PRECIS和RegCM3对中国区域气候的长期模拟比较

以欧洲中期天气预报中心的再分析资料(ERA40)为侧边界及初始条件,在相同模拟区域和分辨率设置下,完成了PRECIS和RegCM3两个区域气候模式对中国区域近44a(1958年12月-2001年11月)的气候模拟,并分析比较两个模式对中国区域温度和降水的气候态和年际变率的模拟能力。结果表明,PRECIS和RegCM3均能较好地模拟出中国区域多年平均气温的空间分布特征,但PRECIS比观测气温平均偏暖1.5℃左右,而RegCM3则以冷偏差为主,平均偏低0.8℃左右,PRECIS整体上比RegCM3偏高2～3℃;两个模式均可基本再现气温年际变率的分布特征,但变率中心的位置和强度与观测值存在一定偏差;对于中国区域降水量的平均态及其年际变率而言,PRECIS和RegCM3均具有较好的模拟能力,但PRECIS模拟的降水高值中心、变率较大区域的位置和强度比RegCM3更接近实际。

Inter-comparison of Long-term Simulations of Climate over China by PRECIS and RegCM3

Long-term（ 1958 -12--2001 -11 ）climate simulations over China by both PRECIS and RegCM3, with the same configuration of boundary and initial conditions, domain and horizontal resolution, were carried out, so as to ana- lyze and compare the two models＇ simulation capacity for climatology and inter-annual variability of temperature and precipitation over China. The principal conclusions were given as follows. Both models performed well in simulating the spatial distribution features of annual mean temperature. However, there was about 1.5~C of warm bias for PRECIS while 0. 8~C of cold bias for RegCM3, a mean 2 -3~C difference could be found between the two models. The models could also well reproduce the inter-annual variability of temperature, but compared with observation, there were still some differences about the location and intensity of variability centre in the simulated results of the two models. As for the annual precipitation and the corresponding inter-annual variability, both PRECIS and RegCM3 had certain simula- tion capacity. Compared with RegCM3, PRECIS was more consistent with observations in terms of the simulated loca- tion and intensity of heavy precipitation centre and areas with larger variability.