Sabiia Seb
PortuguêsEspañolEnglish
Embrapa
        Busca avançada

Botão Atualizar


Botão Atualizar

Ordenar por: RelevânciaAutorTítuloAnoImprime registros no formato resumido
Registros recuperados: 53
Primeira ... 123 ... Última
Imagem não selecionada

Imprime registro no formato completo
A kinetic energy budget and internal instabilities in the Fine Resolution Antarctic Model ArchiMer
Ivchenko, Vladimir O; Treguier, Anne-marie; Best, Se.
An energy analysis of the Fine Resolution Antarctic Model (FRAM) reveals the instability processes in the model. The main source of time-mean kinetic energy is the wind stress and the main sink is transfer to mean potential energy. The wind forcing thus helps maintain the density structure. Transient motions result from internal instabilities of the Bow rather than seasonal variations of the forcing. Baroclinic instability is found to be an important mechanism in FRAM. The highest values of available potential energy are found in the western boundary regions as well as in the Antarctic Circumpolar Current (ACC) region. All subregions with predominantly zonal flow are found to be baroclinically unstable. The observed deficit of eddy kinetic energy in FRAM...
Tipo: Text
Ano: 1997 URL: http://archimer.ifremer.fr/doc/00337/44779/44598.pdf
Imagem não selecionada

Imprime registro no formato completo
A Lagrangian Method to Isolate the Impacts of Mixed Layer Subduction on the Meridional Overturning Circulation in a Numerical Model ArchiMer
Thomas, Matthew; Treguier, Anne-marie; Blanke, Bruno; Deshayes, Julie; Voldoire, Aurore.
Large differences in the Atlantic meridional overturning circulation (AMOC) exhibited between the available ocean models pose problems as to how they can be interpreted for climate policy. A novel Lagrangian methodology has been developed for use with ocean models that enables a decomposition of the AMOC according to its source waters of subduction from the mixed layer of different geographical regions. The method is described here and used to decompose the AMOC of the Centre National de Recherches Météorologiques (CNRM) ocean model, which is approximately 4.5 Sv (1 Sv = 106 m3 s−1) too weak at 26°N, compared to observations. Contributions from mixed layer subduction to the peak AMOC at 26°N in the model are dominated by the Labrador Sea, which contributes...
Tipo: Text Palavras-chave: Circulation; Dynamics; Convection; Lagrangian circulation; Transport; Meridional overturning circulation; Atm; Ocean Structure; Phenomena; Oceanic mixed layer; Models and modeling; General circulation models.
Ano: 2015 URL: http://archimer.ifremer.fr/doc/00284/39523/38016.pdf
Imagem não selecionada

Imprime registro no formato completo
A model-based study of ice and freshwater transport variability along both sides of Greenland ArchiMer
Lique, Camille; Treguier, Anne-marie; Scheinert, Markus; Penduff, Thierry.
We investigate some aspects of the variability of the Arctic freshwater content during the 1965-2002 period using the DRAKKAR eddy admitting global ocean/sea-ice model (12 km resolution in the Arctic). A comparison with recent mooring sections shows that the model realistically represents the major advective exchanges with the Arctic basin, through Bering, Fram and Davis Straits, and the Barents Sea. This allows the separate contributions of the inflows and outflows across each section to be quantified. In the model, the Arctic freshwater content variability is explained by the sea-ice flux at Fram and the combined variations of ocean freshwater inflow (at Bering) and outflow (at Fram and Davis). At all routes, except trough Fram Strait, the freshwater...
Tipo: Text Palavras-chave: Fram Strait; Davis Strait; Freshwater flux; Freshwater budget; Arctic Ocean.
Ano: 2009 URL: http://archimer.ifremer.fr/doc/2009/publication-6713.pdf
Imagem não selecionada

