Analysis of the typhoon wave distribution simulated in WAVEWATCH-Ⅲ model in the context of Kuroshio and wind-induced current

摘要

To investigate the relationship between surface currents and wave distributions in typhoons,we took the Typhoon Talim in 2017 as a case,and found that the track of the typhoon winds up to 50 m/s was almost consistent with the Kuroshio track,particularly from September 13 to 16,2017.The surface current data,derived from the NCEP Climate Forecast System Version 2(CFSv2)from the National Center of Atmospheric Research(NCAR),revealed that the speed of the wind-induced current exceeded that of the Kuroshio in the region with the maximum wind speed.In this study,was utilized a third-generation numeric wave model,WAVEWATCH-Ⅲ(the latest version 5.16),developed by the National Oceanic and Atmospheric Administration(NOAA),to simulate the wave fields of Typhoon Talim using the European Centre for Medium-Range Weather Forecasts(ECMWF)reanalysis wind data in 0.125°×0.125°grid as the forcing field.We found that the root-mean-square error(RMSE)of the significant wave height(SWH)was 0.34 m when validated against measurements from altimeter Jason-2.In addition,we discovered that the SWH had a similar tendency to the change in the surface current speed that was approximately 0.5 m/s at the beginning of Typhoon Talim.However,the relationship became weak as the surface current speed was below 0.2 m/s.Our findings show that the distribution of typhoon waves is resulted from the interaction of surface current and the wind-sea portion of the wave system,since the distribution pattern of wind-sea is consistent with the surface current,and there is a weak relationship between surface current and swell.