The big challenge of the next decade for the oceanic sciences is to adopt a multi-scale approach because of the strong nonlinearity of the oceanic fluid. This can be undertaken only through numerical simulations with ultra-high resolution. Within this context, the purpose of our projects is to fully explore two energetic dynamical oceanic regimes that have a major impact on the general oceanic circulation: the mesoscale eddy regime at mid-latitudes and the equatorial regime. Expected results will help for the configuration of realistic numerical simulations to be performed in 2006 by the OFES group on the Earth Simulator and they should benefit to future climate models. These studies make use of the Primitive Equations model ROMS (Regional Ocean Modelling System).