Consulta: creatorFacets:"Madec, Gerard"
Registros recuperados: 4
Data/hora: 26/07/2024 22:33:33

An eddy-permitting model of the Atlantic circulation: Evaluating open boundary conditions
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Treguier, Anne-marie; Barnier, B; De Miranda, A; Molines, J; Grima, N; Imbard, M; Madec, Gerard; Messager, Christophe; Reynaud, Thierry; Michel, Sylvain.
As part of the French CLIPPER project, an eddy permitting model of the Atlantic circulation has been run for 22 years. The domain has open boundaries at Drake passage and at 30 degreesE, from Africa to Antarctica. The simulated mean circulation, as well as the eddy activity, is satisfactory for a 1/3 degrees model resolution, and the meridional heat transport at 30 degreesS is within the range estimated from observations. We use the "mixed" open boundary algorithm of Barnier et al. [1998], which has both a radiation condition and a relaxation to climatology. The climatological boundary forcing strongly constrains the solution in the whole domain. The model heat balance adjusts through the surface (heat flux retroaction term) more than the open boundaries....
Tipo: Text
Palavras-chave: General circulation; Numerical modeling; Oceanography.
Ano: 2001
URL: http://archimer.ifremer.fr/doc/2001/publication-454.pdf

Impact of global ocean model resolution on sea-level variability with emphasis on interannual time scales
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Penduff, Thierry; Juza, Melanie; Brodeau, L.; Smith, G. C.; Barnier, B.; Molines, J. -m.; Treguier, Anne-marie; Madec, Gerard.
Four global ocean/sea-ice simulations driven by the same realistic 47-year daily atmospheric forcing were performed by the DRAKKAR group at 2 degrees, 1 degrees, 1/2 degrees, and 1/4 degrees resolutions. Simulated mean sea-surface heights (MSSH) and sea-level anomalies (SLA) are collocated over the period 1993-2004 onto the AVISO dataset. MSSH fields are compared with an inverse estimate. SLA datasets are filtered and compared over various time and space scales with AVISO regarding three characteristics: SLA standard deviations, spatial correlations between SLA variability maps, and temporal correlations between observed and simulated band-passed filtered local SLA timeseries. Beyond the 2 degrees-1 degrees transition whose benefits are moderate, further...
Tipo: Text
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00003/11386/7965.pdf

Improvements of simulated Western North Atlantic current system and impacts on the AMOC
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Talandier, Claude; Deshayes, Julie; Treguier, Anne-marie; Capet, Xavier; Benshila, Rachid; Debreu, Laurent; Dussin, Raphael; Molines, J. -m.; Madec, Gerard.
Previous studies have shown that low horizontal resolution (of the order of 1°) ocean models, hence climate models, are not able to adequately represent boundary currents nor mesoscale processes which affect the dynamics and thermohaline circulation of the ocean. While the effect of mesoscale eddies can be parameterized in low resolution models, boundary currents require relatively high horizontal resolution. We clarify the impact of increasing the resolution on the North Atlantic circulation, with emphasis on the Atlantic Meridional Overturning Circulation (AMOC), by embedding a 1/8° nest covering the North Atlantic into a global 1/2° model.  Increasing the resolution in the nest leads to regional improvements of the circulation and thermohaline...
Tipo: Text
Palavras-chave: Deep Western Boundary Current; Atlantic Meridional Overturning Circulation; North Atlantic Current; Gulf Stream; Subpolar gyre.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00173/28472/26812.pdf

Strong sensitivity of Southern Ocean carbon uptake and nutrient cycling to wind stirring
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Rodgers, K. B.; Aumont, Olivier; Fletcher, S. E. Mikaloff; Plancherel, Y.; Bopp, L.; De Boyer Montegut, Clement; Iudicone, D.; Keeling, R. F.; Madec, Gerard; Wanninkhof, R.
Here we test the hypothesis that winds have an important role in determining the rate of exchange of CO2 between the atmosphere and ocean through wind stirring over the Southern Ocean. This is tested with a sensitivity study using an ad hoc parameterization of wind stirring in an ocean carbon cycle model, where the objective is to identify the way in which perturbations to the vertical density structure of the planetary boundary in the ocean impacts the carbon cycle and ocean biogeochemistry. Wind stirring leads to reduced uptake of CO2 by the Southern Ocean over the period 2000-2006, with a relative reduction with wind stirring on the order of 0.9 Pg C yr(-1) over the region south of 45 degrees S. This impacts not only the mean carbon uptake, but also the...
Tipo: Text
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00211/32236/30684.pdf