[A-CG36] Satellite Earth Environment Observation

[ACG36-18] Recent progress in impact assessment of hyperspectral sounder for a Himawari follow-on satellite

*Kozo OKAMOTO¹, Hiromi OWADA², Tadashi Fujita¹, Masahiro Hayashi¹, Kotaro Bessho² (1.Meteorological Research Institute, 2.Japan Meteorological Agency)

Keywords:satellite data assimilation, Himawari follow-on program, Hyperspectral infrared sounder, Observing System Simulation Experiment (OSSE)

Potential impacts on numerical weather prediction of a hyperspectral infrared sounder (HSS) on Himawari-8/-9 follow-on geostationary satellite (GeoHSS) have been investigated using an observing system simulation experiment (OSSE) approach. Hypothetical GeoHSS observations were simulated by using the fifth generation of European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis (ERA5) and assimilated in global and regional data assimilation systems of the Japan Meteorological Agency (JMA). The global data assimilation experiments showed that assimilation of hourly clear-sky radiances of GeoHSS improved the prediction of large-scale atmospheric field and typhoon track. The assimilation of three hourly GeoHSS synthetic observations still demonstrated improvements although with smaller magnitude. Assimilation of temperature and humidity profiles in the reginal data assimilation system resulted in better prediction of moisture flow and then large-scale heavy rain. However, some experiments revealed that GeoHSS did not improve a localized convective rain system, suggesting the necessity of further development of data assimilation system and forecast model. We also developed a one-dimensional variational (1D-Var) scheme to derive temperature and humidity profiles from GeoHSS radiances. The profileswill be used for nowcasting and more realistic impact assessment in the regional data assimilation for GeoHSS.