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Registros recuperados: 58 | |
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Bourassa, Mark A.; Meissner, Thomas; Cerovecki, Ivana; Chang, Paul S.; Dong, Xiaolong; De Chiara, Giovanna; Donlon, Craig; Dukhovskoy, Dmitry S.; Elya, Jocelyn; Fore, Alexander; Fewings, Melanie R.; Foster, Ralph C.; Gille, Sarah T.; Haus, Brian K.; Hristova-veleva, Svetla; Holbach, Heather M.; Jelenak, Zorana; Knaff, John A.; Kranz, Sven A.; Manaster, Andrew; Mazloff, Matthew; Mears, Carl; Mouche, Alexis; Portabella, Marcos; Reul, Nicolas; Ricciardulli, Lucrezia; Rodriguez, Ernesto; Sampson, Charles; Solis, Daniel; Stoffelen, Ad; Stukel, Michael R.; Stiles, Bryan; Weissman, David; Wentz, Frank. |
Strengths and weakness of remotely sensed winds are discussed, along with the current capabilities for remotely sensing winds and stress. Future missions are briefly mentioned. The observational needs for a wide range of wind and stress applications are provided. These needs strongly support a short list of desired capabilities of future missions and constellations. |
Tipo: Text |
Palavras-chave: Satellite; Wind; Stress; Ocean; Requirements. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00511/62312/66565.pdf |
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Wang, He; Yang, Jingsong; Mouche, Alexis; Shao, Weizeng; Zhu, Jianhua; Ren, Lin; Xie, Chunhua. |
Gaofen-3 (GF-3) is the first Chinese civil C-band synthetic aperture radar (SAR) launched on 10 August 2016 by the China Academy of Space Technology (CAST), which operates in 12 imaging modes with a fine spatial resolution up to 1 m. As one of the primary users, the State Oceanic Administration (SOA) operationally processes GF-3 SAR Level-1 products into ocean surface wind vector and plans to officially release the near real-time SAR wind products in the near future. In this paper, the methodology of wind retrieval at C-band SAR is introduced and the first results of GF-3 SAR-derived winds are presented. In particular, the case of the coastal katabatic wind off the west coast of the U.S. captured by GF-3 is discussed. The preliminary accuracy assessment of... |
Tipo: Text |
Palavras-chave: GF-3; Synthetic aperture radar (SAR); Ocean surface wind; Validation. |
Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00396/50731/51435.pdf |
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Mouche, Alexis; Chapron, Bertrand; Knaff, John; Zhao, Yili; Zhang, Biao; Combot, Clement. |
C‐Band high resolution radar (SAR) is the only space‐borne instrument able to probe at very high resolution and over all ocean basins the sea surface under extreme weather conditions. When co‐analyzed with Stepped Frequency Microwave Radiometer (SFMR) wind estimates, the radar backscatter signals acquired in major Hurricanes from Sentinel‐1 and Radarsat‐2 SAR, reveal high sensitivity in the cross‐polarized channel for wind speeds up to 75 m/s. The combination of the two co‐ and cross‐ polarized channels can then be used to derive high resolution surface wind estimates. The retrieval methods and impacts of intense rainfall are discussed in the context of a Hurricane Irma (2017) case study. On September 7, 2017, Sentinel‐1 measurements intercepted Hurricane... |
Tipo: Text |
Palavras-chave: SAR; Copolarization and cross-polarization; High resolution; Category 5 Hurricane; Hurricane Irma. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00497/60898/64236.pdf |
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Fan, Shengren; Kudryavtsev, Vladimir; Zhang, Biao; Perrie, William; Chapron, Bertrand; Mouche, Alexis. |
We present new results for ocean surface current signatures in dual co- and cross-polarized synthetic aperture radar (SAR) images. C-band RADARSAT-2 quad-polarized SAR ocean scenes are decomposed into resonant Bragg scattering from regular (non-breaking) surface waves and scattering from breaking waves. Surface current signatures in dual co- and cross-polarized SAR images are confirmed to be governed by the modulations due to wave breaking. Due to their small relaxation scale, short Bragg waves are almost insensitive to surface currents. Remarkably, the contrast in sensitivity of the non-polarized contribution to dual co-polarized signals is found to largely exceed, by a factor of about 3, the contrast in sensitivity of the corresponding cross-polarized... |
