Numerical Simulation Analysis of Typhoon Moving Track on Sea Surface Cooling

Typhoons are mainly generated in the tropical ocean where the temperature is higher than 26°C. When typhoons move on the ocean, they will cause obvious sea surface cooling (SSC) along their track. The translation speed and moving direction of typhoons are two important components of the typhoons track, and they are also important factors affecting SSC. SSC reduces the heat flux from ocean to typhoons, and thus weakens the intensity of typhoons. Because the air-sea heat exchange mainly occurs in the inner-core region of typhoons, the SSC in the inner-core plays a crucial role in weakening the intensity of typhoons. Based on the numerical experiments, this study analysed the distribution of SSC caused by typhoons under different moving tracks. The results show that under the same ocean environment, typhoon intensity and translation speed, the inner-core SSC caused by sharp-right-turning typhoons is significantly stronger than that caused by the straight-moving typhoons (about 1.34 times) and sharp-left-turning typhoons (about 1.45 times). Without considering the air-sea heat flux, the contribution of vertical mixing to inner-core SSC is about 93.1% and that of advection is about 6.9% when typhoon is moving straight, and the contribution of advection is increasing with the increase of typhoon right turning angle.