Numerical Simulation Of Wind Waves And Typhoon Air-sea Interaction Process

Activity at the sea-air interface is an important factor affecting the earth's space environment.Wind waves,especially typhoon waves,play a central role in air-sea transfer processes.This paper uses SWAN model to simulate the arise,growth and decay of wind waves in the Taiwan Strait,China's offshore area and the area where the typhoon passed,shows the transfer of momentum and distribution of energy in detail in the process of air-sea interaction.The simulated results are compared with the ERA-Interim reanalysis data provided by ECMWF(European Centre for Medium-Range Weather Forecasts).A numerical simulation of the waves in the China' offshore area during the northeast monsoon period is carried out in this paper,and the numerical simulation results of the SWAN model and the ERA-Interim are compared with the measured data of the buoy respectively.The results show that at the buoy point,the correlation coefficients between the SWAN simulation results and the ERA-Interim reanalysis data and the buoy results are 0.98 and 0.93,respectively,the deviations of the means of the significant wave height between them are 0.25 m and 0.67 m,respectively,and the average significant wave height of the ERA-Interim data is about 51% of the buoy data and 70% of the SWAN results.The monthly average value of the spatial anomaly correlation coefficient(ACC)between the SWAN simulation results of the significant wave height in the Taiwan Strait region and the ERA-Interim reanalysis data is greater than 0.5.The peak frequency of the wave spectrum under strong and weak sea conditions is below 0.2 Hz.The results show that the significant wave height simulated by SWAN is generally greater than the result of ERA-Interim reanalysis data.The direction of the wave is about 10°off the wind direction.The topography of Taiwan Island and Penghu Islands has a great influence on the spatial distribution of waves.During the typhoon,the center of the maximum significant wave height and the center of the wave field vortex are located on the right and left of the typhoon's moving path.The Taiwan Island has a weakening effect on the intensity of the typhoon after entering the Taiwan Strait.The sea wave data obtained in this paper under strong and weak sea conditions in the China's offshore area provides effective large-area wind wave field comparison data for HF radar,and provides data support for in-depth study of the air-sea interaction process.