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A magnetospheric magnetic field model with flexible current systems driven by independent physical parametersA tilt-dependent magnetic field model of the Earth's magnetosphere with variable magnetopause standoff distance is presented. Flexible analytic representations for the ring and cross-tail currents, each composed of the elements derived from the Tsyganenko and Usmanov (1982) model, are combined with the fully shielded vacuum dipole configurations of Voigt (1981). Although the current sheet does not warp in the y-z plane, changes in the shape and position of the neutral sheet with dipole tilt are consistent with both MHD equilibrium theory and observations. In addition, there is good agreement with observed Delta B profiles and the average equatorial contours of magnetic field magnitude. While the dipole field is rigorously shielded within the defined magnetopause, the ring and cross-tails currents are not similarly confined, consequently, the model's region of validity is limited to the inner magnetosphere. The model depends on four independent external parameters. We present a simple but limited method of simulating several substorm related magnetic field changes associated with the disrupion of the near-Earth cross-tail current sheet and collapse of the midnight magnetotail field region. This feature further facilitates the generation of magnetic field configuration time sequences useful in plasma convection simulations of real magnetospheric events.
Document ID
19950056440
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Hilmer, Robert V.
(Boston University Boston, MA, United States)
Voigt, Gerd-Hannes
(Rice University Houston, TX, United States)
Date Acquired
August 16, 2013
Publication Date
April 1, 1995
Publication Information
Publication: Journal of Geophysical Research
Volume: 100
Issue: A4
ISSN: 0148-0227
Subject Category
Geophysics
Accession Number
95A88039
Funding Number(s)
CONTRACT_GRANT: NSF ATM-91-1426
CONTRACT_GRANT: AF-F19628-90-K-0012
CONTRACT_GRANT: AF-F19628-91-K-0025
CONTRACT_GRANT: NAGW-2824
CONTRACT_GRANT: AF-F19628-90-K-0003
Distribution Limits
Public
Copyright
Other

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