, S.-P., Xu, H., Kessler, W.S., and Nonaka, M. (2005). Air-Sea Interaction Over the Eastern Pacific Warm Pool: Gap Winds, Thermocline Dome, and Atmospheric Convection, Journal of Climate, 18(1), 5-20, 10.1175/JCLI-3249.1. Journal Article »
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Title: Air-Sea Interaction Over the Eastern Pacific Warm Pool: Gap Winds, Thermocline Dome, and Atmospheric Convection
Type: Journal Article
Publication: Journal of Climate
Author(s): Xie, S.-P., Xu, H., Kessler, W.S., and Nonaka, M.
Year: 2005
Formatted Citation: Xie, S.-P., Xu, H., Kessler, W.S., and Nonaka, M., 2005: Air-Sea Interaction Over the Eastern Pacific Warm Pool: Gap Winds, Thermocline Dome, and Atmospheric Convection, Journal of Climate, 18(1), 5-20, 10.1175/JCLI-3249.1.
Abstract: High-resolution satellite observations are used to investigate air-sea interaction over the eastern Pacific warm pool. In winter, strong wind jets develop over the Gulfs of Tehuantepec, Papagayo, and Panama, accelerated by the pressure gradients between the Atlantic and Pacific across narrow passes of Central American cordillera. Patches of cold sea surface temperatures (SSTs) and high chlorophyll develop under these wind jets as a result of increased turbulent heat flux from the ocean and enhanced mixing across the base of the ocean mixed layer. Despite a large decrease in SST (exceeding 3°C in seasonal means), the cold patches associated with the Tehuantepec and Papagayo jets do not have an obvious effect on local atmospheric convection in winter since the intertropical convergence zone (ITCZ) is located farther south. The cold patch of the Panama jet to the south, on the other hand, cuts through the winter ITCZ and breaks it into two parts. A pronounced thermocline dome develops west of the Gulf of Papagayo, with the 20°C isotherm only 30 m deep throughout the year. In summer when the Panama jet disappears and the other two wind jets weaken, SST is 0.5°C lower over this Costa Rica Dome than the background. This cold spot reduces local precipitation by half, punching a hole of 500 km in diameter in the summer ITCZ. The dome underlies a patch of open-ocean high chlorophyll. This thermocline dome is an ocean dynamic response to the positive wind curls south of the Papagayo jet, which is optimally oriented to excite ocean Rossby waves that remotely affect the ocean to the west. The meridionally oriented Tehuantepec and Panama jets, by contrast, only influence the local thermocline depth with few remote effects on SST and the atmosphere. The orographical-triggered air-sea interaction described here is a good benchmark for testing high-resolution climate models now under development.
Keywords: Central America , Pacific Ocean , Equatorial Pacific , Space remote sensing , Climatology , Climate models , Rossby wave , ocean waves , Dynamic response , Ocean dynamics , Costa Rica , Summer , Intertropical convergence zone , Mixed layer , heat transfer
Mission:
URL: https://doi.org/10.1175/JCLI-3249.1
Other URLs:
Bourassa, M.A. (2004). An Improved Sea State Dependency for Surface Stress Derived from In Situ and Remotely Sensed Winds, Advances in Space Research, 33(7), 1136-1142, 10.1016/S0273-1177(03)00753-1. Journal Article »
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Title: An Improved Sea State Dependency for Surface Stress Derived from In Situ and Remotely Sensed Winds
Type: Journal Article
Publication: Advances in Space Research
Author(s): Bourassa, M.A.
Year: 2004
Formatted Citation: Bourassa, M.A., 2004: An Improved Sea State Dependency for Surface Stress Derived from In Situ and Remotely Sensed Winds, Advances in Space Research, 33(7), 1136-1142, 10.1016/S0273-1177(03)00753-1.
Abstract: An improved model is developed for the dependency of surface turbulent stress on wave characteristics. Recent studies have used differences between satellite and in situ observations to gain insights into the physical processes that might be related to air-sea interaction. Both scatterometers and buoys provide very accurate measurements of wind speed. Differences between these measurements can be explained in terms of the different mechanisms to which the instruments respond. A physically-based flux model is developed herein. Prior results suggest that the stress parameterizations, converting neutral equivalent wind speed to stress, applied to in situ observations differ subtlety from those that should be used for scatterometer-derived winds. These differences are due to water waves modifying the surface stress. This model provides a physical explanation of the observed differences, and provides a model for calculating stresses from scatterometer winds. The model is validated with recent in situ observations gathersevere conditions. The model explains more wave-related variability in surface stress than previous models.
Keywords: Space, satellite
Mission: |SeaWinds|
URL: https://doi.org/10.1016/S0273-1177(03)00753-1
Other URLs:
Bourassa, M.A. (2004). A Sea Surface Stress Parameterization Dependent on Directional Sea State, CAS/JSC Working Group on Numerical Experimentation, Research Activities, 4.07-4.08. Report »
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Title: A Sea Surface Stress Parameterization Dependent on Directional Sea State
Type: Report
Publication: CAS/JSC Working Group on Numerical Experimentation, Research Activities
Author(s): Bourassa, M.A.
Year: 2004
Formatted Citation: Bourassa, M.A., 2004: A Sea Surface Stress Parameterization Dependent on Directional Sea State, CAS/JSC Working Group on Numerical Experimentation, Research Activities, 4.07-4.08.
Abstract:
Keywords: stress, scatterometer, seastate, model
Mission:
URL: https://www.wcrp-climate.org/WGNE/BlueBook/2004/individual-articles/04_Bourassa_Mark_Surface_Stress_Parameterization_Bourassa.pdf
Other URLs:
Chan, S.H., Halterman, R.R., and Long, D.G. (2004). Cross-Validation of Jason-1 and QuikSCAT Wind Speeds, 2004 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `04), 2730-2733, 10.1109/IGARSS.2004.1369866. Conference Paper »
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Title: Cross-Validation of Jason-1 and QuikSCAT Wind Speeds
Type: Conference Paper
Publication: 2004 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `04)
Author(s): Chan, S.H., Halterman, R.R., and Long, D.G.
Year: 2004
Formatted Citation: Chan, S.H., Halterman, R.R., and Long, D.G., 2004: Cross-Validation of Jason-1 and QuikSCAT Wind Speeds, 2004 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `04), 2730-2733, 10.1109/IGARSS.2004.1369866.
Abstract: Observing near-surface ocean winds is important to the understanding of global weather patterns. Wind speed information can be retrieved from σ^o measurements made by Jason-1 and SeaWinds on QuikSCAT. Though co-located measurements from the two satellites generally agree, significant differences between the co-located measurements are occasionally observed, particularly associated with rain events. Co-located data from TRMM PR 2A25 and ECMWF is used to study the effects of rain on Jason-1. Key observations are discussed.
Keywords: atmospheric techniques data acquisition rain remote sensing wind ECMWF Jason-1 QuikSCAT SeaWinds TRMM PR 2A25 global weather pattern near-surface ocean wind rain events wind speed measurement
Mission: |SeaWinds|
URL: https://doi.org/10.1109/IGARSS.2004.1369866
Other URLs:
Chelton D.B., Schlax M.G., Freilich M.H., and Milliff R.F. (2004). Satellite Measurements Reveal Persistent Small-Scale Features in Ocean Winds, Science, 303(5660), 978-983, 10.1126/science.1091901. Journal Article »
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Title: Satellite Measurements Reveal Persistent Small-Scale Features in Ocean Winds
Type: Journal Article
Publication: Science
Author(s): Chelton D.B., Schlax M.G., Freilich M.H., and Milliff R.F.
Year: 2004
Formatted Citation: Chelton D.B., Schlax M.G., Freilich M.H., and Milliff R.F., 2004: Satellite Measurements Reveal Persistent Small-Scale Features in Ocean Winds, Science, 303(5660), 978-983, 10.1126/science.1091901.
Abstract: Four-year averages of 25-kilometer-resolution measurements of near-surface wind speed and direction over the global ocean from the QuikSCAT satellite radar scatterometer reveal the existence of surprisingly persistent small-scale features in the dynamically and thermodynamically important curl and divergence of the wind stress. Air-sea interaction over sea surface temperature fronts throughout the world ocean is evident in both the curl and divergence fields, as are the influences of islands and coastal mountains. Ocean currents such as the Gulf Stream generate distinctive patterns in the curl field. These previously unresolved features have important implications for oceanographic and air-sea interaction research.
Keywords: SEA-SURFACE TEMPERATURE, TROPICAL INSTABILITY WAVES, EASTERN EQUATORIAL PACIFIC, GREENLAND TIP JET, SEASONAL CYCLE, STRESS, FRONT, CIRCULATION, VARIABILITY, CURRENTS
Mission: |SeaWinds|WindSat|
URL: https://doi.org/10.1126/science.1091901
Other URLs:
Curry, J.A., Bentamy, A., Bourassa, M.A., Bourras, D., Bradley, E.F., Brunke, M., Castro, S., Chou, S.H., Clayson, C.A., Emery, W.J., Eymard, L., Fairall, C.W., Kubota, M., Lin, B., Perrie, W., Reeder, R.A., Renfrew, I.A., Rossow, W.B., Schulz, J., Smith, S.R., Webster, P.J., Wick, G.A., and Zeng, X. (2004). SEAFLUX, Bulletin of the American Meteorological Society, 85(3), 409-424, 10.1175/BAMS-85-3-409. Journal Article »
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Title: SEAFLUX
Type: Journal Article
Publication: Bulletin of the American Meteorological Society
Author(s): Curry, J.A., Bentamy, A., Bourassa, M.A., Bourras, D., Bradley, E.F., Brunke, M., Castro, S., Chou, S.H., Clayson, C.A., Emery, W.J., Eymard, L., Fairall, C.W., Kubota, M., Lin, B., Perrie, W., Reeder, R.A., Renfrew, I.A., Rossow, W.B., Schulz, J., Smith, S.R., Webster, P.J., Wick, G.A., and Zeng, X.
Year: 2004
Formatted Citation: Curry, J.A., Bentamy, A., Bourassa, M.A., Bourras, D., Bradley, E.F., Brunke, M., Castro, S., Chou, S.H., Clayson, C.A., Emery, W.J., Eymard, L., Fairall, C.W., Kubota, M., Lin, B., Perrie, W., Reeder, R.A., Renfrew, I.A., Rossow, W.B., Schulz, J., Smith, S.R., Webster, P.J., Wick, G.A., and Zeng, X., 2004: SEAFLUX, Bulletin of the American Meteorological Society, 85(3), 409-424, 10.1175/BAMS-85-3-409.
Abstract:
Keywords: air-sea fluxes, fluxes, satellite, research vessel, FSU_fluxes
Mission: |SeaWinds|
URL: https://doi.org/10.1175/BAMS-85-3-409
Other URLs:
Draper, D.W., and Long, D.G. (2004). Assessing the Quality of SeaWinds Rain Measurements, IEEE Transactions on Geoscience and Remote Sensing, 42(7), 1424-1432, 10.1109/TGRS.2004.828194. Journal Article »
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Title: Assessing the Quality of SeaWinds Rain Measurements
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Draper, D.W., and Long, D.G.
Year: 2004
Formatted Citation: Draper, D.W., and Long, D.G., 2004: Assessing the Quality of SeaWinds Rain Measurements, IEEE Transactions on Geoscience and Remote Sensing, 42(7), 1424-1432, 10.1109/TGRS.2004.828194.
Abstract: While SeaWinds was designed to measure ocean Winds, it can also measure rain over the ocean. SeaWinds on QuikSCAT active measurements of integrated columnar rain rate obtained via simultaneous wind/rain retrieval are evaluated via Monte Carlo simulation and the Cramer-Rao lower bound on estimate accuracy. Although sufficiently accurate in many conditions, the simultaneous wind/rain retrieval method used with SeaWinds on QuikSCAT data is ill-conditioned for certain wind directions and measurement geometries, sometimes yielding spurious rain rates in zero-rain conditions. To assess the validity of SeaWinds-derived rain rates, a simple empirically based rain thresholding scheme is presented, derived from simulated data. Thresholded QuikSCAT rain rates are compared to Tropical Rainfall Measuring Mission Microwave Imager monthly-averaged data, demonstrating good correlation for monthly-averaged data.
Keywords: WIND SCATTEROMETER, ACCURACY, TRMM, maximum likelihood, SeaWinds, scatterometer, simultaneous wind/rain retrieval, Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI)
Mission: |SeaWinds|
URL: https://doi.org/10.1109/TGRS.2004.828194
Other URLs:
Draper, D.W., and Long, D.G. (2004). Simultaneous Wind and Rain Retrieval Using SeaWinds Data, IEEE Transactions on Geoscience and Remote Sensing, 42(7), 1411-1423, 10.1109/TGRS.2004.830169. Journal Article »
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Title: Simultaneous Wind and Rain Retrieval Using SeaWinds Data
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Draper, D.W., and Long, D.G.
Year: 2004
Formatted Citation: Draper, D.W., and Long, D.G., 2004: Simultaneous Wind and Rain Retrieval Using SeaWinds Data, IEEE Transactions on Geoscience and Remote Sensing, 42(7), 1411-1423, 10.1109/TGRS.2004.830169.
Abstract: The SeaWinds scatterometers onboard the QuikSCAT and the Advanced Earth Observing Satellite 2 measure ocean winds on a global scale via the relationship between the normalized radar backscattering cross section of the ocean and the vector wind. The current wind retrieval method ignores scattering and attenuation of ocean rain, which alter backscatter measurements and corrupt retrieved winds. Using a simple rain backscatter and attenuation model, two methods of improving wind estimation in the presence of rain are evaluated. First, if no suitable prior knowledge of the rain rate is available, a maximum-likelihood estimation technique is used to simultaneously retrieve the wind velocity and rain rate. Second, when a suitable outside estimate of the rain rate is available, wind retrieval is performed by correcting the wind geophysical model function for the known rain via the rain backscatter model. The new retrieval techniques are evaluated via simulation and validation with data from the National Centers for Environmental Prediction and the Tropical Rainfall Measuring Mission Precipitation Radar. The simultaneous wind/rain estimation method yields most accurate winds in the sweet spot of SeaWinds' swath. On the outer-beam edges of the swath, simultaneous wind/rain estimation is not usable. Wind speeds from simultaneous wind/rain retrieval are nearly unbiased for all rain rates and wind speeds, while conventionally retrieved wind speeds become increasingly biased with rain rate. A synoptic example demonstrates that the new method is capable of reducing the rain-induced wind vector error while producing a consistent (yet noisy) estimate of the rain rate.
Keywords: KU-BAND, SCATTEROMETER, ACCURACY, OCEAN, NSCAT, ERRORS, maximum-likelihood scatterometer, SeaWinds, simultaneous wind/rain retrieval, Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR)
Mission: |NSCAT|SeaWinds|
URL: https://doi.org/10.1109/TGRS.2004.830169
Other URLs:
Etcheto, J., Dinnat, E.P., Boutin, J., Camps, A., Miller, J., Contardo, S., Wesson, J., Font, J., and Long, D.G. (2004). Wind Speed Effect on L-Band Brightness Temperature Inferred from EuroSTARRS and WISE 2001 Field Experiments, IEEE Transactions on Geoscience and Remote Sensing, 42(10), 2206-2213, 10.1109/TGRS.2004.834644. Journal Article »
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Title: Wind Speed Effect on L-Band Brightness Temperature Inferred from EuroSTARRS and WISE 2001 Field Experiments
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Etcheto, J., Dinnat, E.P., Boutin, J., Camps, A., Miller, J., Contardo, S., Wesson, J., Font, J., and Long, D.G.
Year: 2004
Formatted Citation: Etcheto, J., Dinnat, E.P., Boutin, J., Camps, A., Miller, J., Contardo, S., Wesson, J., Font, J., and Long, D.G., 2004: Wind Speed Effect on L-Band Brightness Temperature Inferred from EuroSTARRS and WISE 2001 Field Experiments, IEEE Transactions on Geoscience and Remote Sensing, 42(10), 2206-2213, 10.1109/TGRS.2004.834644.
Abstract: The results from two field experiments in the Mediterranean Sea are used to study the wind speed dependence of brightness temperature at L-band. During the EuroSTARRS airborne experiment, an L-band radiometer made measurements across a large wind speed gradient, enabling us to study this dependence at high wind speed. We compare our results with a two-scale emissivity model using several representations of the sea state spectrum. While the results are encouraging, unfortunately the accuracy of the measurements does not permit us to distinguish between the so-called twice Durden and Vesecky spectrum and the Elfouhaily spectrum above 7 m s^-1. The effect of foam is certainly small. During the WISE 2001 field experiment carried on an oil rig, we studied this dependence at low wind speed, finding an abrupt decrease of the wind speed effect on the brightness temperature below 3 m s^-1.
Keywords: Foam L-band radiometry sea state spectrum sea surface salinity wave wind
Mission:
URL: https://doi.org/10.1109/TGRS.2004.834644
Other URLs:
Haarpaintner, J., Tonboe, R.T., Long, D.G., and Van Woert, M.L. (2004). Automatic Detection and Validity of the Sea-Ice Edge: An Application of Enhanced-Resolution QuikScat/SeaWinds Data, IEEE Transactions on Geoscience and Remote Sensing, 42(7), 1433-1443, 10.1109/TGRS.2004.828195. Journal Article »
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Title: Automatic Detection and Validity of the Sea-Ice Edge: An Application of Enhanced-Resolution QuikScat/SeaWinds Data
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Haarpaintner, J., Tonboe, R.T., Long, D.G., and Van Woert, M.L.
Year: 2004
Formatted Citation: Haarpaintner, J., Tonboe, R.T., Long, D.G., and Van Woert, M.L., 2004: Automatic Detection and Validity of the Sea-Ice Edge: An Application of Enhanced-Resolution QuikScat/SeaWinds Data, IEEE Transactions on Geoscience and Remote Sensing, 42(7), 1433-1443, 10.1109/TGRS.2004.828195.
Abstract: Sea-ice edge detection is an essential task at the different national ice services to secure navigation in ice-covered seas. Comparison between the Remund and Long ice mask image from enhanced-resolution QuikScat/SeaWinds (QS) products and the analyzed ice edge from high-resolution RADARSAT synthetic aperture radar has shown that the automatically determined QS ice mask underestimates the Arctic ice extent. QS data was statistically analyzed by colocating the data with ice charts around Greenland and with the National Aeronautics and Space Administration Team's Special Sensor Microwave/Imager (SSM/I) ice concentration algorithm over the whole Arctic region. All variables, i.e., the backscatter in vertical and horizontal polarization, the active polarization ratio (APR) and the daily standard deviation, are sensitive to ice types and are strongly correlated with ice concentration when the relationship is expressed in exponential form. Our study showed that the APR is especially suitable for ice-ocean separation, and a threshold of -0.02 was determined. An ice edge algorithm based on this APR threshold was developed using the other variables with conservative season-dependent thresholds to eliminate additional ocean noise. Also, the history of the ice cover is considered in order to detect single ice fields that are separated from the main Arctic pack ice. Validation with RADARSAT 1 and with the Advanced Very High Resolution Radiometer showed that the new algorithm successfully detects very low ice concentrations of about 10% during the entire year. The validity of the detected ice edge for near-real-time issues is also discussed in relation to the ice motion in the Marginal Ice Zone and the integration time necessary to produce the enhanced-resolution images. The new algorithm improves the automatic global ice edge resolution by a factor of two when compared to SSM/I products and could be used in both model initialization and data assimilation.
Keywords: BAND SCATTEROMETER DATA, BACKSCATTER MAPS, NSCAT, STORFJORDEN, SVALBARD, OCEAN, COVER, Arctic, backscatter, ice edge, polarization, scatterometer, sea ice
Mission: |SeaWinds|
URL: https://doi.org/10.1109/TGRS.2004.828195
Other URLs:
Kelly, K.A. (2004). Wind Data: A Promise in Peril, Science, 303(5660), 962-963, 10.1126/science.1094584. Journal Article »
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Title: Wind Data: A Promise in Peril
Type: Journal Article
Publication: Science
Author(s): Kelly, K.A.
Year: 2004
Formatted Citation: Kelly, K.A., 2004: Wind Data: A Promise in Peril, Science, 303(5660), 962-963, 10.1126/science.1094584.
Abstract: Satellite-based radars called scatterometers are yielding a wealth of new data about wind and ocean currents. In her Perspective, Kelly discusses the report by Chelton et al., in which scatterometer data are analyzed to show the importance of small-scale wind structures in interactions between wind and ocean. What is needed now, writes Kelly, is a sustained program of such observations to provide data for improved weather and climate prediction.
Keywords:
Mission:
URL: https://doi.org/10.1126/science.1094584
Other URLs:
Kunz, L.B., and Long, D.G. (2004). Melt Detection in Antarctic Ice-Sheets Using Spaceborne Scatterometers and Radiometers, International Geoscience and Remote Sensing Symposium, IGARSS `04, vol. 1, 117-120, 10.1109/IGARSS.2004.1368959. Conference Paper »
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Title: Melt Detection in Antarctic Ice-Sheets Using Spaceborne Scatterometers and Radiometers
Type: Conference Paper
Publication: International Geoscience and Remote Sensing Symposium, IGARSS `04
Author(s): Kunz, L.B., and Long, D.G.
Year: 2004
Formatted Citation: Kunz, L.B., and Long, D.G., 2004: Melt Detection in Antarctic Ice-Sheets Using Spaceborne Scatterometers and Radiometers, International Geoscience and Remote Sensing Symposium, IGARSS `04, vol. 1, 117-120, 10.1109/IGARSS.2004.1368959.
Abstract: Backscatter measurements from the Sea Winds on QuikSCAT scatterometer are used to determine periods of surface freeze and melt on Antarctic ice-shelves. A maximum likelihood method is used to infer the daily ice-surface conditions for various study points located on the Ronne, Ross, Larsen, Fimbul, Amery, and Shackleton ice-shelves. Criteria for determining the dates of melt-onset and freeze-up for each Austral summer are presented. Validation of the ice-state and melt-onset date estimates is performed by analyzing the corresponding brightness temperature (T/sub b/) measurements from special sensor microwave/imager (SSM/I) radiometers. QuikSCAT /spl sigma//spl deg/ measurements from 1999 through 2003 are analyzed and found to be very useful for determining periods of melt in Antarctic ice-sheets and provide high temporal and spatial resolution ice-state estimates.
Keywords: glaciology ice image sensors maximum likelihood detection radar cross-sections radiometry spaceborne radar AD 1999 to 2003 Amery ice-shelf Antarctic ice-sheets Austral summer Fimbul ice-shelf Larsen ice-shelf Qu
Mission: |SeaWinds|
URL: https://doi.org/10.1109/IGARSS.2004.1368959
Other URLs:
Liu, Q., Jiang, X., Xie, S.-P., and Liu, W.T. (2004). A Gap in the Indo-Pacific Warm Pool Over the South China Sea in Boreal Winter: Seasonal Development and Interannual Variability, Journal of Geophysical Research: Oceans, 109, C07012, 10.1029/2003JC002179. Journal Article »
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Title: A Gap in the Indo-Pacific Warm Pool Over the South China Sea in Boreal Winter: Seasonal Development and Interannual Variability
Type: Journal Article
Publication: Journal of Geophysical Research: Oceans
Author(s): Liu, Q., Jiang, X., Xie, S.-P., and Liu, W.T.
Year: 2004
Formatted Citation: Liu, Q., Jiang, X., Xie, S.-P., and Liu, W.T., 2004: A Gap in the Indo-Pacific Warm Pool Over the South China Sea in Boreal Winter: Seasonal Development and Interannual Variability, Journal of Geophysical Research: Oceans, 109, C07012, 10.1029/2003JC002179.
Abstract: The Indo-Pacific warm water pool in boreal winter shows a conspicuous gap over the South China Sea (SCS) where sea surface temperature (SST) is considerably lower than over the oceans both to the west and east. The formation mechanisms for the climatology and interannual variability of SCS SST in boreal winter are investigated using a suite of new satellite measurements. The winter SCS is divided into two parts by the axis of the maximum northeasterly monsoonal winds. The positive wind curl in the southeastern half of the ocean drives a cyclonic gyre circulation in the deep basin. As its western boundary current, an intense southward flow is found south of Vietnam on the continental slope separating the Sunda Shelf to the west and the deep SCS basin to the east. This slope current exceeds 0.5 m s^-1 in speed and advects cold water from the north. This cold advection results in a distinct cold tongue in the winter SST climatology. Both the slope current and the cold tongue are strongest in November to February. This winter cold tongue displays considerable interannual variability that is highly correlated with eastern equatorial Pacific SST. In an El Niño the winter monsoon weakens, causing the SCS ocean circulation to spin down. The reduced western boundary current and its thermal advection result in a warming in the SCS winter cold tongue. Both SST variance and its correlation with the El Niño-Southern Oscillation peak along the climatological cold tongue indicate that ocean dynamics are an important player in SCS climate variability.
Keywords: * Indo-Pacific warm pool * South China Sea * cold tongue
Mission:
URL: https://doi.org/10.1029/2003JC002179
Other URLs:
Long, D.G. (2004). Reconstruction of High Resolution Ocean Wind Vectors from Low Resolution Scatterometer Measurements, Image Reconstruction from Incomplete Data III, 196-207, 10.1117/12.565721. Conference Paper »
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Title: Reconstruction of High Resolution Ocean Wind Vectors from Low Resolution Scatterometer Measurements
Type: Conference Paper
Publication: Image Reconstruction from Incomplete Data III
Author(s): Long, D.G.
Year: 2004
Formatted Citation: Long, D.G., 2004: Reconstruction of High Resolution Ocean Wind Vectors from Low Resolution Scatterometer Measurements, Image Reconstruction from Incomplete Data III, 196-207, 10.1117/12.565721.
Abstract: Designed to retrieve near-surface winds over the ocean, the SeaWinds scatterometer makes 13.4 GHz Ku-band measurements of the normalized radar backscatter of the Earth's surface from which the near-surface vector (speed and direction) wind is estimated. Conventional processing of the backscatter measurements results in 25 km resolution winds. However, by applying reconstruction algorithms the backscatter can be estimated at much finer resolution, albeit at reduced accuracy. This innovative application of reconstruction theory has a number of novel elements including irregular sampling, a two dimensional vector signal, multiplicative and additive noise, and a nonlinear transfer function between the measurements and the signal. This paper describes the high resolution wind retrieval problem, the solution approaches adopted, and sample results.
