MHD simulations of magnetic reconnection in a skewed three-dimensional tail configuration
- Los Alamos National Lab., NM (USA)
Using the three-dimensional MHD code, the authors have studied the dynamic evolution of a non-symmetric magnetotail configuration, initiated by the sudden occurence of (anomalous) resistivity. The initial configuration included variations in all three space dimensions, consistent with average tail observations. In addition, it was skewed due to the presence of a net cross-tail magnetic field component B{sub yN} with a magnitude as typically observed, so that it lacked commonly assumed mirror symmetries around the midnight meridian and the equatorial planes. The field evolution was found to be very similar to that of a symmetric configuration studied earlier, indicating plasmoid formation and ejection. The most noticeable new feature in the evolution of the individual field components is a reduction of B{sub y} on the reconnected dipole-like field lines earthward from the reconnection region. The topological structure of the magnetic field, however, defined by the field line connections, shows remarkable differences from the symmetric case, consistent with conclusions by Hughes and Sibeck (1987) and Birn et al. (1989). The plasmoid, which is a magnetically separate entity in the symmetric case, becomes open, connected initially with the Earth, but getting gradually connected with the interplanetary field, as reconnection of lobe field lines proceeds from the midnight region to the flanks of the tail. The separation of the plasmoid from the Earth is thus found to take a finite amount of time. When the plasmoid begins to separate from the Earth, a filamentary structure of field connections develops, not present in the spatial variation of the fields; this confirms predictions by Birn et al. (1989). A localization of the electric field parallel to the magnetic field is found consistent with conclusions on general magnetic reconnection.
- OSTI ID:
- 5223586
- Journal Information:
- Journal of Geophysical Research; (United States), Vol. 96:A1; ISSN 0148-0227
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GENERAL PHYSICS
MAGNETIC RECONNECTION
COMPUTERIZED SIMULATION
MAGNETOTAIL
ELECTRIC FIELDS
INTERPLANETARY MAGNETIC FIELDS
MAGNETIC FIELD CONFIGURATIONS
MAGNETIC SURFACES
MAGNETOHYDRODYNAMICS
PLASMOIDS
THREE-DIMENSIONAL CALCULATIONS
TOPOLOGY
EARTH ATMOSPHERE
EARTH MAGNETOSPHERE
FLUID MECHANICS
HYDRODYNAMICS
MAGNETIC FIELDS
MATHEMATICS
MECHANICS
SIMULATION
640201* - Atmospheric Physics- Auroral
Ionospheric
& Magetospheric Phenomena