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

这一合作奖的目的是研究热层风的可变性与热带对流层产生的波结构引起的可变性之间的关系。这种耦合是由可以垂直传播到热层的热带对流层深层对流所激发的波驱动的。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中季节内变化的主要模式，已知的是调制向上传播的重力波和开尔文波的强度。以前的工作表明，2009-2010年期间对流层对流的90天振荡在热层平均风和向东传播的波数3日(DE3)潮汐幅度上都留下了印记。GOCE和CHAMP卫星观测到了这种调制，并用时间-GCM进行了模拟。这项研究工作将通过科罗拉多大学的大胆实习计划让两名本科生实习生参与并培训他们，以扩大参与范围，该计划的重点是促进传统上代表性较低的工程学学生的招聘、留住和发展。这项新的研究将跟进最近的研究结果，这些结果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20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2：在热带对流层季节内变化与热层的动态耦合中，大尺度向上传播波扮演了什么看似合理的角色？问：是否有任何观测证据表明对流层-热层季节内耦合与MJO、准两年期振荡(QBO)和厄尔尼诺-南方涛动(ENSO)之间存在联系？将研究现有的高层大气卫星数据与地面数据集和模型数据集的结合，以深入了解波的季节内变化是由对流层源的可变性造成的，还是由波-平均流相互作用造成的。在后一种情况下，研究将确定这些相互作用发生的高度。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，从而解决对雪松社区至关重要的悬而未决的问题。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审查标准进行评估，被认为值得支持。

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.