MHD modeling of magnetotail instability for anisotropic pressure

Journal Article · Wed Jul 01 00:00:00 EDT 1992 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/92JA00793· OSTI ID:7012642

Hesse, M; Birn, J ^[1]

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1. Los Alamos National Lab., NM (United States)

Results of three-dimensional MHD simulations of magnetotail dynamics with anisotropic pressure are presented. The pressure tensor is assumed to be gyrotropic, satisfying a modified double adiabatic approximation including Ohmic heating. It is found that these constraints tend to stabilize the tail with respect to the resistive tearing instability. Including an increasing level of additional isotropization results in a gradual transition to the fast instability found in an isotropic model, which is discussed for comparison. Possible isotropization mechanisms yielding magnetotail instability are discussed also. The stabilizing anisotropies are found primarily in the plasma sheet boundary region. This fact indicates a possibly important role of isotropization mechanisms operating in this region in destabilizing the magnetotail and initiating a tearing instability without the necessity of changes in fluctuation levels in the neutral sheet.

• OSTI ID: 7012642
• Journal Information: Journal of Geophysical Research; (United States), Vol. 97:A7; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
MAGNETOTAIL
MATHEMATICAL MODELS
COMPARATIVE EVALUATIONS
COMPUTERIZED SIMULATION
MAGNETOHYDRODYNAMICS
PLASMA HEATING
PLASMA PRESSURE
PLASMA SHEET
STABILITY
TEARING INSTABILITY
THREE-DIMENSIONAL CALCULATIONS
TIME DEPENDENCE
EARTH ATMOSPHERE
EARTH MAGNETOSPHERE
EVALUATION
FLUID MECHANICS
HEATING
HYDRODYNAMICS
INSTABILITY
MECHANICS
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
SIMULATION
661320* - Auroral
Ionospheric
& Magnetospheric Phenomena- (1992-)