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| Registros recuperados: 12 | |
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| Gourcuff, Claire; Lherminier, Pascale; Mercier, Herle; Le Traon, Pierre-yves. |
| A method to estimate mass and heat transports across hydrographic sections using hydrography together with altimetry data in a geostrophic box inverse model is presented. Absolute surface velocities computed from AVISO altimetry products made up of a combination of sea surface height measurements and geoid estimate are first compared to Ship Acoustic Doppler Current Profiler (S-ADCP) measurements of the Ovide project along hydrographic sections repeated every 2 years in summer from Portugal to Greenland. The rms difference between S-ADCP and altimetry velocities averaged on distances of about a hundred km accounts to 3.3 cm s−1. Considering that the uncertainty of S-ADCP velocities is found at 1.5 cm s−1, altimetry errors are estimated at 3 cm s−1.... |
| Tipo: Text |
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| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00038/14921/13751.pdf |
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| Treguier, Anne-marie; Gourcuff, Claire; Lherminier, Pascale; Mercier, Herle; Barnier, Bernard; Madec, Gurvan; Molines, Jean-marc; Penduff, Thierry; Czeschel, Lars; Boning, Claus. |
| Numerical models are used to estimate the meridional overturning and transports along the paths of two hydrographic cruises, carried out in 1997 and 2002 from Greenland to Portugal. We have examined the influence of the different paths of the two cruises and found that it could explain 0.4 to 2 Sv of difference in overturning (the precise value is model-dependent). Models show a decrease in the overturning circulation between 1997 and 2002, with different amplitudes. The CLIPPER ATL6 model reproduces well the observed weakening of the overturning in density coordinates between the cruises; in the model, the change is due to the combination of interannual and high-frequency forcing and internal variability associated with eddies and meanders. Examination of... |
| Tipo: Text |
Palavras-chave: Ocean model; Thermohaline circulation; North Atlantic; Climate variability; Oceanography. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-2199.pdf |
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| Mercier, Herle; Lherminier, Pascale; Sarafanov, Artem; Gaillard, Fabienne; Daniault, Nathalie; Desbruyeres, Damien; Falina, Anastasia; Ferron, Bruno; Gourcuff, Claire; Huck, Thierry; Thierry, Virginie. |
| The meridional overturning circulation (MOC) in the North Atlantic transports heat from the subtropics to high latitudes and hence plays an important role in the Earth’s climate. A region crucial for the MOC is the northern North Atlantic and the adjacent Nordic Seas, where waters transported northward in the MOC upper limb progressively cool, gain density and eventually sink. Here we discuss the variability of the gyre circulation, the MOC and heat flux as quantified from a joint analysis of hydrographic and velocity data from six repeats of the Greenland to Portugal OVIDE section (1997–2010), satellite altimetry and Argo float measurements. For each repeat of the OVIDE section, the full-depth absolute circulation and transports were assessed using an... |
| Tipo: Text |
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| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00165/27583/25742.pdf |
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| Mercier, Herle; Lherminier, Pascale; Gourcuff, Claire. |
| The OVIDE project studies the variability of the north Atlantic subbpolar gyre circulation based on repeated hydrography and current measurements, satellite observations, diagnostic and prognostic models. Here, we present an analysis of volume and heat transports between Greenland and Portugal from the 2002 OVIDE data. The results are compared to a previous analysis based on 1997 data (4x project). We focus on the thermohaline circulation. The thermohaline circulation, deep western boundary current and heat flux variability are correlated. |
| Tipo: Text |
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| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-6102.pdf |
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| Sarafanov, Artem; Falina, Anastasia; Lherminier, Pascale; Mercier, Herle; Sokov, Alexey; Gourcuff, Claire. |
| [1] In earlier studies, the decadal variability of the Deep Western Boundary Current (DWBC) transport in the vicinity of Cape Farewell, Greenland, has been assessed from changes in the baroclinic velocities computed from hydrographic data and referenced to 1000 m depth. The main limitation of using such an estimate as an index for the DWBC absolute transport variability comes from the unaccounted for decadal velocity changes at the reference level (1000 m). These changes may substantially contribute to the DWBC absolute transport variability by compensating for or adding to the baroclinic transport changes. To assess this contribution to variability, we quantify the decadal velocity changes which occurred at 1000 m depth southeast of Cape Farewell since... |
| Tipo: Text |
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| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00017/12855/9820.pdf |
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| Alvarez, Marta; Gourcuff, Claire. |
