Effects of Background Wind on the Eastward Propagation of Madden Julian Oscillation (MJO)

马登-朱利安振荡（MJO）是指有组织的大尺度热带对流系统缓慢向东传播，平均时间尺度为40-60天。当它们这样做时，它们会影响全球天气模式。其中一个有待完全理解的问题是，为什么这些事件中的一些比另一些移动得更快或更慢。该项目旨在通过将其与缓慢演变的背景风联系起来，解释MJO向东传播速度的部分变化。通过对观测数据和模型数据的分析，该项目将确定这些背景风如何改变热带降雨区的移动以及相关的全球天气模式。一个独特的组合的统计和背景动量预算分析将有助于隔离热带入侵的外来扰动的作用，在调节背景风系统，从而事件间的变化的东移传播速度的MJO.天气模型不能很好地预测这些热带降雨模式的演变。更好地了解MJO如何与全球天气相互作用，将有助于改善未来2-5周重要决策时期的天气预报。更好地了解这些背景风模式如何影响MJO的传播也有助于确定现有数值天气预报模型的误差来源。研究生将接受培训，以开展研究活动，并将在会议上发表论文，并提交结果供同行评审。该奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

The Madden Julian Oscillation (MJO) is referred to organized large-scale tropical convection system that slowly propagate eastward with an average time scale of 40-60 days around the equator. As they do so, they influence global weather patterns. One of the questions that remains to be understood fully is why some of these events move faster or slower than others. This project aims to explain part of the variability in the eastward propagating speed of MJO by linking it to slowly evolving background winds. Through analysis of observed and model data, this project will identify how these background winds alter the movements of the regions of tropical rainfall and the associated global weather patterns. A unique combination of statistics and the background momentum budget analyses will help to isolate the roles of tropical intrusion of extratropical disturbances in regulating the background wind system and thereby inter-event variations of eastward propagating speeds of MJO.Weather models do not predict well how these tropical rainfall patterns evolve. The improved understanding of how MJO interacts with the global weather would help improve weather forecasting in the important period for decision, 2-5 weeks into the future. Better understanding how these background wind patterns influence MJO's propagation also help identify error sources of existing numerical weather prediction models. Graduate students will be trained to perform research activities and will present papers at conferences and submit results for peer review.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.