RUI: Gravity Wave Effects in the Mesosphere/Lower Thermosphere (MLT) Region with a 2-D, Nonlinear, Multiple-Airglow Chemistry-Dynamics Model

该项目将开发一个二维时间相关的中间层/低层热层非线性化学动力学模型，以模拟两种气辉发射对大气重力波的响应。引力波很重要，因为它们将能量和动量从低层大气输送到高层大气，在那里它们可以通过波平均流相互作用将能量和动量沉积下来。这些相互作用可通过化学扰动和垂直输送的联合作用对大气物种的分布造成扰动；放热变化也可能引起。除了重力波之外，中间层/低层热层区的气辉也是大气科学界的另一个重要研究课题：气辉强度的变化通常可以用来推断引起这种变化的重力波或其他类型的波的特征。该项目包括两个元素，重力波和气辉发射，通过构建一个模型，其中包括单色重力波动力学代码和化学代码，模拟两种气辉发射：OH和O2大气（0,1）波段。该模式将用于研究以下主题：1)无风大气和恒定背景风条件下重力波对OH和O2（b1）气辉发射层的影响；2)气辉对各种不同重力波特性的响应；3)气辉强度和两层气辉强度加权温度的波致长期变化；4)与气辉层的各种模拟有关的幅值增长因子；5)波动引起的气体种类浓度的长期变化；6)不同重力波通过引起的波致放热。将与观测结果进行比较，以检验和验证该模型。本科生将参与该项目，通过分析模拟气辉发射来确定重力波的影响，共同撰写描述工作的论文，并在年度雪松会议等专业会议上展示部分结果。这项研究产生的模型将为社区提供独特的工具。

The project will develop a 2-D time-dependent nonlinear chemistry-dynamics model of the mesosphere/lower thermosphere region to simulate the response of two airglow emissions to atmospheric gravity waves. Gravity waves are important because they transport energy and momentum from the lower atmosphere to the upper atmosphere, where they can deposit their energy and momentum through wave-mean flow interactions. These interactions can result in perturbations to the distributions of atmospheric species by the combined effects of chemical perturbations and vertical transport; exothermic heating variations may also be induced. In addition to gravity waves, airglow in the mesosphere/lower thermosphere region constitutes another important research topic in the atmospheric science community: variations in airglow intensity can oftentimes be used to deduce characteristics of gravity waves or other types of waves that cause the variations. The project includes both elements, gravity waves and airglow emissions, by constructing a model that includes a monochromatic gravity wave dynamics code and a chemistry code that simulates two airglow emissions: OH and the O2 atmospheric (0,1) band. The model will be used to study the following topics: 1) gravity wave effects on the OH and O2(b1) airglow emission layers in a windless atmosphere and for a constant background wind condition; 2) the airglow response to a variety of different gravity wave characteristics; 3) wave-induced secular variations of the airglow intensities and the intensity-weighted temperatures of the two airglow layers; 4) the amplitude growth factor associated with the various simulations of the airglow layers; 5) wave-induced secular variations of gas species concentrations; and 6) wave-induced exothermic heating associated with the passage of different gravity waves. Comparisons with observations will be made to test and validate the model. Undergraduate students will participate in the project by analyzing the simulated airglow emissions to determine the effects of gravity waves, co-authoring the papers describing the work, and presenting some of the results at professional meetings such as the annual CEDAR meeting. The model resulting from this research will provide a unique tool to the community.