A Numerical Simulation of Extratropical Storm Surge and Hydrodynamic Response in the Bohai Sea

A hindcast of typical extratropical storm surge occurring in the Bohai Sea in October 2003 isperformed using a three-dimensional (3D) Finite Volume Coastal Ocean Model (FVCOM). The storm surgemodel is forced by 10 m winds obtained from the Weather Research Forecasting (WRF) model simulation. Itis shown that the simulated storm surge and tides agree well with the observations. The nonlinear interactionbetween the surge and astronomical tides, the spatial distribution of the maximum surge level, and thehydrodynamic response to the storm surge are studied. The storm surge is the interaction of the surge and theastronomical tides. The currents change rapidly during the storm surge and turn to be the unidirectional atsome places where the tidal currents are usually rectilinear. The results show that the local surge currentvelocity in each depth, with a magnitude of the same order as the astronomic tidal currents, increases ordecreases rapidly depending on the relationship between the winds and current directions. Furthermore, thecurrent pattern gets more complicated under the influence of the direction of the winds, which might affectsand movement in the coastal water of the Bohai Sea