Abstract :
The Mediterranean Sea is one of the most oligotrophic regions of the oceans, and nu-trients have been shown to limit both phytoplankton and bacterial activities. This has di-rect implications on the stock of dissolved organic carbon (DOC), whose high variabilityhas already been well-documented even if measurements are still sparse and are as-5sociated with important uncertainties. We here propose a Mediterranean Basin-scaleview of the export of organic carbon, under its dissolved and particulate forms. Forthis purpose, we have used a coupled model combining a mechanistic biogeochemicalmodel (Eco3M-MED) and a high-resolution (eddy-resolving) hydrodynamic simulation(NEMO-MED12). This is the first Basin-scale application of the biogeochemical model10Eco3M-MED and is shown to reproduce the main spatial and seasonal biogeochemicalcharacteristics of the Mediterranean Sea. Model estimations of carbon export are of thesame order of magnitude as estimations from in situ observations, and their respec-tive spatial patterns are consistent with each other. As for surface chlorophyll, nutrientconcentrations, and productivity, strong dierences between the Western and Eastern15Basins are evidenced by the model for organic carbon export, with only 39 % of organiccarbon (particulate and dissolved) export taking place in the Western Basin. The majorresult is that except for the Alboran Sea, dissolved organic carbon (DOC) contributionto organic carbon export is higher than that of particulate (POC) in the whole Basin,especially in the Eastern Basin. This paper also investigates the seasonality of DOC20and POC exports as well as the dierences in the processes involved in DOC and POCexports.