Downward surface shortwave radiation over the subtropical Asia–Pacific region simulated by CMIP5 models

Abstract

AbstractThe downward surface shortwave radiation (DSSR) over the subtropical Asia–Pacific region simulated by the historical experiments of 15 CMIP5 models is evaluated in this study. The simulated DSSR is compared against two satellite observational datasets, and the possible causes for the DSSR bias of the models are further investigated by dividing the subtropical Asia–Pacific region into five areas. Most of the CMIP5 models underestimate DSSR over the oceans, but overestimate DSSR over land. Aside from the Mediterranean–West Asia (MWA) and Central Asia (CA) areas, both the biases in annual and seasonal mean DSSR are well explained by the bias in surface shortwave cloud radiative forcing (CRF), with an overestimation of the CRF effect over the subtropical North Pacific but an underestimation over other land regions. The effect of cloud plays a dominant role over the subtropical Asia–Pacific region, with relatively weaker influences over MWA and CA in boreal summer and fall.