Imprime registro no formato completo
Agulhas eddy fluxes in a 1/6 degrees Atlantic model ArchiMer
Treguier, Anne-marie; Boebel, O; Barnier, B; Madec, G.
A 1/6degrees resolution primitive equation model of the Atlantic circulation is analyzed in the Agulhas region. The model has a realistic level of eddy kinetic energy, and produces anticyclonic Agulhas rings as well as cyclonic structures. In the model as well as in the data, ring trajectories undergo a transition between a turbulent character in the Cape Basin and a steady propagation in the rest of the South Atlantic. The topography of the Walvis Ridge does not seem to play a part in generating this contrast in the model. The model shows that cyclones are primarily generated from the negative shear vorticity side of the Agulhas Current as it leaves the coast, and they are most of the time paired with anticyclones in dipolar or tripolar structures....
Tipo: Text Palavras-chave: South Africa; South Atlantic Ocean; Numerical model; Ocean currents; Oceanic eddies; Eddy flux.
Ano: 2003 URL: http://archimer.ifremer.fr/doc/2003/publication-453.pdf
Imagem não selecionada

Imprime registro no formato completo
An assessment of global and regional sea level for years 1993-2007 in a suite of interannual CORE-II simulations ArchiMer
Griffies, Stephen M.; Yin, Jianjun; Durack, Paul J.; Goddard, Paul; Bates, Susan C.; Behrens, Erik; Bentsen, Mats; Bi, Daohua; Biastoch, Arne; Boening, Claus W.; Bozec, Alexandra; Chassignet, Eric; Danabasoglu, Gokhan; Danilov, Sergey; Domingues, Catia M.; Drange, Helge; Farneti, Riccardo; Fernandez, Elodie; Greatbatch, Richard J.; Holland, David M.; Ilicak, Mehmet; Large, William G.; Lorbacher, Katja; Lu, Jianhua; Marsland, Simon J.; Mishra, Akhilesh; Nurser, A. J. George; Salas Y Melia, David; Palter, Jaime B.; Samuels, Bonita L.; Schroeter, Jens; Schwarzkopf, Franziska U.; Sidorenko, Dmitry; Treguier, Anne-marie; Tseng, Yu-heng; Tsujino, Hiroyuki; Uotila, Petteri; Valcke, Sophie; Voldoire, Aurore; Wang, Qiang; Winton, Michael; Zhang, Xuebin.
The Palomares Margin, an NNE–SSW segment of the South Iberian Margin located between the Alboran and the Algerian–Balearic basins, is dissected by two major submarine canyon systems: the Gata (in the South) and the Alías–Almanzora (in the North). New swath bathymetry, side-scan sonar images, accompanied by 5 kHz and TOPAS subbottom profiles, allow us to recognize these canyons as Mediterranean examples of medium-sized turbidite systems developed in a tectonically active margin. The Gata Turbidite System is confined between residual basement seamounts and exhibits incised braided channels that feed a discrete deep-sea fan, which points to a dominantly coarse-grained turbiditic system. The Alías–Almanzora Turbidite System, larger and less confined, is a...
Tipo: Text Palavras-chave: Sea level; CORE global ocean-ice simulations; Steric sea level; Global sea level; Ocean heat content.
Ano: 2014 URL: http://archimer.ifremer.fr/doc/00188/29904/28349.pdf
Imagem não selecionada

Imprime registro no formato completo
An eddy-permitting model of the Atlantic circulation: Evaluating open boundary conditions ArchiMer
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
Imagem não selecionada

Imprime registro no formato completo
An ERA40-based atmospheric forcing for global ocean circulation models ArchiMer
Brodeau, Laurent; Barnier, Bernard; Treguier, Anne-marie; Penduff, Thierry; Gulev, Sergei.
We develop, calibrate and test a dataset intended to drive global ocean hindcasts simulations of the last five decades. This dataset provides surface meteorological variables needed to estimate air-sea fluxes and is built from 6-hourly surface atmospheric state variables of ERA40. We first compare the raw fields of ERA40 to the CORE.v1 clataset of Large and Yeager (2004). used here as a reference, and discuss our choice to use daily radiative fluxes and monthly precipitation products extracted from satellite data rather than their ERA40 counterparts. Both datasets lead to excessively high global imbalances of heat and freshwater fluxes when tested with a prescribed climatological sea surface temperature. After identifying unrealistic time discontinuities...
Tipo: Text Palavras-chave: Ocean; Hindcast; Atmospheric forcing; Air sea fluxes; Weather reanalyzes; Satellite.
Ano: 2010 URL: http://archimer.ifremer.fr/doc/00000/11154/14032.pdf
Imagem não selecionada

