Assessment of climate simulation over the Tibetan Plateau based on multidomain simulations within CORDEX-II

The climate simulation over the Tibetan Plateau (TP) remains a challenge for climate models, limiting the reliability of future climate projections over there. This study focuses on the performance of regional climate models (RCMs) under the Coordinated Regional Climate Downscaling Experiment (CORDEX-II) in reproducing the climate over the TP, an overlapping regions that is encompassed by the CORDEX-EA, CORDEX-CA and CORDEX-WA, and assesses the uncertainty due to the choice of domain. The results show that all RCMs can capture the observed spatial distribution and annual cycle of temperature and precipitation over the TP, with overall cold and wet biases. Compared to the RCM itself, the choice of domain has little impact on the simulations, and such impact is larger in summer than in other seasons. Further analysis suggests that the downward shortwave radiation is the main contributor to the diverse temperature simulations among the RCMs for all seasons, and the underestimated number of wet days (R1mm) in the RCMs may be related to the lower frequency of 1-5mm rainfall. Furthermore, the effects of the choice of domain on precipitation simulation are mainly in the magnitude, while the effects on temperature simulation are mianly in the interannual variability.