Eigenmode Analysis of Compressional Poloidal Modes in a Self-Consistent Magnetic Field

dc.contributor.ORCID0000-0003-2489-3571 (Chen, L)
dc.contributor.ORCID/0000-0001-9068-4431 (Zheng, L)
dc.contributor.authorXia, Zhiyang
dc.contributor.authorChen, Lunjin
dc.contributor.authorZheng, Liheng
dc.contributor.authorChan, Anthony A.
dc.contributor.utdAuthorXia, Zhiyang
dc.contributor.utdAuthorChen, Lunjin
dc.contributor.utdAuthorZheng, Liheng
dc.date.accessioned2019-07-12T22:26:45Z
dc.date.available2019-07-12T22:26:45Z
dc.date.created2017-10-23
dc.description.abstractIn this study, we simulate a self-consistent magnetic field that satisfies force balance with a model ring current that is radially localized, axisymmetric, and has anisotropic plasma pressure. We find that the magnetic field dip forms near the high plasma pressure region with plasma β >~ 0.6, and the formed magnetic dip becomes deeper for larger plasma β and also slightly deeper for larger anisotropy. We perform linear analysis on a ppol of self-consistent equilibria for second harmonic compressional poloidal modes of sufficiently high azimuthal wave number. We investigate the effect of anisotropic pressure on the eigenfrequency of the poloidal modes and the characteristics of the compressional magnetic field component. We find that the eigenfrequency is reduced at the outer edge of the thermal pressure peak and increased at the inner edge. The compressional magnetic field component occurs primarily within 10 degrees of the equator on both the inner and outer edges, with stronger compressional magnetic field component on the outer edge. Larger β and smaller anisotropy can increase the change of eigenfrequency and the strength of the compressional magnetic field component. The critical condition on plasma β and pressure anisotropy of an Alfven ballooning instability is also identified.
dc.description.departmentSchool of Natural Sciences and Mathematics
dc.description.sponsorshipNSF Geospace Environment Modeling Grant 1405041, the AFOSR grant FA9550‐16‐1‐0344, and NASA grant NNX15AF55G and NNX17AI52G.
dc.identifier.bibliographicCitationXia, Zhiyang, Lunjin Chen, Liheng Zheng, and Anthony A. Chan. 2017. "Eigenmode analysis of compressional poloidal modes in a self-consistent magnetic field." Journal of Geophysical Research: Space Physics 122(10), 10369-10381, doi:10.1002/2017JA024376
dc.identifier.issue10
dc.identifier.urihttps://hdl.handle.net/10735.1/6703
dc.identifier.volume122
dc.language.isoen
dc.publisherAmer Geophysical Union
dc.relation.urihttp://dx.doi.org/10.1002/2017JA024376
dc.rights©2017 American Geophysical Union
dc.source.journalJournal of Geophysical Research: Space Physics
dc.subjectSpace plasmas
dc.subjectMagnetosphere
dc.subjectMagnetohydrodynamic waves
dc.subjectMagnetospheric physics
dc.subjectMagnetic fields
dc.subjectAnisotropy
dc.titleEigenmode Analysis of Compressional Poloidal Modes in a Self-Consistent Magnetic Field
dc.type.genrearticle

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