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| Registros recuperados: 39 | |
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| Grodsky, Semyon A.; Kudryavtsev, Vladimir N.; Bentamy, Abderrahim; Carton, James A.; Chapron, Bertrand. |
| Scatterometer radar backscatter depends on the relationship linking surface stress and surface roughness. SST can alter the growth rate of centimeter-scale waves through its impact on air and water density and water viscosity. This SST-dependency has not been included in the standard Geophysical Model Functions. This study uses a radar imaging model to evaluate this SST-dependence and compares the results to observations from QuikScat Ku-band and ASCAT C-band scatterometers. A SST correction could raise wind speeds by up to 0.2 ms(-1) in the storm track region of the Southern Ocean for C-band scatterometers. For the higher frequency Ku-band scatterometers, a SST-induced reduction up to 0.4 ms(-1) is predicted south of 60(-S), where SST is cold and winds... |
| Tipo: Text |
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| Ano: 2012 |
URL: https://archimer.ifremer.fr/doc/00088/19898/17552.pdf |
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| Bentamy, Abderrahim; Grodsky, Semyon A.; Chapron, Bertrand; Carton, James A.. |
| 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... |
| Tipo: Text |
Palavras-chave: Scatterometer winds; SST; Inter-instrument bias. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00139/25071/23190.pdf |
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| Bentamy, Abderrahim; Croize-fillon, Denis. |
| The main objective of this paper is to thoroughly examine the remotely sensed wind characteristics around the coasts of Brittany as well as some more specific areas. The offshore wind power potential is then assessed. To achieve this objective, information on wind speed and direction with sufficient spatial and temporal sampling under all weather conditions and during day and night is required. This study uses more than 12 years (December 1999–December 2012) of consistent remotely sensed data retrieved from the ASCAT and QuikSCAT scatterometers to estimate the conventional moments and associated wind distribution parameters. The latter are comparable to wind observations from meteorological stations. Furthermore, combining in-situ and scatterometer wind... |
| Tipo: Text |
Palavras-chave: Wind; Energy; Scatterometer; Remote sensing; Brittany. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00175/28648/28552.pdf |
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| Quilfen, Yves; Bentamy, Abderrahim; Delecluse, P; Katsaros, K; Grima, N. |
| Uncertainties in the surface wind field have long been recognized as a major limitation in the interpretation of results obtained by oceanic circulation models. It is especially true in the tropical oceans, where the response to wind forcing is very strong on short time scales. The purpose of this paper is to show that these uncertainties can be greatly reduced by using spaceborne wind sensors that provide accurate measurements on a global basis.Surface winds over the global oceans have been measured by scatterometry since the launch of the European Remote Sensing Satellite (ERS-1) in August 1991 by the European Space Agency, Noordwijk, The Netherlands, and is currently provided by ERS-2, launched in April 1995. The ground track wind vectors are processed... |
| Tipo: Text |
Palavras-chave: Ocean model; Ocean surface; Scatterometer; Sea level. |
| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/00000/10501/9560.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; Aguiar, Eva; Álvarez Fanjul, Enrique; Alvera-azcárate, Aida; Aouf, Lotfi; Barciela, Rosa; Behrens, Arno; Belmonte Rivas, Maria; Ben Ismail, Sana; Bentamy, Abderrahim; Borgini, Mireno; Brando, Vittorio E.; Bensoussan, Nathaniel; Blauw, Anouk; Bryère, Philippe; Buongiorno Nardelli, Bruno; Caballero, Ainhoa; Çağlar Yumruktepe, Veli; Cebrian, Emma; Chiggiato, Jacopo; Clementi, Emanuela; Corgnati, Lorenzo; De Alfonso, Marta; De Pascual Collar, Álvaro; Deshayes, Julie; Di Lorenzo, Emanuele; Dominici, Jean-marie; Dupouy, Cécile; Drévillon, Marie; Echevin, Vincent; Eleveld, Marieke; Enserink, Lisette; García Sotillo, Marcos; Garnesson, Philippe; Garrabou, Joaquim; Garric, Gilles; Gasparin, Florent; Gayer, Gerhard; Gohin, Francis; Grandi, Alessandro; Griffa, Annalisa; Gourrion, Jerome; Hendricks, Stefan; Heuzé, Céline; Holland, Elisabeth; Iovino, Doroteaciro; Juza, Mélanie; Kurt Kersting, Diego; Kipson, Silvija; Kizilkaya, Zafer; Korres, Gerasimos; Kõuts, Mariliis; Lagemaa, Priidik; Lavergne, Thomas; Lavigne, Heloise; Ledoux, Jean-baptiste; Legeais, Jean Francois; Lehodey, Patrick; Linares, Cristina; Liu, Ye; Mader, Julien; Maljutenko, Ilja; Mangin, Antoine; Manso-narvarte, Ivan; Mantovani, Carlo; Markager, Stiig; Mason, Evan; Mignot, Alexandre; Menna, Milena; Monier, Maeva; Mourre, Baptiste; Müller, Malte; Nielsen, Jacob Woge; Notarstefano, Giulio; Ocaña, Oscar; Pascual, Ananda; Patti, Bernardo; Payne, Mark R.; Peirache, Marion; Pardo, Silvia; Pérez Gómez, Begoña; Pisano, Andrea; Perruche, Coralie; Peterson, K. Andrew; Pujol, Marie-isabelle; Raudsepp, Urmas; Ravdas, Michalis; Raj, Roshin P.; Renshaw, Richard; Reyes, Emma; Ricker, Robert; Rubio, Anna; Sammartino, Michela; Santoleri, Rosalia; Sathyendranath, Shubha; Schroeder, Katrin; She, Jun; Sparnocchia, Stefania; Staneva, Joanna; Stoffelen, Ad; Szekely, Tanguy; Tilstone, Gavin H.; Tinker, Jonathan; Tintoré, Joaquín; Tranchant, Benoît; Uiboupin, Rivo; Van Der Zande, Dimitry; Wood, Richard; Woge Nielsen, Jacob; Zabala, Mikel; Zacharioudaki, Anna; Zuberer, Frédéric; Zuo, Hao. |
