CMIP5和CMIP6模式在历史试验下对AMO和PDO的模拟评估

利用Hadley中心的观测海温资料,以及耦合模式比较计划的第五阶段和耦合模式比较计划的第六阶段历史试验的模式资料,分析和评估了2个最为重要的年代际尺度模态,北大西洋年代际振荡、太平洋年代际振荡在耦合模式比较计划的第五阶段和耦合模式比较计划的第六阶段中的模拟能力。通过对比多模式集合发现,在空间模态方面,耦合模式比较计划的第五阶段和耦合模式比较计划的第六阶段都能模拟出北大西洋年代际振荡在北大西洋地区的信号,但耦合模式比较计划的第六阶段的模拟更好,对于太平洋年代际振荡模态而言,都能模拟出在北太平洋地区的信号,而太平洋年代际振荡在热带太平洋地区的信号,耦合模式比较计划的第六阶段模拟的振幅明显更接近观测。在周期的模拟方面,耦合模式比较计划的第五阶段和耦合模式比较计划的第六阶段结果相似,都能模拟出北大西洋年代际振荡存在60~70年的周期,以及太平洋年代际振荡存在20年和60~70年的双周期。整体而言,耦合模式比较计划的第六阶段相比于耦合模式比较计划的第五阶段在空间特征模拟方面有一定进步,但是对于周期的模拟能力,没有明显进步。

Simulation Evaluation of AMO and PDO with CMIP5 and CMIP6 Models in Historical Experiment

Using the observed sea surface temperature data of the Hadley Center,as well as the model data under historical experiments in the Coupled Model Intercomparison Project Phase 5(CMIP5)and the Coupled Model Intercomparison Project Phase 6(CMIP6),the simulation ability of the two most important interdecadal scale modes,the Atlantic Multi-decadal Oscillation(AMO)and the Pacific Decadal Oscillation(PDO),in CMIP5 and CMIP6 was analyzed and evaluated.By comparing the multi-model ensemble,it is found that in terms of spatial patterns,both CMIP6 and CMIP5 can simulate the signals of AMO in the North Atlantic region,but the simulation of CMIP6 is better.For PDO modes,both can simulate the signal in the North Pacific region,while for the PDO signal in the tropical Pacific region,the amplitude of the CMIP6 simulation is significantly closer to the observation.In terms of periodic simulation,the results of CMIP5 and CMIP6 are similar,and both can simulate the 60~70-year period of the AMO and the double periods,namely 20 and 60~70 years,of the PDO.On the whole,CMIP6 has a certain improvement in the simulation of spatial characteristics compared with CMIP5.But there is no significant improvement in the ability of periodic simulation.