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| Registros recuperados: 52 | |
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| Reverdin, Gilles; Gascard, Jean-claude; Le Cann, Bernard; Prieur, Loic; Assenbaum, Michel; Lherminier, Pascale. |
| An anticyclonic mode water vortex and its environment were investigated from November 2000 to September 2001 in the northeast Atlantic (near 43.5 degrees N, 15 degrees-19 degrees W) with neutrally buoyant drifting floats, moored current meters, satellite altimetric sea surface height, and several hydrological surveys and sections. These observations reveal a coherent inner core (similar to 0 km in diameter) made of very oxygenated northeast Atlantic central waters (11 degrees-12.7 degrees C and 35.5-35.7 on the 1978 practical salinity scale) from 150 m down to about 750-m depth. The core presents high relative vorticity (up to approximately -0.5 times the Coriolis frequency f) within at least 10 km of its center, near 400-700 m. Peak velocity along the... |
| Tipo: Text |
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| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6357.pdf |
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| Kolodziejczyk, Nicolas; Reverdin, Gilles; Gaillard, Fabienne; Lazar, Alban. |
| Low-frequency variability of spiciness is observed in the Subtropical South Atlantic over the period 2002–2013 with the Argo gridded product In Situ Analysis System. Within the pycnocline, spiciness anomalies propagate at a mean speed of 0.04 ± 0.02 m s−1, the same speed as the gyre mean circulation, from the Agulhas Retroflection region off South Africa (~35°S–20°E) toward the South American coast (~18°S–35°W). After 2010, propagation is still found, but stationary local spiciness generation is also found over the Subtropical South Atlantic. This spiciness increase is associated with high values of vertical Turner angle below the mixed layer base during late winter. This suggests spice injection resulting from penetrative convective mixing due to air-sea... |
| Tipo: Text |
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| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00212/32310/30756.pdf |
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| Reverdin, Gilles; Thierry, Virginie; Utiz, Julia; D'Ortenzio, Fabrizio; Bradshaw, Elizabeth; Pfeil, Benjamin. |
| The purpose of task 1 in WP7 in AtlantOS project is to harmonize data exchange and data processing procedures for the EOVs that are acquired by multiple networks. In this framework, the present report [D7.2] establishes recommendations for automatic quality control procedures in Near RT (a few hours to several days) for the core of 7 EOVs (measured by more than one of Networks involved in AtlantOS): • Physics : temperature (T), Salinity (T), Current for surface and subsurface and Sea level • Biogeochemistry : Oxygen (O2), Chlorophyll-A, Nitrate (NO3) and Carbon (pCO2) for surface and subsurface The recommendations have been compiled by experts on those EOVs and validated by the Networks acquiring those EOVs in NRT (link with WP2, WP3 and WP4). These... |
| Tipo: Text |
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| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00371/48244/48379.pdf |
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| Boutin, Jacqueline; Martin, Nicolas; Reverdin, Gilles; Yin, Xiaoming; Gaillard, Fabienne. |
| The sea surface salinity (SSS) measured from space by the Soil Moisture and Ocean Salinity (SMOS) mission has recently been revisited by the European Space Agency first campaign reprocessing. We show that, with respect to the previous version, biases close to land and ice greatly decrease. The accuracy of SMOS SSS averaged over 10 days, 100 x 100 km(2) in the open ocean and estimated by comparison to ARGO (Array for Real-Time Geostrophic Oceanography) SSS is on the order of 0.3-0.4 in tropical and subtropical regions and 0.5 in a cold region. The averaged negative SSS bias (-0.1) observed in the tropical Pacific Ocean between 5 degrees N and 15 degrees N, relatively to other regions, is suppressed when SMOS observations concomitant with rain events, as... |
| Tipo: Text |
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| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00139/25073/23161.pdf |
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| Szekely, Tanguy; Gourrion, Jerome; Pouliquen, Sylvie; Reverdin, Gilles. |
| We present the Copernicus in situ ocean dataset of temperature and salinity (version 5.2). Ocean subsurface sampling varied widely from 1950 to 2017 as a result of changes in instrument technology and the development of in situ observational networks (in particular, tropical moorings for the Argo program). Thus, global ocean temperature data coverage on an annual basis grew from 10 % in 1950 (30 % for the North Atlantic basin) to 25 % in 2000 (60 % for the North Atlantic basin) and reached a plateau exceeding 80 % (95 % for the North Atlantic Ocean) after the deployment of the Argo program. The average depth reached by the profiles also increased from 1950 to 2017. The validation framework is presented, and an objective analysis-based method is developed... |
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| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00595/70726/69005.pdf |
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| Lahaye, Noe; Gula, Jonathan; Thurnherr, Andreas M.; Reverdin, Gilles; Bouruet-aubertot, Pascale; Roullet, Guillaume. |