Keywords:
Mission: |SeaWinds|
URL: https://doi.org/10.1117/12.565721
Other URLs:
Milliff, R.F., Morzel, J., Chelton, D.B., and Freilich, M.H. (2004). Wind Stress Curl and Wind Stress Divergence Biases from Rain Effects on QSCAT Surface Wind Retrievals, Journal of Atmospheric and Oceanic Technology, 21(8), 1216-1231, 10.1175/1520-0426(2004)021<1216:WSCAWS>2.0.CO,2. Journal Article »
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Title: Wind Stress Curl and Wind Stress Divergence Biases from Rain Effects on QSCAT Surface Wind Retrievals
Type: Journal Article
Publication: Journal of Atmospheric and Oceanic Technology
Author(s): Milliff, R.F., Morzel, J., Chelton, D.B., and Freilich, M.H.
Year: 2004
Formatted Citation: Milliff, R.F., Morzel, J., Chelton, D.B., and Freilich, M.H., 2004: Wind Stress Curl and Wind Stress Divergence Biases from Rain Effects on QSCAT Surface Wind Retrievals, Journal of Atmospheric and Oceanic Technology, 21(8), 1216-1231, 10.1175/1520-0426(2004)021<1216:WSCAWS>2.0.CO,2.
Abstract: Surface vector wind datasets from scatterometers provide essential high-resolution surface forcing information for analyses and models of global atmosphere-ocean processes affecting weather and climate. The importance of realistic amplitude, high-wavenumber, surface wind forcing from scatterometer data has been demonstrated in a variety of ocean modeling applications. However, the radar backscatter signal from which surface vector wind estimates are retrieved is attenuated and/or contaminated in heavy rain. The QuikSCAT (QSCAT) dataset flags rain-contaminated wind vector cells where retrievals are either highly uncertain or not available. Zonal and annual averages of wind stress curl and divergence for 2000, 2001, and 2002 are derived and compared across three surface wind datasets: QSCAT only, reanalysis winds from the National Centers for Environmental Prediction (NCEP reanalysis), and blended QSCAT+NCEP. Missing QSCAT surface wind retrievals due to rain contamination lead to statistically significant discrepancies of up to 50% in the implied Sverdrup transports in subtropical and subpolar gyre regions of the Northern and Southern Hemispheres. Dataset-to-dataset wind stress divergence amplitude differences due to rain contamination are also large in the midlatitude storm track regions. Discrepancies occur in the Tropics due to rain contamination effects on QSCAT data and due to high-wavenumber deficiencies in the NCEP reanalysis winds. In addition, NCEP operational forecast model surface wind analyses (NCEP-FNL) have been trilinearly interpolated to the QSCAT wind vector cell locations and sample times. The NCEP-FNL winds are not affected by rain, so it is possible to compare NCEP-FNL-interpolated surface wind fields and related quantities calculated with and without wind vectors at the rain-flagged wind vector cell locations. When all locations are included, wind stress curl amplitudes are found to be skewed toward cyclonic curl in both hemispheres. Vectors at rain-flagged locations in both hemispheres are also skewed toward large-amplitude, cyclonic curls. This is because midlatitude synoptic systems are the meteorological sources of large-amplitude cyclonic curls, as well as the places where the rain-flag bias in wind stress curl is largest. Blended QSCAT+NCEP surface winds ameliorate the rain-flag-induced biases in zonal averages of wind stress curl and wind stress divergence, while retaining high-wavenumber properties of the scatterometer winds. Evidence to support rainflag algorithm refinement for high wind speeds is presented.
Keywords: SCATTEROMETER WINDS, TROPICAL PACIFIC, OCEAN, TEMPERATURE, SENSITIVITY, RESOLUTION, FIELDS, SCALE, NSCAT,
Mission: |NSCAT|SeaWinds|
URL: https://doi.org/10.1175/1520-0426(2004)021%3C1216:WSCAWS%3E2.0.CO;2
Other URLs:
Moore, R.K., and Jones, W.L. (2004). Satellite Scatterometer Wind Vector Measurements - The Legacy of the Seasat Satellite Scatterometer, IEEE Geoscience and Remote Sensing Newsletter, Sept.(132), 18-32.
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Title: Satellite Scatterometer Wind Vector Measurements - The Legacy of the Seasat Satellite Scatterometer
Type: Journal Article
Publication: IEEE Geoscience and Remote Sensing Newsletter
Author(s): Moore, R.K., and Jones, W.L.
Year: 2004
Formatted Citation: Moore, R.K., and Jones, W.L., 2004: Satellite Scatterometer Wind Vector Measurements - The Legacy of the Seasat Satellite Scatterometer, IEEE Geoscience and Remote Sensing Newsletter, Sept.(132), 18-32.
Abstract:
Keywords:
Mission: |SeaWinds|
URL:
Other URLs:
Perlin, N., Samelson, R.M., and Chelton, D.B. (2004). Scatterometer and Model Wind and Wind Stress in the Oregon-Northern California Coastal Zone, Monthly Weather Review, 132(8), 2110-2129, 10.1175/1520-0493(2004)132<2110:SAMWAW>2.0.CO,2. Journal Article »
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Title: Scatterometer and Model Wind and Wind Stress in the Oregon-Northern California Coastal Zone
Type: Journal Article
Publication: Monthly Weather Review
Author(s): Perlin, N., Samelson, R.M., and Chelton, D.B.
Year: 2004
Formatted Citation: Perlin, N., Samelson, R.M., and Chelton, D.B., 2004: Scatterometer and Model Wind and Wind Stress in the Oregon-Northern California Coastal Zone, Monthly Weather Review, 132(8), 2110-2129, 10.1175/1520-0493(2004)132<2110:SAMWAW>2.0.CO,2.
Abstract: Measurements of surface wind stress by the SeaWinds scatterometer on NASA`s Quick Scatterometer (QuikSCAT) satellite are analyzed and compared with several different atmospheric model products, from an operational model and two high-resolution nested regional models, during two summer periods, June through September 2000 and 2001, in the coastal region west of Oregon and northern California. The mean summer wind stress had a southward component over the entire region in both years. Orographic intensifications of both the mean and fluctuating wind stress occurred near Cape Blanco, Cape Mendocino, and Point Arena. Substantial differences between the model products are found for the mean, variable, and diurnal wind stress fields. Temporal correlations with the QuikSCAT observations are highest for the operational model, and are not improved by either nested model. The highest-resolution nested model most accurately reproduced the mean observed stress fields, but slightly degrades the temporal correlations due to incoherent high-frequency (0.5-2 cpd) fluctuations. The QuikSCAT data reveal surprisingly strong diurnal fluctuations that extend offshore 150 km or more with magnitudes that are a significant fraction of the mean wind stress. Wind stress curl fields from QuikSCAT and the models show local cyclonic and anticyclonic maxima associated with the orographic wind intensification around the capes. The present results are consistent with the hypothesis of a wind-driven mechanism for coastal jet separation and cold water plume and anticyclonic eddy formation in the California Current System south of Cape Blanco.
Keywords: ATMOSPHERIC BOUNDARY-LAYER, OCEAN DYNAMICS EXPERIMENT, CURRENT SYSTEM, UPWELLING REGION, MARINE-LAYER, WEST-COAST, JET, FLOW, SIMULATION, TURBULENCE,
Mission: |SeaWinds|
URL: https://doi.org/10.1175/1520-0493(2004)132%3C2110:SAMWAW%3E2.0.CO;2
Other URLs:
Rignot, E., Thomas, R.H., Kanagaratnam, P., Casassa, G., Frederick, E., Gogineni, S., Krabill, W., Rivera, A., Russell, R., Sonntag, J., Swift, R., and Yungel, J. (2004). Improved Estimation of the Mass Balance of Glaciers Draining into the Amundsen Sea Sector of West Antarctica from the CECS/NASA 2002 Campaign, Annals of Glaciology, 39(1), 231-237, 10.3189/172756404781813916. Journal Article »
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Title: Improved Estimation of the Mass Balance of Glaciers Draining into the Amundsen Sea Sector of West Antarctica from the CECS/NASA 2002 Campaign
Type: Journal Article
Publication: Annals of Glaciology
Author(s): Rignot, E., Thomas, R.H., Kanagaratnam, P., Casassa, G., Frederick, E., Gogineni, S., Krabill, W., Rivera, A., Russell, R., Sonntag, J., Swift, R., and Yungel, J.
Year: 2004
Formatted Citation: Rignot, E., Thomas, R.H., Kanagaratnam, P., Casassa, G., Frederick, E., Gogineni, S., Krabill, W., Rivera, A., Russell, R., Sonntag, J., Swift, R., and Yungel, J., 2004: Improved Estimation of the Mass Balance of Glaciers Draining into the Amundsen Sea Sector of West Antarctica from the CECS/NASA 2002 Campaign, Annals of Glaciology, 39(1), 231-237, 10.3189/172756404781813916.
Abstract: In November-December 2002, a joint airborne experiment by Centro de Estudios Cientificos and NASA flew over the Antarctic ice sheet to collect laser altimetry and radio-echo sounding data over glaciers flowing into the Amundsen Sea. A P-3 aircraft on loan from the Chilean Navy made four flights over Pine Island, Thwaites, Pope, Smith and Kohler glaciers, with each flight yielding 1.5-2 hours of data. The thickness measurements reveal that these glaciers flow into deep troughs, which extend far inland, implying a high potential for rapid retreat. Interferometric synthetic aperture radar data (InSAR) and satellite altimetry data from the European Remote-sensing Satellites (ERS-1/-2) show rapid grounding-line retreat and ice thinning of these glaciers. Using the new thickness data, we have re-evaluated glacier fluxes and the present state of mass balance, which was previously estimated using ice thicknesses deduced largely from inversion of elevation data assuming hydrostatic equilibrium. The revised total ice discharge of 241 ± 5 km³ a^-1 exceeds snow accumulation by 81 +/- 17 km³ a^-1 of ice, equivalent to a sea-level rise of 0.21 +/- 0.04 mm a^-1. This magnitude of ice loss is too large to be caused by atmospheric forcing and implies dynamic thinning of the glaciers. This is confirmed by ice-flow acceleration observed with InSAR. We attribute the flow acceleration and ice thinning to enhanced bottom melting of the ice shelves by a warmer ocean, which reduces buttressing of the glaciers, and in turn accelerates them out of balance.
Keywords: PINE-ISLAND GLACIER, GREENLAND ICE-SHEET, THWAITES GLACIER, POLAR ICE, SHELF, THICKNESS, OCEAN,
Mission:
URL: https://doi.org/10.3189/172756404781813916
Other URLs:
Stephen, H., and Long, D.G. (2004). Analysis of Scatterometer Observations of Saharan Ergs Using a Simple Rough Facet Model, 2004 IEEE International Geoscience & Remote Sensing Symposium (IGARSS '04), 1534-1537, 10.1109/IGARSS.2004.1370604. Conference Paper »
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Title: Analysis of Scatterometer Observations of Saharan Ergs Using a Simple Rough Facet Model
Type: Conference Paper
Publication: 2004 IEEE International Geoscience & Remote Sensing Symposium (IGARSS '04)
Author(s): Stephen, H., and Long, D.G.
Year: 2004
Formatted Citation: Stephen, H., and Long, D.G., 2004: Analysis of Scatterometer Observations of Saharan Ergs Using a Simple Rough Facet Model, 2004 IEEE International Geoscience & Remote Sensing Symposium (IGARSS '04), 1534-1537, 10.1109/IGARSS.2004.1370604.
Abstract: The Sahara desert includes large expanses of sand dunes called ergs. These dunes are formed and constantly reshaped by prevailing winds. Previous study shows that Saharan ergs exhibit significant radar backscatter (sigmadeg) modulation with azimuth angle (Phi). We use sigmadeg measurements observed at various incidence angles (thetas) and Phi from the NASA scatterometer (NSCAT), the Seawinds scatterometer aboard QuikSCAT (QS-CAT), the ERS scatterometer (ESCAT) and the Tropical Rain Monitoring Mission`s Precipitation Radar (TRMM-PR) to model the sigmadeg response from sand dunes. Sand dunes are modeled as a composite of tilted rough facets and small ripples. The dune fields are modeled as composed of many simple dunes. The sigmadeg measured by the scatterometer from (thetas, Phi) look direction is the sum of the returns from all the rough facets in the footprint. The model is applied to linear and transverse dunes with rough facets and Gaussian tilt distributions. The model results in a sigmadeg response similar to the NSCAT and ESCAT observations over areas of known dune types in the Sahara. This analysis gives a unique insight into scattering by large scale sand bedforms
Keywords: Gaussian distribution backscatter geomorphology remote sensing by radar sand terrain mapping wind ERS scatterometer observation ESCAT Gaussian tilt distributions NASA scatterometer observation NSCAT QS-CAT Sahara
Mission: |NSCAT|SeaWinds|
URL: https://doi.org/10.1109/IGARSS.2004.1370604
Other URLs:
Stockwell, R.G., Large, W.G., Milliff, R.F. (2004). Resonant Inertial Oscillations in Moored Buoy Ocean Surface Winds, Tellus A: Dynamic Meteorology and Oceanography, 56(5), 536-547, 10.1111/j.1600-0870.2004.00086.x. Journal Article »
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Title: Resonant Inertial Oscillations in Moored Buoy Ocean Surface Winds
Type: Journal Article
Publication: Tellus A: Dynamic Meteorology and Oceanography
Author(s): Stockwell, R.G., Large, W.G., Milliff, R.F.
Year: 2004
Formatted Citation: Stockwell, R.G., Large, W.G., Milliff, R.F., 2004: Resonant Inertial Oscillations in Moored Buoy Ocean Surface Winds, Tellus A: Dynamic Meteorology and Oceanography, 56(5), 536-547, 10.1111/j.1600-0870.2004.00086.x.
Abstract: The surface winds from the moored buoy data set available from the National Data Buoy Center are examined for the occurrence of inertial range oscillations in the surface winds by employing a novel joint time frequency analysis of the two-component vector winds. This data set was chosen for its high time resolution (1-h sampling) that enabled the full characterization of these inertial oscillations, its at least partially global coverage, and its record length, which is needed to extract the signals from the background noise. The observation system is comprised of over 200 sites with measurements as far back as 1972. Because of the large amount of data, many harmonics of the diurnal atmospheric tidal signature in the surface winds (24, 12, 8, and 3 h) were found in high-precision power spectra. These tidal oscillations are found to be important contributors to the inertial range oscillation at latitudes of 30, where the largest inertial range oscillations are found. By turning to local (in time) spectral analysis using the S-transform, considerable energy was also found in the inertial frequency ranges at other latitudes, typically in the form of very large (>10 m s-1), yet short-lived (of the order of a few days) events. The surface wind rotation direction in near inertial frequency bands favors resonant inertial oscillations at all latitudes, and in every season of the year.
Keywords: Ocean dynamics , Atmospheric dynamics , spectral analysis , Power spectrum , Background noise , sampling , high resolution , Surface wind , Sea surface , Buoy
Mission:
URL: https://doi.org/10.1111/j.1600-0870.2004.00086.x
Other URLs:
Vecchi, G.A., Xie, S.-P., and Fischer, A.S. (2004). Ocean-Atmosphere Covariability in the Western Arabian Sea, Journal of Climate, 17(6), 1213-1224, 10.1175/1520-0442(2004)017<1213:OCITWA>2.0.CO,2. Journal Article »
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Title: Ocean-Atmosphere Covariability in the Western Arabian Sea
Type: Journal Article
Publication: Journal of Climate
Author(s): Vecchi, G.A., Xie, S.-P., and Fischer, A.S.
Year: 2004
Formatted Citation: Vecchi, G.A., Xie, S.-P., and Fischer, A.S., 2004: Ocean-Atmosphere Covariability in the Western Arabian Sea, Journal of Climate, 17(6), 1213-1224, 10.1175/1520-0442(2004)017<1213:OCITWA>2.0.CO,2.
Abstract: The western Arabian Sea exhibits strong spatial variability in sea surface temperature (SST) during the southwest monsoon, with changes in SST that can exceed 5°C over 200 km. Exploration of satellite-based and in situ data shows a strong connection between mesoscale SST features and changes in the atmospheric boundary layer. The fundamental relationship is that of weak (strong) wind velocities overlying cold (warm) SST features. There are also coherent changes in other near-surface meteorological parameters, such as the air-sea temperature difference and relative humidity-indicating changes in the stability of the planetary boundary layer over the mesoscale SST features. These relationships are similar to those recently reported over the equatorial Pacific tropical instability wave region. This observed covariability of atmospheric boundary layer structure and SST results in variations of the surface heat and moisture fluxes, latent heat flux is modified by changes in relative humidity (principally through the temperature dependence of saturation specific humidity), wind speed, and boundary layer stability over the cold filaments. The nonlinear dependence of latent heat flux on the three parameters leads to a net enhancement of latent heat flux from the mesoscale features, as compared to that computed using spatially averaged parameters. Additionally, the spatial structure of the heat-flux variability will tend to dampen the mesoscale SST features. The mesoscale wind variability results in strong wind stress curl patterns on the same spatial scales as the oceanic features. The resulting Ekman pumping variations may play an important role in the evolution of the ocean eddy fields in this region. Further examination of the processes controlling the observed covariability, and the oceanic and atmospheric response to the coupling should therefore be undertaken.
Keywords: Pacific Ocean , Indian Ocean , troposphere , Climatology , coupling , Ekman pumping , Wind effect , winds , Specific humidity , saturation , Temperature dependence , Latent heat , heat transfer , Tropical instability wave , Equatorial Pacific , stability
Mission:
URL: https://doi.org/10.1175/1520-0442(2004)017%3C1213:OCITWA%3E2.0.CO;2
Other URLs:
Weissman, D.E., Apgar, G., Tongue, J.S., and Bourassa, M.A. (2004). Corrections to Scatterometer Wind Vectors - Removing the Effects of Rain, American Meteorological Society 13th Conference on Satellite Meteorology and Oceanography. Conference Paper »
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Title: Corrections to Scatterometer Wind Vectors - Removing the Effects of Rain
Type: Conference Paper
Publication: American Meteorological Society 13th Conference on Satellite Meteorology and Oceanography
Author(s): Weissman, D.E., Apgar, G., Tongue, J.S., and Bourassa, M.A.
Year: 2004
Formatted Citation: Weissman, D.E., Apgar, G., Tongue, J.S., and Bourassa, M.A., 2004: Corrections to Scatterometer Wind Vectors - Removing the Effects of Rain, American Meteorological Society 13th Conference on Satellite Meteorology and Oceanography.
Abstract:
Keywords:
Mission:
URL: https://ams.confex.com/ams/pdfpapers/79262.pdf
Other URLs:
Weissman, D.E., Bourassa, M.A., and Durden, S.L. (2004). Corrections to the SeaWinds Scatterometer Wind Vectors by Removing the Effects of Rain from the NRCS, IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2004), 10.1109/IGARSS.2004.1368521. Conference Paper »
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Title: Corrections to the SeaWinds Scatterometer Wind Vectors by Removing the Effects of Rain from the NRCS
Type: Conference Paper
Publication: IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2004)
Author(s): Weissman, D.E., Bourassa, M.A., and Durden, S.L.
Year: 2004
Formatted Citation: Weissman, D.E., Bourassa, M.A., and Durden, S.L., 2004: Corrections to the SeaWinds Scatterometer Wind Vectors by Removing the Effects of Rain from the NRCS, IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2004), 10.1109/IGARSS.2004.1368521.
Abstract: A method of correcting the errors caused by rain, to the normalized radar cross section measured by spaceborne scatterometers is presented. The simultaneous, collocated measurements of the vertical precipitation profile by the TRMM and AMSR passive radiometers are converted into reflectivity and attenuation to develop a method for removing the effects of rain backscatter and signal attenuation from the total signal received at the satellite. A mathematical model has been developed, which represents the principal electromagnetic mechanisms of K_u-band attenuation and scattering, using the polarization and illumination details for this scatterometer. The rain-impact NRCS is also considered. The amount of correction to the L2A data product values depends on the wind speed, rainrate and polarization.
Keywords: atmospheric techniques oceanography radar cross-sections radiometry rain remote sensing by radar wind
Mission: |SeaWinds|
URL: https://doi.org/10.1109/IGARSS.2004.1368521
Other URLs:
Xie, S.-P. (2004). Satellite Observations of Cool Ocean-Atmosphere Interaction, Bulletin of the American Meteorological Society, 85(2), 195-208, 10.1175/BAMS-85-2-195. Journal Article »
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Title: Satellite Observations of Cool Ocean-Atmosphere Interaction
Type: Journal Article
Publication: Bulletin of the American Meteorological Society
Author(s): Xie, S.-P.
Year: 2004
Formatted Citation: Xie, S.-P., 2004: Satellite Observations of Cool Ocean-Atmosphere Interaction, Bulletin of the American Meteorological Society, 85(2), 195-208, 10.1175/BAMS-85-2-195.
Abstract: Over most of the World Ocean, sea surface temperature (SST) is below 26°C and atmospheric deep convection rarely takes place. Cool ocean-atmosphere interaction is poorly understood and this lack of understanding is a stumbling block in the current effort to study non-ENSO climate variability. Using new satellite observations, the response of surface wind and low clouds to changes in SST is investigated over cool oceans, where the planetary boundary layer (PBL) is often capped by a temperature inversion. While one-way atmospheric forcing is a major mechanism for basin-scale SST variability in the extratropics, clear wind response is detected in regions of strong ocean currents. In particular, SST modulation of vertical momentum mixing emerges as the dominant mechanism for SST-induced wind variability near oceanic fronts around the world, which is characterized by a positive SST-wind speed correlation. Several types of boundary layer cloud response are found, whose correlation with SST varies from positive to negative, depending on the role of surface moisture convergence. Noting that the surface moisture convergence is strongly scale dependent, it is proposed that horizontal scale is important for setting the sign of this SST-cloud correlation. Finally, the processes by which a shallow PBL response might lead to a deep, tropospheric-scale response and the implications for the study of extratropical basin-scale air-sea interaction are discussed.
Keywords:
Mission:
URL: https://doi.org/10.1175/BAMS-85-2-195
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Yoho, P.K., and Long, D.G. (2004). Correlation and Covariance of Satellite Scatterometer Measurements, IEEE Transactions on Geoscience and Remote Sensing, 42(6), 1179-1187, 10.1109/TGRS.2004.825588. Journal Article »
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Title: Correlation and Covariance of Satellite Scatterometer Measurements
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Yoho, P.K., and Long, D.G.
Year: 2004
Formatted Citation: Yoho, P.K., and Long, D.G., 2004: Correlation and Covariance of Satellite Scatterometer Measurements, IEEE Transactions on Geoscience and Remote Sensing, 42(6), 1179-1187, 10.1109/TGRS.2004.825588.
Abstract: Capable scatterometer designs have been developed that seek improved resolution through the use of higher pulse sampling rates. The high sampling rates bring the traditional scatterometry assumption of measurement independence into question. This paper uses fundamental scattering theory to derive general expressions for correlation and covariance between scatterometer measurements and provides practical analysis using current and future instruments as examples. The paper derives expressions for the measurement variance parameter K/sub p/ when measurement correlation due to Rayleigh fading effects is present and relates K/sub p/ to the statistics of multiple pulse measurements. A function of the transmit signal modulation and receive processing, the measurement correlation is zero for nonoverlapping measurements but can become significant for overlapping measurements at high pulse sampling rates. The paper discusses the effects of correlation on the accuracy of scatterometer measurements and evaluates tradeoffs between spatial overlap, levels of additive noise, and measurement precision.
Keywords: $K_p$ Correlation HYDROS Hydrosphere States Mission QuikSCAT SeaWinds covariance scatterometry
Mission: |SeaWinds|
URL: https://doi.org/10.1109/TGRS.2004.825588
Other URLs:
Ashcraft, I.S., and Long, D.G. (2003). Increasing Temporal Resolution in Greenland Ablation Estimation Using Passive and Active Microwave Data, 2003 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `03), 1604-1606, 10.1109/IGARSS.2003.1294190. Conference Paper »
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Title: Increasing Temporal Resolution in Greenland Ablation Estimation Using Passive and Active Microwave Data
Type: Conference Paper
Publication: 2003 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `03)
Author(s): Ashcraft, I.S., and Long, D.G.
Year: 2003
Formatted Citation: Ashcraft, I.S., and Long, D.G., 2003: Increasing Temporal Resolution in Greenland Ablation Estimation Using Passive and Active Microwave Data, 2003 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `03), 1604-1606, 10.1109/IGARSS.2003.1294190.
Abstract:
Keywords:
Mission: |SeaWinds|
URL: https://doi.org/10.1109/IGARSS.2003.1294190
Other URLs:
Ashcraft, I.S., and Long, D.G. (2003). The Spatial Response Function of SeaWinds Backscatter Measurements, Earth Observing Systems VIII, 609-618, 10.1117/12.506255. Conference Paper »
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Title: The Spatial Response Function of SeaWinds Backscatter Measurements
Type: Conference Paper
Publication: Earth Observing Systems VIII
Author(s): Ashcraft, I.S., and Long, D.G.
Year: 2003
Formatted Citation: Ashcraft, I.S., and Long, D.G., 2003: The Spatial Response Function of SeaWinds Backscatter Measurements, Earth Observing Systems VIII, 609-618, 10.1117/12.506255.
Abstract: Designed to retrieve near-surface winds over the ocean, the SeaWinds scatterometer makes 13.4 GHz Ku-band measurements of the normalized radar backscatter of the Earth's surface. SeaWinds backscatter measurements are being used in a wide variety of studies, including ocean wind retrieval, sea-ice mapping and classification, iceberg tracking, vegetation, soil moisture, and snow accumulation. Two SeaWinds instruments are currently flying in orbit. Due to the high spatial sampling density, SeaWinds data is ideally suited for the application of reconstruction and resolution enhancement algorithms. Such algorithms require accurate knowledge of the spatial response function of the individual measurements, "slices" and "eggs." Standard SeaWinds data products from JPL include the locations of the measurements, but not the response functions. In this paper we derive the spatial response function for both egg and slices. The response functions vary with antenna azimuth and orbit location. Because computation of the response function is laborious, methods of tabularizing and interpolating the response function have been developed. These are described in this paper. We provide code and the tables to enable computation the response function using information from standard JPL data products. We hope these will further the development of resolution-enhanced SeaWinds data. Examples of resulting enhanced resolution images are included.
Keywords:
Mission: |SeaWinds|
URL: https://doi.org/10.1117/12.506255
Other URLs:
Berliner, L.M., Milliff, R.F., and Wikle, C.K. (2003). Bayesian Hierarchical Modeling of Air-Sea Interaction, Journal of Geophysical Research, 108(C4), 3104, 10.1029/2002JC001413. Journal Article »
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Title: Bayesian Hierarchical Modeling of Air-Sea Interaction
Type: Journal Article
Publication: Journal of Geophysical Research
Author(s): Berliner, L.M., Milliff, R.F., and Wikle, C.K.
Year: 2003
Formatted Citation: Berliner, L.M., Milliff, R.F., and Wikle, C.K., 2003: Bayesian Hierarchical Modeling of Air-Sea Interaction, Journal of Geophysical Research, 108(C4), 3104, 10.1029/2002JC001413.
