Numerical modelling of biological-physical interactions in coastal marine environment

This study deals with numerical simulations combining both biological and physical models of pelagic system behavior in coastal mediums. The physical field is calculated by solving Navier-Stokes, temperature and salinity equations for the three spatial dimensions, with a two-equation closure model for the turbulence (k-e model). The three-dimensional fields established for speed and diffusion are used as forcing variables of the biological model comprising five compartments: live and dead phytoplankton, inorganic dissolved nitrogen, herbivores and zooplanktonic waste. The results obtained in the mediterranean coastal region of Cannes, which has a very irregular seabed profile, under a wide variety of wind conditions, were compared with in situ measurements of nitrates. Three-dimensional effects appearing on these distributions are explained by the description of the dynamic field.