Tipo: Text |
Palavras-chave: Quad-polarized SAR; Ocean surface current; Polarization decomposition; Bragg scattering; Breaking waves. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00588/70030/67948.pdf |
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Stoffelen, Ad; Aaboe, Signe; Calvet, Jean-christophe; Cotton, James; De Chiara, Giovanna; Saldana, Julia Figa; Mouche, Alexis; Portabella, Marcos; Scipal, Klaus; Wagner, Wolfgang. |
The second-generation exploitation of meteorological satellite polar system (EPS-SG) C-band-wavelength scatterometer instrument (called SCA), planned for launch in 2022, has a direct heritage from the successful advanced scatterometer (ASCAT) flown on the current EPS satellites. In addition, SCA will represent three major innovations with respect to ASCAT, namely: 1) Cross polarization and horizontal copolarization; 2) a nominal spatial resolution of 25 km; and 3) 20% greater spatial coverage than ASCAT. The associated expected science and application benefits that led the SCA design are discussed with respect to ocean, land, and sea ice applications for near-real time, climate monitoring, and research purposes. Moreover, an option to implement an ocean... |
Tipo: Text |
Palavras-chave: Eddy currents; Radar signal processing; Sea ice; Soil measurements; Storms; Wind. |
Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00386/49774/50320.pdf |
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Combot, Clement; Quilfen, Yves; Mouche, Alexis; Gourrion, Jerome; De Boyer Montegut, Clement; Chapron, Bertrand; Tournadre, Jean. |
In this section, a new focus is given on the ocean response induced by Tropical Cyclones. Tropical Cyclones are among the most devastating and destructive natural hazards. Unfortunately, predicting the intensity and evolution of such individual event is still extremely difficult, owing to various internal and environmental factors, including interactions with the ocean interior. In that context, multiple satellite remote sensing observations are essential, and today, combined with denser ARGO interior measurements, the upper ocean responses to moving tropical cyclones can be more efficiently captured and monitored. |
Tipo: Text |
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Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00655/76663/77809.pdf |
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Mouche, Alexis; He, W.; Husson, R.; Guitton, Gilles; Chapron, Bertrand; Li, Huimin. |
Sentinel-1 A now routinely acquires data over the ocean since 2014. Data are processed by ESA through the Payload Data Ground Segment up to Level-2 for Copernicus users. Level-2 products consist of geo-located geophysical parameters related to wind, waves and ocean current. In particular, Sentinel-1A wave measurements provide 2D ocean swell spectra (2D wave energy distribution as a function of wavelength and direction) as well as integrated parameters such as significant wave height, dominant wavelength and direction for each partition. In 2016, Sentinel-1 B will be launched by ESA and GF-3 by CNSA. Then in 2018, CFOSAT (China France Oceanography Satellite project), a joint mission from the Chinese and French Space Agencies, will be launched. They will... |
Tipo: Text |
Palavras-chave: Ocean remote sensing; Synthetics aperture radar; Ocean wave-spectrometer; 2D ocean wave spectrum; Level-4. |
Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00364/47469/47488.pdf |
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Li, Huimin; Mouche, Alexis; Stopa, Justin E.; Chapron, Bertrand. |
Sentinel-1 (S-1) is a two-satellite constellation for continuity of operational synthetic aperture radar (SAR) observations. Wave mode (WV) is the default mode over open ocean for S-1 to monitor global ocean waves and wind field. Therefore, proper radiometric calibration is essential to accurately infer these geophysical quantities. Based on the global data set acquired by S-1A WV, assessment of normalized radar cross section (NRCS) is carried out through comparison with CMOD5.N predictions over open ocean. The calibration accuracy quantified by NRCS residuals between SAR measurements and CMOD5.N demonstrates distinct features for two incidence angles (23.8° and 36.8°). Particularly, NRCS at 23.8° is overall consistent with CMOD5.N, while NRCS at 36.8°... |