| Over mid-ocean ridges, the interaction between the currents and the topography gives rise to complex flows, which drive the transport properties of biogeochemical constituents, and especially those associated with hydrothermal vents, thus impacting associated ecosystems. This paper describes the circulation in the rift valley along the Azores sector of the North Mid-Atlantic Ridge, using a combination of in-situ data from several surveys and realistic high-resolution modeling. It confirms the presence of a mean deep current with an up-valley branch intensified along the right inner flank of the valley (looking downstream), and a weaker down-valley branch flowing at shallower depth along the opposite flank. The hydrographic properties of the rift-valley... |
| Tipo: Text |
Palavras-chave: Deep currents; Transport; Deep turbulence; Internal waves and tides; Realistic modeling; In situ observation. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00584/69630/67486.pdf |
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| Tonnard, Manon; Planquette, Hélène; Bowie, Andrew R.; Van Der Merwe, Pier; Gallinari, Morgane; Desprez De Gésincourt, Floriane; Germain, Yoan; Gourain, Arthur; Benetti, Marion; Reverdin, Gilles; Tréguer, Paul; Boutorh, Julia; Cheize, Marie; Menzel Barraqueta, Jan-lukas; Pereira-contreira, Leonardo; Shelley, Rachel; Lherminier, Pascale; Sarthou, Géraldine. |
| Dissolved Fe (DFe) samples from the GEOVIDE voyage (GEOTRACES GA01, May–June 2014) in the North Atlantic Ocean were analysed using a SeaFAST-picoTM coupled to an Element XR HR-ICP-MS and provided interesting insights on the Fe sources in this area. Overall, DFe concentrations ranged from 0.09 ± 0.01 nmol L−1 to 7.8 ± 0.5 nmol L−1. Elevated DFe concentrations were observed above the Iberian, Greenland and Newfoundland Margins likely due to riverine inputs from the Tagus River, meteoric water inputs and sedimentary inputs. Air-sea interactions were suspected to be responsible for the increase in DFe concentrations within subsurface waters of the Irminger Sea due to deep convection occurring the previous winter, that provided iron-to-nitrate ratios sufficient... |
| Tipo: Text |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00441/55233/56714.pdf |
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| Vage, Kjetil; Pickart, Robert S.; Thierry, Virginie; Reverdin, Gilles; Lee, Craig M.; Petrie, Brian; Agnew, Tom A.; Wong, Amy; Ribergaard, Mads H.. |
| In the process of open-ocean convection in the subpolar North Atlantic Ocean, surface water sinks to depth as a distinct water mass, the characteristics of which affect the meridional overturning circulation and oceanic heat flux. In addition, carbon is sequestered from the atmosphere in the process. In recent years, this convection has been shallow or non-existent, which could be construed as a consequence of a warmer climate. Here we document the return of deep convection to the subpolar gyre in both the Labrador and Irminger seas in the winter of 2007-2008. We use profiling float data from the Argo programme to document deep mixing. Analysis of a variety of in situ, satellite and reanalysis data shows that contrary to expectations the transition to a... |
| Tipo: Text |
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| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6415.pdf |
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| Reverdin, Gilles; Gaillard, Fabienne; Contardo, Stephanie; Mathias, Delphine; Gouriou, Yves; Dagorne, Dominique. |
| Les travaux présentés dans ce rapport ont été réalisés dans le cadre d’un « réseau bleu Coriolis ». Le comité scientifique MERCATOR/CORIOLIS de mai 2003 avait alors souligné la nécessité de soutenir les actions de validation des mesures issues des thermosalinographes (TSG) installés sur les navires de recherche labellisés Coriolis et les navires de l’ORE/SSS, afin d’aboutir à la définition d’une procédure homogène qui pourrait être mise en place en mode opérationnel par CORIOLIS. La responsabilité scientifique de ce travail a été confiée à Gilles Reverdin. Yves Gouriou et Fabienne Gaillard ont contribué à l’encadrement de ce travail qui a été réalisé par Stéphanie Contardo et Delphine Mathias dans les locaux de l’Unité de... |
| Tipo: Text |
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| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/00115/22585/20273.pdf |
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| Le Cann, Bernard; Assenbaum, Michel; Gascard, Jean-claude; Reverdin, Gilles. |
| Lagrangian instruments and altimetry data are used to investigate the upper ( 0 to similar to 500 m) mean and mesoscale circulations in a region of the midlatitude northeast Atlantic (36 degrees - 47 degrees N, 13 degrees - 23 degrees W), a formation and subduction area of Subpolar Mode Water. Lagrangian data were collected between September 2000 and September 2001 with isobaric subsurface floats, totaling 34.0 float years, and surface drifting buoys, totaling 27.9 buoy years. The near-surface ( 0 - 100 m) mean circulation is dominated by two weak ( similar to 5 cm/s) eastward currents which veer southward in the domain. In the 100- to 500-m-deep layer, these eastward mean currents retroflect westward and form two anticyclonic circulation cells, opened to... |
| Tipo: Text |
Palavras-chave: Altimetry; Drifting buoys; Acoustic floats; Lagrangian circulation; Mesoscale eddies; Northeastern Atlantic. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-745.pdf |
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| Registros recuperados: 52 | |
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