Abstract: By means of Bayesian hierarchical modeling (BHM), we develop a model for aspects of vigorous air-sea interactions on a basin scale. The approach relies on both physical reasoning and statistical techniques for data processing and uncertainty management. The theory and current practice of BHM of air-sea interaction physics will be introduced and demonstrated in this paper. The demonstration is in the context of an observing system simulation experiment. An ocean truth simulation is driven by idealized surface winds in a testbed domain abstracted from the Labrador Sea. Artificial observations analogous to scatterometer and altimeter data are supplied to a BHM and comparisons made with the evolution of the truth simulation over a ten day experiment. Substantial attention is devoted to description of computational techniques.
Keywords: Atlantic Ocean , North Atlantic , Labrador Sea , Quasi geostrophic approximation , Monte Carlo method , Data assimilation , Surface wind , Uncertainty , Data processing , Numerical simulation , Ocean atmosphere interaction
Mission:
URL: https://doi.org/10.1029/2002JC001413
Other URLs:
Bourassa, M.A., and Weissman, D.E. (2003). A Direct Surface Wind Stress Algorithm for the SeaWinds Scatterometer, 12th Conference on Satellite Meteorology and Oceanography. Conference Paper »
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Title: A Direct Surface Wind Stress Algorithm for the SeaWinds Scatterometer
Type: Conference Paper
Publication: 12th Conference on Satellite Meteorology and Oceanography
Author(s): Bourassa, M.A., and Weissman, D.E.
Year: 2003
Formatted Citation: Bourassa, M.A., and Weissman, D.E., 2003: A Direct Surface Wind Stress Algorithm for the SeaWinds Scatterometer, 12th Conference on Satellite Meteorology and Oceanography.
Abstract: The sea surface characteristics to which scatterometers respond are considered to respond more directly to stress than to wind, however, due to vastly more plentiful and more accurate wind observations, scatterometers are calibrated to winds. Wind speed is the dominant consideration in determining equivalent neutral surface stress, however, directional sea state can contribute to substantial variability. Calculating stress directly from the scatterometers observed backscatter can theoretically account for this variability. Such an algorithm is described. Fields of stress are determined directly from backscatter, and compared to stress fields derived from scatterometer winds and common drag coefficients. Regional biases are discussed.
Keywords:
Mission: |SeaWinds|
URL: http://ams.confex.com/ams/pdfpapers/57348.pdf
Other URLs:
Chou, S.-H., Nelkin, E., Ardizzone, J., Atlas, R., and Shie, C.-L. (2003). Surface Turbulent Heat and Momentum Fluxes Over Global Oceans Based on the Goddard Satellite Retrievals, Version 2 (GSSTF2), Journal of Climate, 16(20), 3256-3273, 10.1175/1520-0442(2003)016<3256:STHAMF>2.0.CO,2. Journal Article »
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Title: Surface Turbulent Heat and Momentum Fluxes Over Global Oceans Based on the Goddard Satellite Retrievals, Version 2 (GSSTF2)
Type: Journal Article
Publication: Journal of Climate
Author(s): Chou, S.-H., Nelkin, E., Ardizzone, J., Atlas, R., and Shie, C.-L.
Year: 2003
Formatted Citation: Chou, S.-H., Nelkin, E., Ardizzone, J., Atlas, R., and Shie, C.-L., 2003: Surface Turbulent Heat and Momentum Fluxes Over Global Oceans Based on the Goddard Satellite Retrievals, Version 2 (GSSTF2), Journal of Climate, 16(20), 3256-3273, 10.1175/1520-0442(2003)016<3256:STHAMF>2.0.CO,2.
Abstract: Information on the turbulent fluxes of momentum, latent heat, and sensible heat at the airsea interface is essential in improving model simulations of climate variations and in climate studies. A 13.5-yr (July 1987December 2000) dataset of daily surface turbulent fluxes over global oceans has been derived from the Special Sensor Microwave Imager (SSM/I) radiance measurements. This dataset, Goddard Satellite-based Surface Turbulent Fluxes, version 2 (GSSTF2), has a spatial resolution of 1^o x 1^o latitude-longitude and a temporal resolution of 1 day. Turbulent fluxes are derived from the SSM/I surface winds and surface air humidity, as well as the 2-m air and sea surface temperatures (SST) of the NCEPNCAR reanalysis, using a bulk aerodynamic algorithm based on the surface layer similarity theory. The GSSTF2 bulk flux model is validated by comparing hourly turbulent fluxes computed from ship data using the model with those observed fluxes of 10 field experiments over the tropical and midlatitude oceans during 199199. In addition, the GSSTF2 daily wind stress, latent heat flux, wind speed, surface air humidity, and SST compare reasonably well with those of the collocated measurements of the field experiments. The global distributions of 19882000 annual- and seasonal-mean turbulent fluxes show reasonable patterns related to the atmospheric general circulation and seasonal variations. Zonal averages of latent heat fluxes and input parameters over global oceans during 1992-93 have been compared among several flux datasets: GSSTF1 (version 1), GSSTF2, the Hamburg OceanAtmosphere Parameters and Fluxes from Satellite Data (HOAPS), NCEPNCAR reanalysis, and one based on the Comprehensive OceanAtmosphere Data Set (COADS). Significant differences are found among the five. These analyses suggest that the GSSTF2 latent heat flux, surface air humidity, and winds are likely to be more realistic than the other four flux datasets examined, although those of GSSTF2 are still subject to regional biases. The GSSTF2 is useful for climate studies and has been submitted to the sea surface turbulent flux project (SEAFLUX) for intercomparison studies.
Keywords: Retrieval algorithm , Sea surface temperature , Validation , Similarity theory , Algorithm , Data analysis , Radiance , Microwave radiometry , Satellite observation , Space remote sensing , Ocean atmosphere interaction , Climatology , Latent heat , Sensib
Mission:
URL: https://doi.org/10.1175/1520-0442(2003)016%3C3256:STHAMF%3E2.0.CO;2
Other URLs:
Cronin, M.F., Xie, S.-P., and Hashizume, H. (2003). Barometric Pressure Variations Associated with Eastern Pacific Tropical Instability Waves, Journal of Climate, 16(18), 3050-3057, 10.1175/1520-0442(2003)016<3050:BPVAWE>2.0.CO,2. Journal Article »
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Title: Barometric Pressure Variations Associated with Eastern Pacific Tropical Instability Waves
Type: Journal Article
Publication: Journal of Climate
Author(s): Cronin, M.F., Xie, S.-P., and Hashizume, H.
Year: 2003
Formatted Citation: Cronin, M.F., Xie, S.-P., and Hashizume, H., 2003: Barometric Pressure Variations Associated with Eastern Pacific Tropical Instability Waves, Journal of Climate, 16(18), 3050-3057, 10.1175/1520-0442(2003)016<3050:BPVAWE>2.0.CO,2.
Abstract: Barometric pressure, surface temperature, and wind time series in the eastern equatorial Pacific are analyzed to determine if oceanic tropical instability wave (TIW) sea surface temperature variations cause barometric pressure gradients large enough to influence the atmospheric boundary layer. During the study period from April 2001 to September 2002, 11 TIWs propagated westward past 110°W, causing a spectral peak at 20-30 days in the sea surface temperature (SST) meridional difference between 2°N, 110°W and 0°, 110°W. Likewise, the meridional pressure difference also had a spectral peak in the 20-30-day TIW band. Cross-spectral analysis shows that within the TIW band, SST-induced pressure variations were roughly -0.1 hPa °C^-1 in magnitude. The resulting pressure gradient force is comparable in magnitude to other terms in the meridional momentum balance. Implications about the role of the boundary layer capping in the adjustment to SST forcing are discussed.
Keywords: Pacific Ocean , Equatorial Pacific , Spectral analysis , Mooring , Observation data , Atmospheric boundary layer , Ocean atmosphere interaction , Marine atmosphere , Tropical instability wave , Ocean wave , Sea surface , Surface temperature , Forcing , Se
Mission:
URL: https://doi.org/10.1175/1520-0442(2003)016%3C3050:BPVAWE%3E2.0.CO;2
Other URLs:
Davis, S.R., Bourassa, M.A., Atlas, R., Ardizzone, J., Brin, E., O`Brien, J.J., and Zierden, D.F. (2003). Near-Realtime Sea surface Pressure Fields from NASA's SeaWinds Scatterometer and Their Impact in NWP, CAS/JSC Working Group on Numerical Experimentation, Research Activities, ed. H. Ritchie, 01:2.
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Title: Near-Realtime Sea surface Pressure Fields from NASA's SeaWinds Scatterometer and Their Impact in NWP
Type: Report
Publication: CAS/JSC Working Group on Numerical Experimentation, Research Activities
Author(s): Davis, S.R., Bourassa, M.A., Atlas, R., Ardizzone, J., Brin, E., O`Brien, J.J., and Zierden, D.F.
Year: 2003
Formatted Citation: Davis, S.R., Bourassa, M.A., Atlas, R., Ardizzone, J., Brin, E., O`Brien, J.J., and Zierden, D.F., 2003: Near-Realtime Sea surface Pressure Fields from NASA's SeaWinds Scatterometer and Their Impact in NWP, CAS/JSC Working Group on Numerical Experimentation, Research Activities, ed. H. Ritchie, 01:2.
Abstract:
Keywords: QSCAT, pressure
Mission: |SeaWinds|
URL:
Other URLs:
Draper, D.W., and Long, D.G. (2003). Simultaneous Wind and Rain Measurements from SeaWinds Data, Ocean Remote Sensing and Imaging II, 226-237, 10.1117/12.506393. Conference Paper »
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Title: Simultaneous Wind and Rain Measurements from SeaWinds Data
Type: Conference Paper
Publication: Ocean Remote Sensing and Imaging II
Author(s): Draper, D.W., and Long, D.G.
Year: 2003
Formatted Citation: Draper, D.W., and Long, D.G., 2003: Simultaneous Wind and Rain Measurements from SeaWinds Data, Ocean Remote Sensing and Imaging II, 226-237, 10.1117/12.506393.
Abstract: A maximum likelihood estimation (MLE) method for simultaneously retrieving wind and rain from SeaWinds scatterometer data is introduced and evaluated. The new method incorporates rain backscatter and attenuation into the retrieval process via a simple wind/rain backscatter model. Two retrieval methods are examined: First, when no estimate of the rain rate is available, the new MLE method simultaneously estimates wind speed, wind direction and rain rate. Second, when an estimate of the rain is available, the wind is retrieved by directly correcting the geophysical model function using the rain/wind backscatter model. From simulation, the simultaneous wind/rain retrieval approach demonstrates improved wind vector estimates where the rain is significant. The improvement in retrieval is more pronounced in the "sweet spot" of SeaWinds" cross track. The rain-corrected wind retrieval approach gives somewhat improved wind speed estimates for rain-contaminated wind vectors over the simultaneous wind/rain retrieval method, especially when the effect of rain is small. Validation of the SeaWinds rain data with co-located Tropical Rainfall Measuring Mission precipitation radar rain rates shows that with some limitations the SeaWinds scatterometer can measure rain.
Keywords:
Mission: |SeaWinds|
URL: https://doi.org/10.1117/12.506393
Other URLs:
Draper, D.W., and Long, D.G. (2003). An Advanced Ambiguity Selection Algorithm for SeaWinds, IEEE Transactions on Geoscience and Remote Sensing, 41(3), 538-547, 10.1109/TGRS.2003.810228. Journal Article »
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Title: An Advanced Ambiguity Selection Algorithm for SeaWinds
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Draper, D.W., and Long, D.G.
Year: 2003
Formatted Citation: Draper, D.W., and Long, D.G., 2003: An Advanced Ambiguity Selection Algorithm for SeaWinds, IEEE Transactions on Geoscience and Remote Sensing, 41(3), 538-547, 10.1109/TGRS.2003.810228.
Abstract: SeaWinds on QuikSCAT, a spaceborne Ku-band scatterometer, estimates ocean winds via the relationship between the normalized radar backscatter and the vector wind. Scatterometer wind retrieval generates several possible wind vector solutions or ambiguities at each resolution cell, requiring a separate ambiguity selection step to give a unique solution. In processing SeaWinds on QuikSCAT data, the ambiguity selection is nudged or initialized using numerical weather prediction winds. We describe a sophisticated new ambiguity selection approach developed at Brigham Young University (BYU) that does not require nudging. The BYU method utilizes a low-order data-driven Karhunen-Loeve (KL) wind field model to promote self-consistency. Ambiguity selected winds from the BYU method and standard SeaWinds processing are compared over a set of 102 revs. A manual examination of the data suggests that the nonnudging BYU method selects a more self-consistent wind field in the absence of cyclonic storms. Over a set of cyclonic storm regions, BYU performs better in 9% of the cases and worse in 20% of the cases. Overall, the BYU algorithm selects 93% of the same ambiguities as the standard dataset. This comparison helps validate both nonnudging and nudging techniques and indicates that SeaWinds ambiguity selection can be generally accomplished without nudging.
Keywords: WIND ESTIMATION, SCATTEROMETER, NSCAT, REMOVAL, ambiguity selection, Karhunen-Loeve model, nudging, scatterometer, SeaWinds
Mission: |NSCAT|SeaWinds|
URL: https://doi.org/10.1109/TGRS.2003.810228
Other URLs:
Gutierrez, S., and Long, D.G. (2003). Optical Flow and Scale-Space Methods and Applications in Sea-Ice Motion in Antarctica, 2003 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `03), 2805-2807, 10.1109/IGARSS.2003.1294592. Conference Paper »
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Title: Optical Flow and Scale-Space Methods and Applications in Sea-Ice Motion in Antarctica
Type: Conference Paper
Publication: 2003 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `03)
Author(s): Gutierrez, S., and Long, D.G.
Year: 2003
Formatted Citation: Gutierrez, S., and Long, D.G., 2003: Optical Flow and Scale-Space Methods and Applications in Sea-Ice Motion in Antarctica, 2003 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `03), 2805-2807, 10.1109/IGARSS.2003.1294592.
Abstract: Sea-ice motion in Antarctica is studied applying methods from computer vision and scale-space theory to a sequence of images obtained from scatterometer data. The proposed method can obtain a dense motion vector field for any specific observation scale. Spatial and temporal scales are used to focus on relevant geophysical features and events. A preprocessing stage involving spatial and temporal filtering at selected scales reduces noise and artifacts produced in the image generation phases, allowing reliable feature extraction and tracking at relevant scales. Optical flow (OF) methods provide a dense estimation of the motion field. The limitations and advantages of this approach are discussed. Optical flow sea-ice motion data are in agreement with sea winds data obtained independently and with very different methodologies. OF results are compared to data from wavelet methods.
Keywords: computer vision geophysical signal processing image motion analysis image sequences oceanographic techniques remote sensing sea ice spatial filters Antarctica computer vision feature extraction image sequences mo
Mission:
URL: https://doi.org/10.1109/IGARSS.2003.1294592
Other URLs:
Gutierrez, S., and Long, D.G. (2003). Application of Optical Flow and Scale Space Methods to Sea-Ice Motion in Antarctica, Ocean Remote Sensing and Imaging II, 249-256, 10.1117/12.506209. Conference Paper »
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Title: Application of Optical Flow and Scale Space Methods to Sea-Ice Motion in Antarctica
Type: Conference Paper
Publication: Ocean Remote Sensing and Imaging II
Author(s): Gutierrez, S., and Long, D.G.
Year: 2003
Formatted Citation: Gutierrez, S., and Long, D.G., 2003: Application of Optical Flow and Scale Space Methods to Sea-Ice Motion in Antarctica, Ocean Remote Sensing and Imaging II, 249-256, 10.1117/12.506209.
Abstract: Methods from computer vision and scale-space theory are applied to the study of sea-ice motion in Antarctica. The input data is a sequence of daily images of the continent, obtained from scatterometer data and processed with a resolution enhancing algorithm. The information contained in these images can be studied at different scales when the appropriate filters are applied. Large scales omit detail and smoothen local variations of intensity while smaller scales show much detail and local variation. When motion is studied through different scales, different patterns might be observed. We assume that all the information coded in these images is the radar backscatter, and that it is closely coupled with advection. The Optical Flow method is used to obtain a dense vector field representing sea-ice motion, the method"s limitations are overcome by adding second order constraints to the main equation and through the use of large neighborhoods to normalize the direction of flow. Validation of results has been done to the extent possible, taking into account that there is practically no ground-truth data available for Antarctica in the form of buoy-data. Sea-ice motion results are displayed along available ocean surface wind data, observing a clear consistency along the ocean-ice border. The results are compared to existing studies applying wavelets and it is shown that differences can be explained by the fact that each method is observing motion at a different scale.
Keywords:
Mission:
URL: https://doi.org/10.1117/12.506209
Other URLs:
Hoar, T.J., Milliff, R.F., Nychka, D., Wikle, C.K., and Berliner, L.M. (2003). Winds from a Bayesian Hierarchical Model: Computation for Atmosphere-Ocean Research, Journal of Computational & Graphical Statistics, 12(4), 781-807, 10.1198/1061860032616. Journal Article »
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Title: Winds from a Bayesian Hierarchical Model: Computation for Atmosphere-Ocean Research
Type: Journal Article
Publication: Journal of Computational & Graphical Statistics
Author(s): Hoar, T.J., Milliff, R.F., Nychka, D., Wikle, C.K., and Berliner, L.M.
Year: 2003
Formatted Citation: Hoar, T.J., Milliff, R.F., Nychka, D., Wikle, C.K., and Berliner, L.M., 2003: Winds from a Bayesian Hierarchical Model: Computation for Atmosphere-Ocean Research, Journal of Computational & Graphical Statistics, 12(4), 781-807, 10.1198/1061860032616.
Abstract: Advances in computing power are allowing researchers to use Bayesian hierarchical models (BHM) on problems previously considered computationally infeasible. This article discusses the procedure of migrating a BHM from a workstation-class implementation to a massively parallel architecture, indicative of the current direction of advances in computing hardware. The parallel implementation is nearly 500 times larger than the workstation-class implementation from the data perspective. The BHM in question combines the information from a scatterometer on board a polar-orbiting satellite and the result of a numerical weather prediction model and produces an ensemble of high-resolution tropical surface wind fields with physically realistic variability at all spatial scales.
Keywords: FORTRAN 90, GIBBS SAMPLING, PARALLEL COMPUTING, SPATIO-TEMPORAL PROCESSES
Mission:
URL: https://doi.org/10.1198/1061860032616
Other URLs:
Lagerloef, G., Lukas, R., Bonjean, F., Gunn, J., Mitchum, G., Bourassa, M., and Busalacchi, T. (2003). El Niño Tropical Pacific Ocean Surface Current and Temperature Evolution in 2002 and Outlook for Early 2003, Geophysical Research Letters, 30(10), 1514, 10.1029/2003GL017096. Journal Article »
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Title: El Niño Tropical Pacific Ocean Surface Current and Temperature Evolution in 2002 and Outlook for Early 2003
Type: Journal Article
Publication: Geophysical Research Letters
Author(s): Lagerloef, G., Lukas, R., Bonjean, F., Gunn, J., Mitchum, G., Bourassa, M., and Busalacchi, T.
Year: 2003
Formatted Citation: Lagerloef, G., Lukas, R., Bonjean, F., Gunn, J., Mitchum, G., Bourassa, M., and Busalacchi, T., 2003: El Niño Tropical Pacific Ocean Surface Current and Temperature Evolution in 2002 and Outlook for Early 2003, Geophysical Research Letters, 30(10), 1514, 10.1029/2003GL017096.
Abstract: The timing and magnitude of the 20022003 El Niño Southern Oscillation (ENSO) warm episode has been monitored for the first time with near real time satellite-derived surface current (SC) fields in addition to the operational temperature, wind and sea level satellite and in situ measurements previously used. The record of the past decade shows that dominant SC anomalies generally lead ENSO sea surface temperature (SST) anomalies by 2.53 months, and that a rapid SC anomaly reversal has coincided with the peak SST of warm events. During September to December 2002, SST anomalies increased and spread eastward in conjunction with strong, sustained eastward SC anomalies that began in July. The SC anomaly peaked in early October, followed by a sharp decrease in November and December to negative values in January. This was much like the SC sequence during the same months of the 19971998 El Niñ0 when the SST anomaly peaked in December 1997. The recent SST anomalies were maximum in November 2002 and declined thereafter. These SC and SST trends signify that the present warm event has peaked and SST anomalies will continue to decline in early 2003.
Keywords: ENSO, QSCAT, Altimetry, currents
Mission: |SeaWinds|
URL: https://doi.org/10.1029/2003GL017096
Other URLs:
Long, D.G. (2003). Reconstruction and Resolution Enhancement Techniques for Microwave Sensors, Frontiers of Remote Sensing Information Processing, 255-281, 10.1142/9789812796752_0011. Chapter »
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Title: Reconstruction and Resolution Enhancement Techniques for Microwave Sensors
Type: Chapter
Publication: Frontiers of Remote Sensing Information Processing
Author(s): Long, D.G.
Year: 2003
Formatted Citation: Long, D.G., 2003: Reconstruction and Resolution Enhancement Techniques for Microwave Sensors, Frontiers of Remote Sensing Information Processing, 255-281, 10.1142/9789812796752_0011.
Abstract:
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Mission:
URL: https://doi.org/10.1142/9789812796752_0011
Other URLs:
Long, D.G., and Luke, J.B. (2003). High Resolution Wind Retrieval for SeaWinds, Ocean Remote Sensing and Imaging II, 216-225, 10.1117/12.506336. Conference Paper »
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Title: High Resolution Wind Retrieval for SeaWinds
Type: Conference Paper
Publication: Ocean Remote Sensing and Imaging II
Author(s): Long, D.G., and Luke, J.B.
Year: 2003
Formatted Citation: Long, D.G., and Luke, J.B., 2003: High Resolution Wind Retrieval for SeaWinds, Ocean Remote Sensing and Imaging II, 216-225, 10.1117/12.506336.
Abstract: The SeaWinds instrument on the QuikSCAT satellite was designed to measure near surface winds over the ocean at a nominal resolution of 25 km with daily global coverage. Recently, reconstruction and resolution enhancement algorithms have been applied to the QuikSCAT measurements to generate high resolution backscatter fields. These high resolution fields make it possible to retrieve the wind at higher spatial resolution. Substantially finer wind and rain features are evident in the dense wind fields. The tradeoff is a higher noise level in the estimated winds. This paper describes the high resolution wind retrieval approach and the accuracy of the resulting high resolution winds. The limitations of the high resolution winds are considered. Methods for improving the accuracy of the data are presented.
Keywords:
Mission: |SeaWinds|
URL: https://doi.org/10.1117/12.506336
Other URLs:
Long, D.G., Ashcraft, I.S., and Luke, J.B. (2003). Radar Scatterometer Observations of Sastrugi on the Great Ice Sheets, Earth Observing Systems VIII, 85-93, 10.1117/12.506291. Conference Paper »
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Title: Radar Scatterometer Observations of Sastrugi on the Great Ice Sheets
Type: Conference Paper
Publication: Earth Observing Systems VIII
Author(s): Long, D.G., Ashcraft, I.S., and Luke, J.B.
Year: 2003
Formatted Citation: Long, D.G., Ashcraft, I.S., and Luke, J.B., 2003: Radar Scatterometer Observations of Sastrugi on the Great Ice Sheets, Earth Observing Systems VIII, 85-93, 10.1117/12.506291.
Abstract: The SeaWinds instrument on the QuikSCAT satellite was designed to measure near surface winds over the ocean, however, this remarkable remote sensing instrument has proven very useful in polar ice studies. Unlike previous radar scatterometers which were limited to 2 or 3 azimuth angles, the Ku-band SeaWinds instrument uses a circular scanning pencil beam, allowing it to make radar backscatter measurements from all azimuth angles. This geometry makes it an ideal candidate for studies of azimuth modulation of the normalized radar cross section of natural surfaces. Previous studieshave observed a second order azimuth modulation of radar backscatter on the Antartic ice sheet, which has been related to wind-generated sastrugi (snow dunes) on the surface. In this paper we use SeaWinds data to make more detailed studies of the azimuth modulation in both Antarctica and Greenland where little has been done. Using the higher azimuth resolution possible with SeaWinds, we find that the azimuth variation of the backscatter is better described using a fourth order model in areas with the highest modulation. The orientation of these fourth order terms appears to be highly correlated to the katabatic wind direction. Azimuth modulation is as observed over Greenland, but it is much smaller than over Antarctica. Comparing SeaWinds and ERS-1/2 satterometer mode data we examine the frequency dependence, finding the modulation larger at C-band than Ku-band. The largest azimuth modulation in Greenland is observed in the transition region between dry snow and percolation zones.
Keywords:
Mission: |SeaWinds|
URL: https://doi.org/10.1117/12.506291
Other URLs:
Long, D.G., Luke, J.B., and Plant, W. (2003). Ultra High Resolution Wind Retrieval for SeaWinds, International Geoscience and Remote Sensing Symposium, 2003. IGARSS `03., 2, 1264-1266, 10.1109/IGARSS.2003.1294077. Conference Paper »
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Title: Ultra High Resolution Wind Retrieval for SeaWinds
Type: Conference Paper
Publication: International Geoscience and Remote Sensing Symposium, 2003. IGARSS `03.
Author(s): Long, D.G., Luke, J.B., and Plant, W.
Year: 2003
Formatted Citation: Long, D.G., Luke, J.B., and Plant, W., 2003: Ultra High Resolution Wind Retrieval for SeaWinds, International Geoscience and Remote Sensing Symposium, 2003. IGARSS `03., 2, 1264-1266, 10.1109/IGARSS.2003.1294077.
Abstract: The SeaWinds series of scatterometer instruments were designed to measure vector winds over the ocean at a nominal resolution of 25 km. However, the radar backscatter measurements from which the wind is inferred are made at finer resolution than this. Further, the spatial sampling of the backscatter measurements can support reconstruction of finer scale backscatter values which can then be used to estimate the near-surface wind vector field at high resolution (pixel spacing of 2.5 km). At this resolution, the data can be used to study coastal and mesoscale wind features such as tropical cyclones and convective storms. In this paper we use simulation and actual data to validate the accuracy of the retrieved winds and analyze the effective resolution of the wind estimates. An empirical technique to compensate for the estimate bias ism developed and applied and an improved method for ambiguity selection is developed. Comparison of the derived vector winds with a variety of other wind sensors is very encouraging.
