Understanding the Role of Convective Momentum Transport for the Madden-Julian Oscillation

该项目旨在了解对流动量输运（CMT）在麦登-朱利安振荡（MJO）生命周期中的作用。MJO是从印度洋传播到太平洋的有组织对流的包络层，构成了热带季节内降水和大气环流变率的主要形式。MJO影响各种热带天气和气候现象，包括热带气旋（影响墨西哥湾的飓风）、亚洲、澳大利亚、非洲和美洲的季风和降雨的开始和季节内波动，以及厄尔尼诺现象的开始。CMT是指在对流云中由于上升气流和下降气流而发生的水平动量的垂直输送。MJO的传统理论强调对流云在输送热量和水分以及通过潜热释放驱动大尺度环流中的作用。但最近的一些研究表明，CMT可能通过MJO和更大的MJO包络内对流耦合赤道波（CCEWs）之间的双向动力学相互作用，对MJO环流的发展起着关键作用。通过对最新可用数据集的详细分析，包括在MJO动力学（DYNAMO）现场活动期间产生的数据集，主要研究人员试图实现与MJO相关的CMT的全面表征，从而提高我们对积云效应在MJO发展中的作用的理解。鉴于MJO活动对气候和天气的许多影响，MJO具有实用和科学意义。这里进行的工作有可能改善MJO的预测，通过参数化的发展，CMT的影响可以包括在用于产生MJO的长期预测的数值模型中。此外，该项目还提供支持和培养博士后，从而为该领域未来的科学劳动力提供支持。

This project seeks to understand the role of convective momentum transport (CMT) in the lifecycle of the Madden-Julian Oscillation (MJO). The MJO is an envelope of organized convection that propagates from the Indian Ocean to the Pacific Ocean and constitutes the dominant form of intraseasonal precipitation and atmospheric circulation variability in the tropics. The MJO influences a variety of tropical weather and climate phenomena,including tropical cyclones (affecting hurricanes in the Gulf of Mexico), the onset and intraseasonal fluctuations of the monsoons and rainfall over Asia, Australia, Africa, and the Americas, and the onset of El Nino events. CMT refers to the vertical transport of horizontal momentum that takes place due to the updrafts and downdrafts in convective clouds. Traditional theories of the MJO have emphasized the role of convective clouds in transporting heat and moisture, and in driving large-scale circulations through latent heat release. But some recent studies suggest that CMT may play a critical role for the development of the MJO circulation through a two-way dynamical interaction between the MJO and convectively coupled equatorial waves (CCEWs) within the much larger MJO envelope. Through detailed analysis of newly available datasets, including those produced during the Dynamics of the MJO (DYNAMO) field campaign, the principal investigators seek to achieve a comprehensive characterization of CMT associated with the MJO, and thereby improve our understanding of the role of cumulus effects on MJO development.The MJO is of practical as well as scientific interest, given the many climate and weather impacts of MJO activity. The work performed here has the potential to improve MJO forecasts, through the development of parameterizations through which the effects of CMT can be included in numerical models used to produce long-range predictions of the MJO. In addition, In addition, the project provides support and train a postdoc, thereby providing for the future scientific workforce in this area.