Show simple item record

dc.contributor.authorLin, Dongen_US
dc.date.accessioned2020-11-21T07:00:16Z
dc.date.available2020-11-21T07:00:16Z
dc.date.issued2019-05-30
dc.identifier.othervt_gsexam:19911en_US
dc.identifier.urihttp://hdl.handle.net/10919/100903
dc.description.abstractSolar wind-magnetosphere-ionosphere (SW-M-I) coupling is investigated with three different computational models that characterize space plasma dynamics on distinct spatial/temporal scales. These models are used to explore three important aspects of SW-M-I coupling. A particle-in-cell (PIC) model has been developed to explore the kinetic scale dynamics associated with the magnetotail dipolarization front (DF), which is generated as a result of magnetotail reconnection. The PIC study demonstrates that the electron-ion hybrid (EIH) instability could relax the velocity shear within the DF via emitting lower hybrid waves. The velocity inhomogeneity driven instability is highlighted as an important mechanism for energy conversion and wave emission during the solar wind-magnetosphere coupling, which has been long neglected before. The Lyon-Fedder-Mobbary (LFM) global magnetohydrodynamic (MHD) model is used to explore the fluid scale electrodynamic response of the magnetosphere-ionosphere to the interplanetary electric field (IEF). It is found that the cross polar cap potential (CPCP) varies linearly with very large IEF if the solar wind density is high enough. With controlled experiments of global MHD modeling driven by observed parameters, the linearity was interpreted as a result of the magnetosheath force balance theory. This study highlights the role of solar wind density in the electrodynamic SW-M-I coupling under extreme driving conditions. The LFM-TIEGCM-RCM (LTR) model, which is the Coupled-Magnetosphere-Ionosphere-Thermosphere (CMIT) model with Ring Current extension, is used to explore the integrated SW-M-I system. The LTR simulation study focuses on the subauroral polarization streams (SAPS), which involve both MHD and non-MHD processes and three-way coupling in the SW-M-I system. The global structure and dynamic evolution of SAPS are illustrated with state-of-the-art first-principle models for the first time. This study has successfully utilized multiscale models to characterize the forefront issues in the space plasma dynamics, which is required by the facts that plasmas have both particle and fluid featured properties and those properties are vastly different across geospace regions. It is highlighted that SW-M-I coupling could be significantly influenced by both microscopic and macroscopic processes. In order for a comprehensive understanding of the SW-M-I coupling, multiscale models and integrated framework of their combinations are critical.en_US
dc.format.mediumETDen_US
dc.publisherVirginia Techen_US
dc.rightsThis item is protected by copyright and/or related rights. Some uses of this item may be deemed fair and permitted by law even without permission from the rights holder(s), or the rights holder(s) may have licensed the work for use under certain conditions. For other uses you need to obtain permission from the rights holder(s).en_US
dc.subjectSW-M-I couplingen_US
dc.subjectParticle-in-cell modelen_US
dc.subjectGlobal MHD modelen_US
dc.subjectLTR modelen_US
dc.titleSolar Wind-Magnetosphere-Ionosphere Coupling: Multiscale Study with Computational Modelsen_US
dc.typeDissertationen_US
dc.contributor.departmentElectrical Engineeringen_US
dc.description.degreeDoctor of Philosophyen_US
thesis.degree.nameDoctor of Philosophyen_US
thesis.degree.leveldoctoralen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
thesis.degree.disciplineElectrical Engineeringen_US
dc.contributor.committeechairScales, Wayne A.en_US
dc.contributor.committeememberZhu, Yizhengen_US
dc.contributor.committeememberRuohoniemi, John Michaelen_US
dc.contributor.committeememberBaker, Joseph Benjaminen_US
dc.contributor.committeememberSrinivasan, Bhuvanaen_US
dc.contributor.committeememberClauer, C. Roberten_US


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record