Keywords: atmospheric techniques backscatter oceanography radar resolution remote sensing by radar spaceborne radar storms wind SeaWinds coastal wind features convective storms mesoscale wind features near-surface wind vect
Mission: |SeaWinds|
URL: https://doi.org/10.1109/IGARSS.2003.1294077
Other URLs:
Nonaka, M., and Xie, S.-P. (2003). Co-Variations of Sea Surface Temperature and Wind Over the Kuroshio and Its Extension: Evidence for Ocean-to-Atmospheric Feedback, Journal of Climate, 16(9), 1404-1413, 10.1175/1520-0442(2003)16<1404:COSSTA>2.0.CO,2. Journal Article »
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Title: Co-Variations of Sea Surface Temperature and Wind Over the Kuroshio and Its Extension: Evidence for Ocean-to-Atmospheric Feedback
Type: Journal Article
Publication: Journal of Climate
Author(s): Nonaka, M., and Xie, S.-P.
Year: 2003
Formatted Citation: Nonaka, M., and Xie, S.-P., 2003: Co-Variations of Sea Surface Temperature and Wind Over the Kuroshio and Its Extension: Evidence for Ocean-to-Atmospheric Feedback, Journal of Climate, 16(9), 1404-1413, 10.1175/1520-0442(2003)16<1404:COSSTA>2.0.CO,2.
Abstract: Satellite microwave measurements are analyzed, revealing robust covariability in sea surface temperature (SST) and wind speed over the Kuroshio Extension (KE) east of Japan. Ocean hydrodynamic instabilities cause the KE to meander and result in large SST variations. Increased (reduced) wind speeds are found to be associated with warm (cold) SST anomalies. This positive SST-wind correlation in KE is confirmed by in situ buoy measurements and is consistent with a vertical shear adjustment mechanism. Namely, an increase in SST reduces the static stability of the near-surface atmosphere, intensifying the vertical turbulence mixing and bringing fast-moving air from aloft to the sea surface. South of Japan, the Kuroshio is known to vary between nearshore and offshore paths. These paths are very persistent and can last for months to years. As the Kuroshio shifts its path, coherent wind changes are detected from satellite data. In particular, winds are high south of Tokyo when the Kuroshio takes the nearshore path while they are greatly reduced when this warm current leaves the coast in the offshore path. The positive SST-wind correlation over the strong Kuroshio Current and its extension is opposite to the negative one often observed in regions of weak currents such as south of the Aleutian low. The latter correlation is considered to be indicative of atmosphere-to-ocean forcing.
Keywords: Asia , Pacific Ocean , North Pacific , Japan , Kuroshio , Turbulent mixing , Adjustment(atmosphere, ocean) , Ocean atmosphere interaction , Forcing , Atmospheric turbulence , Atmospheric stability , Buoy , Measurement in situ , Anomaly , Meander , Hydrody
Mission:
URL: https://doi.org/10.1175/1520-0442(2003)16%3C1404:COSSTA%3E2.0.CO;2
Other URLs:
O'Neill L.W., Chelton D.B., and Esbensen S.K. (2003). Observations of SST-Induced Perturbations of the Wind Stress Field Over the Southern Ocean on Seasonal Timescales, Journal of Climate, 16(14), 2340-2354, 10.1175/2780.1. Journal Article »
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Title: Observations of SST-Induced Perturbations of the Wind Stress Field Over the Southern Ocean on Seasonal Timescales
Type: Journal Article
Publication: Journal of Climate
Author(s): O'Neill L.W., Chelton D.B., and Esbensen S.K.
Year: 2003
Formatted Citation: O'Neill L.W., Chelton D.B., and Esbensen S.K., 2003: Observations of SST-Induced Perturbations of the Wind Stress Field Over the Southern Ocean on Seasonal Timescales, Journal of Climate, 16(14), 2340-2354, 10.1175/2780.1.
Abstract: The surface wind stress response to sea surface temperature (SST) over the latitude range 30^o-60^oS in the Southern Ocean is described from the National Aeronautics and Space Administration's QuikSCAT scatterometer observations of wind stress and Reynolds analyses of SST during the 2-yr period August 1999 to July 2001. While ocean-atmosphere coupling at midlatitudes has previously been documented from several case studies, this is the first study to quantify this relation over the entire Southern Ocean. The spatial structures of the surface wind perturbations with wavelengths shorter than 10 latitude by 30 longitude are closely related to persistent spatial variations of the SST field on the same scales. The wind stress curl and divergence are shown to be linearly related, respectively, to the crosswind and downwind components of the SST gradient. The curl response has a magnitude only about half that of the divergence response. This observed coupling is consistent with the hypothesis that SST modification of marine atmospheric boundary layer (MABL) stability affects vertical turbulent mixing of momentum, inducing perturbations in the surface winds. The nonequivalence between the responses of the curl and divergence to the crosswind and downwind SST gradients suggests that secondary circulations in the MABL may also play an important role by producing significant perturbations in the surface wind field near SST fronts that are distinct from the vertical turbulent transfer of momentum. The importance of the wind stress curl in driving Ekman vertical velocity in the open ocean implies that the coupling between winds and SST may have important feedback effects on upper ocean processes near SST fronts.
Keywords: SEA-SURFACE TEMPERATURE, ATMOSPHERIC BOUNDARY-LAYER, EASTERN EQUATORIAL PACIFIC, TROPICAL INSTABILITY WAVES, GULF-STREAM, AGULHAS CURRENT, NORTH WALL, FRONT, GRADIENTS, VARIABILITY
Mission:
URL: https://doi.org/10.1175/2780.1
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Otterman, J., Atlas, R., Russell, G.L., and Saaroni, H. (2003). Impact on Regional Winter Climate by CO₂ Increases vs. by Maritime-Air Advection, Geophysical Research Letters, 30(15), 10.1029/2003GL017545. Journal Article »
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Title: Impact on Regional Winter Climate by CO₂ Increases vs. by Maritime-Air Advection
Type: Journal Article
Publication: Geophysical Research Letters
Author(s): Otterman, J., Atlas, R., Russell, G.L., and Saaroni, H.
Year: 2003
Formatted Citation: Otterman, J., Atlas, R., Russell, G.L., and Saaroni, H., 2003: Impact on Regional Winter Climate by CO₂ Increases vs. by Maritime-Air Advection, Geophysical Research Letters, 30(15), 10.1029/2003GL017545.
Abstract: Fractional Outgoing Radiation, FOR (dimensionless), defined as the ratio of Outgoing Longwave Radiation, OLR (W/m²), to upward Surface Longwave Emission, SLE (W/m2), is a basic parameter for analyzing regional greenhouse effect. Here, FOR values are derived from a General Circulation Model by extracting OLR and SLE over areas in east-central Europe (at about 60^oN) one hour after injecting appropriate CO₂ concentration (adjustments to the atmospheric profile are thus excluded) to the Feb. 1 midnight simulation. The reduction in FOR is 0.00051 when atmospheric CO₂ increases by 14 ppm, which is the currently expected per-decade increase. Fluctuations in the North-Atlantic surface winds produce fluctuations in FOR over central Europe: monthly-mean FOR in strong-wind February 1990 was 0.679, but 0.758 in weak-wind, lower cloud-fraction February 1996. Strong maritime-air advection in 1990 resulted thus in FOR reduced by 0.079, effect by two orders-of-magnitude stronger than the decrease effected by the per-decade increase in CO₂.
Keywords: TROPOSPHERIC TEMPERATURE, NORTH-ATLANTIC, SURFACE, TRENDS, EUROPE
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URL: https://doi.org/10.1029/2003GL017545
Other URLs:
Otterman, J., Starr, D.O'C., Atlas, R., Jusem, J.C., and Saaroni, H. (2003). Circumpolar Circulation Patterns Over the Northern Hemisphere Oceans in Late Winter, 1949-2002, Meter. Zeit..
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Title: Circumpolar Circulation Patterns Over the Northern Hemisphere Oceans in Late Winter, 1949-2002
Type: Journal Article
Publication: Meter. Zeit.
Author(s): Otterman, J., Starr, D.O'C., Atlas, R., Jusem, J.C., and Saaroni, H.
Year: 2003
Formatted Citation: Otterman, J., Starr, D.O'C., Atlas, R., Jusem, J.C., and Saaroni, H., 2003: Circumpolar Circulation Patterns Over the Northern Hemisphere Oceans in Late Winter, 1949-2002, Meter. Zeit..
Abstract: To assess interannual changes in ocean-to-land advection, we extract zonal winds for February and March, 1949-2002, from NCEP/NCAR Reanalysis. Winds are analyzed at pairs of locations (55 deg N and 35 deg N) in the N. Pacific (15 deg W), N. Atlantic (30 deg W) and Baltic/Mediterranean (30 deg E). The monthly means at the northern and southern sites are negatively correlated. For N. Pacific, winds at 55 deg N show negative trends at all levels (magnitude increasing with altitude), versus positive at 35 deg N. An opposite scenario is observed over N. Atlantic, positive (negative) trends at 55 deg N (35 deg N) and similarly, but weaker, over the Baltic/Mediterranean. The geographic variability of trends is attributed to displacement of the polar vortex wave pattern. Increasing storm strength/frequency over N. Hemisphere oceans is inherently related to the strong positive trends in wind speed and vertical shear.
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Plant, W.J., Foster, R., Graber, H., Drennan, W.M., Mahrt, L., Irisov, V., and Long, D.G. (2003). Comparison of Wind Vectors and Air-Sea Temperature Differences Measured During SHOWEX, 2003 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `03), 242-244, 10.1109/IGARSS.2003.1293737. Conference Paper »
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Title: Comparison of Wind Vectors and Air-Sea Temperature Differences Measured During SHOWEX
Type: Conference Paper
Publication: 2003 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `03)
Author(s): Plant, W.J., Foster, R., Graber, H., Drennan, W.M., Mahrt, L., Irisov, V., and Long, D.G.
Year: 2003
Formatted Citation: Plant, W.J., Foster, R., Graber, H., Drennan, W.M., Mahrt, L., Irisov, V., and Long, D.G., 2003: Comparison of Wind Vectors and Air-Sea Temperature Differences Measured During SHOWEX, 2003 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `03), 242-244, 10.1109/IGARSS.2003.1293737.
Abstract: During ONR's Shoaling Waves Experiment (SHOWEX) off the coast of North Carolina in November and December 1999, measurements of wind speed and direction as well as air and water temperatures were made using a variety of techniques. This paper shows a comparison of the measurements taken on December 3, 1999.
Keywords: atmospheric measuring apparatus atmospheric temperature oceanography seawater wind AD 1999 11 to 12 AD 1999 12 03 Air-Sea Interaction Spar Buoys North Carolina coast ONR Office of Naval Research SHOWEX Shoaling Waves
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URL: https://doi.org/10.1109/IGARSS.2003.1293737
Other URLs:
Remund, Q.P., and Long, D.G. (2003). Large-Scale Inverse Ku-Band Backscatter Modeling of Sea Ice, IEEE Transactions on Geoscience and Remote Sensing, 41(8), 1821-1833, 10.1109/TGRS.2003.813495. Journal Article »
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Title: Large-Scale Inverse Ku-Band Backscatter Modeling of Sea Ice
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Remund, Q.P., and Long, D.G.
Year: 2003
Formatted Citation: Remund, Q.P., and Long, D.G., 2003: Large-Scale Inverse Ku-Band Backscatter Modeling of Sea Ice, IEEE Transactions on Geoscience and Remote Sensing, 41(8), 1821-1833, 10.1109/TGRS.2003.813495.
Abstract: Polar sea ice characteristics provide important inputs to models of several geophysical processes. Microwave scatterometers are ideal for monitoring these regions due to their sensitivity to ice properties and insensitivity to atmospheric distortions. Many forward electromagnetic scattering models have been proposed to predict the normalized radar cross section (sigmadegrees) from sea ice characteristics. These models are based on very small scale ice features and generally assume that the region of interest is spatially homogeneous. Unfortunately, spaceborne scatterometer footprints are very large (5-50 km) and usually contain very heterogeneous mixtures of sea ice surface parameters. In this paper, we use scatterometer data in a large-scale inverse modeling experiment. Given the limited data resolution, we adopt a simple geometric optics forward-scattering model to analyze surface and volume scattering contributions to observed Ku-band signatures. A model inversion technique based on recursive optimization of an objective function is developed. The result is a least squares estimate of three surface parameters: the power reflection coefficient at nadir, the rms surface slope, and the volume scattering albedo. Simulations demonstrate the performance of the method in the presence of noise. The inverse model is implemented using Ku-band image reconstructed data collected by the National Aeronautics and Space Administration scatterometer. The results are used to analyze and interpret sigmadegrees phenomena occurring in the Antarctic and the Arctic.
Keywords: ENHANCED RESOLUTION, SCATTEROMETER DATA, RADAR, IDENTIFICATION, SHEET, ERS-1, inverse modeling, national aeronautics and space administration (NASA) scatterometer (NSCAT), scattering models, sea ice, special sensor microwave/imager (SSM/I)
Mission: |NSCAT|
URL: https://doi.org/10.1109/TGRS.2003.813495
Other URLs:
Sharp, R.J., Bourassa, M.A., and O'Brien, J.J. (2003). Tropical Cyclogenesis Detection in the East Pacific Hurricane Basin, CAS/JSC Working Group on Numerical Experimentation, Research Activities, 2.21-2.22.
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Title: Tropical Cyclogenesis Detection in the East Pacific Hurricane Basin
Type: Report
Publication: CAS/JSC Working Group on Numerical Experimentation, Research Activities
Author(s): Sharp, R.J., Bourassa, M.A., and O'Brien, J.J.
Year: 2003
Formatted Citation: Sharp, R.J., Bourassa, M.A., and O'Brien, J.J., 2003: Tropical Cyclogenesis Detection in the East Pacific Hurricane Basin, CAS/JSC Working Group on Numerical Experimentation, Research Activities, 2.21-2.22.
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Sharp, R.J., Bourassa, M.A., O'Brien, J.J., Katsaros, K.B., and Forde, E.B. (2003). Early Detection Tropical Cyclones Using SeaWinds-Derived Vorticity, CAS/JSC Working Group on Numerical Experimentation, Research Activities, 02:23-24.
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Title: Early Detection Tropical Cyclones Using SeaWinds-Derived Vorticity
Type: Report
Publication: CAS/JSC Working Group on Numerical Experimentation, Research Activities
Author(s): Sharp, R.J., Bourassa, M.A., O'Brien, J.J., Katsaros, K.B., and Forde, E.B.
Year: 2003
Formatted Citation: Sharp, R.J., Bourassa, M.A., O'Brien, J.J., Katsaros, K.B., and Forde, E.B., 2003: Early Detection Tropical Cyclones Using SeaWinds-Derived Vorticity, CAS/JSC Working Group on Numerical Experimentation, Research Activities, 02:23-24.
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Small, R.J., Xie, S.-P., and Wang, Y. (2003). Numerical Simulation of Atmospheric Response to Pacific Tropical Instability Waves, Journal of Climate, 16(22), 3723-3741, 10.1175/1520-0442(2003)016<3723:NSOART>2.0.CO,2. Journal Article »
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Title: Numerical Simulation of Atmospheric Response to Pacific Tropical Instability Waves
Type: Journal Article
Publication: Journal of Climate
Author(s): Small, R.J., Xie, S.-P., and Wang, Y.
Year: 2003
Formatted Citation: Small, R.J., Xie, S.-P., and Wang, Y., 2003: Numerical Simulation of Atmospheric Response to Pacific Tropical Instability Waves, Journal of Climate, 16(22), 3723-3741, 10.1175/1520-0442(2003)016<3723:NSOART>2.0.CO,2.
Abstract: Tropical instability waves (TIWs) are 1000-km-long waves that appear along the sea surface temperature (SST) front of the equatorial cold tongue in the eastern Pacific. The study investigates the atmospheric planetary boundary layer (PBL) response to TIW-induced SST variations using a high-resolution regional climate model. An investigation is made of the importance of pressure gradients induced by changes in air temperature and moisture, and vertical mixing, which is parameterized in the model by a 1.5-level turbulence closure scheme. Significant turbulent flux anomalies of sensible and latent heat are caused by changes in the air-sea temperature and moisture differences induced by the TIWs. Horizontal advection leads to the occurrence of the air temperature and moisture extrema downwind of the SST extrema. High and low hydrostatic surface pressures are then located downwind of the cold and warm SST patches, respectively. The maximum and minimum wind speeds occur in phase with SST, and a thermally direct circulation is created. The momentum budget indicates that pressure gradient, vertical mixing, and horizontal advection dominate. In the PBL the vertical mixing acts as a frictional drag on the pressure-gradient-driven winds. Over warm SST the mixed layer deepens relative to over cold SST. The model simulations of the phase and amplitude of wind velocity, wind convergence, and column-integrated water vapor perturbations due to TIWs are similar to those observed from satellite and in situ data.
Keywords: Pacific Ocean , Sea surface temperature , East Pacific , Equatorial Pacific , Mixing process , Pressure gradient , Wind field , Momentum transfer , Sensible heat , Latent heat , Turbulent transfer , High resolution , Climate models , Regional scope , Nume
Mission:
URL: https://doi.org/10.1175/1520-0442(2003)016%3C3723:NSOART%3E2.0.CO;2
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Spencer, M.W., Tsai, W.-Y., and Long, D.G. (2003). High-Resolution Measurements with a Spaceborne Pencil-Beam Scatterometer Using Combined Range/Doppler Discrimination Techniques, IEEE Transactions on Geoscience and Remote Sensing, 41(3), 567-581, 10.1109/TGRS.2003.809938. Journal Article »
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Title: High-Resolution Measurements with a Spaceborne Pencil-Beam Scatterometer Using Combined Range/Doppler Discrimination Techniques
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Spencer, M.W., Tsai, W.-Y., and Long, D.G.
Year: 2003
Formatted Citation: Spencer, M.W., Tsai, W.-Y., and Long, D.G., 2003: High-Resolution Measurements with a Spaceborne Pencil-Beam Scatterometer Using Combined Range/Doppler Discrimination Techniques, IEEE Transactions on Geoscience and Remote Sensing, 41(3), 567-581, 10.1109/TGRS.2003.809938.
Abstract: Conically scanning pencil-beam scatterometer systems, such as the SeaWinds radar, constitute an important class of instruments for spaceborne climate observation. In addition to ocean winds, scatterometer data are being applied to a wide range of land and cryospheric applications. A key issue for future scatterometer missions is improved spatial resolution. Pencil-beam scatterometers to date have been real-aperture systems where only range discrimination is used, resulting in a relatively coarse resolution of approximately 25 km. In this paper, the addition of Doppler discrimination techniques is proposed to meet the need for higher resolution. The unique issues associated with the simultaneous application of range and Doppler processing to a conically scanning radar are addressed, and expressions for the theoretical measurement performance of such a system are derived. Important differences with side-looking imaging radars, which also may employ Doppler techniques, are highlighted. Conceptual design examples based on scatterometer missions of current interest are provided to illustrate this new high-resolution scatterometer approach. It is shown that spatial resolution of pencil-beam scatterometer systems can be improved by an order of magnitude by utilizing combined range/Doppler discrimination techniques, while maintaining the wide-swath and constant incidence angle needed for many geophysical measurements.
Keywords: Doppler radar remote sensing by radar spaceborne radar wind
Mission: |SeaWinds|
URL: https://doi.org/10.1109/TGRS.2003.809938
Other URLs:
Stephen, H., and Long, D.G. (2003). Surface Statistics of the Saharan Ergs Observed in the σ^o Azimuth Modulation, 2003 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `03), 1549-1551, 10.1109/IGARSS.2003.1294171. Conference Paper »
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Title: Surface Statistics of the Saharan Ergs Observed in the σ^o Azimuth Modulation
Type: Conference Paper
Publication: 2003 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `03)
Author(s): Stephen, H., and Long, D.G.
Year: 2003
Formatted Citation: Stephen, H., and Long, D.G., 2003: Surface Statistics of the Saharan Ergs Observed in the σ^o Azimuth Modulation, 2003 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `03), 1549-1551, 10.1109/IGARSS.2003.1294171.
Abstract:
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Mission: |NSCAT|
URL: https://doi.org/10.1109/IGARSS.2003.1294171
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Weissman, D.E. and Bourassa, M.A. (2003). Evaluating the QuikSCAT/SeaWinds Radar for Measuring Rainrate Over the Oceans Using Collocations with NEXRAD and TRMM, 12th Conference on Satellite Meteorology and Oceanography. Conference Paper »
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Title: Evaluating the QuikSCAT/SeaWinds Radar for Measuring Rainrate Over the Oceans Using Collocations with NEXRAD and TRMM
Type: Conference Paper
Publication: 12th Conference on Satellite Meteorology and Oceanography
Author(s): Weissman, D.E. and Bourassa, M.A.
Year: 2003
Formatted Citation: Weissman, D.E. and Bourassa, M.A., 2003: Evaluating the QuikSCAT/SeaWinds Radar for Measuring Rainrate Over the Oceans Using Collocations with NEXRAD and TRMM, 12th Conference on Satellite Meteorology and Oceanography.
Abstract: Recent studies have demonstrated that the SeaWinds radar has the potential to operate as a meteorological weather radar, from space. This research program seeks to enable the SeaWinds scatterometer (as well as future Ku-band scatterometers) to convert its measurement of radar cross section into rainrate estimates over the earth`s oceans, with the same spatial resolution with which it can make wind vector measurements.One unique benefit of the Scatterometer is its global reach. Its swath width is 1400 km and its latitude range is 80o. This exceeds the coverage of TRMM and the reach of coastal NEXRAD stations. Measurements indicate that the radar backscatter from the rain volume in the atmosphere can exceed the sea surface radar cross section (at 14 GHz) in many situations. The relative magnitudes of received radar backscatter depend on the volumetric rainrate, the rain column height and surface wind speed. Algorithms for inverting the RCS are being developed using methods of calibration and validation of the rainrate with TRMM and NEXRAD, and with winds from buoys. The dual polarization of the SeaWinds instrument (H-pol and V-pol) enables the application of a highly sensitive technique for measuring rainrate, which is commonly used in radar meteorology. Comparing the collocated V-pol and H-pol radar cross section data, it is seen that for rainrates greater than 5 mm/hr, the H-pol magnitudes tend to exceed the V-pol. This is the differential reflectivity, caused by the increasing, significant oblateness of raindrops at the higher rainrates. The size of this observed differential reflectivity and its dependence on rainrate is in agreement with the theoretical results in the literature. A broad set of collocations among TRMM, NEXRAD and QuikSCAT is being analyzed to compare their absolute rainrate estimates, and to conduct extensive statistical analysis of these rainrates in their 0.25o and 0.50o LAT/LON cells, and their spatial distribution. Other physical variables are being examined using complementary sensors and component analysis. The approach is to determine what additional variables are affecting the each sensors response, so that the volumetric rainrate can be separated and extracted.
Keywords:
Mission: |SeaWinds|
URL: http://ams.confex.com/ams/pdfpapers/57226.pdf
Other URLs:
Weissman, D.E., Bourassa, M.A., and Durden, S.L. (2003). Calibrating the QuikSCAT/SeaWinds Radar for Measuring Rainrate Over the Oceans and Improving Wind Vector Estimates, IEEE Geoscience and Remote Sensing Symposium (IGARSS 2003), 10.1109/IGARSS.2003.1294039. Conference Paper »
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Title: Calibrating the QuikSCAT/SeaWinds Radar for Measuring Rainrate Over the Oceans and Improving Wind Vector Estimates
Type: Conference Paper
Publication: IEEE Geoscience and Remote Sensing Symposium (IGARSS 2003)
Author(s): Weissman, D.E., Bourassa, M.A., and Durden, S.L.
Year: 2003
Formatted Citation: Weissman, D.E., Bourassa, M.A., and Durden, S.L., 2003: Calibrating the QuikSCAT/SeaWinds Radar for Measuring Rainrate Over the Oceans and Improving Wind Vector Estimates, IEEE Geoscience and Remote Sensing Symposium (IGARSS 2003), 10.1109/IGARSS.2003.1294039.
Abstract: The sensitivity of the SeaWinds scatterometer to rainrates as small as 0.5 mm/hr (for winds less than 6m/s) is a result of backscattering and attenuation by the rain column. This creates both a need to correct the measured radar cross sections, to improve the accuracy of wind vector estimates, and an opportunity to estimate the ocean rain rate to supplement ocean precipitation studies. Both the sea surface and atmospheric rain contribute to the total radar cross section. A comprehensive method is being developed to identify, separate and estimate these two different targets. The goal is to utilize this new method to correct the measured NCRS so that the sea surface reflection can be estimated in a manner that will lead to more accurate wind vector estimates. Also an opportunity exists to estimate the ocean rain rate to supplement ocean precipitation studies.
Keywords: atmospheric techniques backscatter calibration radar cross-sections rain remote sensing by radar spaceborne radar wind NCRS SeaWinds scatterometer atmospheric rain attenuation backscattering calibration ocean precipitatio
Mission: |SeaWinds|
URL: https://doi.org/10.1109/IGARSS.2003.1294039
Other URLs:
Weissman, D.E., Bourassa, M.A., O'Brien, J.J., and Tongue, J.S. (2003). Calibrating the Quikscat/SeaWinds Radar for Measuring Rainrate Over the Oceans, IEEE Transactions on Geoscience and Remote Sensing, 41(12), 2814-2820, 10.1109/TGRS.2003.817975. Journal Article »
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Title: Calibrating the Quikscat/SeaWinds Radar for Measuring Rainrate Over the Oceans
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Weissman, D.E., Bourassa, M.A., O'Brien, J.J., and Tongue, J.S.
Year: 2003
Formatted Citation: Weissman, D.E., Bourassa, M.A., O'Brien, J.J., and Tongue, J.S., 2003: Calibrating the Quikscat/SeaWinds Radar for Measuring Rainrate Over the Oceans, IEEE Transactions on Geoscience and Remote Sensing, 41(12), 2814-2820, 10.1109/TGRS.2003.817975.
Abstract: This effort continues a study of the effects of rain, over the oceans, on the signal retrieved by the SeaWinds scatterometer. It is determined that the backscatter radar cross section can be used to estimate the volumetric rain rate, averaged horizontally, across the surface resolution cells of the scatterometer. The dual polarization of the radar has a key role in developing this capability. The relative magnitudes of the radar backscatter depends on the volumetric rain rate, the rain column height and surface wind velocity, the viewing angle, as well as the polarization (due to the oblateness of raindrops at the higher rain rates). The approach to calibrating the SeaWinds normalized radar cross section (NRCS) is to collect National Weather Service Next Generation Weather Radar (NEXRAD) radar-derived rain rate measurements (4-km spatial resolution and 6-min rotating cycles) colocated in space (offshore) and time with scatterometer observations. These calibration functions lead to a Z-R relationship, which is then used at mid-ocean locations to estimate the rain rate in 0.25degrees or larger resolution cells, which are compared with Tropical Rainfall Mapping Mission (TRMM) Microwave Imager (TMI) rain estimates. Experimental results to date are in general agreement with simplified theoretical models of backscatter from rain, for this frequency, 14 GHz. These comparisons show very good agreement on a cell-by-cell basis with the TMI estimates for both wide areas (1000 km) and smaller area rain events.
