Abstract
Studying the sea–air interaction between the upper ocean and typhoons is crucial to improve our understanding of heat and momentum exchange between the atmosphere and the ocean. There is a strong heat flux exchange between the atmosphere and the ocean during the impact of a typhoon, and the physical fields, such as the wind field, wave field, flow field, and SST field, also interact with each other. A fully coupled Atmosphere–Wave–Ocean model in the South China Sea was established by the mesoscale atmospheric model WRF, wave model SWAN, and the regional ocean model ROMS based on the COAWST model system. Typhoon Kai-tak was simulated using this fully coupled model and some other coupled schemes. In this paper, the variation of sea surface temperature (SST) and ocean subsurface temperature caused by Typhoon Kai-tak is analyzed by the fully coupled model, and the basic characteristics of the response of the upper ocean to the typhoon are given. The simulation results demonstrate that the fully coupled WRF-SWAN-ROMS model shows that the typhoon passes through the sea with obvious cooling. In the cold eddy region, the sea surface temperature cools 4 to 5 °C, and the cooling zone is concentrated on the right side of the track. The change of sea surface temperature lags more than 12 h behind the change of sea surface height. The decrease of SST on the left side of the track was relatively small: ranging from 1.5 to 2.5 °C. The disturbance of typhoon causes the subsurface water to surge to the surface, changes the temperature distribution of the surface, and causes the mixing layer to deepen about 40 m to 60 m. The simulation results reveal the temporal and spatial distribution of sea temperature and mixed layer depth. The sea surface temperature field has an asymmetrical distribution in space and has a lag in time. The heat exchange at the air–sea interface is very strong under the influence of the typhoon. The heat exchange between the air and sea is divided into latent heat and sensible heat, 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 the typhoon.
Highlights
Tropical cyclones are some of the most destructive natural disasters, which often bring huge losses to people’s life and property
The fully coupled Atmosphere–Wave–Ocean model of the South China Sea was established based on the WRF-SWAN-ROMS model and the model coupling toolkit (MCT) coupler in this study
South China Sea was similar to that under the influence of the astronomical tide. It can be seen from the figure that at 2012-08-17 00:00:00 UTC, the mixed layer depth under the influence of storm surge caused by Typhoon Kai-tak based on the Exp-CWR and Exp-CWSR schemes is significantly greater than the mixed layer depth under the influence of the astronomical tide
Summary
Tropical cyclones are some of the most destructive natural disasters, which often bring huge losses to people’s life and property. There is a strong mass transport, energy exchange, and interaction between the atmosphere and the ocean during a typhoon process [25,26] The physical fields such as the wind field, flow field, and wave field influence each other and restrict each other. The forcing effect of the atmosphere on the ocean mainly includes wind stress, pressure, heat flux, and solar radiation on the sea surface. The typhoon wind and pressure field, typhoon waves and storm surge under the influence of actual Typhoon Kai-tak were simulated based on this coupled model and some other coupled schemes. The characteristics of atmospheric, wave, and oceanic results in the South China Sea under the influence of typhoon were calculated. The response of the upper ocean during the Typhoon Kai-tak is studied to reveal the characteristics of SST, SSA, and subsurface temperature changes
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
