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Registros recuperados: 12
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A global wave parameter database for geophysical applications. Part 1: Wave-current-turbulence interaction parameters for the open ocean based on traditional parameterizations 5
Rascle, N; Ardhuin, Fabrice; Queffeulou, Pierre; Croize-fillon, Denis.
Ocean surface mixing and drift are influenced by the mixed layer depth, buoyancy fluxes and currents below the mixed layer. Drift and mixing are also functions of the surface Stokes drift U, volume Stokes transport T-s, a wave breaking height scale H-swg, and the flux of energy from waves to ocean turbulence Phi(oc). Here we describe a global database of these parameters, estimated from a well-validated numerical wave model, that uses traditional forms of the wave generation and dissipation parameterizations, and covers the years 2003-2007. Compared to previous studies, the present work has the advantage of being consistent with the known physical processes that regulate the wave field and the air-sea fluxes, and also consistent with a very large number of...
Tipo: Text Palavras-chave: Ocean mixing; Surface drift; Air sea fluxes; Surface gravity waves.
Ano: 2008 URL: http://archimer.ifremer.fr/doc/2008/publication-5903.pdf
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Accuracy of Wind Measurements Performed on Buoys, Ship, and Island during the TOSCANE-2 Experiment 5
Queffeulou, Pierre.
In 1983 the project "Travaux d'Oceanographie Spatiale: Capteurs Actifs dans l'Atlantique Nord-Est" (TOSCANE) was initiated in view of calibration, validation, and use of satelliteborne scatterometer and altimeter measurements in terms of wind and wave data, with special emphasis on the ERS-1 satellite to be launched in 1991 by the European Space Agency. The wind measurements from an array of buoys and ship and land stations, deployed during the last experiment within the program, TOSCANE-2, are described, and a method is given to evaluate their accuracy. When comparing wind data from two measuring stations at sea, the averaging time has to be selected according to the separation distance between the two locations to filter out the space-induced wind...
Tipo: Text
Ano: 1991 URL: http://archimer.ifremer.fr/doc/00182/29313/28271.pdf
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Assessment of SARAL/AltiKa Wave Height Measurements Relative to Buoy, Jason-2, and Cryosat-2 Data 5
Hito Sepulveda, Hector; Queffeulou, Pierre; Ardhuin, Fabrice.
SARAL/AltiKa GDR-T are analyzed to assess the quality of the significant wave height (SWH) measurements. SARAL along-track SWH plots reveal cases of erroneous data, more or less isolated, not detected by the quality flags. The anomalies are often correlated with strong attenuation of the Ka-band backscatter coefficient, sensitive to clouds and rain. A quality test based on the 1Hz standard deviation is proposed to detect such anomalies. From buoy comparison, it is shown that SARAL SWH is more accurate than Jason-2, particularly at low SWH, and globally does not require any correction. Results are better with open ocean than with coastal buoys. The scatter and the number of outliers are much larger for coastal buoys. SARAL is then compared with Jason-2 and...
Tipo: Text Palavras-chave: Radar altimeter; Significant wave height; Satellite; SARAL; AltiKa; Validation.
Ano: 2015 URL: http://archimer.ifremer.fr/doc/00286/39675/38199.pdf
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Evaluation of high-resolution surface wind products at global and regional scales 5
Bentamy, Abderrahim; Croize-fillon, Denis; Queffeulou, Pierre; Liu, C.; Roquet, H..
High resolution surface wind fields covering the global ocean, estimated from remotely sensed wind data and ECMWF wind analyses, have been available since 2005 with a spatial resolution of 0.25 degrees in longitude and latitude, and a temporal resolution of 6h. Their quality is investigated through various comparisons with surface wind vectors from 190 buoys moored in various oceanic basins, from research vessels and from QuikSCAT scatterometer data taken during 2005-2006. The NCEP/NCAR and NCDC blended wind products are also considered. The comparisons performed during January-December 2005 show that speeds and directions compare well to in-situ observations, including from moored buoys and ships, as well as to the remotely sensed data. The...
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Ano: 2009 URL: http://archimer.ifremer.fr/doc/00004/11546/10549.pdf
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Improved near real time surface wind resolution over the Mediterranean Sea 5
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...
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Ano: 2007 URL: http://archimer.ifremer.fr/doc/2007/publication-3528.pdf
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Improvements to estimating the air-sea gas transfer velocity by using dual-frequency, altimeter backscatter 5
Goddijn-murphy, Lonneke; Woolf, David; Chapron, Bertrand; Queffeulou, Pierre.
Air-sea gas exchange is affected by sea surface roughness and a previous study shows a significant relation between Ku-band backscattering from satellite altimeters and field estimates of gas transfer velocity, K. Recently C-band backscatter data were made available for altimeters on board the JASON-1 and JASON-2 satellites. In this paper we used experimental data from the same cruises to show that using the difference between the Ku-band and C-band signals to estimate sea surface roughness, and thus reducing the contribution from longer waves, improved the K estimates. This is consistent with the theory that gas transfer is largely controlled by short capillary-gravity waves. For satellite data closer than 2 hr and 0.5 degrees from the K sample stations,...
Tipo: Text Palavras-chave: Air-sea gas transfer; Satellite altimetry; DMS.
