厄尔尼诺—南方涛动 (ENSO) 是地球气候系统中最强的年际变率。本项目主要研究目标是揭示“超级”厄尔尼诺事件的发生机制，厄尔尼诺和拉尼娜事件生命史不对称的机理，以及在全球变暖背景下ENSO振幅变化的原因及机理。本项目拟采取理论分析，观测资料（包括多套再分析资料和CMIP5模式结果）诊断，和理想数值试验相结合的方法研究以下三个方面的内容:（1）揭示“超级”厄尔尼诺与“常规”厄尔尼诺之间在前期信号及发展阶段存在的显著差异; 定量分析造成2014年超级厄尔尼诺流产的动力原因及2015超级厄尔尼诺形成的机理。（2）通过混合层热收支诊断，深入理解厄尔尼诺和拉尼娜冷、暖事件转型演变不对称的机理。（3）通过对20多个CMIP5模式分析，揭示导致ENSO振幅预估明显分歧的关键海气动力和热力反馈过程。根据太平洋平均经圈环流（STC）和ENSO强度变化的紧密关系，提出预估未来ENSO强度变化的新方法。

El Niño-Southern Oscillation is the strongest interannual variability in the globe. The objectives of this proposed research is to investigate the specific physical mechanisms responsible for the occurrence of a super El Niño event, the asymmetric life cycle evolution of El Niño and La Niña, and divergent projections of ENSO amplitude changes under global warming. We will take a combined approach of theoretical analysis, observational data (including reanalysis and CMIP5 model output) diagnosis, and idealize numerical modeling. For the first part, we will reveal statistically significantly different precursor signals between super El Niño and regular El Niño groups and possible “accelerating” and “prohibiting” processes during their developing phase. For the second part, we will investigate, through a mixed layer heat budget analysis, the nonlinearity in the atmospheric response to El Niño and La Niña and the oceanic response to surface wind stress forcing. For the third part, we will examine the relative contribution of the mean state change and the ENSO perturbation change and the impact of various dynamic and thermodynamic feedback processes in regulating ENSO amplitude change within 20+ CMIP5 models.