CAREER: Quantification of Ionosphere/Thermosphere System Drivers, State Parameters, and Fundamental Coupling Mechanisms

该项目的目标是获得中性原子氧和电离原子氧之间电荷交换的温度依赖截面的第一个明确的量化，这介导了地球电离层和热层（IT系统）之间的动量和能量交换。这些参数的历史不确定性限制了许多航空计算的定量准确性，例如电离层温度和密度分布、扩散系数和等离子体漂移速度，有效地排除了对耦合IT系统稳态和动态行为的可靠预测。该研究项目将涉及硬件开发和部署、反演和层析分析开发、基于物理的模型开发以及科学数据分析和解释。获得这些参数的关键量化的方法将利用波多黎各阿雷西博天文台的无源光学和非相干散射雷达（ISR）仪器的嵌套配置，包括一个新的光度成像系统（层析氢传感光度计阵列；PATHS），该系统将由伊利诺伊大学的本科生通过顶点项目课程设计和建造。所得到的数据，加上光学发射的实际辐射输运模型的发展和从ISR光谱估计光离子速度的进展，将使中性、离子和电子温度的高度和时间依赖的量化成为可能；不同的质子和氧离子速度；中性经向风速；电离氧、氢和氦的密度；并且，第一次，中性氧和氢的密度分布在整个上层热层。电离层和热层之间的电荷交换耦合（通过参数动量平衡）以及外逸层和等离子层之间的电荷交换耦合（通过参数连续性平衡）的量化将有助于理解质量、能量和动量如何在耦合区域内传输。该项目将涉及研究生和本科生，并包括针对上大学前女孩的外展活动，以促进该学科未来的性别多样性。

The goal of this project is to obtain the first unambiguous quantification of the temperature-dependent cross section for charge exchange between neutral and ionized atomic oxygen which mediates momentum and energy exchange between the terrestrial ionosphere and thermosphere (IT system). Historical uncertainty in these parameters has limited the quantitative accuracy of numerous aeronomical calculations, such as ionospheric temperatures and density distributions, diffusion coefficients, and plasma drift speeds, effectively precluding reliable prediction of both steady-state and dynamic behavior of the coupled IT system. The research program will involve hardware development and deployment, inverse and tomographic analysis development, physics-based model development, and scientific data analysis and interpretation. The methodology to obtain the crucial quantification of these parameters will utilize a nested configuration of passive optical and incoherent scatter radar (ISR) instrumentation at Arecibo Observatory in Puerto Rico, including a novel photometric imaging system (Photometer Array for Tomographic Hydrogen Sensing; PATHS) that will be designed and built by undergraduate students at the University of Illinois through a capstone project course. The resulting data, together with the development of realistic radiative transport models of optical emissions and advances in the estimation of light ion velocity from ISR spectra, will enable the height- and time-dependent quantification of neutral, ion, and electron temperatures; distinct proton and oxygen ion velocities; neutral meridional wind speed; ionized oxygen, hydrogen, and helium density; and, for the first time, the neutral oxygen and hydrogen density distributions throughout the upper thermosphere. Quantification of the charge exchange coupling between the ionosphere and thermosphere (via parametric momentum balance) as well as between the exosphere and plasmasphere (via parametric continuity balance) will enable advances in understanding how mass, energy and momentum are transported throughout the coupled regions. The project will involve graduate and undergraduate students, and include outreach activities targeting pre-college girls in order to promote the future gender diversity in this discipline.