Collaborative Research: The Pacific Meridional Mode and El Niño-Southern Oscillation (ENSO)

本研究旨在加深对太平洋“经向模态”（MM）的结构、动力学和影响及其对厄尔尼诺-南方涛动（ENSO）季节性的影响的认识。尽管对变化的解释比ENSO少，但太平洋MM在热带年际和年代际气候变率中发挥了重要作用：观测和模拟研究都提供了令人信服的证据，表明MM有助于启动ENSO变率，可能强烈影响ENSO季节性，并有助于热带ENSO样年代际变率的时空结构。因此，需要更好地了解导致太平洋MM变率的潜在物理过程及其与ENSO的联系。该研究解决了关于MM变率及其与ENSO关系的三个主要问题：Q1)我们能否描述太平洋MM的详细结构和动力学特征，包括其与ENSO的联系，在自然界和当前一代的环流模式中？Q2)平均状态和季节周期如何影响太平洋MM？什么过程促成了太平洋MM变率的季节性及其与ENSO的关系？Q3)太平洋MM与ENSO之间的动力学机制是什么？MM变率的季节性如何影响ENSO对季节周期的相位锁定？这项研究将包括对来自政府间气候变化专门委员会第四次评估报告的观测数据和模式数据的分析；开发了一系列线性耦合模型，增强了对影响MM变率的主要物理过程的理解；以及利用美国国家大气研究中心（NCAR）大气环流模式（AGCMs）和两种不同的海洋模式进行的一系列建模研究。本研究的更广泛影响包括通过与气候预测界的联系（通过共同的研究兴趣、pi的个人专业活动和在一次主要会议上的拟议会议）、培训两名研究生、开发和测试最终将分发给更广泛的科学界的工具，以及pi继续努力将研究和教育结合起来，从而对社会做出贡献。并鼓励他们的研究环境中的种族和性别多样性。

This research is aimed at enhanced understanding of the structure, dynamics, and impacts of the Pacific "meridional mode" (MM), as well as its influence on El-Nino-Southern Oscillation (ENSO) seasonality. Despite explaining less variance than ENSO, the Pacific MM plays an important role in tropical interannual and decadal climate variability: both observational and modeling studies provide compelling evidence that the MM assists in initiating ENSO variability, may strongly influence ENSO seasonality, and contributes to the spatial and temporal structure of tropical ENSO-like decadal variability. Thus, a better understanding of the underlying physical processes that contribute to MM variability in the Pacific, as well as its link with ENSO, is needed. The research addresses three major questions concerning MM variability and its relationship with ENSO: Q1) Can we characterize the detailed structure and dynamics of the Pacific MM, including its link with ENSO, in nature and in the current generation of general circulation models? Q2) How does the mean state and seasonal cycle influence the Pacific MM? What processes contribute to the seasonality of Pacific MM variability and its relationship to ENSO? Q3) What are the dynamical mechanisms that link the Pacific MM to ENSO? How does the seasonality of MM variability affect ENSO's phase locking to the seasonal cycle? The research will include analyses of observational data, and model data from the Intergovernmental Panel on Climate Change 4th Assessment Report; the development of a series of linear coupled models that enhance understanding of the dominant physical processes that affect MM variability; and a series of modeling studies using the National Center for Atmospheric Research (NCAR) atmospheric general circulation models (AGCMs) coupled with two different ocean models Broader Impacts: The broader impacts of this research include its societal contribution through links with the climate prediction community (through common research interests, individual professional activities by the PIs, and a proposed session at a major meeting), training of two graduate students, the development and testing of tools that will eventually be distributed to the broader scientific community, and by continuing efforts by the PIs to integrate research and education, and to encourage ethnic and gender diversity in their research environments.