Tipo: Text |
Palavras-chave: CMOD5.N; Radiometric calibration; Sentinel-1A (S-1A); Wave mode (WV). |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00457/56882/59006.pdf |
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Badger, Merete; Pena, Alfredo; Hahmann, Andrea N.; Mouche, Alexis; Hasager, Charlotte B.. |
Ocean wind retrievals from satellite sensors are typically performed for the standard level of 10 m. This restricts their full exploitation for wind energy planning, which requires wind information at much higher levels where wind turbines operate. A new method is presented for the vertical extrapolation of satellite-based wind maps. Winds near the sea surface are obtained from satellite data and used together with an adaptation of the Monin–Obukhov similarity theory to estimate the wind speed at higher levels. The thermal stratification of the atmosphere is taken into account through a long-term stability correction that is based on numerical weather prediction (NWP) model outputs. The effect of the long-term stability correction on the wind profile is... |
Tipo: Text |
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Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00334/44477/44158.pdf |
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Nouguier, Frederic; Mouche, Alexis; Rascle, Nicolas; Chapron, Bertrand; Vandemark, Douglas. |
Global colocalized ocean surface measurements using the Global Precipitation Measurement near-nadir dual-frequency Ku- and Ka-band microwave measurements are analyzed and compared. Focusing on the Ka and Ku cross-sections fall-off with incidence angles, the contemporaneous measurements enable to more precisely document differing ocean scattering characteristics for both microwave frequencies. Sensitivity with wind speed and significant wave height is further reported using global comparisons with numerical estimates. As demonstrated, the bifrequency capability can provide direct means to efficiently separate short-scale wave contributions, between mean squared slope and curvature characteristics, and to further gain valuable insights concerning near-nadir... |
Tipo: Text |
Palavras-chave: Microwave; Radar cross section; Scattering; Spaceborne radar. |
Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00352/46334/47128.pdf |
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Rascle, Nicolas; Molemaker, Jeroen; Marie, Louis; Nouguier, Frederic; Chapron, Bertrand; Lund, Bjorn; Mouche, Alexis. |
Fine scale current gradients at the ocean surface can be observed by sea surface roughness. More specifically, directional surface roughness anomalies are related to the different horizontal current gradient components. This paper reports results from a dedicated experiment during the LASER (LAgrangian Submesoscale ExpeRiment) drifter deployment. A very sharp front, 50 m wide, is detected simultaneously in drifter trajectories, sea surface temperature and sea surface roughness. A new observational method is applied, using sun glitter reflections during multiple airplane passes to reconstruct the multi-angle roughness anomaly. This multi-angle anomaly is consistent with wave-current interactions over a front, including both cross-front convergence and... |
Tipo: Text |
Palavras-chave: Sea surface roughness; Surface current; Remote sensing; Sun glitter; High resolution; Oceanic fronts. |
Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00386/49767/50301.pdf |
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Alpers, Werner; Mouche, Alexis; Horstmann, Jochen; Ivanov, Andrei Yu.; Barabanov, Vladyslav S.. |
