Typhoon-induced wind waves in the northern East China Sea during two typhoon events: the impact of wind field and wave-current interaction

We examined the influences of the wind field and wave-current interaction (WCI) on the numerical simulation results of typhoon-induced wind waves in the northern East China Sea (NECS) using the coupled Simulating Waves Nearshore+Advanced Circulation (SWAN+ADCIRC) model. The simulations were performed during two typhoon events (Lekima and Muifa), and two widely used reanalysis wind fields, the Climate Forecast System Version 2 (CFSv2) from the National Centers for Environmental Prediction (NCEP) and the fifth-generation European Centre for Medium-Range Weather Forecasts (ECMWF) Reanalysis (ERA5), were compared. The results indicate that the ERA5 and CFSv2 wind fields both reliably reproduced the wind variations measured by in-situ buoys, and the accuracy of the winds from ERA5 were generally better than those from CFSv2 because CFSv2 tended to overestimate the wind speed and the simulated significant wave height (SWH), particularly the peak SWH. The WCI effects between the two wind field simulations were similar; these effects enhanced the SWH throughout the nearshore NECS during both typhoons but suppressed the SWH on the right side of the Typhoon Muifa track in the deep and offshore sea areas. In summary, variations in the water depth and current propagation direction dominate the modulation of wave height.