RegCM3对东亚环流和中国气候模拟能力的检验

SIMULATION OF THE ATMOSPHERIC CIRCULATION OVER EAST ASIA AND CLIMATE IN CHINA BY REGCM3

使用RegCM3区域气候模式,嵌套ERA40再分析资料,对东亚地区进行了15年（1987～2001年）时间长度的数值积分试验,分析了模式对东亚平均环流及中国地区气温和降水的模拟。结果表明,模式对东亚平均环流的特征和中国地区降水、地面气温的年、季地理分布和季节变化特征均具有一定的模拟能力,对气温和降水年际变率的模拟也较好。此外模式模拟在测站稀少地区,可以提供局地如降水分布更可靠的信息。模式对气温的模拟存在1-3℃的系统性冷偏差;对中国地区降水地理分布的模拟也存在一定偏差,如对年平均降水的模拟中,降水最大值位置与观测有一定差距,特别是对冬季降水中心的模拟存在较大偏差。模式模拟的夏季降水,在中国北方地区总体偏大100-200 mm,南方总体偏小100-200 mm。模式对地面气温的模拟效果好于降水。

15 years＇ simulation of climate over East Asia is carried out by the latest version of a regional climate model （RegCM3） nested to ERA40 Re-analysis data. The performance of the model in simulating the present climate in East Asia and China is investigated. Results show that RegCM3 can reproduce well the atmospheric circulation over East Asia. The simulation of the main distribution patterns of surface air temperature and precipitation over China and their seasonal change/evolution, as well as the inter-annual variability, are basically reasonable. Furthermore, the model simulation provides more information about local precipitation in places where little observation data can be acquired. However a general cold bias is found in the simulation of temperature. As for the precipitation, the model did not reproduce well the high precipitation centers in southern China, especially in wither. It tends to overestimate the precipitation in northern China while underestimating it in southern China. In summer, 100-200 mm more precipitation in northern China and 100-200 mm less precipitation in southern China are simulated. In general, the model has better performance in simulating temperature than precipitation.