Several algorithms have been proposed to retrieve near-surface wind fields from C-band synthetic aperture radar (SAR) images acquired over the ocean. They mainly differ in the way they retrieve the wind direction. Conventionally, the wind direction is taken from atmospheric models or is extracted from the linear features sometimes visible in SAR images. Recently, a new wind retrieval algorithm has been proposed, which also includes the Doppler shift induced by motions of the sea surface. In this article, we apply three wind retrieval algorithms, including the one using Doppler information, to three complex wind events encountered over the Black Sea and compare the SAR-derived wind fields with model wind fields calculated using the high-resolution weather... |
Tipo: Text |
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Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00253/36390/35443.pdf |
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Bentamy, Abderrahim; Mouche, Alexis; Grouazel, Antoine; Moujane, Abderrahim; Mohamed, Ait Ahmed. |
Scatterometer surface wind speed and direction observations in combination with radiometer wind speeds allow to generate surface wind analyses with high space and time resolutions over global as well as at regional scales. Regarding scatterometer sampling schemes and physics, the resulting surface wind analyses suffer from lack of accuracy in areas near coasts. The use of the synthetic aperture radar (SAR) onboard the Sentinel-1A satellite attempts to address the enhancement of surface wind analyses issues. In this study, SAR wind speeds and directions retrieved from backscatter coefficients acquired in interferometric wide (IW) swath mode are used. Their accuracy is determined through comprehensive comparisons with moored buoy wind measurements. SAR and... |
Tipo: Text |
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Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00464/57611/59848.pdf |
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Gommenginger, Christine; Chapron, Bertrand; Hogg, Andy; Buckingham, Christian; Fox-kemper, Baylor; Eriksson, Leif; Soulat, Francois; Ubelmann, Clément; Ocampo-torres, Francisco; Nardelli, Bruno Buongiorno; Griffin, David; Lopez-dekker, Paco; Knudsen, Per; Andersen, Ole; Stenseng, Lars; Stapleton, Neil; Perrie, William; Violante-carvalho, Nelson; Schulz-stellenfleth, Johannes; Woolf, David; Isern-fontanet, Jordi; Ardhuin, Fabrice; Klein, Patrice; Mouche, Alexis; Pascual, Ananda; Capet, Xavier; Hauser, Daniele; Stoffelen, Ad; Morrow, Rosemary; Aouf, Lotfi; Breivik, Øyvind; Fu, Lee-lueng; Johannessen, Johnny A.; Aksenov, Yevgeny; Bricheno, Lucy; Hirschi, Joel; Martin, Adrien Ch; Martin, Adiran P; Nurser, George; Polton, Jeff; Wolf, Judith; Johnsen, Harald; Soloviev, Alexander; Jacobs, Gregg A.; Collard, Fabrice; Groom, Steve; Kudryavtsev, Vladimir; Wilkin, John; Navarro, Victor; Babanin, Alex; Martin, Matthew; Siddorn, John; Saulter, Andrew; Rippeth, Tom; Emery, Bill; Maximenko, Nikolai; Romeiser, Roland; Graber, Hans; Azcarate, Aida Alvera; Hughes, Chris W.; Vandemark, Doug; Silva, Jose Da; Leeuwen, Peter Jan Van; Naveira-garabato, Alberto; Gemmrich, Johannes; Mahadevan, Amala; Marquez, Jose; Munro, Yvonne; Doody, Sam; Burbidge, Geoff. |
High-resolution satellite images of ocean color and sea surface temperature reveal an abundance of ocean fronts, vortices and filaments at scales below 10 km but measurements of ocean surface dynamics at these scales are rare. There is increasing recognition of the role played by small scale ocean processes in ocean-atmosphere coupling, upper-ocean mixing and ocean vertical transports, with advanced numerical models and in situ observations highlighting fundamental changes in dynamics when scales reach 1 km. Numerous scientific publications highlight the global impact of small oceanic scales on marine ecosystems, operational forecasts and long-term climate projections through strong ageostrophic circulations, large vertical ocean velocities and mixed layer... |
Tipo: Text |
Palavras-chave: Satellite; Air sea interactions; Upper ocean dynamics; Submesoscale; Coastal; Marginal ice zone; Radar; Along-track interferometry. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00510/62121/66325.pdf |
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Wang, Chen; Mouche, Alexis; Tandeo, Pierre; Stopa, Justin; Longépé, Nicolas; Erhard, Guillaume; Foster, Ralph C.; Vandemark, Douglas; Chapron, Bertrand. |
