Numerical investigation of Typhoon Kai-tak (1213) using a mesoscale coupled WRF-ROMS model

Abstract

The Typhoon Kai-tak that occurred in August 2012 produced strong winds, heavy rain, extreme wave, and storm surge, which also had a significant impact on the coastal areas of China and Vietnam. Studying the formation and tracking the movement mechanism of this typhoon will help reduce future coastal disasters, as well as have important scientific significance. The impact of a typhoon creates strong mass transport and energy exchange between the atmosphere and the ocean which produces a strong interaction between the wind field and the flow field. A coupled atmosphere-ocean model in the South China Sea was established based on the mesoscale atmospheric model WRF and the regional ocean model ROMS. Typhoon Kai-tak was simulated using this model. The simulation results show that the coupled WRF-ROMS model indicate high simulation accuracy with respect of storm surge in the South China Sea under the influence of Typhoon Kai-tak. The simulation results also reveal the temporal and spatial distribution of Typhoon Kai-tak's field, storm surge, and wind-induced flow fields. The spatial asymmetry and time lag in the spatial–temporal distribution of sea surface temperature during Typhoon Kai-tak have been discussed. The heat exchange at the air-sea interface was very strong under the influence of Typhoon Kai-tak, and the latent heat generated by water vapor evaporation plays a dominant role in the heat exchange at the air-sea interface, which shows that the heat carried by the vaporization of the sea surface is one of the important factors for the decrease of sea temperature under the influence of a typhoon.