不同水平分辨率区域气候模式对青藏高原气候特征模拟OA北大核心CSTPCD

The Qinghai-Tibet Plateau has a unique climate,complex topography,and few meteorological observa-tion stations,which makes it difficult to observe and simulate its regional climate and water cycle processes.Us-ing the regional climate models RegCM and WRF,the spatial and temporal distribution of the climate in this re-gion from 1989 to 2008 was systematically analyzed,and the simulation capability of the RegCM and WRF mod-els was investigated at 10,25,and 50 km horizontal resolutions in the Qinghai-Tibet Plateau.Results show that the trend of annual average temperature simulated by both models at 10 km horizontal resolution is 1.60-2.12℃lower than the multiyear average temperature simulation at 25 and 50 km horizontal resolution.With increasing horizontal resolution,the simulation biases of annual and seasonal temperatures simulated by the WRF model de-crease,and the cold bias of temperature in the central and western parts of the Qinghai-Tibet Plateau improves.The simulated temperature in the RegCM model at a 10 km horizontal resolution has the lowest error,and it is sig-nificantly better for simulating the spatial distribution of temperature in the Qinghai-Tibet Plateau.The correla-tion between the simulated temperature of both models in different seasons and the observation data has been im-proved.In the precipitation simulation,the WRF model at a horizontal resolution of 25 km has the best correla-tion with the observed data but has the largest error.With the increase of horizontal resolution,the overestimation of precipitation in the southeastern and southern Qinghai-Tibet Plateau by the WRF model has been significantly improved,and the annual precipitation simulated by the RegCM model gradually approaches the measured values(the overestimation decreases from about 2.73 times to 1.77 times).However,the overall overestimation of pre-cipitation by both models still exists.In the simulation of the five major river sources on the Qinghai-Tibet Pla-teau,with increasing horizontal spatial resolution,the WRF model reduces the biases of the air temperature in the source region of the Mekong river and Salween River,whereas the RegCM model reduces the biases of the air temperature in the source region of the Brahmaputra River and Mekong river.The largest reduction in precipita-tion bias was achieved in the Brahmaputra River source region at 10 km horizontal resolution by the WRF and RegCM models.This study can lay the foundation for understanding the impact of climate change on the water cycle process in the Qighai-Tibet Plateau.