A Theoretical Study of Climate Dynamics

研究人员对大尺度地球物理流体流动的结构、稳定性和稳定性进行了研究，以更好地了解与气候低频变化典型来源有关的这些流动的预测性和可预报性。这项工作研究了两个领域的具体主题：1)原始方程的理论问题，2)年际变化特征对基本物理空间中模式参数变化的存在、敏感性和稳健性。在第一区，研究者研究了大尺度海洋/大气流动的原始方程。具体问题包括原始方程和相关简单模型的稳定性和分叉问题，特别是与气候低频变化有关的问题。区域2的主要目标是对与边界层现象有关的典型大尺度大气/海洋环流流型进行分类，并研究它们的结构分叉。这一领域的部分工作是基于该研究员和T.Ma最近发展起来的一种新的几何理论。研究人员使用物理模型、渐近方法、严格的数学理论和大规模计算的组合来产生对物理现象的新见解。这项工作涉及与大气/海洋科学家的具体合作。该项目的主要目标是，通过仔细的理论研究，记录美洲大陆西北部毗邻的洋盆中是否存在定期的年际和年代际变化，验证这种变化特征对模式参数变化的稳健性，并帮助解释其物理机制。对这种变异性的透彻理解对于确定气候系统在次大陆和更小空间尺度上的可预测性和预报至关重要，因为时间尺度等于或超过几年。相关现象包括由风驱动的双涡旋海洋环流和厄尔尼诺-南方涛动(ENSO)现象，后者主导着太平洋大部分地区以及世界各地的年际气候变化。这些研究可能会改进对天气、气候和环境现象的预测。

Wang0072612 The investigator studies the structure, its robustness andstability, and the transitions of large scale geophysical fluidflows, to arrive at a better understanding of the prediction andpredictability of these flows relevant to the typical sources oflow frequency variabilities in climate. The work studies specifictopics in two areas: 1) theoretical issues of the primitiveequations, and 2) the presence, sensitivity and robustness ofinterannual variability characteristics to changes in modelparameters in the underlying physical space. In Area 1, theinvestigator studies the primitive equations of large scaleocean/atmosphere flows. Specific problems include stability andbifurcation issues of the primitive equations and related simplermodels, especially in connection to climate low frequencyvariabilities. The main objectives in Area 2 are to classifytypical large scale atmosphere/ocean circulation flow patternsassociated with boundary layer phenomena, and to study theirstructural bifurcations. Part of the work in this area is basedon a new geometric theory developed recently by the investigatorand T. Ma. The investigator uses a combination of physicalmodelling, asymptotic methods, rigorous mathematical theory, andlarge scale computing to yield new insights into physicalphenomena. The work involves specific collaborations withatmosphere/ocean scientists. The primary goal of this project is to document, throughcareful theoretical studies, the presence of regular interannualand interdecadal variability in the ocean basins adjacent to theNorth American continent, to verify the robustness of thisvariability's characteristics to changes in model parameters, andto help explain its physical mechanisms. The thoroughunderstanding of this variability is of the essence indetermining the climate system's predictability and prediction onsubcontinental and smaller spatial scales, for time scales thatequal and exceed a few years. The associated phenomena includethe double-gyre wind-driven ocean circulation and the ElNino-Southern Oscillation (ENSO) phenomenon, which dominatesinter-annual climate variability over much of the Pacific Ocean,and hence the world. The studies could lead to improvedpredictions of weather, climate, and environmental phenomena.