Dynamics of the Tropical Intraseasonal Oscillation

摘要ATM-9400759王斌夏威夷大学题目：热带季节内振荡的动力学 这项研究的目的是进一步发展对热带季节内扰动（TIS）复杂行为的物理理解。 从研究中获得的结果，预计将是有用的未来的MJO和相关的气候变化的预测。 将开展三个相互关联的研究项目。 1. TIDS与平均热带环流的相互作用 一个同时描述湿赤道波和时间平均流的三层热带大气模式将被用来研究三维平均流对波的发展和传播的影响，以及与波活动有关的动量和热量输送（或E-P通量）引起的平均流的变化。 2. MJO与热带海洋的相互作用 为了解海-气相互作用在季节内时间尺度上的性质，PI将（a）使用一个中等热带海洋模式进行数值试验，以评估季节内强迫集合对ENSO循环的可能影响，（B）对SST和MJO季节内变化之间的关系进行经验研究，以评估SST和MJO之间的耦合程度，（3）分析与暖洋区相关的可能由大气和海洋热力耦合引起的耦合不稳定性。 3. MJO的多尺度结构和高频扰动 PI将利用小波分析和其他有效手段研究MJO的多尺度时空结构及其与云团，热带气旋和热带外强迫的关系。 采用理论、数值和实证分析相结合的策略。 实证分析用于揭示新的事实和提出假设，而理论和数值模型用于解释现象和检验假设。 这项研究很重要，因为它试图了解季节内时间尺度的变化。

Abstract ATM-9400759 Wang, Bin University of Hawaii Title: Dynamics of the Tropical Intraseasonal Oscillation The goal of this proposed research is to futher develop physical understanding of the complex behavior of tropical intraseasonal disturbances (TIS). The results gained from the study are expected to be useful for future predictions of MJO and related climate variations. Three interrelated research projects will be undertaken. 1. Interaction of TIDS and mean tropical circulations A three-layer tropical atmospheric model describing both the moist equatorial waves and time-mean flows will be used to investigate the effects of a three-dimensional mean flow on wave development and propagation, and the change of mean flow caused by momentum and heat transports (or E-P flux) associated with wave activities. 2. Interaction of MJO and tropical ocean To understand the nature of atmosphere-ocean interaction on intraseasonal time scales, the PI will (a) perform numerical experiments with an intermediate tropical ocean model to access the possible influences of an ensemble of intraseasonal forcing on the ENSO cycle, (b) conduct an empirical study of the relation between intraseasonal variation of SST and MJO to access the degree of the coupling between SST and MJO, and c) analyze coupled instability possibly arising from the thermodynamic coupling of the atmosphere and ocean relevant to warm ocean regions. 3. Multi-scale structure of MJO and higher-frequency disturbances The PI will investigate the multi-scale temporal and spatial structure of the MJO and its relation to cloud clusters, tropical cyclones, and extratropical forcing, using wavelet analysis and other effective means. A strategy of combining theoretical, numerical, and empirical analyses is adopted. Empirical analysis is used for revealing new facts and formulating hypotheses, while theoretical and numerical modeling are used to explain the phenomenon and te st the hypotheses. This research is important because it seeks to understand variability on intraseasonal time scales.