Internal Wave Activity in Rotterdam Waterway

Abstract

A variety of internal wave mechanisms is observed in the partially mixed Rotterdam Waterway estuary due to the interaction between stratified tidal flow and topography. The topographically generated waves include lee waves, resonant trapped waves and critical layers, freely propagating waves, breaking internal hydraulic jumps at the banks, and rotor formation. Acoustic images and profiles of density and velocity are presented. The acoustic images are explained on the basis of basic internal wave theory. Mathematical models tend to ignore smallscale internal wave activity as a source of turbulent kinetic energy. The paper investigates whether it is justified to do so on the scale of the topography. On the basis of an estimate of the internal wave‐induced production of turbulent kinetic energy it is concluded that for the observed internal waves this source of energy may not always be neglected when compared with the production by the background flow, in particular when first‐mode short internal waves are i...