On dipolarization and its relation to the substorm current wedge

Journal Article · Fri Nov 01 04:00:00 EST 1991 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/91JA01953· OSTI ID:5813705

Hesse, M; Birn, J ^[1]

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

Within the framework of the three-dimensional self-consistent MHD model of magnetotail activity the authors investigate near-Earth properties of magnetospheric substorms. Particular emphasis is on the generation mechanism and the three-dimensional aspects of the B{sub z} increase which is commonly called magnetic field dipolarization, and its spatial and temporal relation to the field-aligned currents of the substorm current wedge and the current reduction and diversion. They find that the dipolarization can be understood as the flux pileup due to the slowing down of the fast earthward flows carrying reconnected flux from the reconnection region. The gradients of B{sub x} at the dawn and dusk flanks of the depolarization region contribute to the region 1 field-aligned current system of the substorm current wedge. The major contribution, however, is found to be associated with the shear between the y and x components of the magnetic field. They also find that the region where the cross-tail current is reduced (disrupted) and diverted is located tailward from the dipolarization region. The results indicate that the apparent tailward propagation of dipolarization effects does not support the conclusion that the underlying process is initiated further earthward.

• OSTI ID: 5813705
• Journal Information: Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 96:A11; ISSN 0148-0227; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

661320* -- Auroral
Ionospheric
& Magnetospheric Phenomena-- (1992-)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AURORAL ZONES
CURRENTS
EARTH ATMOSPHERE
EARTH MAGNETOSPHERE
ELECTRIC CURRENTS
FLUID MECHANICS
GEOMAGNETIC FIELD
GROUND LEVEL
HYDRODYNAMICS
LEVELS
MAGNETIC BAYS
MAGNETIC FIELDS
MAGNETIC FLUX
MAGNETIC RECONNECTION
MAGNETOHYDRODYNAMICS
MAGNETOTAIL
MATHEMATICAL MODELS
MECHANICS
THREE-DIMENSIONAL CALCULATIONS