IPCC AR4中海气耦合模式对中国东部夏季降水及PDO、NAO年代际变化的模拟能力分析

利用1880—1999年中国东部35站的观测降水资料、英国Hadley中心的海温和海平面气压资料以及IPCC第4次评估报告（AR4）中20世纪气候模拟试验（20C3M）的模式输出结果,对IPCCAR4中22个耦合模式所模拟的我国东部夏季降水的年代际变化情况以及太平洋年代际涛动（PDO）和北大西洋涛动（NAO）的年代际变化情况进行了分析。结果显示,这些模式对20世纪我国东部夏季降水年代际变化的模拟结果并不理想,但对降水在20世纪70年代中期前后的突变具有一定的模拟能力。其中IAP_FGOALSL_0_G可以大致模拟出20世纪70年代中期前后降水型的突变特征,而BCCR_BCM2_0和UKMO_HadGEM1则可以模拟出华北地区降水在20世纪70年代中期之后减少的现象。对于引起我国东部夏季降水年代际变化的重要因子PDO和NAO,模式对它们年代际变化的模拟效果略好于降水。多数模式都可以模拟出PDO和NAO的空间模态,其中CNRM_CM3和UKMO_HadGEM1对PDO年代际变化（8 a以上）的模拟与实际情况比较相似,并可以模拟出20世纪70年代中期之后PDO由负位相转变为正位相的情况,而模式UKMO_HadGEM1也对NAO的年代际变化以及1980年以来不断加强的趋势模拟较好。

Evaluation of the IPCC AR4 Climate Models in Simulating the Interdecadal Variations of the East China Summer Precipitation,PDO and NAO

This paper aims to evaluate the performance of the IPCC AR4（Intergovernmental Panel on Climate Change,the Fourth Assessment Report） climate models in simulating the interdecadal variations of the summer precipitation in East China and its two important influencing factors-the Pacific Decadal Oscillation（PDO） and the North Atlantic Oscillation（NAO）.The results indicate that although most models can not reproduce the interdecadal variations of the summer precipitation during the 20th century,IAP_FGOALSL_0_G can simulate the abrupt change of the precipitation around the 1970s.Besides,models BCCR_BCM2_0 and UKMO_HadGEM1 can simulate the abrupt change of the precipitation in North China around the 1970s.For PDO and NAO,most models can reproduce them as the principal mode in North Pacific sea surface temperature field and in North Atlantic sea level pressure field,respectively.However,only CNRM_CM3 and UKMO_HadGEM1 can reproduce the interdecadal variations of PDO in the 20th century and its abrupt change around the 1970s.And model UKMO_HadGEM1 can also reproduce the interdecadal variations of NAO and its increasing trend since the 1970s.