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

该项目将开发一个中层/低热层区域的二维依赖时间的非线性化学-动力学模式，以模拟两个气辉发射对大气重力波的响应。重力波很重要，因为它们将能量和动量从低层大气传输到高层大气，在那里它们可以通过波-平均流相互作用来储存能量和动量。在化学扰动和垂直输送的共同作用下，这些相互作用可导致大气物种分布的扰动；也可引起放热变化。除了重力波，中间层/低热层区域的气辉是大气科学界的另一个重要研究课题：气辉强度的变化常常可用来推断引起这种变化的重力波或其他类型的波的特征。该项目包括重力波和气辉发射两种元素，通过构建一个模型，其中包括单色重力波动力学代码和模拟两种气辉发射的化学代码：OH和O2大气(0，1)波段。该模型将用于研究以下问题：1)重力波对无风大气和恒定背景风条件下的OH和O2(B1)气辉发射层的影响；2)气辉对各种不同重力波特征的响应；3)波诱导的气辉强度和两个气辉层的强度加权温度的长期变化；4)与气辉层的各种模拟相关的幅度增长因子；5)波诱导的气体物种浓度的长期变化；以及6)与不同的重力波通过有关的波诱导的放热。将与观测结果进行比较，以检验和验证该模型。本科生将通过分析模拟的气辉排放来确定重力波的影响，共同撰写描述这项工作的论文，并在年度雪松会议等专业会议上展示一些结果，从而参与该项目。这项研究得出的模型将为社区提供一个独特的工具。

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.