| Tipo: Text |
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| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00515/62637/67004.pdf |
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| Le Traon, Pierre-yves; Larnicol, Gilles; Guinehut, Stephanie; Pouliquen, Sylvie; Bentamy, Abderrahim; Roemmich, Dean; Donlon, Craig; Roquet, Herve; Jacobs, Gregg; Griffin, David; Bonjean, Fabrice; Hoepffner, Nicolas; Breivik, Lars-anders. |
| Data assembly and processing centers are essential elements of the operational oceanography infrastructure. They provide data and products needed by modeling and data assimilation systems; they also provide products directly usable for applications. This paper discusses the role and functions of the data centers for operational oceanography. It describes some of the main data assembly centers (Argo and in situ data, altimetry, sea surface temperature) developed during the Global Ocean Data Assimilation Experiment. An overview of other data centers (wind and fluxes, ocean color, sea ice) is also given. Much progress has been achieved over the past 10 years to validate, intercalibrate, and merge altimeter data from multiple satellites. Accuracy and... |
| Tipo: Text |
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| Ano: 2009 |
URL: https://archimer.ifremer.fr/doc/2009/publication-6879.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; Croize-fillon, Denis. |
| This article deals with the calculation and validation of daily surface wind vector fields from wind speed and direction observations derived from Advanced SCATterometer (ASCAT) scatterometer measurements over the global ocean. According to the ASCAT sampling scheme, the objective method allowing for the determination of regular in space and time wind speed and direction fields uses ASCAT observations as well as European Centre for Medium Weather Forecasts (ECMWF) analyses. The latter are considered as external drift for the kriging method and as the temporal interpolation basis for ASCAT retrievals. This study focuses on the investigation of the capability of the method to add valuable wind information to the operational atmospheric analyses and on the... |
| Tipo: Text |
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| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00043/15440/12808.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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| De Farias, Eduardo G. G.; Lorenzzetti, Joao A.; Bentamy, Abderrahim; Chapron, Bertrand; Romain, Husson. |
| Recently, with the availability of a great number of synthetic aperture radar (SAR) wave mode spectra, it has been possible to derive a set of great circle lines of swell propagation whose intersection points indicate the position of the storm generating the observed swell field. However, due to the inherent limitations of SAR spectra, the locus of convergence of great circle of swell propagation can be sometimes diffuse or contain multiple convergence regions. In this letter, we adapted the fuzzy cluster logic method to identify the regions of convergence of SAR wave field rays. The analysis of the results of the fuzzy algorithm clearly indicates the ability of this statistical method to identify the cluster center region of swell fields observed in SAR... |
| Tipo: Text |
Palavras-chave: Swell wave fields and fuzzy logic; Synthetic aperture radar (SAR). |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00109/21992/20637.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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| Bentamy, Abderrahim; Ayina, Ludos-herve; Queffeulou, Pierre; Croize-fillon, Denis; Kerbaol, Vincent. |
| Several scientific programs, including the Mediterranean Forecasting System Toward Environmental Predictions (MFSTEP project), request high space and time resolutions of surface wind speed and direction. The purpose of this paper is to focus on surface wind improvements over the global Mediterranean Sea, based on the blending near real time remotely sensed wind observations and ECMWF wind analysis. Ocean surface wind observations are retrieved from QuikSCAT scatterometer and from SSM/I radiometers available at near real time at Meteo-France. Using synchronous satellite data, the number of remotely sensed data available for each analysis epoch ( 00: 00 h; 06: 00 h; 12: 00 h; 18: 00 h) is not uniformly distributed as a function of space and time. On average... |
| Tipo: Text |
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| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3528.pdf |
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| Desbiolles, Fabien; Bentamy, Abderrahim; Blanke, Bruno; Roy, Claude; Mestas-nunez, Alberto M.; Grodsky, Semyon A.; Herbette, Steven; Cambon, Gildas; Maes, Christophe. |
