Evaluation of Shortwave Radiation Budget Algorithm Developed for the Next-Generation Geostationary Operational Environmental Satellite (GOES-R)

An algorithm was developed to estimate shortwave (SW) radiation budget from the Advanced Baseline Imager (ABI) onboard the next generation Geostationary Operational Environmental Satellite (GOES-R). The algorithm makes direct calculation or indirect inference of the SW radiation budget depending on the availability of instantaneous atmosphere and surface retrievals. Algorithm validation with proxy data from the Clouds and the Earth's Radiant Energy System (CERES), Moderate Resolution Imaging Spectroradiometer (MODIS) and Spinning Enhanced Visible and Infrared Imager (SEVIRI) was performed to evaluate the accuracy and precision of retrieved Downward Shortwave Radiation at surface (DSR) and Reflected Shortwave Radiation at TOA (RSR). Validation results show that the performance of direct and indirect path is comparable with each other as well as with other satellite products. There is no obvious seasonal dependence of retrieval error, but performance deteriorates at early morning and late afternoon probably due to unfavorable geometry. Overall accuracy and precision of instantaneous retrievals are estimated as about 20 W/m2 (4%) and 115 W/m2 (20%) for DSR, while 15 W/m2 (5%) and 45 W/m2 (16%) for RSR. Inconsistency of scene fraction between satellite and ground observation contributes to the large part of the discrepancies found at the low and high value ends.