A meso-scale model of the central and southern North Sea: Consequences of an improved resolution

The additional eddy kinetic energy of the residual flow (defined here as the kinetic energy contained in the spatial scales between 3 and 20 km) in general is around two orders of magnitude smaller than the mean kinetic energy. However, there are several areas where the eddy kinetic energy reaches the same order of magnitude as the mean kinetic energy, for instance in the Southern Bight. From the fact that largest eddy kinetic energy rates occur in areas of strongest gradients of the mean flow it could be deduced that barotropic instabilities play the dominant role. Contrarily, baroclinic instabilities seem to be only of minor importance since areas of strongest density gradients only exhibit very localised maxima.