MHD model for the complete open magnetotail boundary

Journal Article · Wed Jul 01 04:00:00 EDT 1987 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JA092iA07p07405· OSTI ID:6277550

Siscoe, G L; Sanchez, E

In the Coroniti-Kennel MHD model for the open magnetotail boundary, a standing slow-mode expansion fan turns the magnetosheath flow into the plasma mantle and converts the magnetosheath field into the tail lobe field. The expansion fan-plasma mantle is also called the high-latitude boundary layer. The Coroniti-Kennel model applies to the noon-midnight meridian plane and the case of a purely southward interplanetary magnetic field (IMF). This paper (1) quantitatively tests and verifies the model, and (2) describes how the relatively thick and rapidly propagating high-latitude expansion fan automatically thins and slows at lower latitudes. It tapers down to a thin, nonpropagating tangential discontinuity representing the low-latitude boundary layer on closed field lines. Thus the model shows how the dawn-to-dusk current sheet that bisects the tail horizontally can return to dawn over the tail's back uninterruptedly across a seamless juncture between the high- and low-latitude boundary layers. Other important properties emerge from the complete boundary mode. A rotational discontinuity preconditions the field to pass through the slow mode wave. It induces a secondary circulation in the cross-sectional plane. This circulation sweeps plasma sheet plasma dawnward and duskward away from the tail's midplane and draws it up the tail's flanks, possibly accounting for the plasma sheet's butterfly-shaped cross section. The along-the-tail currents flowing on the rotational discontinuity have the same IMF B/sub y/ dependence as the cusp currents, which they might feed. The B/sub y/ distortion of the secondary circulation tends to rotate the plasma sheet about the tail axis to face the IMF. copyright American Geophysical Union 1987

• Research Organization: Department of Atmospheric Sciences, University of California, Los Angeles
• OSTI ID: 6277550
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 92:A7; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640201* -- Atmospheric Physics-- Auroral
Ionospheric
& Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BOUNDARY LAYERS
EARTH ATMOSPHERE
EARTH MAGNETOSPHERE
EXPANSION
FLUID MECHANICS
HYDRODYNAMICS
INTERPLANETARY MAGNETIC FIELDS
LAYERS
MAGNETIC FIELD CONFIGURATIONS
MAGNETIC FIELDS
MAGNETOHYDRODYNAMICS
MAGNETOSHEATH
MAGNETOTAIL
MECHANICS
PLASMA EXPANSION
PLASMA SHEET
WAVE PROPAGATION