Validation of the SNPP CrIS Full-Resolution NUCAPS Trace Gas EDRs

This presentation overviews the performance of the operational SNPP NOAA Unique Combined Atmospheric Processing System (NUCAPS) environmental data record (EDR) products. The SNPP Cross-track Infrared Sounder and Advanced Technology Microwave Sounder (CrIS/ATMS) suite, the first of the Joint Polar Satellite System (JPSS) Program, is one of NOAA’s major investments in our nation’s future operational environmental observation capability. The NUCAPS algorithm is a world-class NOAA-operational IR/MW retrieval algorithm based upon the well-established AIRS science team algorithm for deriving temperature, moisture, ozone and carbon trace gas to provide users with state-of-the-art EDR products. Operational use of the products includes the NOAA National Weather Service (NWS) Advanced Weather Interactive Processing System (AWIPS), along with numerous science-user applications. NUCAPS EDR product assessments are made with reference to the JPSS Level 1 requirements. The NUCAPS Phase 4 algorithm incorporated critical updates necessary for compatibility with full spectral-resolution (FSR) CrIS sensor data records (SDRs). These updates included new channel selection, new radiative transfer algorithm (SARTA), coefficient file updates and code changes to handle both full and nominal resolution CrIS SDRs. This work overviews the preliminary validation of the carbon trace gas products (CO, CH4 and CO2), versus the Aqua Atmospheric Infrared Sounder (AIRS), Total Carbon Column Observing Network (TCCON) surface-based sites and available intensive campaigns. In the past, trace gas EDR products did not require validation as no program requirements had been defined, and offline production of SNPP full spectral-resolution (FSR) CrIS SDRs (required for trace gases) did not commence until December 2014, with operational Interface Data Processing Segment (IDPS) production starting in March 2017. Based on our preliminary analyses, the NUCAPS carbon trace gas EDRs show very good agreement against the legacy AIRS sounder, and are shown to be meeting or close to meeting the JPSS requirements for total-column abundances. Lessons learned from the SNPP validation methodology will be leveraged going forward for the JPSS-1 NUCAPS trace gas EDR validation.