以前的研究表明，东亚气温年代际变化受到大西洋海温（SST）长周期年代际振荡（简称AMO）的调制，但最近器测资料分析却显示:东亚气温与AMO的正相关并不是如所期待的同期最强，而是当东亚气温超前AMO指数5至7年时最强。这一新结果对东亚气温受AMO调制的认识提出了挑战。因为大气对SST的响应是快过程，东亚气温受AMO调制意味着二者相关应同期最大。一个可能原因是：近100多年来外强迫干扰了自然气候系统内部东亚气温与AMO的联系。本项目将用IPCC 第5次评估报告耦合模式相互比较计划第5位相（CMIP5）所提供的数据集，包括过去100多年（1850-2005年）气候探测与归因试验多模式数据及其参照试验数据，结合大气环流模式、简单海气耦合模式等的诊断试验，分析外强迫在造成东亚气温超前AMO变化现象中的贡献，揭示其中的大气环流、海洋环流及海气相互作用过程，为过去百年东亚气候年代际变化提供新认识。

Previous studies illustrated that variations of East Asian air temperatures (EATs) are tuned by the AMO (Atlantic Multidecadal Oscillation). But one recent observational study reveals that the correlation between the EATs and the AMO is the strongest when the EATs leads the AMO by 5 to 7 years. This poses a challenge to the above perspective that EATs are tuned by the AMO, because the processes for the atmospheric responses to SST forcing are very rapid and will result in the maximum of their simultaneous correlations. One potential factor responsible for the inconsistence is the external forcing of climate systems, because they may purterbate the intrisic connection between the EATs and the AMO. In this proprosal, we will investigate the lead-lagged connection between the EATs and the AMO by using the long-term historical experimental integrations for understanding climate change during the past century and the pre-industrial control experiments from a multiple of coupled models attending the IPCC AR5 CMIP5. Then, we will attribute the potential external forcing to cause the lead-lagged correlation. Furthermore,we will conduct ensemble experiemnts in atmospheric general circulation models(AGCMs) or simplified air-sea coupled models to understand the processes for the individual external forcing to exert their impacts. This project will expect to provide insights into the decadal variability of East Asian climate.