ENSO遥相关对北太平洋海表面温度变化的影响作用分析

发生在热带太平洋的ENSO事件主要通过遥相关影响热带外区域气候变化。因此提升全球气候年际-年代际变异预测能力，既需要明确ENSO本身的动力学机制，更要加强对ENSO遥相关作用的研究。然而，即使在研究相对充分的北太平洋，不同气候模式模拟的海表面温度（SST）对热带ENSO的响应也存在非常大的差别。形成此问题的原因之一是在海气耦合作用下，难以直接从观测数据中分解SST对大气随机强迫和ENSO遥相关作用的响应，由此给出的ENSO遥相关作用存在很大不确定性，不能为模式提供有效的参考与约束，也因此限制了模式模拟ENSO遥相关作用的能力。基于预研究结果，本申请计划以SST随时间的变化为切入点，实现从观测数据中分离出与热带过程相独立的副热带SST变化的模态、进而确定观测数据中ENSO遥相关对北太平洋SST影响作用的研究目标。

The El Nino and Southern Oscillation (ENSO) cycle, which is the strongest air-sea interactions in the tropical Pacific, dominates the global interannual climate variability through the teleconnection (i.e. atmospheric bridge). A better understanding of ENSO dynamics, as well as the physics of ENSO teleconnection, is equally crucial for an improved global climate prediction and projection. But the impacts of ENSO teleconnection on North Pacific SST simulated by CMIP5-class climate models are very diverse. This diversity can be attributed to the significant uncertainty of the impacts of ENSO teleconnection on the SST variability derived from the observations. It is difficult to decouple the response and the feedback of SST to the surface stochastic atmospheric forcing in the extratropics and the ENSO impacts from the tropical Pacific only using observations; therefore, the weak constrain to the climate models. .Based on our preliminary research, we notice that the response of ocean to atmospheric forcing, instead of the air-sea interaction, can be represented by the SST tendency. We propose to identify the impacts of ENSO teleconnection on the North Pacific SST by studying the SST tendency directly.