The influence of wave-current interaction on sea ice modelling of the Bohai Sea

A sea ice model considering wave-current interaction (WCI) was constructed on the basis of the FVCOM, CICE, and Un-SWAN models for the Bohai Sea. The influence of WCI on sea ice formation and melting in the Bohai Sea during the winter of 2015/2016 was investigated. The results show that the WCI mainly affect the concentration and thickness of sea ice in the Bohai Sea. During the ice melting period, the WCI significantly increased the surface water velocity and sea ice melting rate of the Bohai Sea. The mechanism by which WCI affect the ice melting process is as follows: The non–conservative force(F^w) induced by WCI changes the amplitude and direction of the water velocity. During the ice melting period, the direction of F^w is nearly the same as the direction of the sea surface current in the marginal ice zone of Liaodong Bay, which consequently enhances the surface water current as well as its drag force on the sea ice, such processes accelerate sea ice advection and sea ice melting, and the white-capping breaking term plays a dominant role in the F^w. In the sea ice-covered areas, the presence of sea ice affects the propagation of waves, resulting in different degrees of wave height reduction. When the sea ice concentration is lower, the influence of sea ice on the structure and velocity of the current is more significant. From a thermodynamic perspective, when WCI are considered, the mixed layer depth (MLD) can increase by up to 15 m during the growth period, and the HC of the mixed layer can increase by up to 5000 GJ/m².