西太平洋和印度洋通过印尼贯穿流相互作用的过程与机制

This proposal targets the first key scientific question “Influence of the complex topography of the western Pacific Ocean on ocean dynamical processes and climate systems” of the 2018 NSFC major research project procurement of the cover page category. The study will uncover the processes and dynamics of the interactions between ENSO and Indian Ocean Dipole (IOD) through the Indonesian Throughflow. ENSO and the IOD are the two very strong interannual variabilities in the tropical climate systems. Existing studies focus on the atmospheric bridge in the research of the interactions between the two climatic modes. The interactions through the “oceanic channel”, i.e. the Indonesian Throughflow (ITF), have not been emphasized due to lack of observations. This planned research will use the long time series of the mooring measurements in the Indonesian seas made by the principle investigator’s team, which cover the 2015-2016 strong El Niño event, to study the “oceanic channel” dynamics and predictability of the interactions and exchange between the western Pacific Ocean and Indian Ocean. In addition, the study will diagnose the climate model data and conduct large-scale coupled model experiments. The objectives are the comparisons of the roles of the atmospheric and the “oceanic channel” in different background of time and space, their decadal variability and mechanisms, and an assessment of the ability of the CMIP models in simulating the “oceanic channel” and atmospheric bridge. The study will provide a basis for future climate prediction.

本项目针对2018年封面所属类别的基金委重大研究计划指南中第一个核心科学问题“西太平洋复杂地形对海洋动力过程和气候系统的影响”开展研究,揭示ENSO和印度洋偶极子事件通过印尼贯穿流相互作用的过程与机理。ENSO和偶极子是热带气候非常显著的年际异常现象，已有的研究主要关注两者通过大气桥相互作用的过程，“海洋通道”即印尼贯穿流的作用，因缺乏观测而缺少研究。本项目计划利用申请人在印尼海取得的覆盖2015-2016年强厄尔尼诺事件的长时间序列潜标观测数据，通过气候资料与模式资料的诊断以及大规模耦合气候模式的数值实验，研究“海洋通道”过程在西太平洋和印度洋物质能量交换和气候可预报性中的作用，阐明大气桥和海洋通道的作用效果在不同时空背景下的相对重要性，揭示其年代际变异与机理，评估不同CMIP模式模拟海洋通道和大气桥过程的能力，为预测未来气候提供依据。

项目针对2018年封面所属类别的基金委重大研究计划指南中第一个核心科学问题“西太平洋复杂地形对海洋动力过程和气候系统的影响”开展研究,发现“北赤道次表层流（ NESC）”并揭示其机制，颠覆了经典大洋温跃层理论认为热带西太主温跃层之下存在静止不动的“阴影区”的认识；发现印尼东部海域中层贯穿流，使南太平洋亚南极与印度洋中层环流联系实现从0到1的突破；发现通过哈马黑拉海来自南太平洋ITF分支，揭示印尼利法马托拉海峡深层溢流流量和混合系数；发现印尼东部马鲁古海和利法马托拉海峡上层平均流量流回西太相连，为ITF逆流的存在提供了0-1的关键证据；发现棉兰老流路径在印尼海源区发生剧烈摆动，颠覆了经典线性反射理论。分析了CMIP5气候模式中IOD-ENSO先兆遥相关关系，确立了ITF在印太年际气候变化中的重要作用。