transport advectif, bilans, golfe du Lion, matière particulaire, carbone organique
Nine hydrographic cruises were performed on the Gulf of Lion continental margin between June 1993 and July 1996. These observations are analysed to quantify the fluxes of particulate matter and organic carbon transported along the slope by the Northern Current and to characterise their seasonal variability. Concentration of particulate matter and organic carbon are derived from light-transmission data and water sample analyses. The circulation is estimated from the geostrophic current field. The uncertainty on the transport estimate, related to the error on the prediction of particle concentrations from light-transmission data and the error on velocities, is assessed. The particulate matter inflow entering the Gulf of Lion off Marseille is comparable to the Rhone River input and varies seasonally with a maximum transport between autumn and spring. These modifications result from variations of the water flux rather than Variations of the particulate matter concentration. Residual transports of particulate matter and organic carbon across the entire Gulf of Lion are calculated for two cruises enclosing the domain that were performed in February 1995 and July 1996. The particulate matter budgets indicate a larger export from the shelf to deep ocean in February 1995 (110 +/- 20 kg s(-1)) than in July 1996 (25 +/- 18 kg s(-1)). Likewise, the mean particulate organic carbon export is 12.8 +/- 0.5 kg s(-1) in February 1995 and 0.8 +/- 0.2 kg s(-1) in July 1996. This winter increase is due to larger allochthonous and autochthonous inputs and also to enhanced shelf-slope exchange processes, in particular the cascading of cold water from the shelf. The export of particulate matter by the horizontal currents is moreover two orders of magnitude larger than the vertical particulate fluxes measured at the same time with sediment traps on the continental slope. (C) 2001 Ifremer/CNRS/IRD/Editions scientifiques et medicales Elsevier SAS.
Keyword(s)
advective transport, budget, Gulf of Lion, organic carbon, particulate matter
Lapouyade Agnes, Durrieu de Madron Xavier (2001). Seasonal variability of the advective transport of particulate matter and organic carbon in the Gulf of Lion (NW Mediterranean). Oceanologica Acta. 24 (3). 295-312. https://doi.org/10.1016/S0399-1784(01)01148-3, https://archimer.ifremer.fr/doc/00322/43357/
Lapouyade, Agnès, Durrieu de Madron, Xavier (2001). Current meter time series of HFF-Pieges2-M8 at 275 m depth. PANGAEA. https://doi.org/10.1594/PANGAEA.80065
Lapouyade, Agnès, Durrieu de Madron, Xavier (2001). Current meter time series of HFF-M-PC at 465 m depth. PANGAEA. https://doi.org/10.1594/PANGAEA.80053
Lapouyade, Agnès, Durrieu de Madron, Xavier (2001). Physical oceanography during EUROPE cruise SuiviLion_9. PANGAEA. https://doi.org/10.1594/PANGAEA.802644