Collaborative Research: Modeling the Nonlinear Dynamics of Deep Gravity Waves in the Mesosphere and Thermosphere

地球大气中的重力波(GW)表现出高度多样化的动力学，它们在整个大气中具有多种影响。这些波被认为是中间层和低层大气(MLT)区域的主要驱动力，这就是为什么它们是美国大气学界积极研究和辩论的主题。GW还影响着从潮汐和行星波结构和动力学到电离层中的次要物种输送和等离子体动力学等广泛的其他物理过程。因此，需要准确地描述这种影响，对于模拟气候变化、对变化的太阳强迫的反应以及空间天气等也有更广泛的影响。这个为期三年的项目的主要目的是通过最先进的数值模拟手段详细地研究GW的三维结构和动力学。该研究项目还将为航空学研究生提供一个重要的研究机会。该项目的研究和欧洲专利局议程支持AGS司在发现、学习、多样性和跨学科研究方面的战略目标。众所周知，GW在地球上层大气中发挥着重要作用。然而，由于这些波的空间尺度很小，因此很难直接建模。这导致在全球模型中使用GW参数化。这个为期三年的项目将利用有限体积模拟程序来求解GW模拟中的可压缩或非弹性三维非线性Navier-Stokes方程。该项目团队将对以下关键科学问题进行数值研究：(I)GW的时空分布如何影响GW的自加速不稳定性、耗散、平均强迫和对热层电离层的穿透？(Ii)波-波相互作用、平均风和稳定性在GW演变中扮演什么角色？以及(Iii)GW-潮汐相互作用中影响MLT和热层-电离层动力学的关键动力是什么？这一奖项反映了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。

Gravity Waves (GW) in the Earth's atmosphere exhibit highly diverse dynamics and they have multiple effects throughout the atmosphere. These waves are believed to be the main driver of the Mesosphere and Lower Atmosphere (MLT) region, which is why they are a subject of active research and debate by the Aeronomy community in the U.S. The GW also influence a wide range of other physical processes ranging from tidal and planetary wave structures and dynamics to minor species transport and plasma dynamics in the ionosphere. Therefore, the need to describe such effects accurately also has broader implications for modeling climate variations, responses to variable solar forcing, and space weather, among others. The main purpose of this three-year project is to investigate in great detail the three-dimensional structure and dynamics of GW by means of state-of-the-art numerical simulations. The research project will also provide a significant research opportunity for a graduate student in Aeronomy. The research and EPO agenda of this project supports the Strategic Goals of the AGS Division in discovery, learning, diversity, and interdisciplinary research.It is well established that GW play an important role throughout the upper atmosphere of the Earth. These waves, however, are very difficult to model directly due to their small spatial scales. That leads to the use of GW parameterization in global models. This three-year project will utilize a finite-volume simulation code to solve the compressible, or an-elastic three-dimensional non-linear Navier-Stokes equations in simulations of GW. The project team will investigate numerically the following critical scientific questions: (i) how does GW's spatial and temporal distribution influence GW's self-acceleration instability, dissipation, mean forcing, and penetration to thermosphere ionosphere?; (ii) what role do wave-wave interactions, mean wind, and stability play in GW evolution?; and, (iii) what are the key dynamics in GW-tidal interactions influencing MLT and Thermosphere-Ionosphere dynamics?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.