Keywords: SCATTEROMETER, SYSTEM, Next Generation Weather Radar (NEXRAD), precipitation, radar reflectivity, scatterometer normalized radar cross section (NRCS), space-based radar, Tropical Rain Measuring Mission (TRMM)
Mission: |SeaWinds|
URL: https://doi.org/10.1109/TGRS.2003.817975
Other URLs:
Xie, S.-P., Xie, Q., Wang D.X., and Liu, W.T. (2003). Summer Upwelling in the South China Sea and its Role in Regional Climate Variations, Journal of Geophysical Research: Oceans, 108(C8), 3261, 10.1029/2003JC001867. Journal Article »
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Title: Summer Upwelling in the South China Sea and its Role in Regional Climate Variations
Type: Journal Article
Publication: Journal of Geophysical Research: Oceans
Author(s): Xie, S.-P., Xie, Q., Wang D.X., and Liu, W.T.
Year: 2003
Formatted Citation: Xie, S.-P., Xie, Q., Wang D.X., and Liu, W.T., 2003: Summer Upwelling in the South China Sea and its Role in Regional Climate Variations, Journal of Geophysical Research: Oceans, 108(C8), 3261, 10.1029/2003JC001867.
Abstract: Seasonal and interannual variations of summer upwelling off the South Vietnam coast and the offshore spread of cold water are investigated using a suite of new satellite measurements. In summer, as the southwesterly winds impinge on Annam Cordillera (a north-south running mountain range on the east coast of Indochina) a strong wind jet occurs at its southern tip offshore east of Saigon, resulting in strong wind curls that are important for ocean upwelling off the coast. In July and August an anticyclonic ocean eddy develops to the southeast, advecting the cold coastal water offshore into the open South China Sea (SCS). The center of this cold filament is located consistently north of the wind speed maximum, indicating that open-ocean upwelling helps to cool the ocean surface. Corroborating evidence for the cold filament is found in ocean color observations that reveal a collocated tongue of high chlorophyll concentration. The development of this cold filament disrupts the summer warming of the SCS and causes a pronounced semi-annual cycle in SST. Moreover, the cold filament is an important player in interannual variability in the summer SCS. In 1998, the cold filament and mid-summer cooling never took place, giving rise to a strong basin-wide surface warming. Interannual SST variance has a local maximum over the climatological cold filament, and is much greater than the variance over the adjacent Indian and western Pacific Oceans. A cold filament index is constructed, which displays significant lagged correlation with SST in the eastern equatorial Pacific and Indian Oceans, indicative of a teleconnection from El Nino.
Keywords: * Oceanography: Physical: Air/sea interactions * Oceanography: General: Upwelling and convergences * Oceanography: General: Marginal and semienclosed seas * Oceanography: General: Climate and interannual variability
Mission:
URL: https://doi.org/10.1029/2003JC001867
Other URLs:
Yoho, P.K., and Long, D.G. (2003). An Improved Simulation Model for Spaceborne Scatterometer Measurements, IEEE Transactions on Geoscience and Remote Sensing, 41(11), 2692-2695, 10.1109/TGRS.2003.818340. Journal Article »
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Title: An Improved Simulation Model for Spaceborne Scatterometer Measurements
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Yoho, P.K., and Long, D.G.
Year: 2003
Formatted Citation: Yoho, P.K., and Long, D.G., 2003: An Improved Simulation Model for Spaceborne Scatterometer Measurements, IEEE Transactions on Geoscience and Remote Sensing, 41(11), 2692-2695, 10.1109/TGRS.2003.818340.
Abstract: Development of scatterometer designs and applications requires extensive data simulation. The advancing capabilities of instruments motivates our proposal for an improved simulation model for noisy scatterometer measurements. Previous simulation models do not separately account for the two forms of random variation - signal fading and additive noise - which affect scatterometer measurements. The proposed model is able to generate data that are statistically equivalent (in a mean and variance sense) to actual instrument measurements by accounting for both variations, while maintaining ease of implementation. The model is particularly adept at handling design tradeoffs related to signal-to-noise ratios by appropriately separating fading and additive noise. Unlike previous models, the new model also can account for correlation between measurements, an issue that has recently become important.
Keywords: geophysical signal processing spaceborne radar
Mission:
URL: https://doi.org/10.1109/TGRS.2003.818340
Other URLs:
Atlas, R., Hou, A., and Reale, O. (2002). Hurricane and Flood Prediction, Community Disaster Preparedness, Earth Observation Magazine, 11(8). Journal Article »
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Title: Hurricane and Flood Prediction, Community Disaster Preparedness
Type: Journal Article
Publication: Earth Observation Magazine
Author(s): Atlas, R., Hou, A., and Reale, O.
Year: 2002
Formatted Citation: Atlas, R., Hou, A., and Reale, O., 2002: Hurricane and Flood Prediction, Community Disaster Preparedness, Earth Observation Magazine, 11(8).
Abstract:
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Mission:
URL: http://www.eomonline.com/Common/currentissues/Aug02/atlas.htm
Other URLs:
Ballantyne, J., and Long, D.G. (2002). A Multidecadal Study of the Number of Antarctic Icebergs Using Scatterometer Data, 2002 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `02), 3029-3031, 10.1109/IGARSS.2002.1026859. Conference Paper »
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Title: A Multidecadal Study of the Number of Antarctic Icebergs Using Scatterometer Data
Type: Conference Paper
Publication: 2002 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `02)
Author(s): Ballantyne, J., and Long, D.G.
Year: 2002
Formatted Citation: Ballantyne, J., and Long, D.G., 2002: A Multidecadal Study of the Number of Antarctic Icebergs Using Scatterometer Data, 2002 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `02), 3029-3031, 10.1109/IGARSS.2002.1026859.
Abstract: Tabular Antarctic icebergs are regularly formed by the separation of massive sections of ice from ice shelves and glaciers. The National Ice Center (NIC) uses a variety of satellite sensors to track large Antarctic icebergs and reports iceberg position,. According to the NIC database, the number of large Antarctic icebergs has been increasing in recent years. A long term analysis of Antarctic iceberg activity based on scatterometer and radiometer data is presented. Our analysis suggests this increase is largely due to improved resources and technological advancements for iceberg tracking. Recent calving events may represent natural variability in iceberg activity. This study identifies some of the advantages and limitations of tracking icebergs using scatterometer data.
Keywords: glaciology hydrological techniques oceanographic regions oceanographic techniques remote sensing by radar sea ice spaceborne radar AD 1978 to 2001 Antarctic icebergs NIC National Ice Center Southern Ocean calving ev
Mission:
URL: https://doi.org/10.1109/IGARSS.2002.1026859
Other URLs:
Bourassa, M.A., and O'Brien, J.J. (2002). Assimilation of Scatterometer and In Situ Winds for Regularly Gridded Products, Conference Paper »
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Title: Assimilation of Scatterometer and In Situ Winds for Regularly Gridded Products
Type: Conference Paper
Publication:
Author(s): Bourassa, M.A., and O'Brien, J.J.
Year: 2002
Formatted Citation: Bourassa, M.A., and O'Brien, J.J., 2002: Assimilation of Scatterometer and In Situ Winds for Regularly Gridded Products,
Abstract:
Keywords: QSCAT, assimilate, objective
Mission: |SeaWinds|
URL: http://www.coaps.fsu.edu/RVSMDC/newwinds/pac/FSU_psv_pacv10.pdf
Other URLs:
Draper, D.W., and Long, D.G. (2002). Evidence of a Threshold Wind Speed in Tower-Mounted Scatterometer Data, 2002 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `02), 1977-1979, 10.1109/IGARSS.2002.1026418. Conference Paper »
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Title: Evidence of a Threshold Wind Speed in Tower-Mounted Scatterometer Data
Type: Conference Paper
Publication: 2002 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `02)
Author(s): Draper, D.W., and Long, D.G.
Year: 2002
Formatted Citation: Draper, D.W., and Long, D.G., 2002: Evidence of a Threshold Wind Speed in Tower-Mounted Scatterometer Data, 2002 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `02), 1977-1979, 10.1109/IGARSS.2002.1026418.
Abstract: The normalized radar backscatter (/spl sigma//sup o/) in scatterometer measurements over water is theorized to go to zero below a threshold wind speed due to insufficient friction between the wind and water to create capillary waves from which the radar signal scatters. Evidence of the threshold wind speed and a hysteresis effect have been observed in airship and wave tank data. There is additional evidence for a threshold wind speed in tower-mounted scatterometer data in an uncontrolled marine environment. In situ wind measurements and corresponding /spl sigma//sup o/ values obtained from YSCAT, an ultra-wideband scatterometer deployed on the Canada Centre for Inland Waters research tower at Lake Ontario, are used to detect and estimate the threshold wind speed. There is evidence for a detectable threshold in approximately half of the observations. The observed threshold wind speeds correspond well to theoretical threshold wind speeds.
Keywords: meteorological radar remote sensing by radar wind 2 to 14 GHz AD 1994 Canada Centre for Inland Waters research tower Lake Ontario YSCAT airship data capillary waves hysteresis effect in situ wind measurements normaliz
Mission: |YSCAT|
URL: https://doi.org/10.1109/IGARSS.2002.1026418
Other URLs:
Draper, D.W., and Long, D.G. (2002). Simulation of SeaWinds Measurements in the Presence of Rain Using Collocated TRMM PR Data, 2002 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `02), 1828-1830, 10.1109/IGARSS.2002.1026268. Conference Paper »
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Title: Simulation of SeaWinds Measurements in the Presence of Rain Using Collocated TRMM PR Data
Type: Conference Paper
Publication: 2002 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `02)
Author(s): Draper, D.W., and Long, D.G.
Year: 2002
Formatted Citation: Draper, D.W., and Long, D.G., 2002: Simulation of SeaWinds Measurements in the Presence of Rain Using Collocated TRMM PR Data, 2002 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `02), 1828-1830, 10.1109/IGARSS.2002.1026268.
Abstract: The scatterometer SeaWinds on QuikSCAT measures ocean winds via the relationship between the wind and the normalized radar backscatter cross-section (/spl sigma//spl deg/) from the ocean surface. Scattering and attenuation from falling rain droplets along with ocean surface perturbations due to rain change the backscatter signature of the waves induced by near-surface winds. A Simple model incorporates the effects of rain on ocean /spl sigma//spl deg/. Colocated data from the precipitation radar (PR) aboard the Tropical Rainfall Measuring Mission (TRMM) satellite is used to simulate the effects of rain as seen by SeaWinds. PR-derived backscatter, atmospheric rain attenuation, and rain rates are averaged over the SeaWinds footprint. The enhancement in backscatter from rain striking the ocean surface is estimated as a function of rain rate using a least-squares technique. QuikSCAT /spl sigma//spl deg/ values are simulated from the PR-derived parameters and numerical weather prediction wind data using the simple backscatter model. The simple model estimates 90% of the observed rain-contaminated QuikSCAT /spl sigma//spl deg/ values to within 3 dB.
Keywords: atmospheric techniques backscatter meteorological radar radar cross-sections radar theory remote sensing by radar spaceborne radar wind QuikSCAT SeaWinds TRMM PR data marine atmosphere measurement technique mete
Mission: |SeaWinds|
URL: https://doi.org/10.1109/IGARSS.2002.1026268
Other URLs:
Draper, D.W., and Long, D.G. (2002). An Assessment of SeaWinds on QuikSCAT Wind Retrieval, Journal of Geophysical Research: Oceans, 107(C12), 10.1029/2002JC001330. Journal Article »
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Title: An Assessment of SeaWinds on QuikSCAT Wind Retrieval
Type: Journal Article
Publication: Journal of Geophysical Research: Oceans
Author(s): Draper, D.W., and Long, D.G.
Year: 2002
Formatted Citation: Draper, D.W., and Long, D.G., 2002: An Assessment of SeaWinds on QuikSCAT Wind Retrieval, Journal of Geophysical Research: Oceans, 107(C12), 10.1029/2002JC001330.
Abstract: [1] The scatterometer ocean wind retrieval process produces several possible solutions or ambiguities at each point, requiring a separate ambiguity selection step to infer a unique wind vector field. An ambiguity selection error occurs when the selected wind vector is not the closest ambiguity to the true wind. The current ambiguity selection routine for SeaWinds is ad hoc, but performs well under most circumstances. Factors such as instrument noise and rain can also cause the estimated wind flow to deviate from the true wind. A quality assurance (QA) analysis is performed to assess the ambiguity selection effectiveness and noise level of the retrieved wind using a low-order wind field model. The wind field model is data-driven and shown to be rather insensitive to the training data set. The QA analysis demonstrates that the SeaWinds ambiguity selection process is at least 95% effective. Ambiguity selection errors are correlated with storms and rain corruption. A subjective analysis on a set of cyclonic storm passes confirms that the wind retrieval is somewhat less effective in storm regions.
Keywords: AMBIGUITY REMOVAL, SCATTEROMETER, SCATTERING, ACCURACY, NSCAT, scatterometry, QuikSCAT, wind retrieval, ambiguity selection, dealiasing
Mission: |NSCAT|SeaWinds|
URL: https://doi.org/10.1029/2002JC001330
Other URLs:
Drinkwater, M.R., and Long, D.G. (2002). Satellite Wind Scatterometer Estimates of Greenland Snow Accumulation, Progress in Electromagnetics Research Symposium.
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Title: Satellite Wind Scatterometer Estimates of Greenland Snow Accumulation
Type: Conference Paper
Publication: Progress in Electromagnetics Research Symposium
Author(s): Drinkwater, M.R., and Long, D.G.
Year: 2002
Formatted Citation: Drinkwater, M.R., and Long, D.G., 2002: Satellite Wind Scatterometer Estimates of Greenland Snow Accumulation, Progress in Electromagnetics Research Symposium.
Abstract:
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URL:
Other URLs:
Gutierrez, S., and Long, D.G. (2002). Computer Vision Applications to the Study of Sea-Ice Motion in Antarctica, 2002 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `02), 1512-1514, 10.1109/IGARSS.2002.1026165. Conference Paper »
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Title: Computer Vision Applications to the Study of Sea-Ice Motion in Antarctica
Type: Conference Paper
Publication: 2002 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `02)
Author(s): Gutierrez, S., and Long, D.G.
Year: 2002
Formatted Citation: Gutierrez, S., and Long, D.G., 2002: Computer Vision Applications to the Study of Sea-Ice Motion in Antarctica, 2002 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `02), 1512-1514, 10.1109/IGARSS.2002.1026165.
Abstract: The motion of sea-ice in Antarctica is studied using QuikSCAT scatterometer imagery using methods from computer vision and image processing such as intensity edges and optical flow (OF). Features are computed as differential invariants based on spatial and temporal derivatives at various scales. The first estimates of the motion vector field obtained through optical flow are used as the starting point for a regularization scheme that imposes constraints that bring the estimate closer to feature tracking results and observed motion. Constraints from fluid dynamics are brought in by separating the motion field into its divergence free and rotational free components with another field obtained through a convex combination of these components. The advantages of this approach are that it produces a dense motion field that can be globally processed and locally adjusted to fit data and a model. This study complements the analysis of sea ice motion by application of wavelet theory.
Keywords: geophysical signal processing image motion analysis image sequences oceanographic regions oceanographic techniques radar imaging remote sensing by radar sea ice spaceborne radar Antarctica QuikSCAT QuikSCAT scatterom
Mission: |SeaWinds|
URL: https://doi.org/10.1109/IGARSS.2002.1026165
Other URLs:
Hashizume, H., Xie, S.-P., Fujiwara, M., Shiotani, M., Watanabe, T., Tanimoto, Y., Liu, W.T., and Takeuchi, K. (2002). Direct Observations of Atmospheric Boundary Layer Response to SST Variations Associated with Tropical Instability Waves Over the Eastern Equatorial Pacific, Journal of Climate, 15(23), 3379-3393, 10.1175/1520-0442(2002)015<3379:DOOABL>2.0.CO,2. Journal Article »
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Title: Direct Observations of Atmospheric Boundary Layer Response to SST Variations Associated with Tropical Instability Waves Over the Eastern Equatorial Pacific
Type: Journal Article
Publication: Journal of Climate
Author(s): Hashizume, H., Xie, S.-P., Fujiwara, M., Shiotani, M., Watanabe, T., Tanimoto, Y., Liu, W.T., and Takeuchi, K.
Year: 2002
Formatted Citation: Hashizume, H., Xie, S.-P., Fujiwara, M., Shiotani, M., Watanabe, T., Tanimoto, Y., Liu, W.T., and Takeuchi, K., 2002: Direct Observations of Atmospheric Boundary Layer Response to SST Variations Associated with Tropical Instability Waves Over the Eastern Equatorial Pacific, Journal of Climate, 15(23), 3379-3393, 10.1175/1520-0442(2002)015<3379:DOOABL>2.0.CO,2.
Abstract: Tropical instability waves (TIWs), with a typical wavelength of 1000 km and period of 30 days, cause the equatorial front to meander and result in SST variations on the order of 1°-2°C. Vertical soundings of temperature, humidity, and wind velocity were obtained on board a Japanese research vessel, which sailed through three fully developed SST waves from 140° to 110°W along 2°N during 21-28 September 1999. A strong temperature inversion is observed throughout the cruise along 2°N, capping the planetary boundary layer (PBL) that is 1-1.5 km deep. Temperature response to TIW-induced SST changes penetrates the whole depth of the PBL. In response to an SST increase, air temperature rises in the lowest kilometer and shows a strong cooling at the mean inversion height. As a result, this temperature dipole is associated with little TIW signal in the observed sea level pressure (SLP). The cruise mean vertical profiles show a speed maximum at 400-500 m for both zonal and meridional velocities. SST-based composite profiles of zonal wind velocity show weakened (intensified) vertical shear within the PBL that is consistent with enhanced (reduced) vertical mixing, causing surface wind to accelerate (decelerate) over warm (cold) SSTs. Taken together, the temperature and wind soundings indicate the dominance of the vertical mixing over the SLP-driving mechanism. Based on the authors' measurements, a physical interpretation of the widely used PBL model proposed by Lindzen and Nigam is presented.
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Mission:
URL: https://doi.org/10.1175/1520-0442(2002)015%3C3379:DOOABL%3E2.0.CO;2
Other URLs:
Long, D.G., Ballantyne, J., and Bertoia, C. (2002). Is the Number of Antarctic Icebergs Really Increasing?, EOS, 83(42), 469, 10.1029/2002EO000330. Journal Article »
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Title: Is the Number of Antarctic Icebergs Really Increasing?
Type: Journal Article
Publication: EOS
Author(s): Long, D.G., Ballantyne, J., and Bertoia, C.
Year: 2002
Formatted Citation: Long, D.G., Ballantyne, J., and Bertoia, C., 2002: Is the Number of Antarctic Icebergs Really Increasing?, EOS, 83(42), 469, 10.1029/2002EO000330.
Abstract:
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Mission:
URL: https://doi.org/10.1029/2002EO000330
Other URLs:
Long, D.G., Drinkwater, M., and Holt, B. (2002). The Scatterometer Climate Record Pathfinder, 2002 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `02), 1509-1511, 10.1109/IGARSS.2002.1026164. Conference Paper »
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Title: The Scatterometer Climate Record Pathfinder
Type: Conference Paper
Publication: 2002 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `02)
Author(s): Long, D.G., Drinkwater, M., and Holt, B.
Year: 2002
Formatted Citation: Long, D.G., Drinkwater, M., and Holt, B., 2002: The Scatterometer Climate Record Pathfinder, 2002 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `02), 1509-1511, 10.1109/IGARSS.2002.1026164.
Abstract: While originally designed for ocean wind measurement, radar scatterometers have proven to be very effective in monitoring land cover and ice conditions and in climate studies. The NASA Scatterometer Climate Record Pathfinder (SCP) project has generated a unique climate data record from the series of historic and ongoing scatterometer missions. Image data are archived from the Sea-Winds on QuikSCAT instrument, the scatterometer mode of the ERS-1/-2 AMI, the NASA Scatterometer (NSCAT), and the Seasat Scatterometer (SASS). In this paper we describe several SCP data sets and illustrate their application to studies of climate change over Greenland.
Keywords: atmospheric techniques climatology geophysical techniques glaciology hydrological techniques hydrology remote sensing by radar spaceborne radar terrain mapping Arctic ERS-1 ERS-2 Greenland NASA NASA Scattero
Mission: |NSCAT|SeaWinds|
URL: https://doi.org/10.1109/IGARSS.2002.1026164
Other URLs:
Milliff, R.F., Freilich, M.H., Liu, W.T., Atlas, R., and Large, W.G. (2002). Global Ocean Surface Vector Wind Observations from Space, Observing the Ocean in the 21st Century from Space, 102-119.
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Title: Global Ocean Surface Vector Wind Observations from Space
Type: Chapter
Publication: Observing the Ocean in the 21st Century from Space
Author(s): Milliff, R.F., Freilich, M.H., Liu, W.T., Atlas, R., and Large, W.G.
Year: 2002
Formatted Citation: Milliff, R.F., Freilich, M.H., Liu, W.T., Atlas, R., and Large, W.G., 2002: Global Ocean Surface Vector Wind Observations from Space, Observing the Ocean in the 21st Century from Space, 102-119.
Abstract:
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URL:
Other URLs:
Morey, S.L., Bourassa, M.A., Jia, X., O'Brien, J.J., and Zavala-Hidalgo, J. (2002). Impacts of Satellite Scatterometer Derived Wind Forcing on the West Florida Shelf Ocean Circulation, Report No. 32, Edited by H. Ritchie, 08.18-08.19. Report »
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Title: Impacts of Satellite Scatterometer Derived Wind Forcing on the West Florida Shelf Ocean Circulation
Type: Report
Publication: Report No. 32, Edited by H. Ritchie
Author(s): Morey, S.L., Bourassa, M.A., Jia, X., O'Brien, J.J., and Zavala-Hidalgo, J.
Year: 2002
Formatted Citation: Morey, S.L., Bourassa, M.A., Jia, X., O'Brien, J.J., and Zavala-Hidalgo, J., 2002: Impacts of Satellite Scatterometer Derived Wind Forcing on the West Florida Shelf Ocean Circulation, Report No. 32, Edited by H. Ritchie, 08.18-08.19.
Abstract:
Keywords:
Mission: |SeaWinds|
URL: https://www.wcrp-climate.org/WGNE/BlueBook/2002/individual-articles/07_morey_steven_l._.pdf
Other URLs:
Otterman, J., Angell, J.K., Atlas, R., Bungato, D., Schubert, S., Starr, D., Susskind, J., and Wu, M.-L.C. (2002). Advection from the North Atlantic as the Forcing of Winter Greenhouse Effect Over Europe, Geophysical Research Letters, 29(8), 10.1029/2001GL014187. Journal Article »
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Title: Advection from the North Atlantic as the Forcing of Winter Greenhouse Effect Over Europe
Type: Journal Article
Publication: Geophysical Research Letters
Author(s): Otterman, J., Angell, J.K., Atlas, R., Bungato, D., Schubert, S., Starr, D., Susskind, J., and Wu, M.-L.C.
Year: 2002
Formatted Citation: Otterman, J., Angell, J.K., Atlas, R., Bungato, D., Schubert, S., Starr, D., Susskind, J., and Wu, M.-L.C., 2002: Advection from the North Atlantic as the Forcing of Winter Greenhouse Effect Over Europe, Geophysical Research Letters, 29(8), 10.1029/2001GL014187.
Abstract: In winter, large interannual fluctuations in the surface temperature are observed over central Europe. Comparing warm February 1990 with cold February 1996, a satellite-retrieved surface (skin) temperature difference of 9.8 K is observed for the region 50-60^oN, 535^oE. Previous studies show that advection from the North Atlantic constitutes the forcing to such fluctuations. The advection is quantified by Index Ina, the average of the ocean-surface wind speed over the eastern North Atlantic when the direction is from the southwest (when the wind is from another direction, it counts as a zero speed to the average). Average Ina for February 1990 was 10.6 m s^-1, but for February 1996 Ina was only 2.4 m s^-1. A large value of Ina means a strong southwesterly flow which brings warm and moist air into central Europe at low level, producing a steeper tropospheric lapse rate. Strong ascending motions at 700 mb were observed in association with warm and moist advection from the ocean in February 1990, producing clouds and precipitation. Total precipitable water and cloud-cover fraction have larger values in February 1990 than in 1996. The difference in the greenhouse effect between these two scenarios, this reduction in the heat loss to space, can be translated into a virtual radiative heating of 2.6 W m^-2 above the February 1990 surface/atmosphere system, which contributes to a warming of the surface on the order of 2.6 K. Accepting this estimate as quantitatively meaningful, we evaluate the direct effect, the rise in the surface temperature in Europe as a result of the maritime-air inflow, as 7.2 K (9.8 K-2.6 K). Thus, fractional reinforcement by the greenhouse effect is 2.6/7.2, or 36%, a substantial positive feedback.
Keywords: Atlantic Ocean , Europe , North Atlantic , Feedback , Warming , Heating , Heat loss , Cloud fraction , Precipitable water , Clouds , Troposphere , Wind velocity , Surface wind , Sea surface , Temperature difference , Surface temperature , Ocean atmosphere
Mission:
URL: https://doi.org/10.1029/2001GL014187
Other URLs:
Otterman, J., J.K. Angell, J. Ardizzone, R. Atlas, S. Schubert, D. Starr, and M.-L.C. Wu (2002). North-Atlantic surface winds examined as the source of winter warming in Europe, Geophysical Research Letters, 29(19), 10.1029/2002GL015256. Journal Article »
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Title: North-Atlantic surface winds examined as the source of winter warming in Europe
Type: Journal Article
Publication: Geophysical Research Letters
Author(s): Otterman, J., J.K. Angell, J. Ardizzone, R. Atlas, S. Schubert, D. Starr, and M.-L.C. Wu
Year: 2002
Formatted Citation: Otterman, J., J.K. Angell, J. Ardizzone, R. Atlas, S. Schubert, D. Starr, and M.-L.C. Wu, 2002: North-Atlantic surface winds examined as the source of winter warming in Europe, Geophysical Research Letters, 29(19), 10.1029/2002GL015256.
