The Influence of Wind on the Surface Layer of a Stratified Inlet: Part II. Analysis

Abstract

Analysis of the wind and current data for Alberni Inlet demonstrates the strongly wind-dependent nature of the surface currents, especially at the diurnal frequency. In contrast, the response of the surface layer thickness is mainly restricted to lower than diurnal frequencies. A linear two-layer model with allowance for friction is used to show that frictional damping can account for the poor coupling at high frequencies. In fact the friction is sufficiently large to cause free modes to be critically damped (i.e., non-oscillatory). The model results compare favorably with the observations, using a frictional coefficient estimated from the decay of the internal tide.