The NASA Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) Level-2 (L2) Cloud Mask + Sounder is a new continuity product that combines the MODIS instrument’s high spatial resolution in broad spectral bands with the Atmospheric Infrared Sounder (AIRS) hyperspectral instrument’s more narrow swath absorption channels. While MODIS natively has sufficient spectral sensitivity to measure water vapor and carbon dioxide, the VIIRS instrument lacks this information. To maintain continuity of methodology, this L2 Cloud Mask product synergizes the AIRS water vapor and carbon dioxide absorption to ensure sensitivity to improve cloud detection especially at nighttime and in polar regions. This continuity product is designed to sustain the long-term records of both MODIS and VIIRS heritages.

CLDMSK_L2_MODIS-AIRS_Aqua is the shortname for the Aqua MODIS version of this product that is derived from the MODIS-VIIRS cloud mask (MVCM) continuity algorithm, which itself is based on the MODIS (MOD35) algorithm. The MODIS (from Terra and Aqua missions) and VIIRS (from SNPP and Joint Polar Satellite System (JPSS) missions) data-derived cloud mask products use the MVCM algorithm. Implemented to consistently handle MODIS and VIIRS inputs, the v2.0 Aqua MODIS Cloud Mask + Sounder collection products use calibration-adjusted NASA MODIS L1B as inputs. The nominal spatial resolution of the Aqua MODIS L2 Cloud mask is 1000 meters at nadir. The v2.0 collection starts from March 1, 2012 (2012-061).