Cloud and Aerosol Impacts on the Radiation Budget over China from 2000 to 2023

Aerosols and clouds influence Earth’s radiative energy budget, but their regional radiative impacts remain insufficiently understood. This study investigates the spatial distribution patterns and long-term trends of radiative fluxes over China from March 2000 to February 2023 using CERES-SYN data. Notable decreasing trends in the net radiative fluxes over China at the top of the atmosphere (−0.38 W m−2 year−1) and the surface (−0.35 W m−2 year−1) during the study period have been observed. Cloud properties from CERES-SYN and aerosol properties from MERRA-2 are used to assess the impacts of aerosols and clouds on radiative flux variations. Results show that aerosols are the primary drivers of radiative flux variations across China, while cloud changes exert notable but regionally dependent influences. In southern China, reductions in black carbon and organic carbon aerosols substantially influence radiative flux variations, along with contributions from changes in mid-high, mid-low, and low clouds. In northern China, decreases in dust and organic carbon aerosols primarily drive radiative flux trends. Over the Tibetan Plateau, variations in mid-high clouds predominantly affect radiative flux changes. In Xinjiang and Inner Mongolia, fluctuations in high, mid-high, and mid-low clouds, along with dust and sulfate aerosols, jointly contribute to the radiative flux variations, although the overall impacts remain relatively small.