Steady-state magnetic-field models and tearing-mode instabilities for the Earth's magnetotail

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1988

OSTI ID:5245640

Hau, L N

This thesis addresses a fundamental question in magnetospheric physics, which is whether steady-state convection could theoretically exist in the Earth's plasma sheet. By constructing a numerical two-dimensional magnetohydrostatic equilibrium magnetosphere that is consistent with the condition of steady, lossless, adiabatic, plasma-sheet convection, assertions made by others concerning the non-existence of a physical steady-state solution within the ideal MHD limit (isotropic pressure, perfect conductivity). The computed steady-state magnetic field model, however, is different both from averaged observations and from standard magnetic-field models in that the equatorial magnetic field strength B{sub ze} exhibits a very deep broad minimum in the inner plasma sheet. To study tearing instability of the configurations that possess a B{sub ze}-minimum in the near-earth plasma sheet in the presence of resistivity, a time-dependent numerical resistive MHD code was developed. The calculations suggest that the magnetotail structure associated with adiabatic earthward convection is intrinsically unstable even if the solar wind condition is precisely steady, which may explain why magnetospheric substorms should occur and why the neutral line associated with the substorm should occur in the near-earth plasma sheet.

• Research Organization: Rice Univ., Houston, TX (USA)
• OSTI ID: 5245640
• Country of Publication: United States
• Language: English

Related Subjects

640201* -- Atmospheric Physics-- Auroral
Ionospheric
& Magetospheric Phenomena
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700107 -- Fusion Energy-- Plasma Research-- Instabilities
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
COMPUTERIZED SIMULATION
CONVECTION
EARTH ATMOSPHERE
EARTH MAGNETOSPHERE
ENERGY TRANSFER
FLUID MECHANICS
HEAT TRANSFER
HYDRODYNAMICS
INSTABILITY
MAGNETIC STORMS
MAGNETOHYDRODYNAMICS
MAGNETOTAIL
MASS TRANSFER
MECHANICS
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
PLASMA SHEET
SIMULATION
STEADY-STATE CONDITIONS
TEARING INSTABILITY
TWO-DIMENSIONAL CALCULATIONS