Effects of GPS/RO refractivities on IR/MW retrievals

The ability of Global Positioning System Radio Occultation (GPS/RO) to improve tropospheric profile retrievals was examined. Retrievals were performed using IR and MW radiometric measurements from the ATOVS (Advanced TIROS Operational Vertical Sounder) on current NOAA polar orbiting satellites and simulated high spectral resolution infrared measurements from the Cross-track Infrared Sounder (CrIS) planned for the future NPOESS. First a simulation study will be presented wherein a statistical regression is used to get temperature and moisture retrievals from the combination of the ATOVS/CrIS brightness temperatures (BTs) and GPS/RO refractivity data. Retrievals from the ATOVS/CrIS and GPS/RO combination is found to yield tropospheric profiles in better agreement with those from radiosondes than profiles inferred from either system alone. Second, the associated study with real GPS/RO (CHAMP and SAC-C satellite measurements) and sounder (NOAA16/ATOVS) data is also shown.