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A magnetospheric energy principle for hydromagnetic stability problems
http://hdl.handle.net/2261/38137
http://hdl.handle.net/2261/38137f5e79523-611d-4b43-bfcc-78046335fcfb
名前 / ファイル | ライセンス | アクション |
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JGR_A112_NA06_a06234.pdf (464.1 kB)
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Item type | 学術雑誌論文 / Journal Article(1) | |||||
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公開日 | 2016-12-28 | |||||
タイトル | ||||||
タイトル | A magnetospheric energy principle for hydromagnetic stability problems | |||||
言語 | ||||||
言語 | eng | |||||
キーワード | ||||||
主題Scheme | Other | |||||
主題 | MHD instabilities | |||||
キーワード | ||||||
主題Scheme | Other | |||||
主題 | energy principle | |||||
キーワード | ||||||
主題Scheme | Other | |||||
主題 | pressure-driven instabilities | |||||
資源タイプ | ||||||
資源タイプ識別子 | http://purl.org/coar/resource_type/c_6501 | |||||
資源タイプ | journal article | |||||
著者 |
Miura, Akira
× Miura, Akira |
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著者所属 | ||||||
値 | Department of Earth and Planetary Physics, University of Tokyo | |||||
抄録 | ||||||
内容記述タイプ | Abstract | |||||
内容記述 | A magnetospheric energy principle is formulated to study hydromagnetic stability of a magnetospheric plasma. The magnetospheric plasma is either in a two-dimensional or three-dimensional static equilibrium. It is surrounded by lateral perfectly conducting walls and ideal ionospheres in both cases and also by dawn-dusk periodic boundaries in the two-dimensional case. The two-dimensional case has a translational symmetry and has no unperturbed magnetic field component in the dawn-dusk direction. Unlike the conventional energy principle for a plasma surrounded by a perfectly conducting wall, field lines are assumed to vertically thread the ionospheric boundary, which is not a perfectly conducting rigid wall. Ideal ionospheric boundary conditions are obtained, so that the force operator becomes self-adjoint and the magnetospheric energy principle is valid. There are four ideal ionospheric boundary conditions to satisfy these requirements: horizontally free, conducting, free, and rigid. A change in the potential energy becomes equal to the sum of the change in the fluid energy and an ionospheric surface contribution, which is negative and thus destabilizing for horizontally free and free ionospheric boundary conditions. A minimization condition for the change in the potential energy is obtained. When an unperturbed field-aligned current vanishes, the horizontally free, conducting, free, and rigid boundary conditions allow interchange, incompressible ballooning, incompressible ballooning, and compressible ballooning modes, respectively. Different characteristics of those three pressure-driven modes are clarified. Existing interchange stability criteria are compared and results of several different numerical stability analyses of ballooning instabilities for different magnetospheric equilibria are discussed systematically in light of the present magnetospheric energy principle. | |||||
書誌情報 |
Journal of geophysical research. A 巻 112, 号 6, p. A06234, 発行日 2007-06 |
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ISSN | ||||||
収録物識別子タイプ | ISSN | |||||
収録物識別子 | 01480227 | |||||
書誌レコードID | ||||||
収録物識別子タイプ | NCID | |||||
収録物識別子 | AA10819721 | |||||
DOI | ||||||
識別子タイプ | DOI | |||||
関連識別子 | info:doi/10.1029/2006JA011992 | |||||
権利 | ||||||
権利情報 | copyright 2007 by the American Geophysical Union | |||||
日本十進分類法 | ||||||
主題Scheme | NDC | |||||
主題 | 450 | |||||
出版者 | ||||||
出版者 | American Geophysical Union |