Derivation and Application of Three-dimensional Horizontal Winds from Geostationary Hyperspectral Infrared Observations

Radiance measurements from a geostationary hyperspectral infrared (IR) sounder with high temporal resolution not only provide a continuous weather cube of atmospheric temperature and moisture information at different pressure levels, but also enable derivation of three‐dimensional (3D) horizontal winds by tracking atmospheric moisture features. Both thermodynamic and dynamic information is critical for monitoring and predicting the evolution of atmospheric mesoscale events. Using targeted observations from the Geosynchronous Interferometric Infrared Sounders (GIIRS) onboard Fengyun-4A (or FengYun-4B) with 15-minute to 30-minute temporal resolution, 3D horizontal winds are derived by tracking moisture features depicted in radiances from different wavelength or moisture profile retrievals at different atmospheric pressure levels. The derived 3D horizontal winds are evaluated against different reference sources including atmospheric reanalysis and radiosonde/dropsonde observations. The 3D horizontal winds are assimilated together with other observations in the China Meteorological Administration Global Forecast System (CMA-GFS) with a 4Dvar approach as well as in the regional numerical weather prediction (NWP) models. Impact studies indicate the added value of 3D horizontal winds from geostationary hyperspectral IR measurements for the NWP based high impact weather forecasts.