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| Mouche, Alexis; Collard, Fabrice; Chapron, Bertrand; Dagestad, Knut-frode; Guitton, Gilles; Johannessen, Johnny A.; Kerbaol, Vincent; Hansen, Morten Wergeland. |
| The synthetic aperture radar (SAR) Doppler centroid has been used to estimate the scatter line-of-sight radar velocity. In weak to moderate ocean surface current environment, the SAR Doppler centroid is dominated by the directionality and strength of wave-induced ocean surface displacements. In this paper, we show how this sea state signature can be used to improve surface wind retrieval from SAR. Doppler shifts of C-band radar return signals from the ocean are thoroughly investigated by colocating wind measurements from the ASCAT scatterometer with Doppler centroid anomalies retrieved from Envisat ASAR. An empirical geophysical model function (CDOP) is derived, predicting Doppler shifts at both VV and HH polarization as function of wind speed, radar... |
| Tipo: Text |
Palavras-chave: Doppler; Surface wind; Synthetic aperture radar (SAR). |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00088/19896/17554.pdf |
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| Bentamy, Abderrahim; Grodsky, Semyon A; Cambon, Gildas; Tandeo, Pierre; Capet, Xavier; Roy, Claude; Herbette, Steven; Grouazel, Antoine. |
| More than twelve satellite scatterometers have operated since 1992 through the present, providing the main source of surface wind vector observations over global oceans. In this study, these scatterometer winds are used in combination with radiometers and synthetic aperture radars (SAR) for the better determination and characterization of high spatial and temporal resolution of regional surface wind parameters, including wind speed and direction, wind stress components, wind stress curl, and divergence. In this paper, a 27-year-long (1992–2018) 6-h satellite wind analysis with a spatial resolution of 0.125° in latitude and longitude is calculated using spatial structure functions derived from high-resolution SAR data. The main objective is to improve... |
| Tipo: Text |
Palavras-chave: Satellite scatterometer; Surface wind; Upwelling systems; Long time series. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00682/79416/81989.pdf |
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| Bentamy, Abderrahim; Grodsky, Semyon A.; Elyouncha, Anis; Chapron, Bertrand; Desbiolles, Fabien. |
| Surface winds (10 m equivalent neutral wind velocity) from scatterometer missions since 1992 to present require homogenization to meet the requirements for oceanic and atmospheric climate data records. Sources of differences between winds retrieved from different scatterometer measurements mainly arise from calibration/validation procedures used for each scatterometer and differences in measurement physics. In this study, we focus on the calibration/validation component of the European Remote Sensing Satellite (ERS)-1 and ERS-2 wind speed biases. ERS-1 and ERS-2 data, named as WNF products, are from the Institut Français de Recherche pour l'Exploitation de la MER (IFREMER). In addition to WNF data, the newly calibrated ERS-2 products provided by the... |
| Tipo: Text |
Palavras-chave: Scatterometer; Surface wind; Homogenization. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00334/44536/44468.pdf |
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| Bentamy, Abderrahim; Piolle, Jean-francois; Grouazel, Antoine; Danielson, R.; Gulev, S.; Paul, Frederic; Azelmat, Hamza; Mathieu, P. P.; Von Schuckmann, Karina; 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, Bertrand; Anderson, A.; Hollmann, R.; Josey, S. A.. |
| For over a decade, several research groups have been developing air-sea heat flux information over the global ocean, including latent (LHF) and sensible (SHF) heat fluxes over the global ocean. This paper aims to provide new insight into the quality and error characteristics of turbulent heat flux estimates at various spatial and temporal scales (from daily upwards). The study is performed within the European Space Agency (ESA) Ocean Heat Flux (OHF) project. One of the main objectives of the OHF project is to meet the recommendations and requirements expressed by various international programs such as the World Research Climate Program (WCRP) and Climate and Ocean Variability, Predictability, and Change (CLIVAR), recognizing the need for better... |
| Tipo: Text |
Palavras-chave: Ocean Heat Flux; Latent heat flux; Sensible heat flux; Ocean heat content; Scatterometer; Surface wind; Specfic air humidity; OceanSites; Remotely sensed data. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00403/51403/53729.pdf |
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