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Registros recuperados: 10 | |
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Doglioli, Andrea; Nencioli, Francesco; Petrenko, Anne; Rougier, Gilles; Fuda, Jean-luc; Grima, Nicolas. |
The Lagrangian Transport Experiment (LATEX) was developed to study the influence of coupled physical and biogeochemical dynamics at the meso- and submesoscales on the transfers of matter and heat between the coastal zone and the open ocean. One of the goals of the Latex10 field experiment, conducted during September 2010 in the Gulf of Lion (northwest Mediterranean), was to mark a dynamical mesoscale feature by releasing a passive tracer [sulfur hexafluoride (SF6)] together with an array of Lagrangian buoys. The goal was to release the tracer in an initial patch as homogeneous as possible in the horizontal, and to study its turbulent mixing and dispersion while minimizing the contribution due to advection. For that, it was necessary to continuously adjust... |
Tipo: Text |
Palavras-chave: Dispersion; Lagrangian circulation; Transport; Ship observations; Tracers; Experimental design; Software. |
Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00155/26590/24719.pdf |
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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 |
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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 |
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Dobler, Delphine; Huck, Thierry; Maes, Christophe; Grima, Nicolas; Blanke, Bruno; Martinez, Elodie; Ardhuin, Fabrice. |
In the open ocean, floating surface debris such as plastics concentrate in five main accumulation zones centered around 30° latitude, far from highly turbulent areas. Using Lagrangian advection of numerical particles by surface currents from ocean model reanalysis, previous studies have shown long-distance connection from the accumulation zones of the South Indian to the South Pacific oceans. An important physical process affecting surface particles but missing in such analyses is wave-induced Stokes drift. Taking into account surface Stokes drift from a wave model reanalysis radically changes the fate of South Indian particles. The convergence region moves from the east to the west of the basin, so particles leak to the South Atlantic rather than the... |
Tipo: Text |
Palavras-chave: Marine debris; Microplastics; Stokes drift; Indian Ocean; Lagrangian analysis; Ocean surface pathways. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00512/62320/69273.pdf |
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Caballero, Ainhoa; Ferrer, Luis; Rubio, Anna; Charria, Guillaume; Taylor, Benjamin H.; Grima, Nicolas. |
The presence of a quasi-stationary anticyclonic eddy within the southeastern Bay of Biscay (centred around 44°30′N-4°W) has been reported on various occasions in the bibliography. The analysis made in this study for the period 2003–2010, by using in situ and remote sensing measurements and model results shows that this mesoscale coherent structure is present almost every year from the end of winter-beginning of spring, to the beginning of fall. During this period it remains in an area limited to the east by the Landes Plateau, to the west by Le Danois Bank and Torrelavega canyon and to the northwest by the Jovellanos seamount. All the observations and analysis made in this contribution, suggest that this structure is generated between Capbreton and... |
Tipo: Text |
Palavras-chave: Bay of Biscay; Eddies; SWODDIES; Topographic effects; Vortex; Mesoscale; Altimetry; Satellite oceanography; Drifters; ROMS. |
Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00161/27260/25469.pdf |
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Lique, Camille; Treguier, Anne-marie; Blanke, Bruno; Grima, Nicolas. |
The origin of the water masses exported from the Arctic to the North Atlantic along both sides of Greenland is investigated using an original numerical method. A quantitative Lagrangian analysis is applied to the monthly climatological 3-D output of a global ocean/sea ice high-resolution model. It allows quantification of the different branches of the export to the North Atlantic, as well as related timescales and water mass transformations. In the model, the outflow through Davis Strait consists in equal parts of Pacific and Atlantic water, whilst the export through Fram Strait consists almost fully of Atlantic water (contrary to observations). Pacific water is transferred quickly (O(10 years)) to the North Atlantic through the Beaufort Gyre, where... |
Tipo: Text |
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Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00005/11591/8232.pdf |
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Desbiolles, Fabien; Blanke, Bruno; Bentamy, Abderrahim; Grima, Nicolas. |
Numerous studies have shown the primary importance of wind stress curl in coastal upwelling dynamics. The main goal of this new analysis is to describe the QuikSCAT surface wind stress curl at various scales in the Benguela and Canary upwelling systems. The dominant spatial pattern is characterized by cyclonic curl near continental boundaries and anticyclonic curl offshore, in association with equatorward alongshore (upwelling favorable) wind stress. At a smaller scale, we demonstrate the sensitivity of the QuikSCAT wind stress curl to coastal processes related to sea surface temperature (SST) mesoscale fluctuations by presenting a linear relationship between the curl and crosswind SST gradients. Despite the spatial and temporal sensitivity of the... |
Tipo: Text |
Palavras-chave: Wind stress; Upwelling; SST-wind interactions. |
Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00233/34412/32820.pdf |
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Chenillat, Fanny; Blanke, Bruno; Grima, Nicolas; Franks, Peter J. S.; Capet, Xavier; Rivière, Pascal. |
Eulerian models coupling physics and biology provide a powerful tool for the study of marine systems, complementing and synthesizing in situ observations and in vitro experiments. With the monotonic improvements in computing resources, models can now resolve increasingly complex biophysical interactions. Quantifying complex mechanisms of interaction produces massive amounts of numerical data that often require specialized tools for analysis. Here we present an Eulerian-Lagrangian approach to analyzing tracer dynamics in moving fluids. As an example of its utility, we apply this tool to quantifying plankton dynamics in oceanic mesoscale coherent structures. In contrast to Eulerian frameworks, Lagrangian approaches are particularly useful for revealing... |
Tipo: Text |
Palavras-chave: Biophysicalinteractions; Planktondynamics; Ecosystemfunctioning; Lagrangiantrajectories; Ocean dynamics; Mesoscaleprocesses; Eddytracking; Coherentstructures. |
Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00469/58028/60447.pdf |
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Rimaud, Julie; Speich, Sabrina; Blanke, Bruno; Grima, Nicolas. |
Results from a regional ocean model and numerical Lagrangian analyses are compared with in situ measurements to describe the properties and dynamics of Antarctic Intermediate Water (AAIW) in the region of the Cape Basin. The AAIW that originates in the South Atlantic (A-AAIW) at 8 degrees W follows two branches. A southern branch, flowing mostly south of 40 degrees S, is blocked by topography and is deflected westward without significant changes in its physical properties. A northern branch crosses the Cape Basin with strong modification of its physical properties. The AAIW that originates in the Indian Ocean (I-AAIW) flows into the Atlantic Ocean via the Agulhas Current and undergoes small physical changes in the Cape Basin. In the model, the salinity... |
Tipo: Text |
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Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00098/20921/18532.pdf |
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Registros recuperados: 10 | |
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