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Ayache, Mohamed; Dutay, Jean-claude; Arsouze, Thomas; Revillon, Sidonie; Beuvier, Jonathan; Jeandel, Catherine. |
An extensive compilation of published neodymium (Nd) concentrations and isotopic compositions (Nd IC) was realized in order to establish a new database and a map (using a high-resolution geological map of the area) of the distribution of these parameters for all the Mediterranean margins. Data were extracted from different kinds of samples: river solid discharge deposited on the shelf, sedimentary material collected on the margin or geological material outcropping above or close to a margin. Additional analyses of surface sediments were done in order to improve this data set in key areas (e.g. Sicilian strait). The Mediterranean margin Nd isotopic signatures vary from non-radiogenic values around the Gulf of Lion, (epsilon(Nd) values similar to -11) to... |
Tipo: Text |
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Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00639/75064/75547.pdf |
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Van Hulten, Marco; Middag, Rob; Dutay, Jean-claude; De Baar, Hein; Roy-barman, Matthieu; Gehlen, Marion; Tagliabue, Alessandro; Sterl, Andreas. |
Dissolved manganese (Mn) is a biologically essential element. Moreover, its oxidised form is involved in removing itself and several other trace elements from ocean waters. Here we report the longest thus far (17 500 km length) full-depth ocean section of dissolved Mn in the west Atlantic Ocean, comprising 1320 data values of high accuracy. This is the G Lambda 02 transect that is part of the GEO-TRACES programme, which aims to understand trace element distributions. The goal of this study is to combine these new observations with new, state-of-the-art, modelling to give a first assessment of the main sources and redistribution of Mn throughout the ocean. To this end, we simulate the distribution of dissolved Mn using a global-scale circulation model. This... |
Tipo: Text |
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Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00420/53178/55073.pdf |
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Ayata, Sakina-dorothee; Irisson, Jean-olivier; Aubert, Anais; Berline, Leo; Dutay, Jean-claude; Mayot, Nicolas; Nieblas, Anne-elise; D'Ortenzio, Fabrizio; Palmieri, Julien; Reygondeau, Gabriel; Rossi, Vincent; Guieu, Cecile. |
Regionalisation aims at delimiting provinces within which physical conditions, chemical properties, and biological communities are reasonably homogeneous. This article proposes a synthesis of the many recent regionalisations of the open-sea regions of the Mediterranean Sea. The nine studies considered here defined regions based on different, and sometimes complementary, criteria: dynamics of surface chlorophyll concentration, ocean currents, three-dimensional hydrological and biogeochemical properties, or the distribution of organisms. Although they identified different numbers and patterns of homogeneous regions, their compilation in the epipelagic zone identifies nine consensus frontiers, eleven consensus regions with relatively homogeneous conditions,... |
Tipo: Text |
Palavras-chave: Mediterranean Sea; Regionalisation; Biogeochemistry; Circulation; Mesoscale features; Epipelagic ocean; Management; Spatial planning. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00405/51673/52221.pdf |
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Tachikawa, Kazuyo; Arsouze, Thomas; Bayon, Germain; Bory, Aloys; Colin, Christophe; Dutay, Jean-claude; Frank, Norbert; Giraud, Xavier; Gourlan, Alexandra T.; Jeandel, Catherine; Lacan, Francois; Meynadier, Laure; Montagna, Paolo; Piotrowski, Alexander M.; Plancherel, Yves; Puceat, Emmanuelle; Roy-barman, Matthieu; Waelbroeck, Claire. |
Neodymium isotopic compositions (143Nd/144Nd or εNd) have been used as a tracer of water masses and lithogenic inputs to the ocean. To further evaluate the faithfulness of this tracer, we have updated a global seawater εNd database and combined it with hydrography parameters (temperature, salinity, nutrients and oxygen concentrations), carbon isotopic ratio and radiocarbon of dissolved inorganic carbon. Archive εNd data are also compiled for leachates, foraminiferal tests, deep-sea corals and fish teeth/debris from the Holocene period (< 10,000 years). At water depths ≥ 1500 m, property-property plots show clear correlations between seawater εNd and the other variables, suggesting that large-scale water mass mixing is a primary control of deepwater εNd... |
Tipo: Text |
Palavras-chave: Nd isotopes; Water mass tracer; Data compilation; Predicted seawater epsilon(Nd); Seawater-archive comparison. |
Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00376/48768/49165.pdf |
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Palmiéri, Julien; Dutay, Jean-claude; D'Ortenzio, Fabrizio; Houpert, Loïc; Mayot, Nicolas; Bopp, Laurent. |
Ocean bioregions are generally defined using remotely-sensed sea surface chlorophyll fields, based on the assumption that surface chlorophyll is representative of euphotic layer phytoplankton biomass. Here we investigate the impact of subsurface phytoplankton dynamics on the characterisation of ocean bioregions. The Mediterranean Sea is known for its contrasting bioregimes despite its limited area, and represents an appropriate case for this study. We modelled this area using a high resolution regional dynamical model, NEMO-MED12, coupled to a biogeochemical model, PISCES, and focused our analysis on the bioregions derived from lower trophic levels. Validated by satellite and Biogeochemical-Argo float observations, our model shows that chlorophyll... |
Tipo: Text |
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Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00471/58219/60723.pdf |
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