Geostationary Extended Observations Sounder Radiance Proxy Data Simulation

NOAA’s Geostationary Extended Observations (GeoXO) satellite system is planned to launch in the mid-2030s. The nation’s first geostationary advanced hyperspectral resolution infrared sounder, GeoXO sounder (GXS), will provide unprecedented level of sounding information, critical for weather forecasting and nowcasting. In support of the mission, especially for the quantitative applications of the GXS potentials, CIMSS has been developing the methodology to simulate the GXS radiance proxy data. To account for the GXS’ high spatial resolution of 4km, the 1km resolution of global experimental nature run (XNR1K) generated by the Oak Ridge National Laboratory using the ECMWF’s Integrated Forecast System with explicit convection, was used to provide the surface and atmospheric fields, including temperature, moisture, and cloud hydrometer profiles. Capabilities based on different radiative transfer models is developed for all sky radiance simulation, including the Community Radiative Transfer Model (CRTM), the Radiative Transfer for TOVs (RTTOV), and the Pressure layered Fast Atmospheric Transmittance (PFAAST). Inter-comparisons between different RTMs ensure the consistency of radiance simulation especially in the clear sky. Two GXS radiance proxy datasets will be generated: the hourly full disc and the 30-min continental US (CONUS). Besides the GXS radiances, the datasets will also include the information from the surface and atmospheric fields. These datasets can be used to study many GXS applications, such as soundings, nowcasting, clouds, and winds.