| Surface winds (equivalent neutral wind velocities at 10 m) from scatterometer missions since 1992 have been used to build up a 20-year climate series. Optimal interpolation and kriging methods have been applied to continuously provide surface wind speed and direction estimates over the global ocean on a regular grid in space and time. The use of other data sources such as radiometer data (SSM/I) and atmospheric wind reanalyses (ERA-Interim) has allowed building a blended product available at 1/4° spatial resolution and every 6 hours from 1992 to 2012. Sampling issues throughout the different missions (ERS-1, ERS-2, QuikSCAT, and ASCAT) and their possible impact on the homogeneity of the gridded product are discussed. In addition, we assess carefully the... |
| Tipo: Text |
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| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00366/47686/47725.pdf |
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| Bentamy, Abderrahim; Grodsky, Semyon A.; Katsaros, Kristina; Mestas-nunez, Alberto M.; Blanke, Bruno; Desbiolles, Fabien. |
| 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... |
| Tipo: Text |
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| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00137/24825/23575.pdf |
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| Grodsky, Semyon A.; Carton, James A.; Bentamy, Abderrahim. |
| In the presence of stable near-surface haline stratification, intermittent cold sea surface temperature (SST, upwelling) events produced by gap winds off the Central American Pacific coast should be accompanied by uplifts of saltier water. We illustrate that Aquarius satellite sea surface salinity (SSS) captures these high SSS events. In boreal winter when the intense gap winds are frequent, two tongues of anomalously salty water develop off the Gulfs of Tehuantepec and Papagayo. During that season the average SSS in the meridionally oriented Tehuantepec tongue is about 0.4 psu saltier than the background SSS. The zonally elongated Papagayo tongue stands out even more strongly, being 1-2 psu saltier than SSS in the neighbouring Panama Bight. The spatial... |
| Tipo: Text |
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| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00211/32184/30751.pdf |
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| Bentamy, Abderrahim; Katsaros, Kristina; Queffeulou, Pierre. |
| This chapter addresses the estimation of global surface winds, surface wind stress, latent heat flux, and sensible heat flux over the oceans with high spatial and temporal resolution using satellite radar and radiometer measurements. An overview of the physics of remotely sensed data, of methods and algorithms used to retrieve surface fluxes is provided. The retrievals are used to estimate regular in space and time surface parameters, requested for oceanic forcing function, over global ocean. The characteristics of the former are investigated at global and regional scales. |
| Tipo: Text |
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| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00030/14101/11333.pdf |
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| Desbiolles, Fabien; Blanke, Bruno; Bentamy, Abderrahim. |
| Satellite scatterometers provide continuously valuable surface wind speed and direction estimates over the global ocean on a regular grid both in space and time. The Level 3 data derived from the Advanced Scatterometer (ASCAT), available at 1/4° spatial resolution (hereafter AS25), and Quick Scatterometer (QuikSCAT), available on 1/2° and 1/4° horizontal grids (QS50 and QS25, respectively), are studied at regional scales in both the Benguela and Canary upwelling systems. They are compared to the European Center for Medium-Range Weather Forecast surface wind analysis, with insight into their intrinsic and actual spatial resolutions. In the coastal band, the finest spatial patterns are found in the QS25 winds and are O(75 km). This demonstrates the... |
| Tipo: Text |
Palavras-chave: Satellite scatterometer wind fields; Actual wind resolution at regional scales; Short-lived SST anomalies; Eastern-boundary upwelling systems; Modeling. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00172/28333/26619.pdf |
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| Pinker, R. T.; Bentamy, Abderrahim; Katsaros, Kristina; Ma, Y.; Li, C.. |
| Many studies have been undertaken to evaluate turbulent heat fluxes at the ocean-atmosphere interface; less was done on the total net heat flux. We will compare heat budgets at the ocean-atmosphere interface as derived from satellites and from blended products, compare them to in situ observations, identify the location of largest differences, and attempt to explain reasons for these differences. The results over the Atlantic Sector (50 degrees S-50 degrees N) for a 3 year period show that differences in the turbulent fluxes among two widely used approaches are overshadowed by differences in the radiative fluxes. While the maximum difference in sensible and latent heat fluxes can be about 30 W/m(2), the mean values for latent heat fluxes are -2.27 W/m(2)... |
| Tipo: Text |
Palavras-chave: Oceanic heat fluxes; Oceanic net heat fluxes; Ocean-atmosphere interface. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00186/29713/28119.pdf |
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| Registros recuperados: 39 | |
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