Validation of the SNPP CrIS Full-Resolution NOAA Unique Combined Atmospheric Processing System (NUCAPS)

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 NESDIS/STAR NUCAPS development and validation team recently delivered the Phase 4 algorithm which 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. Based on substantial and comprehensive analyses, the NUCAPS Phase 4 CrIS-FSR algorithm shows good accuracy and yield based upon global ECMWF model, global conventional radiosonde observation (RAOBs) and limited SNPP-dedicated RAOB ensemble. A critical risk has been mitigated concerning the possibility of an ATMS sensor failure. The standard NUCAPS algorithm requires microwave sensor data (e.g., ATMS onboard SNPP and future JPSS), the lack of which would cause a failure of the algorithm. To mitigate this risk, NESDIS/STAR has developed and tested an “IR-only” version of the algorithm, which while not fully matching the quality of the full “IR+MW” algorithm, nevertheless was shown to yield quite reasonable results in the event of an ATMS failure.