Collaborative Research: Gravity Wave-Airglow Interactions in Multiple Emission Layers

地球中高层大气中性密度的扰动被称为重力波（GWs），被认为是中间层和低层热层（MLT）大气区域物理和化学过程的重要驱动因素。GWs影响潮汐和行星波动力学以及许多大气层的环流和输送过程。这个项目的目标是研究GWs和气辉的相互作用，气辉是MLT中原子和分子在夜间发出的微弱光发射。通过这种方法，可以更好地了解GWs对MLT区域化学物种的影响。该项目将在智利安第斯激光雷达观测站（ALO）附近的一系列气辉成像仪进行多个气辉层的观测，这是一个著名的GW“热点”。这将由激光雷达和流星雷达、卫星的观测以及依赖时间的非线性大气模型的结果来补充。该项目将通过支持一名研究生和一名本科生来促进教育，并通过支持包括来自代表性不足群体的成员的团队来扩大参与。这项工作将包括在成像气辉数据的基础上表征靠近ALO的GW活性，并将GW-气辉相互作用的模拟结果与成像观测结果进行比较。最近使用二维、非线性、时变OH化学动力学（OHCD）模型和多气辉化学动力学（MACD）模型的建模结果表明，瞬态耗散GW包可以引起次要物质浓度、气辉强度和放热加热的显著变化。这种变化似乎是非周期性的，但常常被误认为是长周期波。这些是长期变化，是化学活性小物种净循环平均输送的结果。该项目将利用GW传播模型、气辉化学模型、OHCD和MACD，结合ALO的光学、激光雷达和流星雷达观测，以及来自SABER和SCIAMACHY的航天器数据，模拟由GW引起的气辉的长期变化。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。

Perturbations in the neutral density in the Earth's middle and upper atmosphere known as gravity waves (GWs) are thought to be an important driver of physical and chemical processes in the mesosphere and lower thermosphere (MLT) atmospheric region. GWs influence tidal and planetary wave dynamics as well as general circulation and transport processes across many atmospheric layers. The goal of this project is to investigate the interaction of GWs and airglow, faint optical emission emitted by atoms and molecules in MLT during the night. Through this, a better understanding of the impact of GWs on chemical species in the MLT region will be achieved. This project will conduct observations in multiple airglow layers with a chain of airglow imagers near the Andes Lidar Observatory (ALO) in Chile, a well-known GW "hotspot". This will be complemented by observations with the collocated lidar and meteor radar, satellites, and results from time-dependent, nonlinear atmospheric models. This project will promote education by supporting a graduate student and an undergraduate student and contribute to broadening participation by supporting the team that includes members from underrepresented groups.The work will involve characterization of GW activity near ALO based on the imaging airglow data and comparison of simulation results of GW-airglow interactions with imaging observations. Recent modeling results using a 2D, nonlinear, time-dependent OH Chemistry-Dynamics (OHCD) model and a Multiple-Airglow Chemistry-Dynamics (MACD) models have shown that a transient dissipating GW packet can induce significant variations in the concentrations of the minor species, in the airglow intensity, and in exothermal heating. The variations appear to be aperiodic but are often mistaken for long-period waves. These are secular variations which are a result of a net cycle-averaged transport of chemically-active minor species. The project will simulate secular variations in airglow causes by GWs by using a model of GW propagation together with airglow chemistry models, OHCD and MACD, in conjunction with optical, lidar, and meteor radar observations at ALO complemented by spacecraft data from SABER and SCIAMACHY.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.