CAREER: Coherent Structures in Ionospheric-Thermospheric Flows

检查和比较电离层和热层的流场结构可以告诉我们为什么它们在某些时候可能是对齐的，而在其他时候却不是。作为这个职业奖的一部分，PI将整合地球空间科学，等离子体动力学和遥感教育，以不同的背景。教育活动包括：（1）通过波音学者学院向地区高中中代表性不足的少数民族推广地球和空间科学;（2）通过印度理工学院跨专业项目方案，通过跨学科项目学习进行本科教育;（3）印度理工学院AIAA学生分会高空气球项目的本科研究培训和本科生辅导;（4）研究生课程开发; 5）多位博士研究生导师。和史密斯论文除了通过出版物、专题介绍和讲习班向更广泛的科学界进行传播之外，还将开展这些活动。在物理学的许多领域中，一个常见的问题是物质在运动介质中的运动。 近年来，一种称为拉格朗日相干结构（LCS）的数学技术已被用于模拟这些材料如何随时间漂移和扩散。 LCS表示非定常流中的材料表面，分离区域以不同的方式演化。无论动力学方程是未知的还是不可解的，LCS都可以是流中的组织结构，为理解系统相互作用提供了新的背景和框架。LCS分析借鉴了其他学科的最新知识，它处理非定常流，一个历史上复杂和不可预测的现象。LCS通过提供导致非定常流发散的物理过程的证据，可以帮助我们完善对潜在动力学的理解。 虽然LCS已被用于研究风、空气动力学流动和流体中物质云的运动，但它从未被应用于高层大气。 在这项研究中，研究人员将使用LCS来研究结构的行为（例如，大气层上部沉积的大气颗粒物（如流星烟雾颗粒、与气候变化有关的污染物、空间碎片）。目标是利用LCS确定中高纬度流场及其时间演变、在扰动条件下探测和跟踪这些结构的能力以及赤道纬度湍流混合的播种和传播，这会导致影响高频通信和卫星导航的小规模扰动和无线电信号闪烁。本研究中LCS的成功开发可以使未来LCS分析赤道地区垂直流运动的研究成为可能。LCS分析可用于了解IT流体中可能导致闪烁的混沌混合，从而更好地进行操作预测。

Examining and comparing the flow field structures of both ionosphere and thermosphere can tell us why they might be aligned at certain times but not at others. As part of this CAREER award, the PI will integrate geospace science, plasma dynamics and remote sensing education to a diverse range of backgrounds. Educational activities include 1) Earth and space science outreach to underrepresented minorities at area high schools through the Boeing Scholars Academy; 2) undergraduate education through interdisciplinary project-based learning via the IIT Interprofessional Projects program (IPRO); 3) undergraduate research training and undergraduate mentoring of the IIT AIAA student chapter high altitude balloon project; 4) curriculum development at the graduate level; 5) graduate mentoring for multiple Ph.D. and M.S. theses. These activities will be undertaken in addition to dissemination efforts via publications, presentations, and workshops to the broader scientific community. A common problem in many areas of physics is the motion of material in a moving medium. In recent years, a mathematical technique called Lagrangian Coherent Structures (LCS) has been used to model how these materials drift and spread with time. LCS represent the material surface in an unsteady flow separating regions that evolve in qualitatively different ways. Whether the dynamical equations are unknown or unsolvable, the LCS can be an organizing structure in the flow that provides a new context and framework for understanding the system interactions. LCS analysis draws upon the latest knowledge in other disciplines, and it treats the unsteady flow, a historically complex and unpredictable phenomenon. LCS can help to refine our understanding of the underlying dynamics, by providing evidence of the physical processes that lead to unsteady flow divergence. Although LCS has been used to study the motion of clouds of material in wind, aerodynamic flows, and fluids, it has never been applied to the upper atmosphere. In this study, the investigators will use LCS to investigate the behavior of structures (e.g., meteoric smoke particles; climate change-related pollutants; space debris) deposited in the upper atmosphere. The goal is to use LCS to determine the mid-to-high-latitude flow fields and their time evolution, the ability to detect and follow these structures during disturbed conditions, and the seeding and propagation of turbulent mixing at equatorial latitudes, which leads to small-scale disturbances and radio signal scintillation that affects HF communications and satellite-based navigation. Successful development of LCS in this study can enable future studies of LCS analyzing the motion of vertical flow in equatorial regions. LCS analysis can be used to understand the chaotic mixing in IT fluid that may cause scintillation, leading to better operational forecasting.