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

合作研究：CEDAR——对流层和热层季节内变化之间联系的整体大气视角

• 批准号: 2113411
• 负责人: Federico Gasperini
• 金额: $ 36.03万
• 依托单位: ATMOSPHERIC & SPACE TECHNOLOGY RESEARCH ASSOCIATES, L.L.C.
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-06-01 至 2024-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2113411&HistoricalAwards=false
• 关键词: Collaborative; Research; CEDAR; Whole; Atmospheric

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.

该合作奖旨在研究热层风的变率与热带对流层产生的波浪结构引起的变率之间的关系。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的波激发驱动的。与麦登-朱利安涛动（MJO）相关的对流层对流，是热带对流和环流的主要季节性变化模式，已知可调节向上传播的重力和开尔文波的强度。先前的研究表明，在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3波数日（DE3）潮汐振幅上都有印记。这种调制由GOCE和CHAMP卫星观测到，并用TIME-GCM建模。这项研究工作将通过科罗拉多大学BOLD实习计划，通过招募和培训两名本科生实习生来扩大参与范围，该计划的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。新的研究将继续最近的研究结果，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、普遍和持续？Q2：大尺度向上传播波在热带对流层季节内变率与热层的动态耦合过程中扮演了什么貌似合理的角色？Q3：是否有观测证据表明对流层-热层季节性耦合与MJO、准两年一次振荡（QBO）和厄尔尼诺Niño-Southern振荡（ENSO）之间存在联系？将对现有高层大气卫星数据与地面和基于模式的数据集相结合进行研究，以深入了解波的季节内变化是由对流层源的变率还是由波-平均流相互作用引起的。在后者的情况下，研究将确定这些相互作用发生在哪个高度。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CEDAR社区具有根本重要性的突出问题。该奖项反映了美国国家科学基金会的法定使命，并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，被认为值得支持。