北大西洋海温对东亚冬季风异常的影响和机理研究

东亚冬季风变异可造成全球大范围的大气环流异常，引发冰冻雨雪等气象灾害。因此，东亚冬季风变异一直是大气科学领域的热点话题。以往的研究揭示了热带太平洋海温和北极海冰等因子对东亚冬季风变异的影响，而对东亚冬季风变异与北大西洋海温的关系关注较少。本项目拟结合统计分析、动力诊断和数值模式，就北大西洋海温异常对东亚冬季风异常的影响及机理展开系统地研究。首先通过统计分析，找出东亚冬季风变异在大西洋地区海温变化方面的信号并确定关键海温区。再通过资料诊断分析和数值模式试验，揭示和说明北大西洋地区的海温异常影响东亚冬季风变化的具体物理过程。最后通过统计和诊断，研究北大西洋海温与东亚冬季风变异的关系是否存在明显的年代际变化，以及引起这种年代际变化产生的可能原因。上述研究有助于进一步提高对东亚冬季风年际变异的影响因子和机理的认识理解，对提高东亚冬季气候异常的预测水平具有重要的科学价值。

The East Asian winter monsoon variability can exert strong impacts on atmospheric circulation change over both Asia and remote regions and lead to severe disasters, such as freezing rain and snow. Hence, the East Asian winter monsoon variability has been an important scientific issue in atmospheric research. Previous studies have revealed the impacts of the tropical Pacific sea surface temperature (SST) anomalies and the Arctic sea ice change on the East Asian winter monsoon variability. However, little attention has been paid to the relationship between the East Asian winter monsoon and the North Atlantic SST variations. This project intends to make a systematic investigation of the influences of the North Atlantic SST anomalies on the East Asian winter monsoon variability and the associated mechanisms. A combination of statistical analyses, dynamic diagnoses, and numerical model simulations will be employed to achieve this objective. We will conduct statistical analyses to unravel the signal of the East Asian winter monsoon variability in the Atlantic Ocean SST variations and the key oceanic regions with large SST influences. We will demonstrate the physical processes for the influence of the North Atlantic SST anomalies on the East Asian winter monsoon variability through data diagnoses and numerical model experiments. We will perform statistical analyses and diagnoses to investigate whether there have been obvious interdecadal changes in the relationship between the East Asian winter monsoon and the North Atlantic SST variations in the past and the plausible reasons for the interdecadal changes. The accomplishment of this project will advance our understanding of the factors and the mechanisms of the interannual variability of the East Asian winter monsoon. The results obtained in this project have important scientific value to the improvement of the prediction of the East Asian winter climate anomaly.