NUMERICAL SIMULATION OF TYPHOON KROVANH AND TYPHOON-INDUCED OCEAN WAVES

The mesoscale meteorological model MM5 developed by NCAR/PSU and the third generation wind wave model WAVEWATCH III(WW3) were used to simulate Typhoon Krovanh(0312) and typhoon-induced waves.Using the initial condition improved by the three dimensional data assimilation system,MM5 had well simulated the land processes,intensity and moving track of Krovanh.Then,driven by 10-meter wind field output from MM5,the wave model WW3 reproduced the wave center well,but the intensity was 23%～33% lower than the observation by TOPEX/Poseidon(T/P).For typhoon landing,the intensity and spatial characteristics of storm surge were well simulated.Analyses of simulated winds and waves showed that the distribution of typhoon waves were so closely related with the location and intensity of the eye that when the maximum wind speed region was in the right part of the typhoon,the center of significant wave height would be in the downwind direction of the typhoon.In the terms of time series,in the deep water the significant wave height had a good lag correlation with the maximum sea surface wind speed,with the biggest correlation coefficient being at 4 hours lag.While in the shallow water,although the wind speed changed little,the significant wave height increased very effectively as the water depth decreased,and the significant wave height decreased substantially when typhoons landed,which was consistent with the previous results.