The National Oceanic and Atmospheric Administration/National Environmental Satellite Data and Information Service (NOAA/NESDIS) produces global temperature and water vapor sounding products from operational polar-orbiting and geostationary satellites. Within the NESDIS Office of SaTellite Applications and Research (STAR), the NOAA PROducts Validation System (NPROVS) has provided a centralized, integrated real-time monitoring and validation function for inter-comparing derived satellite weather products against collocated radiosonde, dropsonde and numerical weather prediction (NWP) forecast data since April, 2008. The satellite product systems compared include Advanced-TOVS (ATOVS), Atmospheric Infrared Sounder (AIRS), Microwave integrated Retrieval System (MiRS), GOES, Infrared Atmospheric Sounding Interferometer (IASI) from NOAA and EUMETSAT and Constellation Observing System for Meteorology Ionosphere and Climate (COSMIC) Global Positioning System Radio Occultation (GPSRO) derived sounding products from the University Corporation for Atmospheric Research (UCAR).

An accompanying report summarizes the NPROVS system with the emphasis of its routine products monitoring capability and presents results of the overall performance of the above individual processing systems. This study aims to provide detailed accuracy characterization of NOAA IASI temperature and water vapor retrievals by analyzing ~3 years of NPROVS collocation data. We investigate how the accuracy characteristics of NOAA IASI retrievals vary with a) correlative reference datasets, including radiosondes, NWP, and GPSRO all of which have their own bias and noise uncertainties, and b) atmospheric variability arising from the spatial-temporal mismatch of satellite data with the references. The IASI retrievals performance is further assessed for different climate regimes and surface types, such as cold & dry vs. warm & humid air masses, land (snow/ice) vs. sea, for different cloud fractions and for different time-scales including day vs. night and seasonal cycle. Results from the analysis underscore the importance of compiling datasets carefully in order to provide a representative validation of satellite EDRs and identify target areas for improvement within the hyper-spectral IR sounding retrieval approach.

The above work is supported by the NOAA Joint Polar Satellite System (JPSS) in conjunction with CrIS/ATMS Cal/Val team activities in preparation for NPOESS Preparatory Project (NPP) products in October 2011. NPROVS is a pivotal component of the JPSS Cal/Val program for Cross-track Infrared/Microwave Sounding Suite (CrIMSS) Environmental Data Records (EDR) weather products validation.