Imprime registro no formato completo
Biweekly current oscillations on the continental slope of the Gulf of Guinea ArchiMer
Vangriesheim, Annick; Treguier, Anne-marie; Andre, Gael.
Current meter measurements have been carried out for 3 years on the continental slope of the Gulf of Guinea, near 7.5 degrees S off the Angola coast. Currents in a water depth of 1300 m over the continental slope show a remarkable biweekly oscillation, bottom intensified, and with currents oriented nearly parallel to the isobaths. With a peak-to-peak amplitude reaching 20-30 cm s(-1) at 30 in above the bottom, this signal is the most energetic at sub-inertial frequencies. Simultaneous measurements deeper on the continental rise (in a water depth of 4000 m) show a more complex signal dominated by lower frequencies, and with less clear polarization. Simple linear topographic wave theories are compared to the observations. A combination of coastal trapped...
Tipo: Text Palavras-chave: Linear wave model; Current meter measurement; Current oscillation; Continental slope.
Ano: 2005 URL: http://archimer.ifremer.fr/doc/2005/publication-1032.pdf
Imagem não selecionada

Imprime registro no formato completo
Challenges and Prospects in Ocean Circulation Models ArchiMer
Fox-kemper, Baylor; Adcroft, Alistair; Boening, Claus W.; Chassignet, Eric P.; Curchitser, Enrique; Danabasoglu, Gokhan; Eden, Carsten; England, Matthew H.; Gerdes, Ruediger; Greatbatch, Richard J.; Griffies, Stephen M.; Hallberg, Robert W.; Hanert, Emmanuel; Heimbach, Patrick; Hewitt, Helene T.; Hill, Christopher N.; Komuro, Yoshiki; Legg, Sonya; Le Sommer, Julien; Masina, Simona; Marsland, Simon J.; Penny, Stephen G.; Qiao, Fangli; Ringler, Todd D.; Treguier, Anne-marie; Tsujino, Hiroyuki; Uotila, Petteri; Yeager, Stephen G..
We revisit the challenges and prospects for ocean circulation models following Griffies et al. (2010). Over the past decade, ocean circulation models evolved through improved understanding, numerics, spatial discretization, grid configurations, parameterizations, data assimilation, environmental monitoring, and process-level observations and modeling. Important large scale applications over the last decade are simulations of the Southern Ocean, the Meridional Overturning Circulation and its variability, and regional sea level change. Submesoscale variability is now routinely resolved in process models and permitted in a few global models, and submesoscale effects are parameterized in most global models. The scales where nonhydrostatic effects become...
Tipo: Text Palavras-chave: Ocean circulation; Model; Parameterization; Climate; Ocean processes.
Ano: 2019 URL: https://archimer.ifremer.fr/doc/00488/59989/63213.pdf
Imagem não selecionada

Imprime registro no formato completo
Deep currents in the Gulf of Guinea: along slope propagation of intraseasonal waves ArchiMer
Guiavarc'H, Catherine; Treguier, Anne-marie; Vangriesheim, Annick.
In the Gulf of Guinea, intraseasonal variability is large at the equator and along the coast. Current data on the continental slope near 7.5° S show very energetic biweekly oscillations at 1300 m depth. A high resolution primitive equation numerical model demonstrates that this deep variability is forced by equatorial winds, through the generation of equatorial Yanai waves that propagate eastward and at depth, and then poleward as coastally-trapped waves upon reaching the coast of Africa. Intraseasonal variability is intensified along the coast of the Gulf of Guinea, especially in the 10–20 day period range and at depths between 500 and 1500 m. The kinetic energy distribution is well explained at first order by linear theory. Along the equator, eastward...
Tipo: Text
Ano: 2009 URL: http://archimer.ifremer.fr/doc/2009/publication-6739.pdf
Imagem não selecionada

