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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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Durrieu De Madron, X; Denis, L; Diaz, F; Garcia, N; Guieu, C; Grenz, C; Loye-pilot, Md; Ludwig, W; Moutin, T; Raimbault, P; Ridame, C. |
Shelf-slope exchanges and budgets of organic and inorganic nutrients are calculated for the Gulf of Lion continental margin in the northwestern Mediterranean. Computations are based on data from three seasonal marine surveys performed in March 1998, June 1998 and January 1999 in the framework of the French Programme National d'Environnement Cotier. A Land-Ocean Interactions in the Coastal Zone type box model is used to calculate the advective exchanges between the shelf and the adjacent open sea and to estimate the budgets of non-conservative elements (DIP, DIN, DOP, DON, DOC, POC, PON, POP). These budgets consider river discharges, urban sewage supply, atmospheric deposition, and fluxes at the water-sediment and shelf-slope interfaces. Uncertainties on... |
Tipo: Text |
Palavras-chave: Mer Méditerranée; Echanges côte-large; Fonctionnement de l’écosystème; Cycle du carbone; Bilan de sels nutritifs; Mediterranean Sea; Shelf-slope exchanges; Ecosystem functioning; Carbon cycle; Nutrients budget. |
Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/00301/41236/40426.pdf |
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Ridame, C; Moutin, T; Guieu, C. |
A Saharan soil, considered as a proxy for Saharan aerosols, was used to perform radio-labelled phosphate adsorption experiments using (33)PO(4)(3-): leached particles were exposed to poisoned western Mediterranean seawater for varying lengths of time. The measured adsorption capacity of Saharan dust for phosphate was 0.13 mumol g(-1). Considering this value and an annual Saharan dust deposition of 12.5 t km(-2) year(-1), we show that Saharan particles do not represent a significant sink for seawater phosphate in the western Mediterranean Sea. This result is in agreement with that determined from a similar approach conducted in the eastern basin. As a consequence, the unusual NIP ratio measured in the whole Mediterranean Sea (up to 29) cannot be explained... |
Tipo: Text |
Palavras-chave: Poussières sahariennes; Adsorption; Phosphate; Rapport N/P; Méditerranée; Saharan dust; Adsorption; Phosphate; N/P ratio; Mediterranean Sea. |
Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/00321/43254/42985.pdf |
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