Large scale instabilities and dynamics of the magnetotail plasma sheet
The stability properties of the magnetotail current sheet against large scale modes is reviewed in the framework of ideal MHD, resistive MHD, and collisionless Vlasov theory. It appears that the small deviations from a plane sheet pinch (in particular a magnetic field component normal to the sheet) are important to explain the transition of the tail from a quiet stable state to an unstable dynamic state. It is found that the tail is essentially stable in ideal MHD, but unstable in resistive MHD, while both stable and unstable configurations are found within collisionless theory. The results favor an interpretation where the onset of magnetotail dyanmics leading to a sudden thinning of the plasma sheet and the ejection of a plasmoid is caused by the onset of a collisionless instability that either directly leads to the growth of a collisionless tearing mode or via microscopic turbulence to the growth of a resistive mode. The actual onset conditions are not fully explored yet by rigorous methods. The onset may be triggered by local conditions as well as by boundary conditions at the ionosphere or at the magnetopause (resulting from solar wind conditions). 53 refs., 5 figs.
- Research Organization:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Bochum Univ. (Germany, F.R.)
- DOE Contract Number:
- W-7405-ENG-36
- OSTI ID:
- 6736944
- Report Number(s):
- LA-UR-87-183; CONF-8610233-1; ON: DE87005101
- Resource Relation:
- Journal Volume: 44; Conference: 1. Huntsville workshop on magnetosphere/ionosphere plasma models, Guntersville, AL, USA, 13 Oct 1986; Other Information: Portions of this document are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GENERAL PHYSICS
MAGNETOTAIL
DYNAMICS
PLASMA INSTABILITY
COMPUTERIZED SIMULATION
IONOSPHERE
MAGNETOHYDRODYNAMICS
MAGNETOPAUSE
EARTH ATMOSPHERE
EARTH MAGNETOSPHERE
FLUID MECHANICS
HYDRODYNAMICS
INSTABILITY
MECHANICS
PLANETARY IONOSPHERES
SIMULATION
640201* - Atmospheric Physics- Auroral
Ionospheric
& Magetospheric Phenomena