Persistent spring shortwave cloud radiative effect and the associated circulations over southeastern China

AbstractClouds strongly modulate regional radiation balance and their evolution is profoundly influenced by circulations. This study uses 2001-2016 satellite and reanalysis data together with regional model simulations to investigate spring shortwave cloud radiative effect (SWCRE) and the associated circulations over southeastern China (SEC). Strong SWCRE, up to −110 W m−2, persists throughout springtime in this region and its seasonal mean is the largest among the same latitudes of the Northern Hemisphere. SWCRE exhibits pronounced subseasonal variation and is closely associated with persistent regional ascending motion and moisture convergence, which favor to large amounts of cloud liquid water and resultant strong SWCRE. Around pentad 12 (late February), SWCRE abruptly increases and afterwards remains stable between 22-32°N. The thermal and dynamic effects of Tibetan Plateau and westerly jet provide appropriate settings for the maintenance of ascending motion, while water vapor as cloud water supply st...