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| Lacan, F; Jeandel, C. |
| The formation of Subpolar Mode Water (SPMW) is documented by combining neodymium isotopic composition (Nd IC) as a conservative tracer with salinity, temperature and O-2 concentration. Nd IC reveals a more pronounced eastward extension of the Labrador Current, particularly its Subarctic Intermediate Water component, than the other parameters. Nd IC also suggests that waters flowing through the Denmark Strait do not significantly contribute to the SPMW formation. A two end-member mixing, involving Subarctic Intermediate Water ( and maybe ultimately Labrador Current Water) and North Atlantic Central Water, is proposed to explain SPMW formation. These results provide important insight into the processes controlling the Nd IC in the North Atlantic Subpolar... |
| Tipo: Text |
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| Ano: 2004 |
URL: https://archimer.ifremer.fr/doc/00228/33928/32309.pdf |
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| Razouls, S; Du Reau, G; Guillot, P; Maison, J; Jeandel, C. |
| A long-term survey of the monthly variations of the copepod assemblages was carried out off Kerguelen Island (Kerfix Station) from February 1992 through to January 1995. Copepods were clearly dominant in the mesozooplankton (>90% of the total), with population abundances ranging from <100 individuals m(-3) in winter to 700 individuals m(-3) in summer. Calanus simillimus, Rhincalanus gigas, Metridia lucens, Oithona frigida, Oithona similis and Calanoides acutus were the most abundant species. From mid-1993, incubation experiments were performed with copepods in order to estimate the grazing pressure on the phytoplankton standing stock. In addition, estimations of their metabolic cost (oxygen comsumption) were also made. All experimental measurements... |
| Tipo: Text |
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| Ano: 1998 |
URL: https://archimer.ifremer.fr/doc/00300/41133/40309.pdf |
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| Arraes-mescoff, R; Roy-barman, M; Coppola, L; Souhaut, M; Tachikawa, K; Jeandel, C; Sempere, R; Yoro, C. |
| m) concentrations of Al, Sr, Ba, Mn, Rare Earth Elements (REE) and Th isotopes were determined over time. We obtain percentages of dissolution in agreement with the general knowledge about the solubility of these tracers: Th approximate to Al < Heavy REE < Light REE < Mn < Ba < Sr. For Mn and Ce, precipitation/adsorption occurs at the end of the experiment probably due to their oxidation as insoluble oxides. Particulate residence time of the tracers ranged from less than 1 day to 10-14 days. During the experiment, biological activity has a control on the dissolution process through the remineralization of particulate organic carbon, In the 30 m experiment, the observed dissolution of aragonite indicates that the pH of the incubation solution... |
| Tipo: Text |
Palavras-chave: Marine particles; Dissolution; Trace elements; Thorium isotopes; Western Mediterranean Sea. |
| Ano: 2001 |
URL: https://archimer.ifremer.fr/doc/00300/41128/40316.pdf |
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| Guieu, C; Roy-barman, M; Leblond, N; Jeandel, C; Souhaut, M; Le Cann, Bernard; Dufour, A; Bournot, C. |
| In the framework of the Programme Ocean Multidisciplinaire Meso Echelle (POMME) experiment, a 1.5 year record (February 2001-June 2002) of downward particle flux at 400 m and 1000 m was measured by sediment traps at four moorings located in the northeast Atlantic between 39 degrees-43 degrees N and 17 degrees-19 degrees W. Thorium-230 was used to estimate sediment trap efficiency, revealing values ranging from 18.5 to 55%. The lowest trapping efficiency was observed for the trap having experienced the highest currents. Significant interannual variability between 2001 and 2002 was clearly linked to the differences observed in the mixed layer depth. At some sites, particulate organic carbon (POC) export was higher (up to a factor of 1.6) during summer than... |
| Tipo: Text |
Palavras-chave: Sediment traps; Carbon export; Biogenic and lithogenic tracers; Mesoscale circulation; Thorium isotopes. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/00000/10982/7422.pdf |
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