| Chlorofluorocarbon (CFC) 11 and 12 transports across the transoceanic World Ocean Circulation Experiment (WOCE) A25 section in the subpolar North Atlantic are derived from an inverse model using hydrographic and ADCP data (Lherminier et al., 2007). CFC and anthropogenic carbon (C-ANT) advective transports contrary to expected are uncoupled: C-ANT is transported northeastwards (82 +/- 39 kmol s(-1)) mainly within the overturning circulation, while CFC-11 and CFC-12 are transported southwestwards (-24 +/- 4 and -11 +/- 2 mol s(-1), respectively) as part of the large-scale horizontal circulation. The main reason for this uncoupled behaviour is the complex CFC vs. C-ANT relation in the ocean, which stems from the contrasting temperature relation for both... |
| Tipo: Text |
Palavras-chave: Anthropogenic carbon; CFC; Advective transports; Subpolar North Atlantic. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00009/11994/9039.pdf |
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| Kolodziejczyk, Nicolas; Testor, Pierre; Lazar, Alban; Echevin, Vincent; Krahmann, Gerd; Chaigneau, Alexis; Gourcuff, Claire; Wade, Malick; Faye, Saliou; Estrade, Philippe; Capet, Xavier; Mortier, Laurent; Brehmer, Patrice; Schuette, Florian; Karstensen, Johannes. |
| Glider measurements acquired along 4 transects between Cap‐Vert Peninsula and the Cape Verde archipelago in the eastern tropical North Atlantic during March‐April 2014 were used to investigate fine‐scale stirring in an anticyclonic eddy. The anticyclone was formed near 12°N off the continental shelf and propagated north‐west towards the Cape Verde islands. At depth, between 100‐400 m, the isolated anticyclone core contained relatively oxygenated, low salinity South Atlantic Central Water, while the surrounding water masses were saltier and poorly oxygenated. The dynamical and thermohaline subsurface environment favored the generation of fine‐scale horizontal and vertical temperature and salinity structures in and around the core of the anticyclone. These... |
| Tipo: Text |
Palavras-chave: Submesoscale; Stirring; Tropical Atlantic; Meoscale eddy; Glider measurements; OMZ. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00450/56162/57708.pdf |
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| Lherminier, Pascale; Mercier, Herle; Huck, Thierry; Gourcuff, Claire; Perez, Fiz F.; Morin, Pascal; Sarafanov, Artem; Falina, Anastasia. |
| The horizontal circulation of the subpolar gyre and the Meridional Overturning Circulation (MOC) are investigated here by comparing two snapshots of the North Atlantic as delivered by two hydrographic sections between Greenland and Portugal. The corresponding cruises were carried out in June–July 2002 and June–July 2004 on R/V Thalassa within the framework of the Ovide project. The absolute transports in June 2004 are described in detail, and then compared with transports in June 2002. The MOC (in density coordinates), driven by the volume balance between the northward North Atlantic Current (NAC) and the net southward export of dense water from the subpolar gyre, did not change: View the MathML source (1 Sv=106 m3 s−1). Its upper limb, above σ1=32.1, is... |
| Tipo: Text |
Palavras-chave: North Atlantic; Subpolar gyre; Meridional Overturning Circulation; OVIDE; Hydrology; ADCP. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00011/12272/9057.pdf |
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| Dañobeitia, Juan Jose; Pouliquen, Sylvie; Johannessen, Truls; Basset, Alberto; Cannat, Mathilde; Pfeil, Benjamin Gerrit; Fredella, Maria Incoronata; Materia, Paola; Gourcuff, Claire; Magnifico, Giuseppe; Delory, Eric; Del Rio Fernandez, Joaquin; Rodero, Ivan; Beranzoli, Laura; Nardello, Ilaria; Iudicone, Daniele; Carval, Thierry; Gonzalez Aranda, Juan M.; Petihakis, George; Blandin, Jerome; Kutsch, Werner Leo; Rintala, Janne-markus; Gates, Andrew R.; Favali, Paolo. |
| Research Infrastructures (RIs) are large-scale facilities encompassing instruments, resources, data and services used by the scientific community to conduct high-level research in their respective fields. The development and integration of marine environmental RIs as European Research Vessel Operators [ERVO] (2020) is the response of the European Commission (EC) to global marine challenges through research, technological development and innovation. These infrastructures (EMSO ERIC, Euro-Argo ERIC, ICOS-ERIC Marine, LifeWatch ERIC, and EMBRC-ERIC) include specialized vessels, fixed-point monitoring systems, Lagrangian floats, test facilities, genomics observatories, bio-sensing, and Virtual Research Environments (VREs), among others. Marine ecosystems are... |
| Tipo: Text |
Palavras-chave: European marine Research Infrastructures (RIs); Multi- and inter-disciplinary ocean observing systems; Global change; Geo-hazards; Marine ecosystem. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00622/73460/72700.pdf |
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| Sarafanov, Artem; Falina, Anastasia; Mercier, Herle; Sokov, Alexey; Lherminier, Pascale; Gourcuff, Claire; Gladyshev, Sergey; Gaillard, Fabienne; Daniault, Nathalie. |
| A mean state of the full-depth summer circulation in the Atlantic Ocean in the region in between Cape Farewell (Greenland), Scotland and the Greenland-Scotland Ridge (GSR) is assessed by combining 2002–2008 yearly hydrographic measurements at 59.5°N, mean dynamic topography, satellite altimetry data and available estimates of the Atlantic–Nordic Seas exchange. The mean absolute transports by the upper-ocean, mid-depth and deep currents and the Meridional Overturning Circulation (MOCσ = 16.5 ± 2.2 Sv, at σ0 = 27.55) at 59.5°N are quantified in the density space. Inter-basin and diapycnal volume fluxes in between the 59.5°N section and the GSR are then estimated from a box model. The dominant components of the meridional exchange across 59.5°N are the North... |
| Tipo: Text |
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| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00059/16997/14499.pdf |
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| Registros recuperados: 12 | |
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