Imprime registro no formato completo
Detection of coherent oceanic structures via transfer operators ArchiMer
Froyland, G; Padberg, K; England, M; Treguier, Anne-marie.
Coherent nondispersive structures are known to play a crucial role in explaining transport in nonautonomous dynamical systems such as ocean flows. These structures are difficult to extract from model output as they are Lagrangian by nature and not revealed by the underlying Eulerian velocity fields. In the last few years heuristic concepts such as finite-time Lyapunov exponents have been used in an attempt to detect barriers to oceanic transport and thus identify regions that trap material such as nutrients and phytoplankton. In this Letter we pursue a novel, more direct approach to uncover coherent regions in the surface ocean using high-resolution model velocity data. Our method is based upon numerically constructing a transfer operator that controls the...
Tipo: Text
Ano: 2007 URL: http://archimer.ifremer.fr/doc/2007/publication-4349.pdf
Imagem não selecionada

Imprime registro no formato completo
DRAKKAR: developing high resolution ocean components for European Earth system models ArchiMer
Barnier, B.; Blaker, A.t.; Biatosch, A.; Böning, C.w.; Coward, A.; Deshayes, Julie; Hirshi, J.; Le Sommer, J.; Madec, G.; Maze, Guillaume; Molines, J.m.; New, A.; Penduff, T.; Scheinert, M.; Talandier, Claude; Treguier, Anne-marie.
DRAKKAR is a consortium of European ocean modelling teams. It was “created to take up the challenges of developing realistic global eddy-resolving/ permitting ocean/sea-ice models, and of building an ensemble of high resolution model hindcasts representing the ocean circulation from the 1960s to present” (quoting the DRAKKAR Group, 2007, in a CLIVAR Exchanges paper where the DRAKKAR strategy was presented for the first time). Now in the second decade of its existence, the DRAKKAR Group is active and thriving, and it is now timely to present recent developments and future plans in this special issue of CLIVAR Exchanges.
Tipo: Text
Ano: 2014 URL: http://archimer.ifremer.fr/doc/00326/43698/43123.pdf
Imagem não selecionada

Imprime registro no formato completo
Dynamical contribution to sea surface salinity variations in the eastern Gulf of Guinea based on numerical modelling ArchiMer
Berger, Henrick; Treguier, Anne-marie; Perenne, Nicolas; Talandier, Claude.
In this study, we analyse the seasonal variability of the sea surface salinity (SSS) for two coastal regions of the Gulf of Guinea from 1995 to 2006 using a high resolution model (1/12°) embedded in a Tropical Atlantic (1/4°) model. Compared with observations and climatologies, our model demonstrates a good capability to reproduce the seasonal and spatial variations of the SSS and mixed layer depth. Sensitivity experiments are carried out to assess the respective impacts of precipitations and river discharge on the spatial structure and seasonal variations of the SSS in the eastern part of the Gulf of Guinea. In the Bight of Biafra, both precipitations and river runoffs are necessary to observe permanent low SSS values but the river discharge has the...
Tipo: Text Palavras-chave: Gulf of Guinea; Salinity; Modelling; Congo; Bight of Biafra; Mixed layer budget.
Ano: 2014 URL: http://archimer.ifremer.fr/doc/00194/30493/29215.pdf
Imagem não selecionada