Ano: 2013 URL: https://archimer.ifremer.fr/doc/00174/28564/26980.pdf
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Observation and parameterization of small icebergs: Drifting breakwaters in the southern ocean 5
Ardhuin, Fabrice; Tournadre, Jean; Queffeulou, Pierre; Ardhuin, Fanny; Collard, Fabrice.
The variability of small-size iceberg distributions is revealed from a novel analysis of satellite altimeter data. A strong annual cycle is modulated by pulse-like events confined to single ocean basins, with dense iceberg populations in the South Atlantic in 2004-2005, and in the South Pacific in 2008. Anomalies in sea surface temperatures of the order of 1 degrees C may be related to the iceberg distribution. Icebergs also appear very strongly associated with anomalies in the heights of ocean waves. A preliminary parameterization of wave blocking by icebergs significantly reduces wave model errors in the region south of 45 degrees South, and has a perceptible influence on all the west coasts of the Southern hemisphere. (C) 2011 Elsevier Ltd. All rights...
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Ano: 2011 URL: http://archimer.ifremer.fr/doc/00044/15535/13317.pdf
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Phenomenal sea states and swell from a North Atlantic Storm in February 2011: a comprehensive analysis 5
Hanafin, Jennifer; Quilfen, Yves; Ardhuin, Fabrice; Sienkiewicz, Joseph; Queffeulou, Pierre; Obrebski, Mathias; Chapron, Bertrand; Reul, Nicolas; Collard, Fabrice; Corman, David; De Azevedo, Eduardo B.; Vandemark, Doug; Stutzmann, Eleonore.
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Ano: 2012 URL: http://archimer.ifremer.fr/doc/00094/20538/18197.pdf
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Preliminary appraisal of wave power prospects in Lebanon 5
Aoun, N. S.; Harajli, H. A.; Queffeulou, Pierre.
The present work is the first attempt to methodologically assess the wave power prospects off the coast of Lebanon. Working around 1.5 years of buoy data, measurements for the significant wave height and wave period were inputted to establish a joint frequency table that was related to power matrixes of three selected wave energy converters. The spatial and temporal representability of the analysis was extended through assessing altimeter data of H-s over 20 years and for three points off the coast of Lebanon; southern Lebanon, buoy location off the coast of Beirut, and northern Lebanon. The altimeter data indicated that H-s values as measured through the buoy is within 1 standard deviation of the offshore regional mean, however adopting the regional mean...
Tipo: Text Palavras-chave: Wave energy converter; Lebanon; Significant wave height; Wave period; Mediterranean sea.
Ano: 2013 URL: http://archimer.ifremer.fr/doc/00176/28763/27296.pdf
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Satellite Air - Sea fluxes 5
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
Ano: 2011 URL: http://archimer.ifremer.fr/doc/00030/14101/11333.pdf
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The FETCH experiment: An overview - art. no. 8053 5
Hauser, Danièle; Branger, H; Bouffies Cloche, S; Despiau, S; Drennan, W; Dupuis, H; Durand, P; De Madron, X; Estournel, C; Eymard, L; Flamant, C; Graber, H; Guerin, C; Kahma, K; Lachaud, G; Lefevre, J; Pelon, J; Petterson, H; Piguet, B; Queffeulou, Pierre; Tailliez, D; Tournadre, Jean; Weill, A.
The "flux, etat de la mer, et tele'de'tection en conditions de fetch variable'' (FETCH) was aimed at studying the physical processes associated with air-sea exchanges and mesoscale oceanic circulation in a coastal region dominated by frequent strong offshore winds. The experiment took place in March-April 1998 in the northwestern Mediterranean Sea (Gulf of Lion). Observations were collected with the R/V L'Atalante, with an air-sea interaction spar (ASIS) buoy, with waverider buoys, and with research aircraft equipped for in situ and remote sensing measurements. The present paper is an introduction to the following special section, which groups 12 papers (including this one) presenting results on turbulent flux measurements at the ocean surface, on the...
Tipo: Text Palavras-chave: Gulf of Lion; Coastal oceanography; Marine atmospheric boundary layer; Remote sensing; Surface ocean waves; Air/sea interactions.
Ano: 2003 URL: http://archimer.ifremer.fr/doc/2003/publication-747.pdf
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Validation and analysis of ocean parameters using ASCAT data 5
Bentamy, Abderrahim; Ardhuin, Fanny; Croize-fillon, Denis; Queffeulou, Pierre.
This project aims to investigate the quality of ASCAT measurements as well as their use for oceanographic purposes. The accuracy of ASCAT retrievals will be mainly based on the use of collocated data from moored buoys, numerical weather prediction models, and satellites. The resulting collocated data will be used to explore the accuracy of the geophysical model function which relates the backscatter coefficients to surface wind vectors, as well as to assess the quality of ASCAT vector winds at global and local scales. Once this objective reached, it will enable to fully utilize the MetOp data for oceanographic applications. They will contribute to evaluate various estimates of ocean surface flux parameters required to force ocean general circulation...
Tipo: Text Palavras-chave: Fluxes; Sea ice; Wind; Scatterometer; ASCAT; MetOp; Flux; Glaces de mer; Vent; Diffusiomètre; ASCAT; MetOp.
Ano: 2006 URL: http://archimer.ifremer.fr/doc/2006/acte-1272.pdf
Registros recuperados: 12
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