Impacts of Thermodynamic and Dynamic Information From Geostationary Hyperspectral Infrared Sounder on Tropical Cyclone Forecasts

Abstract High temporal and spatial resolution atmospheric thermodynamic and dynamic profiles retrieved from the Fengyun‐4A/Geostationary Interferometric Infrared Sounder (FY‐4A/GIIRS) provide crucial information for monitoring and predicting the rapid evolution of tropical cyclones. This study investigates the impact of assimilating temperature and wind profiles from the GIIRS on typhoon forecasts. The results demonstrate that assimilating thermodynamic and dynamic profiles improves both the model analysis field and the typhoon track forecasts. The increments from wind profile assimilation alone are larger than those from temperature profile assimilation alone near the tropical cyclone. Assimilating wind profiles effectively adjusts the initial wind field structure and corrects the steering flow, significantly improving the accuracy of typhoon track forecasts. In terms of the wind field and precipitation forecasting, assimilating wind profiles, whether combined with temperature profiles or not, positively influence the tropospheric wind field and precipitation forecasts, especially for heavy rainfall. The study further conducted impacts experiments using an operational assimilation configuration in a high‐resolution regional model. Consistent conclusions were obtained for track forecasts. Moreover, for typhoon intensity forecasts, the combined assimilation demonstrated a significant synergistic effect, effectively reducing the forecast error of minimum sea level pressure by more than 50%.