Numerical study on the tidal front in the Western Yellow Sea

Abstract

The formation and evolution of the tidal front in the western Yellow Sea are studied by means of a two-dimensional model in which wind and tide mixing, sun radiation and wind stress, and realistic topography are incorporated. In this numerical study, the schemes employed are stable for time step Δt=900 s, so the model can be run for 4 months to simulate the front evolution. The authors examined the effects of mixing and atmospheric focing on the tidal front under conditions of: mixing and solar heating without wind stress on the sea surface; mixing, solar heating and 50 hours of wind stress; mixing, solar heating and long time periodical wind stress. Results show that (1) the tidal front forms at the beginning of May, and strengthens with the increasing of heat input, (2) the temperature structure in the shallow well-mixed water is dominated by mixing, while in the front and deeper stratified regions, it is controlled by the joint effects of (mainly) mixing and advection, (3) the currents and front all respond to the variation of wind stress on the sea surface with a time lag of 7 and 30 hours respectively, (4) the front strength and position can be affected by the Ekman transport.