CAREER: Coherent Structures in Ionospheric-Thermospheric Flows

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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.