Numerical analysis of the coupled hydromagnetic wave equations in the magnetosphere

Journal Article · Thu Sep 01 04:00:00 EDT 1988 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/JA093iA09p09721· OSTI ID:5994595

Krauss-Varban, D; Patel, V L ^[1]

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1. Univ. of Denver, CO (United States)

Inside the magnetosphere two basic hydromagnetic modes, the poloidal and toroidal, are always coupled. The problem of coupled waves is of fundamental importance for nontrivial geometries and general field configuartions. As a first step the box model is investigated here, using the ideal MHD equations for the cold plasma. The spectrum and eigenfunctions are calculated for several cases by applying the finite element method. Both the improper continuum eigenmodes as well as the discrete solutions are computed. Existing analytical results are confirmed, and it is found that the discrete modes situated inside the Alfven continuum are the best condidates for explaining observed hydromagnetic resonances. Other properites of these global modes are derived and compared with exsperimental data, and satisfactory agreement is obtained despite the simple geometric model employed. Generally, damping of the discrete modes is found to be considerably lower than that of the continuum. The results indicate that the weakly damped global modes lose their energy directly through ionospheric Joule dissipation, and not via mode conversion to field line resonances.

• OSTI ID: 5994595
• Journal Information: Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 93:A9; ISSN JGREA; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

661320* -- Auroral
Ionospheric
& Magnetospheric Phenomena-- (1992-)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
COLD PLASMA
COMPARATIVE EVALUATIONS
EARTH ATMOSPHERE
EARTH MAGNETOSPHERE
ENERGY LOSSES
EVALUATION
FINITE ELEMENT METHOD
HYDROMAGNETIC WAVES
IONOSPHERE
LOSSES
MAGNETIC FIELD CONFIGURATIONS
MATHEMATICAL MODELS
MATHEMATICS
MODE CONVERSION
NUMERICAL ANALYSIS
NUMERICAL SOLUTION
PLANETARY IONOSPHERES
PLASMA