研究表明太平洋海表温度年代际振荡信号（PDO）可以通过对ENSO的调节作用，从而影响东亚夏、冬季风的年代际变化。基于观测资料发现，北大西洋海温年代际振荡信号（AMO）对PDO有着重要的调制作用，存在超前12年的影响，但是AMO对PDO影响的物理机制尚不清楚。本项目拟从热带海气耦合作用与中纬度海气耦合作用两条物理途径出发，利用多种模式资料与观测资料的综合对比分析，试图说明其中的主要物理过程。首先利用观测资料分析，考察AMO异常时南北半球温度梯度的变化，Hadley环流的异常变化，以及热带风场与中纬度气压场的异常变化，探讨AMO对PDO的调制作用。其次，使用CMIP5多个模式的控制试验，通过多个模式的比较和讨论，验证以上物理途径存在的可能性，并找到关键区域。最后，利用淡水扰动实验，讨论AMO变率与强度变化时，这种调节机制是否发生改变，并阐明物理原因，从而帮助我们更好地理解PDO的变化规律。

Some research shows that the Pacific decadal oscillation (PDO) in the sea surface temperature (SST) can modulate ENSO, thus have effect on the interdecadal variation of the East Asia summer, winter monsoon. Based on the observations, the Atlantic Multi-decadal Oscillation (AMO) in SST affects the advance 12 years on PDO, but the physical mechanism of the effect of AMO on PDO we are not very clear. This project aims to discuss the modulation effect of AMO on PDO from the interdecadal time scale, and trying to explain the physical path and mechanism. First, by using the observation data analysis, when the AMO exception will cause the gradient increased from Southern to Northern Hemisphere temperature, So, it impacts on Hadley circulation anomaly, the ascending anomaly on the tropical and descending anomaly in middle latitude, and the PDO. Secondly, by using CMIP5 model, the control experiment are chosen, with which model the PDO amplitude and cycle simulation are relatively good, So we can verify the possibility of these physical pathways and their respective contributions. Finally,on fresh water perturbation experiment, wu discuss whether the change of AMO ‘s rate and intensity makes the regulation mechanism and to elucidate the physical reasons, which helps us understand the mechanism of PDO.