Evaluation of the NASA MODIS-VIIRS Continuity Cloud Product’s Pixel-level Radiative Flux Datasets

Clouds are a critical component of the global radiation budget, and cloud radiative effects at the top-of atmosphere (TOA) and surface can significantly depend on the optical properties of the clouds. Multi-decadal records of satellite retrieved cloud properties are critical for maintaining a comprehensive climate data record. Cloud optical properties at spatial scales of 1-km or less can be retrieved from multi-spectral imagers, such as MODIS and VIIRS. Such cloud properties can subsequently be used as inputs to a radiative transfer model for computations of cloud radiative effects. Pixel-level and aggregated (i.e., level-3) radiative flux datasets derived from cloud property retrievals are useful for understanding the radiative implications of those retrieved cloud properties and estimating cloud radiative effects on global and multi-decadal scales.

This work presents newly developed pixel-level shortwave and longwave surface and TOA radiative flux datasets that are calculated directly from the NASA Aqua MODIS and SNPP/NOAA-20 VIIRS climate data record continuity cloud optical property products (CLDPROP). The CLDPROP algorithm is based on a set of spectral channels common between MODIS and VIIRS, and is applied to each sensor’s observations (i.e., CLDPROP_MODIS and CLDPROP_VIIRS). Radiative fluxes from CLDPROP_MODIS are evaluated globally against collocated ground- and satellite-based (i.e., NASA CERES) radiation measurements. Example pixel-level flux imagery is presented, as well as evaluations for different regions (e.g., polar vs. tropics) and cloud types (e.g., liquid vs. ice clouds). Intercomparisons between CLDPROP_MODIS and CLDPROP_VIIRS surface and TOA radiative fluxes are performed. Level-3 globally gridded all-sky and cloudy-sky flux aggregations are also discussed.