Validation Status of NOAA-21 VIIRS Ice Products

The Visible Infrared Imaging Radiometer Suite (VIIRS) onboard the NOAA-21 satellite provides data that can be used to derive a variety of snow and ice properties. These products, called Environmental Data Records (EDR), are fundamental to weather prediction, hazard detection, transportation, fishery, recreation, and climate monitoring. The NOAA-21 Enterprise ice products include ice surface temperature (IST), sea ice concentration (SIC), and ice thickness (THK) and ice age. The ice products are produced operationally with S-NPP and NOAA-20 data and will soon be declared operational for NOAA-21.

Extensive validation has been performed. Daily and monthly NOAA-21 products have been compared with the same, or similar, NOAA-20 and AMSR2 products over both the Arctic and Antarctic. Results show that NOAA-21 ice properties agree with NOAA-20 and AMSR2 very well. For example, SIC bias is 0.0187% and the precision is 9.42% over the Arctic; the bias is -0.12% and precision is 8.50% over Antarctic when compared to NOAA-20 in June 2023. The comparison results of SIC with Landsat show that accuracy, precision and uncertainty meet the requirements. IST comparison with NOAA-20 shows bias of 0.12K for both Arctic and Antarctic. The ice age products from NOAA-21 and NOAA-20 are almost identical, while very small difference in ice thickness between them is within uncertainty limit. Beta and Provisional Maturity products will be distributed by NOAA's Comprehensive Large Array-Data Stewardship System (CLASS).