Evaluation of the Performance of Beijing Climate Center Climate System Model with Different Horizontal Resolution in Simulating the Annual Surface Temperature over Central Asia

The temporal and spatial distributions of the mean annual surface air temperature and annual precipitation over Central Asia during 1948-2011 have been studied using trend analysis and moving average methods based on the Climatic Research Unit (CRU) dataset and the output of the historical experiments from the Beijing Climate Center Climate System Model version 1.1 (BCC_CSM1.1) and the Beijing Climate Center Climate System Model version 1.1 with a Moderate Resolution (BCC_CSM1.1(m)) for the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC AR5). Heat flux and radiation flux were imported to further assess the capability of the two BCC_CSM versions in simulating the climate over Central Asia. The results show that these two versions effectively simulated the significant upward trend and north-south increasing characteristic of sensible heat flux and radiation flux over Central Asia. The performance of BCC_CSM1.1(m) in simulating the spatial distribution of air temperature, heat flux, and long/short radiation flux improved significantly compared with the results of BCC_CSM1.1. However, the performance of BCC_CSM1.1 in simulating the spatial distribution of the standard deviation of air temperature was better than BCC_CSM1.1(m). The improvement in model resolution more clearly demonstrated the topographic effects and improved the model simulation performance for heat flux and radiation flux. The high-resolution model displayed advantages in simulating the air temperature over Central Asia.