Examining the Influence of Wind and Wind Wave Turbulence on Tidal Currents, Using a Three-Dimensional Hydrodynamic Model Including Wave–Current Interaction

Abstract

This paper presents a very brief overview of the development of a three-dimensional hydrodynamic model involving a flow-dependent eddy viscosity and including enhancements of bottom friction due to wave-current interaction in shallow water. The main point of the paper is to examine the physical nature of the process. Consequently, references to published work are given for the background detail. Calculations using both tidal and wind forcing show that tidal elevation amplitude and phase are significantly changed in shallow near-coastal regions due to enhanced frictional effects associated with wind-driven flow and wind wave turbulence. An analysis of tidal current profiles, at the fundamental harmonic and higher harmonies, computed with tidal and wind forcing, shows that significant changes in tidal current profiles can occur due to coupling between the wind-induced current shear and a time-evolving viscosity. The importance of the nonlinearity produced by a surface wind-induced shear and a flow-dependent viscosity in influencing tidal current profiles is confirmed using a single point model in the vertical.