Influence of ocean-atmosphere interactions on typhoon track and intensity: a case study for typhoon “Hato” (1713)

In general, atmosphere-ocean coupled models have been shown to improve the simulation of typhoon tracks and intensities. However, the mechanisms and quantitative analysis underlying these improvements remain underexplored in the existing literature. This study employed the COAWST (Coupled Ocean-Atmosphere-Wave-Sediment Transport) model, which integrates the Regional Ocean Modeling System (ROMS) and the Weather Research and Forecasting (WRF) model, to simulate Typhoon “Hato” (1713), with results compared to those from the uncoupled WRF model. The effect of coupling on typhoon path simulation was analyzed using the Potential Vorticity Trend (PVT) framework. Additionally, 11 typhoons that made landfall in China between 2011 and 2020 were simulated, and the results were compared with those from the uncoupled WRF model to further examine the influence of ocean-atmosphere coupling on typhoon intensity and path simulation. It is found that coupling enhances track simulation by altering the diabatic heating and residual terms in the PVT framework. However, it had less impact on the horizontal and vertical advection terms. Additionally, coupling results in reduced sea surface temperature (SST) and heat flux to the TC, leading to a weaker intensity simulation. The coupled model demonstrates significant improvements in reducing both track and intensity errors compared to the non-coupled model. Specifically, for every 1 K decrease in SST, the coupled model exhibits a reduction of 0.36 K in SST, a decrease of 207.52 W·m⁻² in heat flux, a decrease of 3.86 m·s⁻¹ in wind speed, and an increase of 6.5 hPa in pressure. These results suggest that atmosphere-ocean coupling can enhance the simulation of tropical cyclone tracks and intensities, providing valuable theoretical insights for disaster prevention and mitigation in coastal regions.