The Sentinel‐1 mission is part of the European Copernicus program aiming at providing observations for Land, Marine and Atmosphere Monitoring, Emergency Management, Security and Climate Change. It is a constellation of two (Sentinel‐1 A and B) Synthetic Aperture Radar (SAR) satellites. The SAR wave mode (WV) routinely collects high‐resolution SAR images of the ocean surface during day and night and through clouds. In this study, a subset of more than 37,000 SAR images is labelled corresponding to ten geophysical phenomena, including both oceanic and meteorologic features. These images cover the entire open ocean and are manually selected from Sentinel‐1A WV acquisitions in 2016. For each image, only one prevalent geophysical phenomenon with its prescribed... |
Tipo: Text |
Palavras-chave: Manual labelling; Ocean surface phenomena; Sentinel-1 wave mode; Synthetic aperture radar. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00512/62406/66659.pdf |
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Von Schuckmann, Karina; Le Traon, Pierre-yves; Smith, Neville; Pascual, Ananda; Djavidnia, Samuel; Gattuso, Jean-pierre; Grégoire, Marilaure; Nolan, Glenn; Aaboe, Signe; Fanjul, Enrique Álvarez; Aouf, Lotfi; Aznar, Roland; Badewien, T. H.; Behrens, Arno; Berta, Maristella; Bertino, Laurent; Blackford, Jeremy; Bolzon, Giorgio; Borile, Federica; Bretagnon, Marine; Brewin, Robert J.w.; Canu, Donata; Cessi, Paola; Ciavatta, Stefano; Chapron, Bertrand; Trang Chau, Thi Tuyet; Chevallier, Frédéric; Chtirkova, Boriana; Ciliberti, Stefania; Clark, James R.; Clementi, Emanuela; Combot, Clement; Comerma, Eric; Conchon, Anna; Coppini, Giovanni; Corgnati, Lorenzo; Cossarini, Gianpiero; Cravatte, Sophie; De Alfonso, Marta; De Boyer Montégut, Clement; De Lera Fernández, Christian; De Los Santos, Francisco Javier; Denvil-sommer, Anna; De Pascual Collar, Álvaro; Dias Nunes, Paulo Alonso Lourenco; Di Biagio, Valeria; Drudi, Massimiliano; Embury, Owen; Falco, Pierpaolo; D’andon, Odile Fanton; Ferrer, Luis; Ford, David; Freund, H.; León, Manuel Garcia; Sotillo, Marcos García; García-valdecasas, José María; Garnesson, Philippe; Garric, Gilles; Gasparin, Florent; Gehlen, Marion; Genua-olmedo, Ana; Geyer, Gerhard; Ghermandi, Andrea; Good, Simon A.; Gourrion, Jerome; Greiner, Eric; Griffa, Annalisa; González, Marcelo; Griffa, Annalisa; Hernández-carrasco, Ismael; Isoard, Stéphane; Kennedy, John J.; Kay, Susan; Korosov, Anton; Laanemäe, Kaari; Land, Peter E.; Lavergne, Thomas; Lazzari, Paolo; Legeais, Jean Francois; Lemieux, Benedicte; Levier, Bruno; Llovel, William; Lyubartsev, Vladyslav; Lien, Vidar S.; Lima, Leonardo; Lorente, Pablo; Mader, Julien; Magaldi, Marcello G.; Maljutenko, Ilja; Mangin, Antoine; Mantovani, Carlo; Marinova, Veselka; Masina, Simona; Mauri, Elena; Meyerjürgens, J.; Mignot, Alexandre; Mcewan, Robert; Mejia, Carlos; Melet, Angélique; Menna, Milena; Meyssignac, Benoît; Mouche, Alexis; Mourre, Baptiste; Müller, Malte; Notarstefano, Giulio; Orfila, Alejandro; Pardo, Silvia; Peneva, Elisaveta; Pérez-gómez, Begoña; Perruche, Coralie; Peterlin, Monika; Poulain, Pierre-marie; Pinardi, Nadia; Quilfen, Yves; Raudsepp, Urmas; Renshaw, Richard; Révelard, Adèle; Reyes-reyes, Emma; Ricker, M.; Rodríguez-rubio, Pablo; Rotllán, Paz; Gelabert, Eva Royo; Rubio, Anna; Ruiz-parrado, Inmaculada; Sathyendranath, Shubha; She, Jun; Solidoro, Cosimo; Stanev, Emil V.; Staneva, Joanna; Storto, Andrea; Su, Jian; Bakhsh, Tayebeh Tajalli; Tilstone, Gavin H.; Tintoré, Joaquín; Toledano, Cristina; Tournadre, Jean; Tranchant, Benoit; Uiboupin, Rivo; Valcarcel, Arnaud; Valcheva, Nadezhda; Verbrugge, Nathalie; Vrac, Mathieu; Wolff, J.-o.; Zambianchi, Enrico; Zielinski, O.; Zinck, Ann-sofie; Zunino, Serena. |
Tipo: Text |
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Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00653/76554/77672.pdf |
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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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Registros recuperados: 58 | |
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