A Typhoon Wave Field Model Based on 2D Wave-Rays Theory and Its Application

The rapid simulation of typhoon wave field is the core work of wave disaster warning. A fast typhoon wave field prediction model is constructed based on a two-dimensional wave-ray theory. This model is driven by the Holland wind field model, and uses the fourth-order Runge- Kutta method to solve differential equations in a polar coordinate grid, obtaining the spatiotemporal distribution of wave energy, peak wave direction, and peak frequency. Taking Typhoon LINFA (2009) as an example, the spatial structure and evolution process of the typhoon wave field are analyzed in the model. The simulation results show the wave field asymmetry caused by group velocity resonance; This reflects the development of wind waves under typhoons, as well as the propagation of swells. High energy and high group velocity wind waves generated in high wind speed areas of typhoons propagate outward; The formation of swells in the low wind speed area of a typhoon is the main component of the mixed wave field as the dominant wave. Moreover, the model was validated using Jason-1 altimeter data, and the results were in good agreement with the altimeter data, with the correlation coefficient R=0.79. It has been proven that the model can quickly and effectively simulate typhoon wave fields.