This thesis was written in the framework of a realistic modelisation for the study of the Iroise Sea. The first two parts deal with its digital implementation and validation based on observation. We then focus on the analysis of the main structures and physical processes operating in the Iroise Sea: first the Ouessant tidal front and the processes associated with the connexion of surface and bottom mixing layers, then the average eulerian residual circulation for which we tried to quantify the relative part of the different processes involved. We then mapped the different dynamic regimes involved: some cyclostrophic regimes can be observed around the islands and in shallow water areas, and a geostrophic regime clearly appears, at front level, especially in... |