Imprime registro no formato completo
Dynamics of an Equatorial River Plume: Theory and Numerical Experiments Applied to the Congo Plume Case ArchiMer
Vic, Clement; Berger, Henrick; Treguier, Anne-marie; Couvelard, Xavier.
The Congo River has the second largest rate of flow in the world and is mainly responsible for the broad tongue of low-salinity water that is observed in the Gulf of Guinea. Despite their importance, near-equatorial river plumes have not been studied as thoroughly as midlatitude plumes and their dynamics remain unclear. Using both theory and idealized numerical experiments that reproduce the major characteristics of the region, the authors have investigated the dynamics of the Congo River plume and examine its sensitivity to different forcing mechanisms. It is found that near-equatorial plumes are more likely to be surface trapped than midlatitude plumes, and the importance of the effect in describing the strong offshore extent of the low-salinity tongue...
Tipo: Text Palavras-chave: Geographic location; Entity; Rivers; Circulation; Dynamics; Coastal flows; Density currents; Eddies; Nonlinear dynamics; Topographic effects.
Ano: 2014 URL: https://archimer.ifremer.fr/doc/00187/29850/28298.pdf
Imagem não selecionada

Imprime registro no formato completo
Dynamique d'un panache fluvial en zone équatoriale : modélisation numérique et application au cas du fleuve Congo ArchiMer
Vic, Clement; Treguier, Anne-marie; Berger, Henrick.
In this study, we describe the dynamics of an equatorial river plume using a numerical model (NEMO). The Congo river parameters are used.
Tipo: Text
Ano: 2012 URL: http://archimer.ifremer.fr/doc/00089/20042/17683.pdf
Imagem não selecionada

Imprime registro no formato completo
Eddy contributions to the meridional transport of salt in the North Atlantic ArchiMer
Treguier, Anne-marie; Deshayes, Julie; Lique, Camille; Dussin, Raphael; Molines, Jean-marc.
The meridional transport of salt in the Atlantic ocean is an important process for climate, controlling the stability of the meridional overturning circulation. The contribution of transient eddies to this transport is quantified in an eddy resolving North Atlantic model at 1/12 degrees resolution (NATL12), and compared with lower resolution North-Atlantic and global 1/4 degrees models. In NATL12 between 10 degrees N and 40 degrees N, there is a volume loss by evaporation of 0.6 Sverdrups (Sv). The divergence of the eddy flux of salt (normalized by a reference salinity of 34.8) is 0.2 Sv over the region, a significant fraction of the total air-seawater exchange, but it is compensated by an opposite convergent transport of salt by the mean flow, so that the...
Tipo: Text
Ano: 2012 URL: http://archimer.ifremer.fr/doc/00083/19441/17052.pdf
Imagem não selecionada

Imprime registro no formato completo
Estimates of the mortality and the duration of the trans-Atlantic migration of European eel Anguilla anguilla leptocephali using a particle tracking model ArchiMer
Bonhommeau, Sylvain; Le Pape, O.; Gascuel, D.; Blanke, Bruno; Treguier, Anne-marie; Grima, Nicolas; Vermard, Youen; Castonguay, M.; Rivot, E..
Using Lagrangian simulations, based on circulation models over three different hydroclimatic periods in the last 45 years in the North Atlantic Ocean, the trans-Atlantic migration of the European eel Anguilla anguilla leptocephali was simulated via the passive drift of particles released in the spawning area. Three different behaviours were modelled: drifting at fixed depth, undergoing a vertical migration or choosing the fastest currents. Simulations included mortality hypotheses to estimate a realistic mean migration duration and relative survival of A. anguilla larvae. The mean migration duration was estimated as 21 months and the mortality rate as 3 center dot 8 per year, i.e. < 0 center dot 2% of A. anguilla larvae may typically survive the...
Tipo: Text Palavras-chave: Migration duration; Leptocephalus mortality; Lagrangian modelling.
Ano: 2009 URL: http://archimer.ifremer.fr/doc/2009/publication-6614.pdf
Imagem não selecionada

