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Registros recuperados: 18 | |
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Assassi, Charefeddine; Morel, Y.; Vandermeirsch, Frederic; Chaigneau, A.; Pegliasco, C.; Morrow, R.; Colas, F.; Fleury, S.; Carton, Xavier; Klein, Patrice; Cambra, R.. |
In this study, we first show that it is difficult to reconstruct the vertical structure of vortices using only surface observations. In particular we show that the recent SQG and ISQG methods systematically lead to surface intensified vortices and those subsurface intensified vortices are thus not correctly modelled. We then investigate the possibility to distinguish between surface and subsurface intensified eddies from surface data only, using the sea surface height and the sea surface temperature available from satellite observations. A simple index, based on the ratio of the sea surface temperature anomaly and the sea level anomaly, is proposed. While the index is expected to give perfect results for isolated vortices, we show that in a complex... |
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Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00343/45406/44921.pdf |
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Assassi, Charefeddine; Vandermeirsch, Frederic; Morel, Yves; Charria, Guillaume; Theetten, Sebastien; Dussin, Raphael; Molines, Jean-marc. |
The aim of this study is to better understand the different overriding mechanisms that control the evolution of the temperature in the Bay of Biscay, through realistic simulations over a period of 50 years. Based on the work of Michel et al. (2009) on the variability of temperature in the Bay of Biscay (Fig1). We will extend the understanding of the interannual variability to the haline contents and the circulation at regional scale. Here we compare two global simulations, ORCA-G70 and ORCA-GRD100 (¼°resolution), that differs mainly in the vertical resolution and we show their variability. |
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Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00197/30778/29137.pdf |
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Vandermeirsch, Frederic; Charraudeau, Romain; Bonnat, Armel; Fichaut, Michele; Maillard, Catherine; Gaillard, Fabienne; Autret, Emmanuelle. |
The Bay of Biscay climatology is the synthesis of all the in situ data collected in the bay of Biscay area as far as 15°W, in the 20th century and mainly by IFREMER, SHOM, and WDCA. It shows temperature and salinity monthly information through the whole water column with a 1/10 degree resolution. The resulting atlas was produced by an optimal analysis which can reflect different scales: shelf and abyssal plain. A fine scale on the coast reveals all the local effects, including plume and upwelling, and a large scale on the shelf where a slower signal is obtained due to the large scale circulation |
Tipo: Text |
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Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00029/14039/11232.pdf |
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Vandermeirsch, Frederic; Carton, Xavier; Morel, Yves. |
The interaction between a stable zonal jet and a vortex is studied numerically with two one-and-a-half layer models, one with quasi-geostrophic dynamics, the other with shallow-water equations. In both models, simulations on the f-plane evidence three regimes occuring with increasing vortex strength: (regime 1) weak vortices do not cross the jet and steadily drift along it; (regime 2) stronger vortices cross the jet, tear an opposite-sign meander from the jet with which they pair as a dipole; the trajectory of this dipole depends on the strength of the initial vortex; since most dipoles are asymmetric, they veer back towards the jet axis where they are split apart in the ambient shear; (regime 3) even stronger vortices cross the jet and tear a vorticity... |
Tipo: Text |
Palavras-chave: Potential vorticity; Vortices; Jets; Nonlinear equations; Stratified flow; Rotating fluids. |
Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/publication-440.pdf |
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Charria, Guillaume; Vandermeirsch, Frederic; Cailleau, Sylvain; Enigme’s Group,. |
In a context of global change, ocean regions as the Bay of the Biscay and the English Channel represent key domains to estimate the local impact on the coasts of these evolutions. Indeed, the coastal (considering in this project regions above the continental shelf) and regional (including the continental slope and the abyssal plain) environments are sensitive to these long- term evolutions driven by the open ocean, the atmosphere and the watersheds. These evolutions can have impacts on the whole ecosystem. To understand and, by extension, forecast evolutions of these ecosystems, we need to go further in the description and the analysis of the past interannual variability over decadal to pluri-decadal periods. The ENIGME project is organised following three... |
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Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00242/35285/33802.pdf |
