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

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 degrees x0.125 degrees 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.