Abstract: Trajectories traced backward from western Europe point to the warm southwestern North Atlantic as the source region of the warm maritime air brought into Europe by low-level southwesterlies. Over the eastern North Atlantic, patterns of ocean-surface winds in late winter changed during the second half of the 20th century, and the southwesterly direction became even more predominant. In January-to-March, the strength of southwesterlies in this region and in source region increased significantly in the years 19481995, and is likely to account for a large part of the observed warming in Europe during this period. For 19962001, however, this trend in southwesterlies appears broken, consistent with a downturn of the winter warming reported from central Europe after 1995. Monthly indexes of North Atlantic Oscillation, NAO, show a similar pattern, rising till 1995 and a downturn for the 19962002 winters and early spring, indicating that this climate oscillation is associated with the NAO.
Keywords: Atlantic Ocean , Europe , North Atlantic , Ocean atmosphere interaction , Westerly wind , Atmospheric advection , North Atlantic oscillation , Sea surface , Warm air , Trajectory , Warming , Winter , Surface wind
Mission:
URL: http://www.agu.org/journals/gl/gl0219/2002GL015256/
Other URLs:
Patoux, J., and Brown, R.A. (2002). A Gradient Wind Correction for Surface Pressure Fields Retrieved from Scatterometer Winds, Journal of Applied Meteorology, 41(2), 133-143, 10.1175/1520-0450(2002)041%3C0133:AGWCFS%3E2.0.CO;2. Journal Article »
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Title: A Gradient Wind Correction for Surface Pressure Fields Retrieved from Scatterometer Winds
Type: Journal Article
Publication: Journal of Applied Meteorology
Author(s): Patoux, J., and Brown, R.A.
Year: 2002
Formatted Citation: Patoux, J., and Brown, R.A., 2002: A Gradient Wind Correction for Surface Pressure Fields Retrieved from Scatterometer Winds, Journal of Applied Meteorology, 41(2), 133-143, 10.1175/1520-0450(2002)041%3C0133:AGWCFS%3E2.0.CO;2.
Abstract: Given a field of geostrophic winds and at least one pressure observation, a pressure field can be computed. If the winds are in reality gradient winds, then a correction must be applied to calculate the actual geostrophic winds. Here a method is proposed for including a gradient wind correction in the retrieval of geostrophic winds from Quick Scatterometer (QuikSCAT) surface measurements with a planetary boundary layer model. This correction translates into a better estimate of the corresponding surface pressure fields. The scheme is assessed by comparing these pressure fields to buoy measurements in the Gulf of Alaska and to radiosonde measurements in Hurricane Floyd. The gradient wind correction has a curvature component and a time-dependent component. Their relative magnitude is evaluated.
Keywords:
Mission: |SeaWinds|
URL: https://doi.org/10.1175/1520-0450(2002)041%3C0133:AGWCFS%3E2.0.CO;2
Other URLs:
Schlax M.G., and Chelton D.B. (2002). Filter Transfer Functions for the Method of Successive Corrections, Monthly Weather Review, 130(2), 372-385, 10.1175/1520-0493(2002)130<0372:FTFFTM>2.0.CO,2. Journal Article »
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Title: Filter Transfer Functions for the Method of Successive Corrections
Type: Journal Article
Publication: Monthly Weather Review
Author(s): Schlax M.G., and Chelton D.B.
Year: 2002
Formatted Citation: Schlax M.G., and Chelton D.B., 2002: Filter Transfer Functions for the Method of Successive Corrections, Monthly Weather Review, 130(2), 372-385, 10.1175/1520-0493(2002)130<0372:FTFFTM>2.0.CO,2.
Abstract: The frequency-domain characteristics of the successive corrections method in one dimension are investigated through the calculation of smoother weights and filter transfer functions. The successive corrections algorithm acts as a low-pass filter that behaves similarly to noniterative smoothers. The spectral content of fixed-span successive corrections estimates depends upon the number of iterations, the selected weighting function and the grid to which the dataset is interpolated. For a given weighting function and grid, increasing the number of iterations for the fixed-span case results in filter transfer functions with increased cutoff frequency and rolloff. Within data gaps, the use of more than one iteration leads to estimates that are more likely to be contaminated by high-frequency variability in the data. It is shown that variable-span successive corrections estimates are nearly independent of the choice of weights for the initial iterations and are almost equivalent to estimates obtained using a single iteration. The greater computational requirements of multiple-iteration successive corrections is a disadvantage for general applications.
Keywords: 4-DIMENSIONAL VARIATIONAL ASSIMILATION, ECMWF OPERATIONAL IMPLEMENTATION, RESOLUTION CAPABILITY, DIAGNOSTICS, SATELLITE, DATASETS, GEOSAT, 3D-VAR, FIELDS
Mission:
URL: https://doi.org/10.1175/1520-0493(2002)130%3C0372:FTFFTM%3E2.0.CO;2
Other URLs:
Sharp, R.J., Bourassa, M.A., and O'Brien, J.J. (2002). Early Detection of Tropical Cyclones Using Seawinds-Derived Vorticity, Bulletin of the American Meteorological Society, 83(6), 879-890, 10.1175/1520-0477(2002)083<0879:EDOTCU>2.3.CO,2. Journal Article »
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Title: Early Detection of Tropical Cyclones Using Seawinds-Derived Vorticity
Type: Journal Article
Publication: Bulletin of the American Meteorological Society
Author(s): Sharp, R.J., Bourassa, M.A., and O'Brien, J.J.
Year: 2002
Formatted Citation: Sharp, R.J., Bourassa, M.A., and O'Brien, J.J., 2002: Early Detection of Tropical Cyclones Using Seawinds-Derived Vorticity, Bulletin of the American Meteorological Society, 83(6), 879-890, 10.1175/1520-0477(2002)083<0879:EDOTCU>2.3.CO,2.
Abstract: A method for early detection of the systems that become tropical cyclones (TCs) in the Atlantic hurricane basin is developed using the SeaWinds scatterometer aboard the QuikSCAT satellite. The method is based on locating positive vorticity signals exceeding a minimum area and magnitude within the swath of vector wind observations. The thresholds applied herein are subjectively derived from the TCs of the 1999 Atlantic hurricane season. The thresholds are applied to two sets of data for the 2000 season: research-quality data and near-realtime (<3 hour delay) data (available starting 18 August 2000). For the 2000 research-quality data, 7 of 18 TCs had signals that were detected an average of 27 hours before the National Hurricane Center (NHC) classified them as tropical depressions. For the near-realtime data 3 of 12 TCs had signals that were detected an average of 20 hours before. The SeaWinds scatterometer is a powerful new tool that, in addition to other conventional products (e.g., satellite images that determine if convection is present), will help the NHC detect potential TCs earlier. The Center for Ocean and Atmospheric Prediction Studies at the Florida State University and the Hurricane Research Division at the Atlantic Oceanographic and Meteorological Laboratory are working to develop a prototype of this technique for operational use at the NHC. The results for the 2001 Atlantic and Eastern Pacific hurricane seasons will be discussed.
Keywords: WATER-SURFACE, OCEAN, NSCAT, WINDS,
Mission: |NSCAT|SeaWinds|
URL: https://doi.org/10.1175/1520-0477(2002)083%3C0879:EDOTCU%3E2.3.CO;2
Other URLs:
Sharp, R.J., Bourassa, M.A., O'Brien, J.J., Katsaros, K.B., and Forde, E.B. (2002). Early Detection of Tropical Cyclones Using SeaWinds-Derived Vorticity for the 2001 Hurricane Season, Conference Paper »
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Title: Early Detection of Tropical Cyclones Using SeaWinds-Derived Vorticity for the 2001 Hurricane Season
Type: Conference Paper
Publication:
Author(s): Sharp, R.J., Bourassa, M.A., O'Brien, J.J., Katsaros, K.B., and Forde, E.B.
Year: 2002
Formatted Citation: Sharp, R.J., Bourassa, M.A., O'Brien, J.J., Katsaros, K.B., and Forde, E.B., 2002: Early Detection of Tropical Cyclones Using SeaWinds-Derived Vorticity for the 2001 Hurricane Season,
Abstract: A method for early detection of the systems that become tropical cyclones (TCs) in the Atlantic hurricane basin is developed using the SeaWinds scatterometer aboard the QuikSCAT satellite. The method is based on locating positive vorticity signals exceeding a minimum area and magnitude within the swath of vector wind observations. The thresholds applied herein are subjectively derived from the TCs of the 1999 Atlantic hurricane season. The thresholds are applied to two sets of data for the 2000 season: research-quality data and near-realtime (<3 hour delay) data (available starting 18 August 2000). For the 2000 research-quality data, 7 of 18 TCs had signals that were detected an average of 27 hours before the National Hurricane Center (NHC) classified them as tropical depressions. For the near-realtime data 3 of 12 TCs had signals that were detected an average of 20 hours before. The SeaWinds scatterometer is a powerful new tool that, in addition to other conventional products (e.g., satellite images that determine if convection is present), will help the NHC detect potential TCs earlier. The Center for Ocean and Atmospheric Prediction Studies at the Florida State University and the Hurricane Research Division at the Atlantic Oceanographic and Meteorological Laboratory are working to develop a prototype of this technique for operational use at the NHC. The results for the 2001 Atlantic and Eastern Pacific hurricane seasons will be discussed.
Keywords: tropical, cyclone, QSCAT, vorticity
Mission: |SeaWinds|
URL: http://ams.confex.com/ams/pdfpapers/33881.pdf
Other URLs:
Stephen, H., and Long, D.G. (2002). Azimuth Modulation of Backscatter from SeaWinds and ERS Scatterometers over the Saharo-Arabian Deserts, 2002 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `02), 2808-2810, 10.1109/IGARSS.2002.1026782. Conference Paper »
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Title: Azimuth Modulation of Backscatter from SeaWinds and ERS Scatterometers over the Saharo-Arabian Deserts
Type: Conference Paper
Publication: 2002 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `02)
Author(s): Stephen, H., and Long, D.G.
Year: 2002
Formatted Citation: Stephen, H., and Long, D.G., 2002: Azimuth Modulation of Backscatter from SeaWinds and ERS Scatterometers over the Saharo-Arabian Deserts, 2002 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `02), 2808-2810, 10.1109/IGARSS.2002.1026782.
Abstract: Saharo-Arabian deserts includes large expanses of sand dunes called ergs. These dunes are formed and constantly reshaped by prevailing winds. We use backscatter (/spl sigma//sup 0/) measurements observed at various azimuth angles from SeaWinds scatterometer (QSCAT) and ERS scatterometer (ESCAT) to determine the /spl sigma//sup 0/ azimuthal modulation over the sand dunes. A second order harmonic equation is used to model the /spl sigma//sup 0/ measurements as a function of azimuth angle and provides similar results for both sensors. Images of the magnitudes of the model harmonics show many small-scale linear features corresponding to the large dune fields in the ergs. The images of the phases of the two harmonics are coherent with the large scale topography of the area. Most ergs exhibit isophase related to the general orientation of large- and small-scale features of the sand surface.
Keywords: backscatter remote sensing by radar sand spaceborne radar terrain mapping Arabian desert Arabian peninsula ERS scatterometer ESCAT North Africa QSCAT Sahara desert SeaWinds scatterometer azimuth angles azimuth
Mission: |SeaWinds|
URL: https://doi.org/10.1109/IGARSS.2002.1026782
Other URLs:
Stephen, H., and Long, D.G. (2002). Multi-Spectral Analysis of the Amazon Basin Using SeaWinds, ERS, Seasat Scatterometers, TRMM-PR and SSM/I, 2002 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `02), 1780-1782, 10.1109/IGARSS.2002.1026252. Conference Paper »
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Title: Multi-Spectral Analysis of the Amazon Basin Using SeaWinds, ERS, Seasat Scatterometers, TRMM-PR and SSM/I
Type: Conference Paper
Publication: 2002 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `02)
Author(s): Stephen, H., and Long, D.G.
Year: 2002
Formatted Citation: Stephen, H., and Long, D.G., 2002: Multi-Spectral Analysis of the Amazon Basin Using SeaWinds, ERS, Seasat Scatterometers, TRMM-PR and SSM/I, 2002 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `02), 1780-1782, 10.1109/IGARSS.2002.1026252.
Abstract: The Amazon basin represents a vast geographical zone containing large proportion of global biomass. We use the SeaWinds scatterometer (QSCAT), ERS-1/-2 scatterometer (ESCAT), NASA scatterometer (NSCAT) Seasat scatterometer (SASS), Tropical Rain Measuring Mission Precipitation Radar (TRMM-PR) and Special Sensor Microwave/Imager (SSM/I) data to study the multi-spectral microwave response of Amazon vegetation. Incidence angle signatures of combined backscatter measurements (/spl sigma//sup o/) from the scatterometers and precipitation radar indicate a good inter-calibration of the sensors. The multi-frequency signatures of both /spl sigma//sup o/ and radiometric temperature measurements (T/sub b/) from SSM/I are also studied. Temporal variability of the Amazon basin is studied using C-band ERS data and a Ku-band time series formed by SASS, NSCAT and QSCAT data. ESCAT data reveals a possible mismatch in the calibration of scatterometers between ERS-1 and ERS-2. Although the central Amazon forest represents an area of very stable radar backscatter measurements, portions of the southern region exhibit backscatter changes over the past two decades.
Keywords: forestry geophysical signal processing geophysical techniques radiometry remote sensing remote sensing by radar sensor fusion spaceborne radar terrain mapping vegetation mapping Amazon basin Brazil ERS SSM/I
Mission: |NSCAT|SeaWinds|
URL: https://doi.org/10.1109/IGARSS.2002.1026252
Other URLs:
Thum N., Esbensen S.K., Chelton D.B., and McPhaden M.J. (2002). Air-Sea Heat Exchange Along the Northern Sea Surface Temperature Front in the Eastern Tropical Pacific, Journal of Climate, 15(23), 3361-3378, 10.1175/1520-0442(2002)015<3361:ASHEAT>2.0.CO,2. Journal Article »
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Title: Air-Sea Heat Exchange Along the Northern Sea Surface Temperature Front in the Eastern Tropical Pacific
Type: Journal Article
Publication: Journal of Climate
Author(s): Thum N., Esbensen S.K., Chelton D.B., and McPhaden M.J.
Year: 2002
Formatted Citation: Thum N., Esbensen S.K., Chelton D.B., and McPhaden M.J., 2002: Air-Sea Heat Exchange Along the Northern Sea Surface Temperature Front in the Eastern Tropical Pacific, Journal of Climate, 15(23), 3361-3378, 10.1175/1520-0442(2002)015<3361:ASHEAT>2.0.CO,2.
Abstract: The atmospheric response to the oceanic forcing in the eastern Pacific along the northern equatorial sea surface temperature (SST) front is investigated in terms of sensible and latent heat flux during the 6-month period from 28 July 1999 to 27 January 2000 and the 7-month period from 28 June 2000 to 27 January 2001. Of particular interest is the atmospheric boundary layer (ABL) response to oceanic tropical instability waves (TIWs) that distort the SST front during May-January in normal years. In previous studies, time series of surface heat fluxes clearly show the influence of TIWs, but the relationship to spatial patterns of SST and wind speed has been inferred only from sparse in situ data. In this study, satellite observations are used as a basis for compositing in situ data from moorings to compensate for the lack of a spatially dense mooring array. The variability in the position of the SST front caused by westward-propagating TIWs enables fixed mooring locations to measure the ABL response from a large range of locations relative to the front. The satellite data enable determination of the precise location of the mooring relative to the front. The advantage of this strategy is the recurring measurement of the ABL response to the SST front over the 13-month period considered here. The results indicate that the TIW-induced perturbations of sensible heat flux are spatially shifted in phase toward the east relative to the perturbations of SST. The maximum fluxes of sensible heat are not centered directly over the warmest water, but are shifted toward the portion of the frontal region where a disequilibrium boundary layer is expected due to the advection of colder air from the equatorial region. The latent heat flux pattern is approximately in phase with the SST, with only a slight shift to the east. The changes of sensible and latent heat fluxes across the SST front have typical magnitudes of about 12 and 125 W m(-2), respectively. The sensible and latent heat flux patterns are interpreted in two complementary ways: 1) as an atmospheric response to the change of oceanic forcing as air flows across the SST front, and 2) as the atmospheric response to westward-propagating TIWs along the SST front.
Keywords: BOUNDARY-LAYER STRUCTURE, EQUATORIAL PACIFIC, INSTABILITY WAVES, GULF-STREAM, OCEAN, WIND, GRADIENTS, VARIABILITY, CONVECTION, SYSTEM
Mission:
URL: https://doi.org/10.1175/1520-0442(2002)015%3C3361:ASHEAT%3E2.0.CO;2
Other URLs:
Weissman, D.E. and Bourassa, M.A. (2002). The Development and Application of a Sea Surface Stress Model Function for the QuikSCAT and ADEOS-II SeaWinds Scatterometers, IEEE/Marine Technology Society OCEANS 2002 Conference, 10.1109/IGARSS.2003.1293736. Conference Paper »
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Title: The Development and Application of a Sea Surface Stress Model Function for the QuikSCAT and ADEOS-II SeaWinds Scatterometers
Type: Conference Paper
Publication: IEEE/Marine Technology Society OCEANS 2002 Conference
Author(s): Weissman, D.E. and Bourassa, M.A.
Year: 2002
Formatted Citation: Weissman, D.E. and Bourassa, M.A., 2002: The Development and Application of a Sea Surface Stress Model Function for the QuikSCAT and ADEOS-II SeaWinds Scatterometers, IEEE/Marine Technology Society OCEANS 2002 Conference, 10.1109/IGARSS.2003.1293736.
Abstract: A prototype of new geophysical model function is developed: it derives sea surface stress from the backscatter of an active microwave sensor (SeaWinds). The results are compared to values derived with a common drag coefficient, and to values derived from a state of the art surface flux model, which has been validated over a wide range of wind and wave conditions. The new model function determines friction velocity, which is the square root of the kinematic stress. The friction velocities appear to be underestimated for typical open ocean values, but appear to be excellent for stronger winds.
Keywords: component, surface stress, SeaWinds, scatterometer, validation
Mission: |SeaWinds|
URL: https://doi.org/10.1109/IGARSS.2003.1293736
Other URLs:
Weissman, D.E., Bourassa, M.A., and Tongue, J. (2002). Rainrate Estimates Over the Oceans Using SeaWinds Radar Measurements with Calibrations from NEXRAD and TRMM, 2002 International Geoscience and Remote Sensing Symposium, (IGARSS 2002).
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Title: Rainrate Estimates Over the Oceans Using SeaWinds Radar Measurements with Calibrations from NEXRAD and TRMM
Type: Conference Paper
Publication: 2002 International Geoscience and Remote Sensing Symposium, (IGARSS 2002)
Author(s): Weissman, D.E., Bourassa, M.A., and Tongue, J.
Year: 2002
Formatted Citation: Weissman, D.E., Bourassa, M.A., and Tongue, J., 2002: Rainrate Estimates Over the Oceans Using SeaWinds Radar Measurements with Calibrations from NEXRAD and TRMM, 2002 International Geoscience and Remote Sensing Symposium, (IGARSS 2002).
Abstract:
Keywords:
Mission: |SeaWinds|
URL:
Other URLs:
Weissman, D.E., Bourassa, M.A., and Tongue, J. (2002). Calibrating the QuikSCAT SeaWinds Radar for Measuring Rainrate Over the Oceans Using Collocations with TRMM Products, International Tropical Rainfall Measuring Mission (TRMM) Science Conference.
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Title: Calibrating the QuikSCAT SeaWinds Radar for Measuring Rainrate Over the Oceans Using Collocations with TRMM Products
Type: Conference Paper
Publication: International Tropical Rainfall Measuring Mission (TRMM) Science Conference
Author(s): Weissman, D.E., Bourassa, M.A., and Tongue, J.
Year: 2002
Formatted Citation: Weissman, D.E., Bourassa, M.A., and Tongue, J., 2002: Calibrating the QuikSCAT SeaWinds Radar for Measuring Rainrate Over the Oceans Using Collocations with TRMM Products, International Tropical Rainfall Measuring Mission (TRMM) Science Conference.
Abstract:
Keywords:
Mission: |SeaWinds|
URL:
Other URLs:
Weissman, D.E., Bourassa, M.A., and Tongue, J. (2002). Using the QuikSCAT/SeaWinds Satellite Radar for Measuring Rainrate over the Oceans ...., IEEE/Marine Technology Society OCEANS 2002 Conference.
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Title: Using the QuikSCAT/SeaWinds Satellite Radar for Measuring Rainrate over the Oceans ....
Type: Conference Paper
Publication: IEEE/Marine Technology Society OCEANS 2002 Conference
Author(s): Weissman, D.E., Bourassa, M.A., and Tongue, J.
Year: 2002
Formatted Citation: Weissman, D.E., Bourassa, M.A., and Tongue, J., 2002: Using the QuikSCAT/SeaWinds Satellite Radar for Measuring Rainrate over the Oceans ...., IEEE/Marine Technology Society OCEANS 2002 Conference.
Abstract:
Keywords:
Mission: |SeaWinds|
URL:
Other URLs:
Weissman, D.E., Bourassa, M.A., and Tongue, J. (2002). Effects of Rain Rate and Wind Magnitude on SeaWinds Scatterometer Wind Speed Errors, Journal of Atmospheric and Oceanic Technology, 19(5), 738-746, 10.1175/1520-0426(2002)019<0738:EORRAW>2.0.CO,2. Journal Article »
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Title: Effects of Rain Rate and Wind Magnitude on SeaWinds Scatterometer Wind Speed Errors
Type: Journal Article
Publication: Journal of Atmospheric and Oceanic Technology
Author(s): Weissman, D.E., Bourassa, M.A., and Tongue, J.
Year: 2002
Formatted Citation: Weissman, D.E., Bourassa, M.A., and Tongue, J., 2002: Effects of Rain Rate and Wind Magnitude on SeaWinds Scatterometer Wind Speed Errors, Journal of Atmospheric and Oceanic Technology, 19(5), 738-746, 10.1175/1520-0426(2002)019<0738:EORRAW>2.0.CO,2.
Abstract: Rain within the footprint of the SeaWinds scatterometer on the QuikSCAT satellite causes more significant errors than existed with its predecessor, the NASA scatterometer (NSCAT) on Advanced Earth Observing Satellite-I (ADEOS-I). Empirical relations are developed that show how the rain-induced errors in the scatterometer wind magnitude depend on both the rain rate and on the wind magnitude. These relations are developed with collocated National Data Buoy Center (NDBC) buoy measurements (to provide accurate sea surface winds) and simultaneous Next Generation Weather Radar (NEXRAD) observations of rain reflectivity. An analysis, based on electromagnetic scattering theory, interprets the dependence of the scatterometer wind errors on volumetric rain rate over a range of wind and rain conditions. These results demonstrate that the satellite scatterometer responds to rain in a manner similar to that of meteorological radars, with a Z-R relationship. These observations and results indicate that the combined (wind and rain) normalized radar cross section will lead to erroneously large wind estimates when the rain-related radar cross section exceeds a particular level that depends on the rain rate and surface wind speed.
Keywords: TRMM PRECIPITATION RADAR, WATER SURFACES, SCATTERING, ALGORITHM,
Mission: |NSCAT|SeaWinds|
URL: https://doi.org/10.1175/1520-0426(2002)019%3C0738:EORRAW%3E2.0.CO;2
Other URLs:
Xie, S.-P., Hafner, J., Tanimoto, Y., Liu, W.T., Tokinaga, H., and Xu, H. (2002). Bathymetric Effect on the Winter Sea Surface Temperature and Climate of the Yellow and East China Seas, Geophys. Res. Lett., 29(24), 2228, 10.1029/2002GL015884. Journal Article »
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Title: Bathymetric Effect on the Winter Sea Surface Temperature and Climate of the Yellow and East China Seas
Type: Journal Article
Publication: Geophys. Res. Lett.
Author(s): Xie, S.-P., Hafner, J., Tanimoto, Y., Liu, W.T., Tokinaga, H., and Xu, H.
Year: 2002
Formatted Citation: Xie, S.-P., Hafner, J., Tanimoto, Y., Liu, W.T., Tokinaga, H., and Xu, H., 2002: Bathymetric Effect on the Winter Sea Surface Temperature and Climate of the Yellow and East China Seas, Geophys. Res. Lett., 29(24), 2228, 10.1029/2002GL015884.
Abstract: Whether and how the atmosphere reacts to changes in extratropical sea surface temperature (SST) is under intense debate and this lack of understanding has been a major obstacle in the study of non-El Nino climate variability. Using new satellite measurements, we detect clear ocean-to-atmospheric feedback in the Yellow and East China (YEC) Seas that is triggered by the submerged ocean bottom topography. Under intense surface cooling in winter, water properties are well mixed up to 100 m deep. Ocean depth thus has a strong influence on SST of the continental shelf, leading to a remarkable collocation of warm tongues and deep channels. High winds and increased cloudiness are found over these warm tongues, one such band of ocean-atmospheric co-variation meanders through the basin, following a deep channel for an amazing distance of 1000 km. In addition to these climatic effects, the Kuroshio Front - where the warm current meets the much colder shelf water - strengthens the growth of storms.
Keywords: * Meteorology and Atmospheric Dynamics: Ocean/atmosphere interactions * Oceanography: General: Marginal and semienclosed seas
Mission:
URL: https://doi.org/10.1029/2002GL015884
Other URLs:
Zhao, Y.H., Liu, A.K., and Long, D.G. (2002). Validation of Sea Ice Motion from QuikSCAT with Those from SSM/I and Buoy, IEEE Transactions on Geoscience and Remote Sensing, 40(6), 1241-1246, 10.1109/TGRS.2002.800442. Journal Article »
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Title: Validation of Sea Ice Motion from QuikSCAT with Those from SSM/I and Buoy
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Zhao, Y.H., Liu, A.K., and Long, D.G.
Year: 2002
Formatted Citation: Zhao, Y.H., Liu, A.K., and Long, D.G., 2002: Validation of Sea Ice Motion from QuikSCAT with Those from SSM/I and Buoy, IEEE Transactions on Geoscience and Remote Sensing, 40(6), 1241-1246, 10.1109/TGRS.2002.800442.
Abstract: Arctic sea ice motion for the period from October 1999 to March 2000 derived from QuikSCAT and special sensor microwave/imager (SSM/I) data using the wavelet analysis method agrees well with ocean buoy observations. Results from QuikSCAT and SSM/I are compatible when compared with buoy observations and complement each other. Sea ice drift merged from daily results from QuikSCAT, SSM/I, and buoy data gives more complete coverage of sea ice motion. Based on observations of six months of sea ice motion maps, the sea ice motion maps in the Arctic derived from QuikSCAT data appear to have smoother (less noisy) patterns than those from NSCAT, especially in boundary areas, possibly due to constant radar scanning incidence angle. For late summer, QuikSCAT data can provide good sea ice motion information in the Arctic as early as the beginning of September. For early summer, QuikSCAT can provide at least partial sea ice motion information until mid-June. In the Antarctic, a case study shows that sea ice motion derived from QuikSCAT data is consistent with pressure field contours.
