Long-term evolution of clear sky surface solar radiation and its driving factors over East Asia

This study evaluated the performance of clear sky surface solar radiation (SSR) and its long-term evolution mechanism in second Modern-Era Retrospective Analysis for Research Applications (MERRA-2) East Asia. The results revealed that although MERRA-2 overestimated clearness index SSR, reanalysis performed well northwestern, northern, northeastern, central From 1980 to 2019, SSRs decreased significantly most areas. Aerosols play a dominant role annual variation SSR rather than water vapor. In northwestern Asia, owing influence increase aerosol optical depth (AOD), showed strong downward trend during 1993–2013. After 2007, vapor played an important weakening SSR. ushered brightening stage at beginning 21st century because reduction AOD. magnitude change Central Asia is even more pronounced. Tarim Basin India, dust plays whereas anthropogenic aerosols drive highly industrialized regions. • Clear-sky impact factors was studied over four decades. dominated clear-sky decrease after 2007.