Effects of advection, mixing and sinking on spatial and temporal evolution of biochemical parameters in the Mediterranean Sea

In the Mediterranean Sea, average fluxes of matter have opposite directions in the upper ocean, one being eastward oriented ant the intermediate one, controlled by LIW, westward. As a consequence fluxes caused by advection, mixing and sinking velocity of particulate matter, strongly affect horizontal spatial distribution and play a major role in giving rise trophic gradient. In this communication, we investigate the effect of sinking velocity on spatial and temporal evolution of biological parameters. Also the influences of advection and mixing are analyzed. Numerical results are obtained with a three-dimensional hydrodynamical ecological model, using a lumped variable description of the first trophic level, while the transport processes are accounted for by a MOM-like structure. They indicate that the sinking term originates a west-east gradient on biological parameters, while large gyres determine the prevailing trophic regime in the open ocean and upwellings/downwellings are most effective along the coastal areas.