Direct Assimilation of FY-3E Microwave Sounding Channel Data in a Regional Model to Improve Typhoon Forecasts

FengYun-3E (FY-3E), the fifth satellite in China's second-generation polar-orbiting satellite FY-3 series, was launched on 5 July 2021. FY-3E carries a third-generation microwave temperature sounder (MWTS-3) and a second-generation microwave humidity Sounder (MWHS-2). In this study, the influence of assimilating FY-3E MWTS-3 and MWHS-2 clear-sky radiance data on tropical cyclone forecasts in a regional model is investigated through a series of data assimilation experiments. More than five typhoons from the northwest Pacific Ocean during 2024 typhoon season are selected for the numerical experiments of assimilation and forecasts, and the assimilation effects of FY-3E MWTS-3 and MWTS-2 are carefully evaluated. The results show that assimilation of MWTS-3 and MWTS-2 has positive impact on typhoon track forecasts, especially for forecasts beyond 12 hours, in terms of intensity forecasts, the impact of the data is neutral or slightly positive.