The CrIMSS EDR Algorithm Assessment: Provisional Maturity and Beyond

The Cross-track Infrared Sounder (CrIS) and the Advanced Technology Microwave Sounder (ATMS) instruments aboard the Suomi National Polar-orbiting Partnership (S-NPP) satellite provide high quality hyper-spectral Infrared (IR) and Microwave (MW) observations to produce atmospheric vertical temperature, moisture, and pressure profiles (AVTP, AVMP and AVPP), and many other Environmental Data Records (EDRs). The official Cross-track Infrared and Microwave Sounder Suite (CrIMSS) EDR algorithm version MX7.1 is currently in operations through the Interface Data Processing Segment (IDPS). Prior to the operational implementation of MX7.1, emulations of MX7.1 were created using an off-line MX7.1 version operated on Linux platforms and the science code version implemented through GRAVITE Algorithm Development Area (G-ADA). These emulations were used to evaluate AVTP and AVMP products with a variety of validation data sets and demonstrate provisional maturity. The validation data sets included global focus-day matches of European Center for Medium-Range Weather Forecasts (ECMWF) analysis fields, the conventional global radiosonde network of measurements, Global Positioning System (GPS) radio occultation (GPSRO) observations, and a limited set of dedicated radiosonde ascents. In addition, the Aqua-Atmosheric Infrared Sounder (AIRS) V6 heritage algorithm retrievals were used as a baseline in evaluating the CrIMSS AVTP and AVMP retrievals. Based on the evaluations and recommendations made by the Joint Polar Satellite System (JPSS) provisional maturity assessment committee, the CrIMSS AVTP and AVMP products associated with the MX7.1 build were declared to be of provisional quality in January 2013. Following provisional maturity, the CrIMSS EDR algorithm team tested numerous optimizations to improve further the accuracy of AVTP and AVMP products. These include an improved precipitation detection algorithm, optimizations to ATMS and CrIS bias correction look-up tables (LUTs), snow and ice microwave emissivity representations, and use of external emissivity data bases to improve CrIS cloud-cleared radiances. This paper presents an assessment of the AVTP and AVMP products from the IDPS MX7.1 operations, and then shows the EDR performance enhancements achieved beyond MX7.1. The AVTP and AVMP product evaluations with dedicated radiosondes and ECMWF analysis data show that these optimizations have improved the AVTP and AVMP accuracies beyond what was observed with the MX7.1 operational version. In addition, the CrIMSS AVTP and AVMP retrievals were found to be comparable to the AIRS science team heritage algorithm retrievals over both land and sea categories, and for tropics, mid-latitudes and polar regions. Overall, yields have improved since launch to include approximately 90% of atmospheric profiles from the first stage ‘MW-only' retrieval, and over 50% of profiles from the 2nd stage ‘IR+MW' retrieval. These results reveal that the CrIMSS EDR algorithm has shown remarkable improvement within two years of operation closely meeting the AVTP and AVMP product requirements.