Synergistic use of high spectral sounder and high spatial imager radiance measurements for atmospheric profiling

Abstract

Hyperspectral infrared (IR) sounder from low earth orbit (LEO) provides temperature and moisture soundings with high accuracy and high vertical resolution, however, due to its low temporal coverage rate (twice every day for one sounder instrument), data are usually missing during short range convective storm development. The Advanced Baseline Imager (ABI) onboard the next generation of geostationary (GEO) satellite, on the other hand, provides very fast coverage rate but lower vertical resolution and less accurate profiles. Combination of GEO ABI measurements and LEO hyperspectral IR sounder data may provide atmospheric evolution with high temporal resolution and fairly vertical structure. An algorithm is developed for monitoring the sounding evolution from combined GEO imager and LEO IR sounder data. The collocated geolocation of GEO imager and LEO sounder systems can (1) provide LEO sounder sub-pixel cloud characterization (mask, amount, phase, layer information, etc.) within the large sounder footprint; (2) be used for LEO sounder cloud-clearing for partly cloudy footprints; (3) provide background information in variational retrieval of cloud properties with sounder cloudy radiances; (4) provide real-time background information for GEO imager instantly without Numerical Weather Prediction (NWP) data. The Moderate-Resolution Imaging Spectroradiometer (MODIS) and the Atmospheric Infrared Sounder (AIRS) measurements from the Earth Observing System's (EOS) Aqua satellite provide the opportunity to study the synergistic use of advanced imager and sounder measurements. The combined MODIS and AIRS data for various scenes are analyzed to study the utility of synergistic use of ABI products and LEO sounder radiances for better retrieving atmospheric soundings and cloud properties.