Keywords: WAVELET ANALYSIS, DRIFT, QuikSCAT, sea ice motion, special sensor nucrowave/imager (SSM/I), wavelet transform
Mission: |NSCAT|SeaWinds|
URL: https://doi.org/10.1109/TGRS.2002.800442
Other URLs:
Ashcraft, I.S., and Long, D.G. (2001). Azimuth Variation in Microwave Backscatter over the Greenland Icesheet, 2001 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `01), 1779-1781, 10.1109/IGARSS.2001.977069. Conference Paper »
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Title: Azimuth Variation in Microwave Backscatter over the Greenland Icesheet
Type: Conference Paper
Publication: 2001 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `01)
Author(s): Ashcraft, I.S., and Long, D.G.
Year: 2001
Formatted Citation: Ashcraft, I.S., and Long, D.G., 2001: Azimuth Variation in Microwave Backscatter over the Greenland Icesheet, 2001 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `01), 1779-1781, 10.1109/IGARSS.2001.977069.
Abstract: Scatterometer backscatter measurements are becoming an important tool for monitoring the dynamic behavior of the Greenland Ice Sheet. However, most Greenland studies assume constant backscatter for varying azimuth angles. Detailed analysis of scatterometer data sets show non-negligible (1-2 dB) azimuth modulation. The magnitude and orientation of the azimuth modulation observed by SeaWinds, NSCAT, and ERS are documented herein. The dominate factor is second order azimuth modulation, which is largest for C-band (ERS). For SeaWinds, the h-pol azimuth modulation is larger than for v-pol.
Keywords: backscatter glaciology hydrological techniques radar cross-sections remote sensing by radar snow C-band Greenland Ice Sheet azimuth modulation azimuth variation glaciology measurement technique microwave backscatter
Mission: |NSCAT|SeaWinds|
URL: https://doi.org/10.1109/IGARSS.2001.977069
Other URLs:
Ashcraft, I.S., and Long, D.G. (2001). Multi-Annual Changes in Microwave Backscatter over the Greenland Ice Sheet, 2001 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `01), 958-960, 10.1109/IGARSS.2001.976693. Conference Paper »
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Title: Multi-Annual Changes in Microwave Backscatter over the Greenland Ice Sheet
Type: Conference Paper
Publication: 2001 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `01)
Author(s): Ashcraft, I.S., and Long, D.G.
Year: 2001
Formatted Citation: Ashcraft, I.S., and Long, D.G., 2001: Multi-Annual Changes in Microwave Backscatter over the Greenland Ice Sheet, 2001 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `01), 958-960, 10.1109/IGARSS.2001.976693.
Abstract: Changes in the location of key ice facies/zones on the Greenland ice sheet are considered key indicators of global climate change. Microwave scatterometers are effective tools for monitoring these changes. Measurements for three Ku-band scatterometers, SASS (1978), NSCAT (1996), and SeaWinds (1999-present), span a 23-year period. While the ERS scatterometer (C-band) offers a continuous 9-year dataset (1992-2000). Using the SIR algorithm to produce spl sigma//sup 0/ images, the measurements made by these sensors over Greenland are compared. We find an increase in /spl sigma//sup 0/ along the southern border between the dry snow zone and percolation zone, and a decrease for C-band measurements along the northern portions of this boundary.
Keywords: backscatter glaciology remote sensing by radar AD 1978 to 2000 C-band measurements ERS scatterometer Greenland ice sheet Ku-band scatterometers NSCAT SASS SIR algorithm SeaWinds dry snow zone global climate change
Mission: |NSCAT|SeaWinds|
URL: https://doi.org/10.1109/IGARSS.2001.976693
Other URLs:
Bourassa, M.A. (2001). Tehuantepec Wind and Pressure Changes Associated with Tropical Cyclones., 11th Conference on Interactions of the Sea and Atmosphere, 27-28. Conference Paper »
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Title: Tehuantepec Wind and Pressure Changes Associated with Tropical Cyclones.
Type: Conference Paper
Publication: 11th Conference on Interactions of the Sea and Atmosphere
Author(s): Bourassa, M.A.
Year: 2001
Formatted Citation: Bourassa, M.A., 2001: Tehuantepec Wind and Pressure Changes Associated with Tropical Cyclones., 11th Conference on Interactions of the Sea and Atmosphere, 27-28.
Abstract:
Keywords: wind, gap, QSCAT
Mission: |SeaWinds|
URL: http://ams.confex.com/ams/pdfpapers/20531.pdf
Other URLs:
Chelton, D.B., Esbensen, S.K., Schlax, G., Thum, N., Freilich, M.H., Wentz, F.J., Gentemann, C.L., McPhaden, M.J., and Schopf, P.S. (2001). Observations of Coupling Between Surface Wind Stress and Sea Surface Temperature in the Eastern Tropical Pacific, Journal of Climate, 14(7), 1479-1498, 10.1175/1520-0442(2001)014<1479:OOCBSW>2.0.CO;2. Journal Article »
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Title: Observations of Coupling Between Surface Wind Stress and Sea Surface Temperature in the Eastern Tropical Pacific
Type: Journal Article
Publication: Journal of Climate
Author(s): Chelton, D.B., Esbensen, S.K., Schlax, G., Thum, N., Freilich, M.H., Wentz, F.J., Gentemann, C.L., McPhaden, M.J., and Schopf, P.S.
Year: 2001
Formatted Citation: Chelton, D.B., Esbensen, S.K., Schlax, G., Thum, N., Freilich, M.H., Wentz, F.J., Gentemann, C.L., McPhaden, M.J., and Schopf, P.S., 2001: Observations of Coupling Between Surface Wind Stress and Sea Surface Temperature in the Eastern Tropical Pacific, Journal of Climate, 14(7), 1479-1498, 10.1175/1520-0442(2001)014<1479:OOCBSW>2.0.CO;2.
Abstract: Satellite measurements of surface wind stress from the QuikSCAT scatterometer and sea surface temperature (SST) from the Tropical Rainfall Measuring Mission Microwave Imager are analyzed for the three-month period 21 July-20 October 1999 to investigate oceanatmosphere coupling in the eastern tropical Pacific. Oceanic tropical instability waves (TIWs) with periods of 20-40 days and wavelengths of 1000-2000 km perturb the SST fronts that bracket both sides of the equatorial cold tongue, which is centered near 1^oS to the east of 130^oW. These perturbations are characterized by cusp-shaped features that propagate systematically westward on both sides of the equator. The spacetime structures of these SST perturbations are reproduced with remarkable detail in the surface wind stress field. The wind stress divergence is shown to be linearly related to the downwind component of the SST gradient with a response on the south side of the cold tongue that is about twice that on the north side. The wind stress curl is linearly related to the crosswind component of the SST gradient with a response that is approximately half that of the wind stress divergence response to the downwind SST gradient. The perturbed SST and wind stress fields propagate synchronously westward with the TIWs. This close coupling between SST and wind stress supports the Wallace et al. hypothesis that surface winds vary in response to SST modification of atmospheric boundary layer stability.
Keywords: EQUATORIAL PACIFIC, INSTABILITY WAVES, OCEAN ALGORITHM, SEASONAL CYCLE, MIXED-LAYER, VARIABILITY, CIRCULATION, GRADIENTS, OSCILLATIONS, CONVECTION
Mission: |SeaWinds|
URL: https://doi.org/10.1175/1520-0442(2001)014%3C1479:OOCBSW%3E2.0.CO;2
Other URLs:
Conaty, A.L., Jusem, J.C., Takacs, L., Keyser, D., and Atlas, R. (2001). The Structure and Evolution of Extratropical Cyclones, Fronts, Jet Streams, and the Tropopause in the GEOS General Circulation Model, Bulletin of the American Meteorological Society, 82(9), 1853-1867, 10.1175/1520-0477-82.9.1853. Journal Article »
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Title: The Structure and Evolution of Extratropical Cyclones, Fronts, Jet Streams, and the Tropopause in the GEOS General Circulation Model
Type: Journal Article
Publication: Bulletin of the American Meteorological Society
Author(s): Conaty, A.L., Jusem, J.C., Takacs, L., Keyser, D., and Atlas, R.
Year: 2001
Formatted Citation: Conaty, A.L., Jusem, J.C., Takacs, L., Keyser, D., and Atlas, R., 2001: The Structure and Evolution of Extratropical Cyclones, Fronts, Jet Streams, and the Tropopause in the GEOS General Circulation Model, Bulletin of the American Meteorological Society, 82(9), 1853-1867, 10.1175/1520-0477-82.9.1853.
Abstract: The realism of extratropical cyclones, fronts, jet streams, and the tropopause in the Goddard Earth Observing System (GEOS) general circulation model (GCM), implemented in assimilation and simulation modes, is evaluated from climatological and casestudy perspectives using the GEOS1 reanalysis climatology and applicable conceptual models as benchmarks for comparison. The latitudelongitude grid spacing of the datasets derived from the GEOS GCM ranges from 2^o x 2.5^o to 0.5^o x 0.5^o. Frontal systems in the higherresolution datasets are characterized by horizontal potential temperature gradients that are narrower in scale and larger in magnitude than their lowerresolution counterparts, and various structural features in the ShapiroKeyser cyclone model are replicated with reasonable fidelity at 1^o x 1^o resolution. The remainder of the evaluation focuses on a 3-month Northern Hemisphere winter simulation of the GEOS GCM at 1^o x 1^o resolution. The simulation realistically reproduces various largescale circulation features related to the North Pacific and Atlantic jet streams when compared with the GEOS1 reanalysis climatology, and conforms closely to a conceptualization of the zonally averaged troposphere and stratosphere proposed originally by Napier Shaw and revised by Hoskins. An extratropical cyclone that developed over the North Atlantic Ocean in the simulation features surface and tropopause evolutions corresponding to the Norwegian cyclone model and to the LC2 life cycle proposed by Thorncroft et al., respectively. These evolutions are related to the position of the developing cyclone with respect to upper-level jets identified in the time-mean and instantaneous flow fields. This article concludes with the enumeration of several research opportunities that may be addressed through the use of state-of-the-art GCMs possessing sufficient resolution to represent mesoscale phenomena and processes explicitly.
Keywords: Extratropical cyclone , Jet stream , Tropopause , General circulation models , Case study , Climatology , Horizontal gradient , Potential temperature , Temperature gradient , Numerical simulation , Winter , Troposphere , Stratosphere , Atmospheric front ,
Mission:
URL: https://doi.org/10.1175/1520-0477-82.9.1853
Other URLs:
Dickinson, S., Kelly, K.A., Caruso, M.J., and McPhaden, M.J. (2001). Comparisons Between the TAO Buoy and NASA Scatterometer Wind Vectors, Journal of Atmospheric and Oceanic Technology, 18(5), 799-806, 10.1175/1520-0426(2001)018<0799:CBTTBA>2.0.CO,2. Journal Article »
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Title: Comparisons Between the TAO Buoy and NASA Scatterometer Wind Vectors
Type: Journal Article
Publication: Journal of Atmospheric and Oceanic Technology
Author(s): Dickinson, S., Kelly, K.A., Caruso, M.J., and McPhaden, M.J.
Year: 2001
Formatted Citation: Dickinson, S., Kelly, K.A., Caruso, M.J., and McPhaden, M.J., 2001: Comparisons Between the TAO Buoy and NASA Scatterometer Wind Vectors, Journal of Atmospheric and Oceanic Technology, 18(5), 799-806, 10.1175/1520-0426(2001)018<0799:CBTTBA>2.0.CO,2.
Abstract: There was an opportunity to compare 10 months of collocated National Aeronautics and Space Administration scatterometer (NSCAT) wind vectors with those from the Tropical Atmosphere Ocean (TAO) buoy array, located in the tropical Pacific Ocean. Over 5500 data pairs, from nearly 70 buoys, were collocated in the calibration/validation effort for NSCAT. These data showed that the wind speeds produced from the NSCAT-1 model function were low by about 7%-8% compared with TAO buoy winds. The revised model function, NSCAT-2, produces wind speeds with a bias of about 1%. The scatterometer directions were within 20 degrees (rms), meeting accuracy requirements, when compared to TAO data. The mean direction bias between the TAO and the NSCAT vectors (regardless of model function) is about 9 degrees with the scatterometer winds to the right of the TAO winds, which may be due to swell. The statistics of the two datasets are discussed, using component biases in lieu of the speed bias, which is naturally skewed. Using ocean currents and buoy winds measured along the equator, it is shown that the scatterometer measures the wind relative to the moving ocean surface. In addition, a systematic effect of rain on the NSCAT wind retrievals is noted. In all analyses presented here, winds less than 3 m s(-1) are removed, due to the difficulty in making accurate low wind measurements.
Keywords: RADAR CROSS-SECTION, OCEAN, STRESS, SYSTEM,
Mission: |NSCAT|
URL: https://doi.org/10.1175/1520-0426(2001)018%3C0799:CBTTBA%3E2.0.CO;2
Other URLs:
Draper, D.W., and Long, D.G. (2001). An Advanced Point-wise Ambiguity Selection Algorithm: Application to SeaWinds, 2001 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `01), 2190-2192, 10.1109/IGARSS.2001.977945. Conference Paper »
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Title: An Advanced Point-wise Ambiguity Selection Algorithm: Application to SeaWinds
Type: Conference Paper
Publication: 2001 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `01)
Author(s): Draper, D.W., and Long, D.G.
Year: 2001
Formatted Citation: Draper, D.W., and Long, D.G., 2001: An Advanced Point-wise Ambiguity Selection Algorithm: Application to SeaWinds, 2001 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `01), 2190-2192, 10.1109/IGARSS.2001.977945.
Abstract: The scatterometer wind estimation process results in several possible wind vectors (ambiguities) at each resolution cell. The current ambiguity selection technique applied to SeaWinds on QuikSCAT data requires outside data as part of the initialization. An advanced ambiguity selection algorithm known as BYU point-wise does not use nudging data, rather, it utilizes a low-order Karhunen Loeve (KL) wind field model to promote self-consistency. In application to a subset of SeaWinds data, BYU point-wise selects 93% of the same ambiguities as the JPL method. On a set of non-storm error regions, BYU point-wise performed subjectively better in 55% of regions and subjectively worse in only 11% of regions. In cyclonic-storm cases, BYU pointwise performed subjectively better in 11% of regions while performing worse in 23% of regions. Thus, BYU point-wise generally produces more consistent results in non-storm regions without the aid of external nudging data.
Keywords: atmospheric techniques geophysical signal processing meteorological radar remote sensing by radar spaceborne radar wind BYU point-wise SeaWinds low-order Karhunen Loeve wind field model marine atmosphere measurement techni
Mission: |SeaWinds|
URL: https://doi.org/10.1109/IGARSS.2001.977945
Other URLs:
Drinkwater, M.R., Long, D.G., and Bingham, A.W. (2001). Greenland Snow Accumulation Estimates from Satellite Radar Scatterometer Data, Journal of Geophysical Research, 106(D24), 33935-33950, 10.1029/2001JD900107. Journal Article »
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Title: Greenland Snow Accumulation Estimates from Satellite Radar Scatterometer Data
Type: Journal Article
Publication: Journal of Geophysical Research
Author(s): Drinkwater, M.R., Long, D.G., and Bingham, A.W.
Year: 2001
Formatted Citation: Drinkwater, M.R., Long, D.G., and Bingham, A.W., 2001: Greenland Snow Accumulation Estimates from Satellite Radar Scatterometer Data, Journal of Geophysical Research, 106(D24), 33935-33950, 10.1029/2001JD900107.
Abstract: Data collected by the C band ERS-2 wind scatterometer (EScat), the Ku band ADEOS-1 NASA scatterometer (NSCAT), and the Ku band SeaWinds on QuikScat (QSCAT) satellite instruments are used to illustrate spatiotemporal variability in snow accumulation on the Greenland ice sheet. Microwave radar backscatter images of Greenland are derived using the scatterometer image reconstruction (SIR) method at 3-day intervals over the periods 1991-1998 and 1996-1997 for EScat and NSCAT, respectively. The backscatter coefficient σ^o normalized to 40^o incidence, A, and gradient in backscatter, B, in the range 20^o-60^o are compared with historical snow accumulation data and recent measurements made in the Program for Arctic Regional Climate Assessment (PARCA) shallow snow pits. Empirical relationships derived from these comparisons reveal different exponential relationships between C and Ku band A values and dry snow zone mean annual accumulation, Q. Frequency difference images between overlapping scatterometer images suggest that C band data are more sensitive to snow layering and buried inhomogeneities, whereas Ku band data are more sensitive to volume scattering from recently accumulated snow. Direct comparisons between NSCAT B values and in situ Q measurements show a linear relationship between ln (Q) and B, with a negative rank correlation of R = -0.8. The root-mean-square residual in fitting regression line equation ln (Q) = 3.08 - 17.83B to the data is 0.05-m snow water equivalent. This simple Ku band empirical relationship is exploited to investigate decadal changes in dry snow zone accumulation between Seasat (1978) and NSCAT (1996). Additional comparisons between NSCAT and recent QSCAT (1999) data reveal significant upslope shifts in the dry snow line along the southwestern flank of the ice sheet. Recent acceleration in the increase in intensity of scattering is observed in the percolation zone, suggesting increased melting between 2000- and 3000-m elevation in the southern half of the ice sheet.
Keywords: Exploration Geophysics: Remote sensing, Global Change: Water cycles, Hydrology: Glaciology, Meteorology and Atmospheric Dynamics: Polar meteorology
Mission: |NSCAT|SeaWinds|
URL: https://doi.org/10.1029/2001JD900107
Other URLs:
Early, D.S., and Long, D.G. (2001). Image Reconstruction and Enhanced Resolution Imaging from Irregular Samples, IEEE Transactions on Geoscience and Remote Sensing, 39(2), 291-302, 10.1109/36.905237. Journal Article »
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Title: Image Reconstruction and Enhanced Resolution Imaging from Irregular Samples
Type: Journal Article
Publication: IEEE Transactions on Geoscience and Remote Sensing
Author(s): Early, D.S., and Long, D.G.
Year: 2001
Formatted Citation: Early, D.S., and Long, D.G., 2001: Image Reconstruction and Enhanced Resolution Imaging from Irregular Samples, IEEE Transactions on Geoscience and Remote Sensing, 39(2), 291-302, 10.1109/36.905237.
Abstract: While high resolution, regularly gridded observations are generally preferred in remote sensing, actual observations are often not evenly sampled and have lower-than-desired resolution. Hence, there is an interest in resolution enhancement and image reconstruction. This paper discusses a general theory and techniques for image reconstruction and creating enhanced resolution images from irregularly sampled data. Using irregular sampling theory, we consider how the frequency content in aperture function-attenuated sidelobes can be recovered from oversampled data using reconstruction techniques, thus taking advantage of the high frequency content of measurements made with nonideal aperture filters. We show that with minor modification, the algebraic reconstruction technique (ART) is functionally equivalent to Grochenig's (1992) irregular sampling reconstruction algorithm. Using simple Monte Carlo simulations, we compare and contrast the performance of additive ART, multiplicative ART, and the scatterometer image reconstruction (SIR) (a derivative of multiplicative ART) algorithms with and without noise. The reconstruction theory and techniques have applications with a variety of sensors and can enable enhanced resolution image production from many nonimaging sensors. The technique is illustrated with ERS-2 and SeaWinds scatterometer data.
Keywords: Monte Carlo methods geophysical signal processing image enhancement image reconstruction image resolution image sampling radar imaging radar resolution remote sensing by radar spaceborne radar
Mission: |SeaWinds|
URL: https://doi.org/10.1109/36.905237
Other URLs:
Forster, R.R., Long, D.G., Jezek, K.C., Drobot, S.D., and Anderson, M.R. (2001). The Onset of Arctic Sea-Ice Snowmelt as Detected with Passive- and Active-Microwave Remote Sensing, Annals of Glaciology, 33(1), 85-93, 10.3189/172756401781818428. Journal Article »
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Title: The Onset of Arctic Sea-Ice Snowmelt as Detected with Passive- and Active-Microwave Remote Sensing
Type: Journal Article
Publication: Annals of Glaciology
Author(s): Forster, R.R., Long, D.G., Jezek, K.C., Drobot, S.D., and Anderson, M.R.
Year: 2001
Formatted Citation: Forster, R.R., Long, D.G., Jezek, K.C., Drobot, S.D., and Anderson, M.R., 2001: The Onset of Arctic Sea-Ice Snowmelt as Detected with Passive- and Active-Microwave Remote Sensing, Annals of Glaciology, 33(1), 85-93, 10.3189/172756401781818428.
Abstract: Daily acquisitions from satellite microwave sensors can be used to observe the spatial and temporal characteristics of the Arctic sea-ice snowmelt onset because the initial presence of liquid water in a dry snowpack causes a dramatic change in the active and passive-microwave response. A daily sequence of backscatter coefficient images from the NASA scatterometer (NSCAT) clearly shows the spatially continuous progression of decreasing backscatter associated,with snowmelt onset across the Arctic Ocean during spring 1997. A time series of the active NSCAT backscatter and a scattering index from the passive Special Sensor Microwave/Imager (SSM/I) show similar trends during the time of the melt onset. An NSCAT snowmelt-onset detection algorithm is developed using the derivative of the backscatter with respect to time to select a melt-onset date for each pixel, generating a melt map for the Arctic sea ice. Comparison between this melt map and one previously generated from an SSM/I scattering index shows the NSCAT algorithm predicts the onset occurs 1-10 days earlier than the SSM/I-based algorithm for most portions of multi-year ice.
Keywords: MELT-ONSET, SCATTEROMETER, VARIABILITY, SCATTERING, CRYOSPHERE, REGIONS, RADAR, ERS,
Mission: |NSCAT|
URL: https://doi.org/10.3189/172756401781818428
Other URLs:
Franz, R.O.W., and Long, D.G. (2001). Multidimensional Reconstruction from Irregular Samples, Optical Society of America Technical Digest: Signal Recovery and Synthesis, 135-137, 10.1364/SRS.2001.SWC2. Conference Paper »
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Title: Multidimensional Reconstruction from Irregular Samples
Type: Conference Paper
Publication: Optical Society of America Technical Digest: Signal Recovery and Synthesis
Author(s): Franz, R.O.W., and Long, D.G.
Year: 2001
Formatted Citation: Franz, R.O.W., and Long, D.G., 2001: Multidimensional Reconstruction from Irregular Samples, Optical Society of America Technical Digest: Signal Recovery and Synthesis, 135-137, 10.1364/SRS.2001.SWC2.
Abstract:
Keywords:
Mission:
URL: https://doi.org/10.1364/SRS.2001.SWC2
Other URLs:
Hashizume, H., Xie, S.-P., Liu, W.T., and Takeuchi, K. (2001). Local and Remote Atmospheric Response to Tropical Instability Waves: A Global View from Space, Journal of Geophysical Research, 106(D10), 10,173-10,185, 10.1029/2000JD900684. Journal Article »
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Title: Local and Remote Atmospheric Response to Tropical Instability Waves: A Global View from Space
Type: Journal Article
Publication: Journal of Geophysical Research
Author(s): Hashizume, H., Xie, S.-P., Liu, W.T., and Takeuchi, K.
Year: 2001
Formatted Citation: Hashizume, H., Xie, S.-P., Liu, W.T., and Takeuchi, K., 2001: Local and Remote Atmospheric Response to Tropical Instability Waves: A Global View from Space, Journal of Geophysical Research, 106(D10), 10,173-10,185, 10.1029/2000JD900684.
Abstract: A La Niña took place in the equatorial Pacific in 1999, and strong tropical instability waves (TIWs) developed, causing large meanders of a sea surface temperature (SST) front between the equator and 3°N. High-resolution satellite measurements are used to describe the variability of SST. surface wind velocity, column-integrated water vapor, cloud liquid water, and precipitation associated with these strong TIWs in 1999. Coherent ocean-atmosphere patterns emerge in both the Pacific and Atlantic, revealing rich regional characteristics. In the far eastern Pacific, southeasterly trades strengthen (weaken) over positive (negative) SST anomalies, apparently due to enhanced (reduced) mixing with high-speed winds aloft. In the central Pacific we find evidence that SST-induced sea level pressure changes also contribute substantially to wind fluctuations. Similar SST-wind covariability also exists in the Southern Hemisphere along 2°S, but the wind variability induced by unit SST anomaly is much larger than that north of the equator. In the central Pacific where the equatorial front is broad, the northern SST pattern has a large meridional scale and reaches as far north as 6°N. Further to the north in the Intertropical Convergence Zone (ITCZ) where local SST anomalies are small, significant variability is found in clouds and precipitation, which is further correlated with surface wind convergence. In the Atlantic, TIW signals in SST are strongly trapped near the equator, but they induce significant remote response in the ITCZ, which takes a more southern position than its Pacific counterpart and thus more susceptible to TIW influence.
Keywords: Ocean wave , Instability , Surface temperature , Sea surface , Meander , Satellite observation , High resolution , Surface wind , Wind velocity , Water vapor , Atmospheric precipitation , Ocean atmosphere interaction , Atmospheric pressure , Sea level , I
Mission:
URL: https://doi.org/10.1029/2000JD900684
Other URLs:
Long, D.G. (2001). High Resolution Wind Retrieval from SeaWinds, 2002 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `02), 2187-2189, 10.1109/IGARSS.2002.1025662. Conference Paper »
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Title: High Resolution Wind Retrieval from SeaWinds
Type: Conference Paper
Publication: 2002 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `02)
Author(s): Long, D.G.
Year: 2001
Formatted Citation: Long, D.G., 2001: High Resolution Wind Retrieval from SeaWinds, 2002 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `02), 2187-2189, 10.1109/IGARSS.2002.1025662.
Abstract: While originally designed for measuring vector winds over the ocean at a nominal resolution of 25 km, data from SeaWinds-on-QuikSCAT can be used to retrieve winds over the ocean at higher resolution with the aid of resolution enhancement reconstruction algorithms. This paper analyzes a technique for retrieving enhanced resolution winds at high resolution from SeaWinds data. Techniques for minimizing the required computation are described. As can be expected the wind estimates are noisier than standard resolution products. Some of the limitations of the approach and resulting products are considered. While validation of this approach to high resolution wind retrieval continues, the results thus far are very encouraging.
Keywords: atmospheric techniques geophysical signal processing meteorological radar remote sensing by radar spaceborne radar wind 13.4 GHz QuikSCAT SHF SeaWinds high resolution marine atmosphere measurement technique meteor
Mission: |SeaWinds|
URL: https://doi.org/10.1109/IGARSS.2002.1025662
Other URLs:
Long, D.G., and Ashcraft, I.S. (2001). SeaWinds Applications for Land and Ice Studies, Proceedings of SPIE, Earth Observing Systems VI, 4483, 10.1117/12.453444. Conference Paper »
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Title: SeaWinds Applications for Land and Ice Studies
Type: Conference Paper
Publication: Proceedings of SPIE, Earth Observing Systems VI
Author(s): Long, D.G., and Ashcraft, I.S.
