The impact of 1D and 3D ocean model to tropical cyclone forecasts with the HWRF-HYCOM coupled model

Accurate tropical cyclone (TC) intensity forecasts require correct representation of SST cooling effects induced by TC wind stress within a numerical model. This study investigates the relative contribution of shear-induced mixing and upwelling to SST cooling and hurricane intensity forecasts, using a fully coupled Hurricane Weather Research Forecast (HWRF) and HYbrid Coordinate Ocean Model (HYCOM) system. The impact of 1D and 3D ocean models on coupled hurricane forecasts is examined in an idealized framework. The 1D HYCOM underestimates SST cooling due to the lack of Ekman pumping and the related ocean upwelling, leading to stronger storms prediction compared to the 3D ocean model. The comparison is also conducted with different storm sizes, environmental conditions, and ocean temperature/salinity profiles to explore the impact under various TC and ocean scenarios. This study also extends the comparison to a real case (Hurricane Edouard 2014) to evaluate the performance of 1D and 3D ocean models for TC intensity forecasts.