Diurnal Cycle in Surface Incident Solar Radiation Characterized by CERES Satellite Retrieval

Abstract

Surface incident solar radiation (Rs) plays an important role in climate change on Earth. Recently, the use of satellite-retrieved datasets to obtain global-scale Rs with high spatial and temporal resolutions has become an indispensable tool for research in related fields. Many studies were carried out for Rs evaluation based on the monthly satellite retrievals; however, few evaluations have been performed on their diurnal variation in Rs. This study used independently widely distributed ground-based data from the Baseline Surface Radiation Network (BSRN) to evaluate hourly Rs from the Clouds and the Earth’s Radiant Energy System Synoptic (CERES) SYN1deg–1Hour product through a detrended standardization process. Furthermore, we explored the influence of cloud cover and aerosols on the diurnal variation in Rs. We found that CERES-retrieved Rs performs better at midday than at 7:00–9:00 and 15:00–17:00. For spatial distribution, CERES-retrieved Rs performs better over the continent than over the island/coast and polar regions. The Bias, MAB and RMSE in CERES-retrieved Rs under clear-sky conditions are rather small, although the correlation coefficients are slightly lower than those under overcast-sky conditions from 9:00 to 15:00. In addition, the range in Rs bias caused by cloud cover is 1.97–5.38%, which is significantly larger than 0.31–2.52% by AOD.