Free surface, current profile and buoyancy effects upon internal wave energy flux profiles in sill regions

Abstract

A non-hydrostatic ocean circulation model is used to determine the distribution of the horizontal energy flux terms due to internal waves in sill regions. Calculations show that although the linear energy flux term is significant, the contribution from the non-linear terms is appreciable. In addition, unlike as is often assumed in deep ocean situations, the free surface contribution to the energy flux distribution often dominates. The magnitude and relative importance of the energy flux terms are influenced by how the fluctuating velocity due to internal waves is computed. In addition changes in vertical stratification affects the relative contribution of the energy flux terms although the free surface term still dominates.