Effects of tidal currents on winter wind waves in the Qiongzhou Strait: a numerical study

Abstract

Effects of currents on winter wind waves in the tide-dominated Qiongzhou Strait (QS) were numerically evaluated via employing the coupled ocean-atmosphere-wave-sediment transport (COAWST) modeling system. Validations showed satisfactory model performance in simulating the intense tidal currents in the QS. Different effects of sea level variations and tidal currents on waves were examined under the maximum eastward (METC) and westward (MWTC) tidal currents. In the east entrance area of the QS, the positive sea levels under the MWTC deepened the water depth felt by waves, benefiting the further propagation of wave energy into the inner strait and causing increased wave height. The METC and the MWTC could both enhance the wave height in the east entrance area of the QS, mainly through current-induced convergence and wavenumber shift, respectively. By current-induced refraction, the METC (MWTC) triggered counterclockwise (clockwise) rotation in peak wave directions in the northern part of the QS while clockwise (counterclockwise) rotation in the southern part.