[A-AS04] Advances in Tropical Cyclone Research: Past, Present, and Future

[AAS04-P11] A New Realistic Model of Generating Pressure and Wind Fields of Typhoon for Storm Surge Forecasting

*Satriana Roguna¹, Tso-Ren Wu¹, Chun-Wei Lin¹ (1.Graduate Institute of Hydrological and Oceanic Sciences, National Central University, Taiwan )

Keywords:COMCOT Storm Surge Model, pressure, realistic, storm surge, wind speed

In conventional Holland-type models, a typhoon or hurricane is modeled as a symmetric or quasi-symmetric vortex. These symmetric assumptions fit the observation well in deep-ocean areas or areas with flat topography. A tall mountain, however, will cause these models to produce significant errors. In this paper, we aim to create a new weather model for storm surge calculation while only the track and intensity are known for a tropical cyclone, and this model shall be able to present the terrain blockage effect. Because the wind velocity is much faster than the moving speed of the typhoon, the flow field soon transfers from a transition stage into a quasi-steady state. As a result, the weather field is primarily controlled by storm intensity and topography and has less effect from the storm trajectory. This paper presents a new statistical method for generating a realistic weather field based on the location and intensity of the typhoon. We adopted the ERA-5 reanalysis data from the European Centre for Medium-Range Weather Forecasts (ECMWF) with total of 3200 data from 1981 to 2021. ERA-5 reanalysis data were validated against ground observation from Central Weather Bureau (CWB) in Taiwan, including pressure and wind speed gauge data. The storm surge was simulated using the COMCOT-SS model. The results were compared with the tidal gauge data from CWB as well. Excellent comparison results can be seen. After the validation, the ERA-5 data were used as the database to generate the weather field by providing the location and intensity of the typhoon.