NPP sounding validation and evaluation

The Suomi National Polar-orbiting Partnership (NPP) was launched on Oct 28, 2011. The official Cross-track Infrared and Advanced Technology Microwave Sounder Suite (CrIMSS) sounding Environmental Data Record (EDR) products include the Atmospheric Vertical Temperature Profile (AVTP) and Atmospheric Vertical Moisture Profile (AVMP). These are very useful products for both nowcasting and data assimilation. Before the products are open to the public, extensive validations are necessary to provide needed quality flag information to users. Some basic quality flags are already generated by the retrieval software and included in the CrIMSS sounding EDR products, such as overall retrieval quality (high: microwave+IR, low: microwave only or IR only, and poor: non-converged), ice mask, rain flag, day/night, cloudiness, etc. To better assist users in understanding and utilizing the sounding EDR products, the Cooperative Institute of Meteorological Satellite Studies (CIMSS) sounding team examines the impacts on the EDR products from 1) the cloud contamination, 2) satellite viewing angle, 3) surface altitude, and 4) scene temperature. These analyses could also be useful for algorithm/product improvement. In addition, a same single field-of-view (SFOV) sounding retrieval algorithm has been applied to both CrIS and Atmospheric InfraRed Sounder AIRS radiance measurements, and results show similar precision between AIRS and CrIS for both temperature and moisture profiles when ECMWF analysis are used as references. Some temperature differences between AIRS and CrIS are noticed and analyzed, those comparisons and feedback are useful for calibration team as well.