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| Arsouze, Thomas; Treguier, Anne-marie; Peronne, Simon; Dutay, J. -c.; Lacan, F.; Jeandel, C.. |
| Boundary Exchange (BE - exchange of elements between continental margins and the open ocean) has been emphasized as a key process in the oceanic cycle of neodymium (Nd) (Lacan and Jeandel, 2005a). Here, we use a regional eddy-permitting resolution Ocean General Circulation Model (1/4A degrees) of the North Atlantic basin to simulate the distribution of the Nd isotopic composition, considering BE as the only source. Results show good agreement with the data, confirming previous results obtained using the same parameterization of the source in a coarse resolution global model (Arsouze et al., 2007), and therefore the major control played by the BE processes in the Nd cycle on the regional scale. We quantified the exchange rate of the BE, and found that the... |
| Tipo: Text |
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| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00013/12412/9201.pdf |
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| Copard, K.; Colin, C.; Frank, N.; Jeandel, C.; Montero-serrano, J-c; Reverdin, G.; Ferron, Bruno. |
| Nd isotopic compositions (epsilon Nd) of seawater profiles and deep-sea corals collected off the coast of Iberia and from the Bay of Biscay were measured (1) to constrain the Nd isotopic composition of water masses along the southwest European margin, (2) to track the Mediterranean Outflow Water (MOW) during its northward propagation, and (3) to establish hydrological changes during the last 1500 years. The Eastern North Atlantic Central Water (ENACW) is characterized by Nd isotopic composition of around -12.0. Mediterranean Sea Water (MSW) is collected from 800 and 1200 m depth and is characterized by epsilon Nd values ranging from -10.9, off the coast of Iberia, to -11.6 in the Bay of Biscay. These epsilon Nd results suggest a strong dilution of the pure... |
| Tipo: Text |
Palavras-chave: European margin; Nd isotopic composition; Deep‐sea corals; Water masses. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00040/15108/12571.pdf |
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| Hoppema, M.; Dehairs, F.; Navez, J.; Monnin, C.; Jeandel, C.; Fahrbach, E.; De Baar, H. J. W.. |
| The Southern Ocean data base of dissolved barium (Bad) has been augmented with two densely sampled sections across the Weddell Gyre sampled by the icebreaker FS Polarstern during February and March 2005. Bad was found to be relatively high in the surface layer as compared to the adjacent waters north (Antarctic Circumpolar Current) and east (Antarctic Zone of the Indian sector). Compared to the inflowing water into the Weddell Gyre and also to the surface water, the deep water is characterized by a significant Ba-d enrichment. Depletion of Bad in the surface layer is associated with well-known biogeochemical processes, but we speculate that also sea-ice formation leads to the extraction of Ba from solution via barite (BaSO4) precipitation. The particulate... |
| Tipo: Text |
Palavras-chave: Barium Silicate Geochemical cycle Southern Ocean; Weddell Sea. |
| Ano: 2010 |
URL: https://archimer.ifremer.fr/doc/00460/57178/59134.pdf |
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| Bown, J.; Boye, M.; Laan, P.; Bowie, A. R.; Park, Y. -h.; Jeandel, C.; Nelson, D. M.. |
| Processes of cobalt (Co) entrainment from shelf sediments over the Kerguelen Plateau were studied during the KEOPS (Kerguelen Ocean Plateau compared Study) in order to explain the exceptionally high dissolved cobalt concentrations that have been measured in the surface waters above the Kerguelen Plateau, and in intermediate and deep waters above its eastern slope. Lateral advection and dissolution of Co contained in basalt sediments around Heard Island, a main source of lithogenic Co in the study area, were shown to imprint the process of surface enrichment over the plateau. Dissolved Co enrichment was strongest at the intercept of the eastern slope with intermediate and deep waters, probably due to more efficient mobilisation of the sediments in the slope... |
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| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00139/25058/23163.pdf |
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| Venchiarutti, C.; Roy-barman, M.; Freydier, R.; Van Beek, P.; Souhaut, M.; Jeandel, C.. |
| Dissolved and particulate excess (230)Th and (231)Pa concentrations (noted (230)Th(xs) and (231)Pa(xs) respectively) and (231)Pa(xs)/(230)Th(xs) activity ratios were investigated on and out of the Kerguelen plateau (Southern Ocean) in the framework of the Kerguelen Ocean and Plateau compared Study project in order to better understand the influence of particle flux and particle chemistry and advection on the scavenging of (231)Pa. In the wake of Kerguelen, particulate (231)Pa(xs) is relatively abundant compared to its content in the dissolved phase. This, together with the low fractionation observed between (230)Th and (231)Pa (F(Th/Pa) ranging from 0.06 +/- 0.01 to 1.6 +/- 0.2) reflects the domination of the biogenic silica in the particle pool. Along the... |
| Tipo: Text |
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| Ano: 2011 |
URL: https://archimer.ifremer.fr/doc/00228/33894/32272.pdf |
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| Lacan, F.; Radic, A.; Jeandel, C.; Poitrasson, F.; Sarthou, Geraldine; Pradoux, C.; Freydier, R.. |
| This work demonstrates for the first time the feasibility of the measurement of the isotopic composition of dissolved iron in seawater for a typical open ocean Fe concentration range (0.1-1 nM). It also presents the first data of this kind. Iron is preconcentrated using a Nitriloacetic Acid Superflow resin and purified using an AG1x4 anion exchange resin. The isotopic ratios are measured with a MC-ICPMS Neptune, coupled with a desolvator (Aridus II), using a Fe-57-Fe-58 double spike mass bias correction. Measurement precision (0.13%, 2SD) allows resolving small iron isotopic composition variations within the water column, in the Atlantic sector of the Southern Ocean (from delta Fe-57 = -0.19 to +0.32 parts per thousand). Isotopically light iron found in... |
| Tipo: Text |
Palavras-chave: MC ICP MS; Chelating resin; Southern ocean; Fractionation; Seawater; Earth; Separation; Accuracy; Pacific; FE(III). |
| Ano: 2008 |
URL: https://archimer.ifremer.fr/doc/00202/31374/29781.pdf |
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| Jeandel, C.; Ruiz-Pino, E.; Gjata, E.; Poisson, A.; Brunet, C.; Charriaud, E.; Dehairs, F.A.; Delille, D.; Fiala, M.; Fravalo, C.; Miquel, J.C.; Park, Y.-H.; Pondaven, P.; Quéguiner, B.; Razouls, S.; Shauer, B.; Tréguer, P.. |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1998 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=10249 |
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| Monnin, C.; Jeandel, C.; Cattaldo, T.; Dehairs, F.A.. |
| This paper addresses the question of the eventual control of barium concentration in seawater by an equilibrium with barite. For this, we have used a new thermodynamic model to compute the barite saturation index of ocean waters, mainly from GEOSECS data. Our results show that equilibrium between barite and seawater is reached in a number of places: cold surface waters of the Southern Ocean, waters at intermediate depths (2000-3500 m) in the Pacific, deep waters (2000-3500 m) of the Gulf of Bengal. The only samples for which a slight barite supersaturation is found are the surface waters at GEOSECS station G89 in the Weddell Gyre. Besides these locations, the rest of the world's oceans is undersaturated, as was established by Church and Wolgemuth [Church,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Aqueous solutions; Oceanography; Oceans; Saturation; Thermodynamics. |
| Ano: 1999 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=10260 |
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