Quantifying the contribution of nonlinear interactions to storm tide simulations during a super typhoon event

Abstract

Wind field data from the National Centers for Environmental Prediction Climate Forecast System Version 2 (CFSV2), the European Centre for Medium-Range Weather Forecasts ERA-Interim and ERA5 and the ERA5 blended into the parametric typhoon model (ERA5H) from September 1 to 30, 2016, were adopted to drive a fully coupled circulation-wave model. The best performance of the maximum storm tide and significant wave height (SWH) and mean wave period simulation for typhoon events was found by applying the ERA5H. The contributions of nonlinear interactions to the storm tide induced by Super Typhoon Meranti in 2016 were quantified using seven scenario simulations. The results indicated that the wave setup had the most significant nonlinear interaction with the storm tide, which was up to 0.97 m both with and without tidal effects. The wave-tide interaction was relatively minor for the total water level and contributed only ± 0.1 m to the storm tide. Significant differences in the tide-surge interactions were detected with and without wave effects, as these interactions provided approximately 0.06–0.08 m and ± 0.02 m of the storm tide, respectively. The spatial distributions of the maximum SWH for typhoon events were similar when coupled and decoupled models were employed. In this paper, it is concluded that storm surge miscalculation can be avoided if wave setups are included when predicting typhoon-generated storm tides.