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Gailhard-rocher, Isabelle; Huret, Martin; Lazure, Pascal; Vandermeirsch, Frederic; Gatti, Julie; Garreau, Pierre; Gohin, Francis. |
Dans le contexte de l’évaluation initiale des eaux communautaires demandée par la Directive cadre stratégie pour le milieu marin (DCSMM), les états membres sont chargés de décrire les types d’habitats dominants de la colonne d’eau pour chaque sous-région marine. La présente étude s’inscrit dans ce contexte et a pour objectif de décrire les principales structures hydrologiques de la colonne d’eau. Sur la base des données existantes et des travaux antérieurs, il s’agit de classer les masses d'eau en fonction de critères physiques (température, salinité, turbidité, stratification), reconnus d’intérêt pour les espèces pélagiques et l’écosystème en général, et ainsi de définir une cartographie de l’habitat pélagique moyen. Les données utilisées correspondent... |
Tipo: Text |
Palavras-chave: DCSMM; Habitat pélagique; Classification; Indices hydrologiques; Distribution des espèces; KeywordsMSFD; Pelagic Habitat; Clustering; Hydrological indices; Species distribution. |
Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00069/18018/15547.pdf |
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Charria, Guillaume; Repecaud, Michel; Quemener, Loic; Menesguen, Alain; Rimmelin-maury, Peggy; L'Helguen, Stephane; Beaumont, Laurence; Jolivet, Aurelie; Morin, Pascal; Mace, E; Lazure, Pascal; Le Gendre, Romain; Jacqueline, Franck; Verney, Romaric; Marie, Louis; Jegou, Paul; Le Reste, Serge; Andre, Xavier; Dutreuil, Vincent; Regnault, Jean-pierre; Jestin, Herve; Lintanf, Herve; Pichavant, Pascal; Retho, Michael; Allenou, Jean-pierre; Stanisiere, Jean-yves; Bonnat, Armel; Nonnotte, Lidwine; Duros, Wenceslas; Tarot, Stephane; Carval, Thierry; Le Hir, Pierre; Dumas, Franck; Vandermeirsch, Frederic; Lecornu, Fabrice. |
To design a prototype for an Integrated Ocean Observing System (IOOS), at least three components are mandatory: a modeling platform, an in situ observing system and a structure to collect and to disseminate the information (e.g. database, website). The PREVIMER project followed this approach and in order to sustain model applications, PREVIMER has developed, funded and organized part of in situ observing networks in the Bay of Biscay and the Channel. For a comprehensive system, focus was addressed on fi xed platforms (MAREL MOLIT, MAREL Iroise, Island network and D4 for sediment dynamics), ships of opportunity (RECOPESCA program and FerryBoxes), and coastal profi lers (ARVOR-C/Cm). Each system is briefl y described and examples of scientifi c results... |
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Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00197/30785/29143.pdf |
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Vandermeirsch, Frederic; Carton, Xavier; Morel, Yves. |
In a two-and-a-half-layer quasi-geostrophic model, a process study is conducted on the interaction between a vortex and a zonal jet, both with constant potential vorticity. The vortex is a stable anticyclone, initially located north of the eastward jet. The potential vorticity of the jet is allowed to have various vertical structures, while the vortex is concentrated in only one layer. The flow parameters are set to values characteristic of the Azores region. First, the jet is stable. Weak vortices steadily drift north of the jet without crossing it while strong vortices can cross the jet and tear off a cyclone with which they pair as a heton (baroclinic dipole). This heton often breaks later in the shear exerted by the jet; the two vortices finally... |
Tipo: Text |
Palavras-chave: Potential vorticity; Vortices; Jets; Nonlinear equations; Stratified flow; Rotating fluids. |
Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/publication-441.pdf |
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Charria, Guillaume; Theetten, Sebastien; Vandermeirsch, Frederic; Yelekci, Ozge; Audiffren, Nicole. |
In the north-east Atlantic Ocean, the Bay of Biscay is an intersection between a coastal constrained dynamics (wide continental shelf and shelf break regions) and an eastern boundary circulation system. In this framework, the eddy kinetic energy is 1 order of magnitude lower than in western boundary systems. To explore this coastal complex system, a high-resolution (1 km, 100 vertical sigma layers) model experiment including tidal dynamics over a period of 10 years (2001–2010) has been implemented. The ability of the numerical environment to reproduce main patterns over interannual scales is demonstrated. Based on this experiment, the features of the (sub)mesoscale processes are described in the deep part of the region (i.e. abyssal plain and continental... |
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Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00403/51468/52038.pdf |
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Registros recuperados: 18 | |
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