Year: 2001
Formatted Citation: Long, D.G., and Ashcraft, I.S., 2001: SeaWinds Applications for Land and Ice Studies, Proceedings of SPIE, Earth Observing Systems VI, 4483, 10.1117/12.453444.
Abstract: While originally designed for making wind vector measurements over the ocean, radar scatterometers are also effective for large-scale monitoring of the Earth's land and ice surfaces. The recently launched SeaWinds scatterometer is the next generation of Ku-band scatterometers and offers many advantages over previous scatterometers including a very wide swath and constant incidence angle measurements. The wide swath of SeaWinds enables much more frequent coverage of the Earth's surface than has previously been possible and enhances the potential of the data in land and ice applications. SeaWinds data has been particularly effective in polar ice applications and SeaWinds data is currently being used for operational sea-ice extent monitoring and large iceberg tracking. Additional applications include monitoring glacial and sea-ice melting and studying the firn structure in Greenland and Antarctica. New applications of SeaWinds are being developed, including high resolution wind retrieval. Several such applications are briefly considered.
Keywords:
Mission: |SeaWinds|
URL: https://doi.org/10.1117/12.453444
Other URLs:
Long, D.G., and Early, D.E. (2001). Comparison of Several Numerical Algorithms for Image Reconstruction from Irregular Samples, Optical Society of America Technical Digest: Signal Recovery and Synthesis, 138-140. Conference Paper »
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Title: Comparison of Several Numerical Algorithms for Image Reconstruction from Irregular Samples
Type: Conference Paper
Publication: Optical Society of America Technical Digest: Signal Recovery and Synthesis
Author(s): Long, D.G., and Early, D.E.
Year: 2001
Formatted Citation: Long, D.G., and Early, D.E., 2001: Comparison of Several Numerical Algorithms for Image Reconstruction from Irregular Samples, Optical Society of America Technical Digest: Signal Recovery and Synthesis, 138-140.
Abstract:
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URL: https://opg.optica.org/abstract.cfm?uri=srs-2001-SWC3
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Otterman, J., Angell, J.K., Atlas, R., Ardizzone, J., Demarée, G., Jusem, J.C., Koslowsky, D., and Terry, J. (2001). The Extremely Warm Early Winter 2000 in Europe: What is the Forcing?, EOS. Journal Article »
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Title: The Extremely Warm Early Winter 2000 in Europe: What is the Forcing?
Type: Journal Article
Publication: EOS
Author(s): Otterman, J., Angell, J.K., Atlas, R., Ardizzone, J., Demarée, G., Jusem, J.C., Koslowsky, D., and Terry, J.
Year: 2001
Formatted Citation: Otterman, J., Angell, J.K., Atlas, R., Ardizzone, J., Demarée, G., Jusem, J.C., Koslowsky, D., and Terry, J., 2001: The Extremely Warm Early Winter 2000 in Europe: What is the Forcing?, EOS.
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URL: https://ntrs.nasa.gov/citations/20010026412
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Otterman, J., Ardizzone, J., Atlas, R., Bungato, D., Cierniewski, J., Jusem, J.C., Przybylak, R., Schubert, S., Starr, D., Walczewski, J., and Wos, A. (2001). Extreme Anomalies of Winter Air Temperature in Mid-Latitude Europe, Geographia Polonica, 74(2), 57-67. Journal Article »
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Title: Extreme Anomalies of Winter Air Temperature in Mid-Latitude Europe
Type: Journal Article
Publication: Geographia Polonica
Author(s): Otterman, J., Ardizzone, J., Atlas, R., Bungato, D., Cierniewski, J., Jusem, J.C., Przybylak, R., Schubert, S., Starr, D., Walczewski, J., and Wos, A.
Year: 2001
Formatted Citation: Otterman, J., Ardizzone, J., Atlas, R., Bungato, D., Cierniewski, J., Jusem, J.C., Przybylak, R., Schubert, S., Starr, D., Walczewski, J., and Wos, A., 2001: Extreme Anomalies of Winter Air Temperature in Mid-Latitude Europe, Geographia Polonica, 74(2), 57-67.
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URL: https://www.geographiapolonica.pl/article/item/7774.html
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Reale, O., and Atlas, R. (2001). Tropical Cyclone-Like Vortices in the Extratropics: Observational Evidence and Synoptic Analysis, Weather and Forecasting, 16(1), 7-34, 10.1175/1520-0434(2001)016<0007:TCLVIT>2.0.CO,2. Journal Article »
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Title: Tropical Cyclone-Like Vortices in the Extratropics: Observational Evidence and Synoptic Analysis
Type: Journal Article
Publication: Weather and Forecasting
Author(s): Reale, O., and Atlas, R.
Year: 2001
Formatted Citation: Reale, O., and Atlas, R., 2001: Tropical Cyclone-Like Vortices in the Extratropics: Observational Evidence and Synoptic Analysis, Weather and Forecasting, 16(1), 7-34, 10.1175/1520-0434(2001)016<0007:TCLVIT>2.0.CO,2.
Abstract: In this article two subsynoptic-scale cyclones that developed between 3 and 10 October 1996 over the western-central Mediterranean, causing floods, strong winds, and severe damage, are analyzed. Surface observations reveal that the accumulated rainfall at Santuario di Polsi (southern Calabria, Italy) is more than 480 mm for the first event (cyclone 9610A). The second cyclone (9610B) was characterized by a storm track predominantly over the sea, thus causing less recorded precipitation, but stronger wind. Satellite imagery shows two intensely convective vortices with a scale of 200-400 km and a spiral structure, with the cyclone 9610B displaying a well-defined eyelike feature. The corresponding National Centers for Environmental Prediction analyses, although limited by 1 resolution, confirm the cyclones positions and intensities, as they can be inferred from satellite imagery, SSM/I data, and observations, but display also the signature of two tropical cyclonelike vortices, including a perfect alignment between the cutoffs at all levels with the surface center, and a warm core. The wind speed cross sections in the meridional and zonal directions through the eyelike feature reveal a virtually motionless column of air. A comparison with the cross sections taken in the same analyses across a named tropical storm in the Atlantic show a strong analogy between the gridded representation of these events. Other remarkable features include very strong horizontal shear in the midtroposphere, and simultaneous lack of vertical shear, increasing low-level vorticity at the expenses of upper-level vorticity, creation of a low-level vorticity maximum, and finally strong low-level convergence and upper-level divergence during the onset and development of each cyclone.
Keywords: Tropical cyclone , Flood , Wind , Rain , Storm , Intensity , Wind velocity , Cross section (collision) , Vorticity , Vortex , Natural damage , Satellite observation , Image analysis , Extratropical zone , East Mediterranean , Italy , Mediterranean Sea , E
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URL: https://doi.org/10.1175/1520-0434(2001)016%3C0007:TCLVIT%3E2.0.CO;2
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Schlax, M.G., Chelton, D.B., and Freilich, M.H. (2001). Sampling Errors in Wind Fields Constructed from Single and Tandem Scatterometer Datasets, Journal of Atmospheric and Oceanic Technology, 18(6), 1014-1036, 10.1175/1520-0426(2001)018<1014:SEIWFC>2.0.CO,2. Journal Article »
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Title: Sampling Errors in Wind Fields Constructed from Single and Tandem Scatterometer Datasets
Type: Journal Article
Publication: Journal of Atmospheric and Oceanic Technology
Author(s): Schlax, M.G., Chelton, D.B., and Freilich, M.H.
Year: 2001
Formatted Citation: Schlax, M.G., Chelton, D.B., and Freilich, M.H., 2001: Sampling Errors in Wind Fields Constructed from Single and Tandem Scatterometer Datasets, Journal of Atmospheric and Oceanic Technology, 18(6), 1014-1036, 10.1175/1520-0426(2001)018<1014:SEIWFC>2.0.CO,2.
Abstract: Sampling patterns and sampling errors from various scatterometer datasets are examined. Four single and two tandem scatterometer mission scenarios are considered. The single scatterometer missions are ERS (with a single, narrow swath), NSCAT and ASCAT (dual swaths), and QuikSCAT (a single, broad swath obtained from the SeaWinds instrument). The two tandem scenarios are combinations of the broad-swath SeaWinds scatterometer with ASCAT and QuikSCAT. The dense, nearly uniform distribution of measurements within swaths, combined with the relatively sparse, nonuniform placement of the swaths themselves create complicated space-time sampling patterns. The temporal sampling of all of the missions is characterized by bursts of closely spaced samples separated by longer gaps and is highly variable in both latitude and longitude. Sampling errors are quantified by the expected squared bias of particular linear estimates of component winds. Modifications to a previous method that allow more efficient expected squared bias calculations are presented and applied. Sampling errors depend strongly on both the details of the temporal sampling of each mission and the assumed temporal scales of variability in the wind field but are relatively insensitive to different spatial scales of variability. With the exception of ERS, all of the scatterometer scenarios can be used to make low-resolution (3° and 12 days) wind component maps with errors at or below the 1 m s^-1 level. Only datasets from the broad-swath and tandem mission scenarios can be used for higher-resolution maps with similar levels of error, emphasizing the importance of the improved spatial and temporal coverage of those missions. A brief discussion of measurement errors concludes that sampling error is generally the dominant term in the overall error budget for maps constructed from scatterometer datasets.
Keywords: LOCALLY WEIGHTED REGRESSION, RESOLUTION CAPABILITY
Mission: |NSCAT|SeaWinds|ASCAT|
URL: https://doi.org/10.1175/1520-0426(2001)018%3C1014:SEIWFC%3E2.0.CO;2
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Weissman, D.E., Bourassa, M.A., O'Brien, J.J., and Tongue, J. (2001). Estimates of the Rainrate Over the Oceans Using SeaWinds Radar Cross Section, American Geophysical Union - 2001 Fall Meeting.
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Title: Estimates of the Rainrate Over the Oceans Using SeaWinds Radar Cross Section
Type: Conference Paper
Publication: American Geophysical Union - 2001 Fall Meeting
Author(s): Weissman, D.E., Bourassa, M.A., O'Brien, J.J., and Tongue, J.
Year: 2001
Formatted Citation: Weissman, D.E., Bourassa, M.A., O'Brien, J.J., and Tongue, J., 2001: Estimates of the Rainrate Over the Oceans Using SeaWinds Radar Cross Section, American Geophysical Union - 2001 Fall Meeting.
Abstract: The unanticipated, relatively strong response of the SeaWinds scatterometer to moderate rainrates was initially viewed as a detrimental situation, because it produces erroneous wind estimates. But it can also be exploited for precipitation detection and measurement on many different time and spatial scales. This program seeks to improve the ability of SeaWinds to estimate sea surface winds in the presence of rain, and it is developing the ability to estimate average rainrate within a scatterometer resolution cell on the surface from the Level 2A standard data. Methods based on the Z-R (reflectivity-rainrate) relationships are being evaluated. Our approach to addressing these new problems and pursuing our objectives is to collect the SeaWinds radar cross section data for both polarizations (Level 2A data product) and the wind vectors (Level 2B) derived from them, with simultaneous, collocated and accurate rain measurements. We are using two sources of rainrate measurements to calibrate our SeaWinds data: NEXRAD radars situated at coastal sites that provide observations every 6 minutes, having a spatial resolution of 4km, and with a useful range of 250 km. Also utilized are hourly TRMM observations of rainrate, using the TMI and PR, that are collocated with QuikSCAT and gridded for ease of use. Measurements indicate that the radar backscatter from the rain volume in the atmosphere can exceed the sea surface radar cross section in many common situations. Their relative dominance depends on the rainrate, the rain column and surface wind speed. Errors in the SeaWind wind speed and direction are being studied using collocated NDBC buoy observation. The in-situ rainrate measurements from NEXRAD and TRMM are being used to calibrate the absolute SeaWinds radar cross section, for both vertical and horizontal polarizations. Also being calibrated is the differential reflectivity between the two polarizations since heavy rain causes this polarization ratio to invert from its value under no-rain conditions. Initial results indicate that a "rain signature" can be developed for the SeaWinds RCS data which will enable the rainrate to be estimated with an accuracy comparable to or better than other satellite-based sensors.
Keywords: marine meteorology , remote sensing and electromagnetic processes
Mission: |SeaWinds|
URL:
Other URLs:
Weissman, D.E., Bourassa, M.A., O'Brien, J.J., and Tongue, J. (2001). SeaWinds Radar Cross Section Measurements Infer Rainrate Over the Ocean, Specialist Meeting on Microwave Remote Sensing.
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Title: SeaWinds Radar Cross Section Measurements Infer Rainrate Over the Ocean
Type: Conference Paper
Publication: Specialist Meeting on Microwave Remote Sensing
Author(s): Weissman, D.E., Bourassa, M.A., O'Brien, J.J., and Tongue, J.
Year: 2001
Formatted Citation: Weissman, D.E., Bourassa, M.A., O'Brien, J.J., and Tongue, J., 2001: SeaWinds Radar Cross Section Measurements Infer Rainrate Over the Ocean, Specialist Meeting on Microwave Remote Sensing.
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Mission: |SeaWinds|
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Weissman, D.E., Levine, D.M., Bailey, M.C., and Johnson, J.W. (2001). Experimental and Theoretical Studies of the Mutual Coupling Among Antenna Elements of the Hydrostar Array, Specialist Meeting on Microwave Remote Sensing.
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Title: Experimental and Theoretical Studies of the Mutual Coupling Among Antenna Elements of the Hydrostar Array
Type: Conference Paper
Publication: Specialist Meeting on Microwave Remote Sensing
Author(s): Weissman, D.E., Levine, D.M., Bailey, M.C., and Johnson, J.W.
Year: 2001
Formatted Citation: Weissman, D.E., Levine, D.M., Bailey, M.C., and Johnson, J.W., 2001: Experimental and Theoretical Studies of the Mutual Coupling Among Antenna Elements of the Hydrostar Array, Specialist Meeting on Microwave Remote Sensing.
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Wikle, C.K., Milliff, R.F., Nychka, D., and Berliner, L.M. (2001). Spatiotemporal Hierarchical Bayesian Modeling: Tropical Ocean Surface Winds, Journal of the American Statistical Association, 96(454), 382-397, 10.1198/016214501753168109. Journal Article »
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Title: Spatiotemporal Hierarchical Bayesian Modeling: Tropical Ocean Surface Winds
Type: Journal Article
Publication: Journal of the American Statistical Association
Author(s): Wikle, C.K., Milliff, R.F., Nychka, D., and Berliner, L.M.
Year: 2001
Formatted Citation: Wikle, C.K., Milliff, R.F., Nychka, D., and Berliner, L.M., 2001: Spatiotemporal Hierarchical Bayesian Modeling: Tropical Ocean Surface Winds, Journal of the American Statistical Association, 96(454), 382-397, 10.1198/016214501753168109.
Abstract: Spatiotemporal processes are ubiquitous in the environmental and physical sciences. This is certainly true of atmospheric and oceanic processes, which typically exhibit many different scales of spatial and temporal variability. The complexity of these processes and the large number of observation/prediction locations preclude the use of traditional covariance-based spatiotemporal statistical methods. Alternatively, we focus on conditionally specified (i.e., hierarchical) spatiotemporal models. These methods offer several advantages over traditional approaches. Primarily, physical and dynamical constraints can be easily incorporated into the conditional formulation, so that the series of relatively simple yet physically realistic conditional models leads to a much more complicated spatiotemporal covariance structure than can be specified directly. Furthermore, by making use of the sparse structure inherent in the hierarchical approach, as well as multiresolution (wavelet) bases, the models can be computed with very large datasets. This modeling approach was necessitated by a scientifically meaningful problem in the geosciences. Satellite-derived wind estimates have high spatial resolution but limited global coverage. In contrast, wind fields provided by the major weather centers provide complete coverage but have low spatial resolution. The goal is to combine these data in a manner that incorporates the space-time dynamics inherent in the surface wind field. This is an essential task to enable meteorological research, because no complete high-resolution surface wind datasets exist over the world oceans. High-resolution datasets of this type are crucial for improving our understanding of global air-sea interactions affecting climate and tropical disturbances, and for driving large-scale ocean circulation models.
Keywords: Statistical estimation , Stochastic process , Statistical forecasting , Filtering , Spatial analysis , Climate , Bayes estimation , Parameter estimation , Algorithm , Conjugate gradient method , Fractal system , Gibbs sampling , Ocean model , Wind driven
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URL: https://doi.org/10.1198/016214501753168109
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Xie, S.-P., Liu, W.T., Liu, Q., and Nonaka, M. (2001). Far-Reaching Effects of the Hawaiian Islands on the Pacific Ocean-Atmosphere System, Science, 292(5524), 2057-2060, 10.1126/science.1059781. Journal Article »
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Title: Far-Reaching Effects of the Hawaiian Islands on the Pacific Ocean-Atmosphere System
Type: Journal Article
Publication: Science
Author(s): Xie, S.-P., Liu, W.T., Liu, Q., and Nonaka, M.
Year: 2001
Formatted Citation: Xie, S.-P., Liu, W.T., Liu, Q., and Nonaka, M., 2001: Far-Reaching Effects of the Hawaiian Islands on the Pacific Ocean-Atmosphere System, Science, 292(5524), 2057-2060, 10.1126/science.1059781.
Abstract: Using satellite data, we detected a wind wake trailing westward behind the Hawaiian Islands for 3000 kilometers, a length many times greater than observed anywhere else on Earth. This wind wake drives an eastward ocean current that draws warm water from the Asian coast 8000 kilometers away, leaving marked changes in surface and subsurface ocean temperature. Standing in the path of the steady trade winds, Hawaii triggers an air-sea interaction that provides the feedback to sustain the influence of these small islands over a long stretch of the Pacific Ocean.
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URL: https://doi.org/10.1126/science.1059781
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Yoho, P.K., and Long, D.G. (2001). Validation of SeaWinds on QuikSCAT Cell Location, 2001 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `01), 508-510, 10.1109/IGARSS.2001.976205. Conference Paper »
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Title: Validation of SeaWinds on QuikSCAT Cell Location
Type: Conference Paper
Publication: 2001 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `01)
Author(s): Yoho, P.K., and Long, D.G.
Year: 2001
Formatted Citation: Yoho, P.K., and Long, D.G., 2001: Validation of SeaWinds on QuikSCAT Cell Location, 2001 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `01), 508-510, 10.1109/IGARSS.2001.976205.
Abstract: Increased interest in high resolution ocean wind measurements, as well as excellent past performance, has led to the development of enhanced resolution applications of SeaWinds on QuikSCAT scatterometer data. An essential requirement of this development is the validation of the cell location accuracy - the latitude and longitude of each measurement. This paper discusses two methods of validating measurement location accuracy. One method entails analysis of normalized backscatter coefficients over specific land/ocean boundaries. This method has proven accurate for nominal resolution, it is refined for increasing resolution. Another technique employs the QuikSCAT Calibration Ground Station (CGS). Telemetry-reported cell location is compared to the known location of the CGS. Calibration of measurement location using these techniques reveals the limits of SeaWinds pointing accuracy and precision
Keywords: atmospheric techniques meteorological radar remote sensing by radar spaceborne radar wind 13.4 GHz Calibration Ground Station QuikSCAT SHF SeaWinds cell location marine atmosphere measurement technique meteorologic
Mission: |SeaWinds|
URL: https://doi.org/10.1109/IGARSS.2001.976205
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Yoho, P.K., and Long, D.G. (2001). Improved Timing Calibration of QuikSCAT, 2001 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `01), 1591-1593, 10.1109/IGARSS.2001.977003. Conference Paper »
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Title: Improved Timing Calibration of QuikSCAT
Type: Conference Paper
Publication: 2001 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `01)
Author(s): Yoho, P.K., and Long, D.G.
Year: 2001
Formatted Citation: Yoho, P.K., and Long, D.G., 2001: Improved Timing Calibration of QuikSCAT, 2001 IEEE International Geoscience & Remote Sensing Symposium (IGARSS `01), 1591-1593, 10.1109/IGARSS.2001.977003.
Abstract: Since being launched in June 1999, QuikSCAT has successfully and accurately measured ocean wind vectors. Current research is attempting to increase performance beyond the original design parameters in order to increase the utility of the data. Timing calibration is critical to this effort. Timing information is used to determine instrument performance as well as to calculate the location of each measurement on the Earth's surface. This paper reports a method of obtaining high-precision time validation measurements through the use of the QuikSCAT Calibration Ground Station (CGS). The QuikSCAT CGS passively records satellite transmissions as it passes overhead. Analysis of CGS data can determine the arrival time of each QuikSCAT pulse to within microseconds. Utilizing the high stability of the onboard pulse repetition interval clock, along with CGS observations, precise instrument timing can be determined during a portion of the orbit, which enables more precise determination of the timing throughout the entire orbit. The improved timing is able to support the requirements of advanced data applications
Keywords: atmospheric techniques calibration meteorological radar remote sensing by radar spaceborne radar wind Calibration Ground Station QuikSCAT atmosphere measurement technique meteorology performance radar remote sensing
Mission: |SeaWinds|
URL: https://doi.org/10.1109/IGARSS.2001.977003
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Yoho, P.K., and Long, D.G. (2001). Model-Based Ground Station Calibration for SeaWinds on QuikSCAT, Proceedings of SPIE, Earth Observing Systems VI, 4483, 10.1117/12.453445. Conference Paper »
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Title: Model-Based Ground Station Calibration for SeaWinds on QuikSCAT
Type: Conference Paper
Publication: Proceedings of SPIE, Earth Observing Systems VI
Author(s): Yoho, P.K., and Long, D.G.
Year: 2001
Formatted Citation: Yoho, P.K., and Long, D.G., 2001: Model-Based Ground Station Calibration for SeaWinds on QuikSCAT, Proceedings of SPIE, Earth Observing Systems VI, 4483, 10.1117/12.453445.
Abstract: SeaWinds on QuikSCAT is the latest of NASA`s wind-observing scatterometer missions. It was launched in June of 1999 with the goal of accurately measuring wind fields over all the oceans. It has also proven to be valuable in monitoring ice changes in polar regions. The value of such data necessitates an extremely accurate and precise calibration of both satellite performance and instrument measurements. In order to assure optimal performance a Calibration Ground Station has been constructed, which provides direct measurements of the instrument transmissions. Each time the spacecraft flies overhead, approximately twice a day, the CGS passively captures microwave pulses transmitted from QuikSCAT. The data is then used with various processing and analysis techniques to validate the system performance and calibration. As part of the calibration analysis, a software simulation model of the instrument system has been constructed. This model is able to simulate critical instrument systems and path loss characteristics and thus predict CGS receive data for any given satellite pass. By comparing model-based simulation data with actual recorded CGS data, calibration of parameters such as system timing, power, attitude, and Doppler compensation can be accurately determined. The analysis has been able to validate the Doppler/range compensation algorithm, instrument timing, and other key system operational parameters. The major contributions of the CGS-based analysis are demonstration of pointing accuracy and overall system stability of SeaWinds. By employing a variance minimization technique between simulated and actual data, the QuikSCAT platform is shown to be extremely stable.
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Mission: |SeaWinds|
URL: https://doi.org/10.1117/12.453445
Other URLs:
Zierden, D.F., Bourassa, M.A., and O'Brien, J.J. (2000). Cyclone Surface Pressure Fields and Frontogenesis from NASA Scatterometer (NSCAT) Winds, Journal of Geophysical Research, 105(C10), 23967-23981, 10.1029/2000JC900062. Journal Article »
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Title: Cyclone Surface Pressure Fields and Frontogenesis from NASA Scatterometer (NSCAT) Winds
Type: Journal Article
Publication: Journal of Geophysical Research
Author(s): Zierden, D.F., Bourassa, M.A., and O'Brien, J.J.
Year: 2000
Formatted Citation: Zierden, D.F., Bourassa, M.A., and O'Brien, J.J., 2000: Cyclone Surface Pressure Fields and Frontogenesis from NASA Scatterometer (NSCAT) Winds, Journal of Geophysical Research, 105(C10), 23967-23981, 10.1029/2000JC900062.
Abstract: Two extratropical marine cyclones and their associated frontal features are examined by computing surface pressure fields from NASA scatterometer (NSCAT) winds. A variational method solves for a new surface pressure field by blending high-resolution (25 km) relative vorticity computed along the satellite track with an initial geostrophic vorticity field. Employing this method with each successive pass of the satellite over the study area allows this surface pressure field to evolve as dictated by the relative vorticity patterns computed from NSCAT winds. The result is a high-resolution surface pressure field that captures features such as fronts and low-pressure centers in more detail than National Centers for Environmental Prediction (NCEP) reanalyses. While using the actual relative vorticity to adjust the geostrophic vorticity ignores the ageostrophy of surface winds, which can be significant in the vicinity of fronts and jet streaks, it is a necessary approximation given that the technique uses only surface data. The NSCAT surface pressure fields prove to be nearly as accurate as NCEP reanalyses when compared to ship and buoy observations, which is an encouraging result given that NCEP reanalyses incorporate a myriad of data sources and the NSCAT fields rely primarily on one source. In addition, the high-resolution relative vorticity fields computed from NSCAT winds reveal the location of surface fronts in great detail. These fronts are verified using NCEP analyses, in situ data, and satellite imagery.
Keywords: Extratropical cyclone , Surface pressure , Frontogenesis , Scatterometer , Satellite observation , Pressure distribution , Vorticity , Cyclogenesis , Case study , ADEOS satellite
Mission: |NSCAT|
URL: https://doi.org/10.1029/2000JC900062
Other URLs:
Zierden, D.F., Bourassa, M.A., and O'Brien, J.J. (1999). Cyclone Surface Pressures and Frontogenesis from NASA Scatterometer (NSCAT) Winds, CAS/JSC Working Group on Numerical Experimentation, Research Activities in Atmospheric and Oceanic Modeling, 1.48-1.49.
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Title: Cyclone Surface Pressures and Frontogenesis from NASA Scatterometer (NSCAT) Winds
Type: Report
Publication: CAS/JSC Working Group on Numerical Experimentation, Research Activities in Atmospheric and Oceanic Modeling
Author(s): Zierden, D.F., Bourassa, M.A., and O'Brien, J.J.
Year: 1999
Formatted Citation: Zierden, D.F., Bourassa, M.A., and O'Brien, J.J., 1999: Cyclone Surface Pressures and Frontogenesis from NASA Scatterometer (NSCAT) Winds, CAS/JSC Working Group on Numerical Experimentation, Research Activities in Atmospheric and Oceanic Modeling, 1.48-1.49.
Abstract:
Keywords: NSCAT, pressure, vorticity
Mission: |NSCAT|
URL:
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