区域气候模式PRECIS对中国气候的长期数值模拟试验

Long Term Climate Numerical Simulation over China by Regional Climate Model PRECIS

利用欧洲中心ERA40再分析资料驱动区域气候模式PRECIS,对中国地区进行了50km水平分辨率、40a（1961-2000年）时间长度的连续积分,并对模拟的温度和降水与观测资料进行了比较分析。结果表明：模式对中国地区温度和降水的年、季空间分布型态均具有一定的模拟能力,对温度和降水的年际变化也有较好的模拟效果,尤其对于20世纪80年代后期出现的暖冬以及1998年的夏季极端降水都有较好的体现。但模式不足在于区域内普遍存在模拟的气温略高于实况的系统性暖偏差,幅度一般在1-3℃;内蒙古和东北地区年降水量比观测值明显偏多,长江以南地区和四川盆地的降水中心范围都明显偏大,位置偏南。总体来看,无论是空间分布还是年际变化,模式对温度的模拟能力明显优于降水。

A numerical simulation during 40 years（1961-2000） with a horizontal resolution of 50km over China was carried out by the regional climate model PRECIS,which was driven by ERA40 reanalysis data.The simulated temperature and precipitation were analyzed by comparing with observations.The results showed that the model performed well in simulating the annual and seasonal patterns of spatial distribution of temperature and precipitation over China,and could reproduce well inter-annual change of temperature and precipitation,especially the warm winters in late 1980s and the summer extreme precipitation in 1998.However there were still some disadvantages about the model.A systematic warm bias of about 1～3℃ was found in the simulated temperature over China,more annual precipitation was simulated in Inner Mongolia and Northeast China, the scope of the precipitation in south of the Yangtze River and Sichuan basin were obviously too large,and the location moved south.Overall,the model showed better in simulating temperature than precipitation,both spatial distribution and inter-annual change.