Simulating tropical cyclone waves in the East China Sea with an event-based, parametric-adjusted model

Abstract

Parametric cyclone wind models with storm characteristics derived from statistical representation do not agreeably delineate the wind field in the East China Sea, leading to uncertain errors in the numerical simulations of Typhoon waves. A new approach to adjust the cyclone wind field in the framework of the Holland model is proposed. The radius of maximum wind speed and the logarithmically varied shape parameter B from the Holland model are iterated out with in situ data and extended to the cyclone track in the East China Sea. This event-based Holland parametric assimilation scheme can model different kinds of unimodal wind profiles and deliver a significant improvement over the original Holland model. The simulated wind fields of three typhoon events, Typhoons Saomai (200608), Fitow (201312) and Maria (201808), are then used to drive the Simulating Waves Nearshore (SWAN) wave model, and wave fields during the three typhoon events show better agreement with the in situ observations. Compared with satellite scatterometer and altimeter products, the effectiveness of modelled typhoon events is largely limited by temporal changes of typhoon structure. This approach is recommended for typhoon events with small temporal changes. Overall, the approach to adjusting wind profiles with observations satisfactorily improves the simulation performances of cyclonic winds and wave heights at a low computation cost.