Date of Award
Spring 2024
Access Type
Dissertation - ERAU Login Required
Degree Name
Doctor of Philosophy in Engineering Physics
Department
Physical Sciences
Committee Chair
Katariina Nykyri
Committee Co-Chair
Matthew Zettergren
First Committee Member
Xuanye Ma
Second Committee Member
Byonghoon Seo
Third Committee Member
Chih-Ping Wang
Abstract
The Earth’s magnetosphere serves as an invisible, yet protective shield, consistently safeguarding the planet and its atmosphere from the potentially harmful effects of the solar wind plasma and the accompanying magnetic field. However, this magnetic shielding is not always absolute. Certain processes allow a portion of the plasma mass, momentum, and energy of solar wind to transfer to the magnetosphere and ionosphere.
A variety of physical mechanisms, including shocks, magnetic reconnection, plasma waves, and instabilities, are proposed to explain these interactions. In this thesis, we focus on multiple topics regarding these physical processes on the dayside geospacer boundaries. First, we revisit the Kelvin-Helmholtz Instability and Flux Transfer Events to determine the influence of misidentifying between those boundary layer signatures on the solar wind and magnetosphere coupling. By using two-dimensional magnetohydrodynamics (MHD) simulations, we are able to demonstrate how the magnetic field fluctuations in the boundary normal component vary with respect to the satellite trajectory and magnetic incline angle. Second, we investigate the origin of microinjections at high-latitude and their dependence on solar wind conditions. We have performed an event search and a statistical study of their properties encompassing a total of approximately 165 hours (47 microinjection events) of Magnetospheric Multiscale (MMS) observations at the pre-dusk sector. We found that over 60% of these microinjections satisfy the criteria of the drift mirror instability, which indicates that temperature anisotropy could play an important role for the microinjection. Furthermore, we provide the estimation of the thicknesses of solar wind current sheets to evaluate the instrumental requirements of the Seven Sisters mission concept, which is dedicated for the study of the inner heliospheric structures, dynamics, and space weather forecasting. We believe that progress in understanding these processes, presented in this thesis, will improve understanding between the dayside geomagnetic system and the interplanetary environment.
Scholarly Commons Citation
Liou, Yu-Lun, "Plasma Physical Processes of the Dayside Geospace Solar Wind-Magnetosphere Coupling" (2024). Doctoral Dissertations and Master's Theses. 811.
https://commons.erau.edu/edt/811
