Collaborative Research: CEDAR--A Whole-Atmospheric Perspective on Connections between Intra-Seasonal Variations in the Troposphere and Thermosphere

该合作奖旨在研究热层风的变化与热带对流层产生的波结构引起的变化之间的关系。这种耦合是由热带对流层中的深对流的波激发驱动的，该深对流可以垂直传播到热层。与马登-朱利安振荡（MJO）相关的对流层对流是热带对流和环流季节内变化的主要模式，已知会调制向上传播的重力波和开尔文波的强度。 先前的工作表明，在2009-2010年期间，对流层对流的90天振荡印在热层平均风和向东传播的波数3日（DE 3）潮汐振幅。GOCE和CHAMP卫星观测到了这种调制，并用TIME-GCM进行了模拟。研究工作将扩大参与，通过参与和培训两名本科生实习生通过科罗拉多大学BOLD实习计划，重点是促进传统上代表性不足的工程专业学生的招聘，保留和发展。这项新研究将对最近的研究结果采取后续行动，这些研究表明对流层和热层之间的强耦合发生在季节内的时间尺度上。该奖项将解决以下问题：Q1：在过去二十年中，对流层、中间层和热层三个区域的30至100天变化之间的相关性有多频繁、普遍和持久？问题2：大尺度向上传播的波在热带对流层季节内变率与热层的动力耦合中扮演什么样的角色？问题3：是否有任何观测证据表明这种对流层-热层季节内耦合与MJO、准两年振荡（QBO）和厄尔尼诺-南方涛动（ENSO）之间存在联系？将对现有高层大气卫星数据与地面数据集和模型数据集的结合进行研究，以便深入了解波浪的季节内变化是由对流层源的变化还是由波浪-平均流相互作用引起的。在后一种情况下，研究将确定在哪些高度发生这些相互作用。这项研究将确定对流层和热层之间的全球尺度波耦合的贡献，从而解决CEDAR社区具有根本重要性的突出问题。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估来支持。

This collaborative award is aimed at studying the relationship between the variability of thermospheric winds to the variability caused by wave structures generated in the tropical troposphere. This coupling is driven by wave excitation by deep convection in the tropical troposphere that can propagate vertically into the thermosphere. Tropospheric convection associated with the Madden‐Julian Oscillation (MJO), the dominant mode of intra-seasonal variability in tropical convection and circulation, is known to modulate the intensity of upward‐propagating gravity and Kelvin waves. Previous work demonstrated that a 90-day oscillation in tropospheric convection during 2009-2010 was imprinted on both thermospheric mean winds and the eastward propagating wavenumber 3 diurnal (DE3) tidal amplitudes. This modulation was observed by the GOCE and CHAMP satellites and modeled with the TIME-GCM. The research effort would broaden participation by involving and training two undergraduate student interns through the University of Colorado BOLD internship program that focuses on promoting the recruitment, retention, and development of traditionally underrepresented engineering students. The new research will follow up on the results obtained in recent studies that demonstrated that strong coupling between the troposphere and the thermosphere occurs on intra-seasonal timescales. The award will address the following questions: Q1: How frequent, prevalent, and persistent are correlations between 30 to 100-day variations in the three regions of troposphere, mesosphere, and thermosphere, during the past two decades? Q2: What plausible roles do large-scale upward propagating waves play in dynamically coupling tropical tropospheric intra-seasonal variability into the thermosphere? Q3: Is there any observational evidence suggesting a connection between this troposphere-thermosphere intra-seasonal coupling and MJO, Quasi-Biennial Oscillation (QBO) and El Niño-Southern Oscillation (ENSO)? The combination of available upper atmosphere satellite data with ground-, and model-based datasets would be studied to provide insight into whether the intra-seasonal variations in the waves are caused by variability in the tropospheric sources or by wave-mean flow interactions. In the case of the latter, the study would determine at which heights these interactions are occurring. This study will determine the contribution of global-scale wave coupling between the troposphere and the thermosphere, thus addressing outstanding issues of fundamental importance to the CEDAR community.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.