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

马登-朱利安振荡(MJO)是指在赤道周围缓慢向东传播的有组织的大尺度热带对流系统，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。有待完全理解的问题之一是，为什么这些事件中的一些比其他事件进展得更快或更慢。该项目旨在通过将MJO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运动和相关的全球天气模式。统计和背景动量收支分析的独特结合将有助于分离热带入侵和温带外扰动在调节背景风系统中的作用，从而有助于分离MJO向东传播速度的事件间变化。天气模式不能很好地预测这些热带降雨型的演变。更好地了解MJO如何与全球天气相互作用，将有助于在未来2-5周后的重要决策期改进天气预报。更好地了解这些背景风型如何影响MJO的传播，也有助于确定现有数值天气预报模式的误差源。研究生将接受进行研究活动的培训，并将在会议上提交论文并提交结果供同行评审。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响评审标准进行评估，被认为值得支持。

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.