Imprime registro no formato completo
Evolution of the Arctic Ocean Salinity, 2007-08: Contrast between the Canadian and the Eurasian Basins ArchiMer
Lique, Camille; Garric, Gilles; Treguier, Anne-marie; Barnier, Bernard; Ferry, Nicolas; Testut, Charles-emmanuel; Ardhuin, Fanny.
The authors investigate the variability of salinity in the Arctic Ocean and in the Nordic and Labrador Seas over recent years to see how the freshwater balance in the Arctic and the exchanges with the North Atlantic have been affected by the recent important sea ice melting, especially during the 2007 sea ice extent minimum. The Global Ocean Reanalysis and Simulations (GLORYS1) global ocean reanalysis based on a global coupled ocean sea ice model with an average of 12-km grid resolution in the Arctic Ocean is used in this regard. Although no sea ice data and no data under sea ice are assimilated, simulation over the 2001-09 period is shown to represent fairly well the 2007 sea ice event and the different components accounting for the ocean and sea ice...
Tipo: Text
Ano: 2011 URL: http://archimer.ifremer.fr/doc/00035/14637/11946.pdf
Imagem não selecionada

Imprime registro no formato completo
Heat budget in the North Atlantic subpolar gyre: impacts of atmospheric weather regimes on the 1995 warming event ArchiMer
Barrier, Nicolas; Deshayes, Julie; Treguier, Anne-marie; Cassou, Christophe.
In the mid 1990’s, the North Atlantic subpolar gyre has shown a dramatic warming event that has been thoroughly investigated from observations and numerical simulations. Some studies suggest that it is due to an interannual, wind-driven weakening and shrinking of the gyre that facilitated the penetration of warm Atlantic Water, the weakening of the gyre being attributed to changes in the North Atlantic Oscillation (NAO) and the East Atlantic Pattern, which are the two dominant modes of atmospheric variability in the North Atlantic. However, other studies suggest that the warming event is due to a decadal, buoyancy-driven strengthening of the meridional overturning circulation and subsequent intensification of the poleward heat transport, in response to the...
Tipo: Text
Ano: 2015 URL: https://archimer.ifremer.fr/doc/00218/32882/31753.pdf
Imagem não selecionada

Imprime registro no formato completo
How fast can the European eel (Anguilla anguilla) larvae cross the Atlantic Ocean? ArchiMer
Bonhommeau, Sylvain; Blanke, Bruno; Treguier, Anne-marie; Grima, Nicolas; Rivot, Etienne; Vermard, Youen; Greiner, Eric; Le Pape, Olivier.
The migration duration of European eel (Anguilla anguilla) larvae (leptocephali) from the spawning areas in the Sargasso Sea to the European continental shelf remains highly controversial, with estimates varying from 6 months to more than 2 yr. We estimated the fastest migration period and the shortest distance travelled by eel larvae by simulating Lagrangian particles released in the Sargasso Sea and by simulating a range of larval behaviours (fixed-depth drift, vertical diurnal migration and active-depth selection to maximize current velocity). This enabled us to compute (i) a passive drift speed, and (ii) a hypothetic swimming speed needed for European eel larvae to cross the Atlantic in 6 months (i.e., the migration duration estimated from otolith...
Tipo: Text Palavras-chave: Sargasso Sea; Migration duration; Leptocephali; Lagrangian modelling; Gulf Stream; Fractals; Anguilla.
Ano: 2009 URL: http://archimer.ifremer.fr/doc/2009/publication-6865.pdf
Registros recuperados: 53
Primeira ... 123 ... Última
 

Empresa Brasileira de Pesquisa Agropecuária - Embrapa
Todos os direitos reservados, conforme Lei n° 9.610
Política de Privacidade
Área restrita

Embrapa
Parque Estação Biológica - PqEB s/n°
Brasília, DF - Brasil - CEP 70770-901
Fone: (61) 3448-4433 - Fax: (61) 3448-4890 / 3448-4891 SAC: https://www.embrapa.br/fale-conosco

Valid HTML 4.01 Transitional