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Effects of a Parallel Electric Field and the Geomagnetic Field in the Topside Ionosphere on Auroral and Photoelectron Energy DistributionsThe consequences of electric field acceleration and an inhomogencous magnetic field on auroral electron energy distributions in the topside ionosphere are investigated. The one- dimensional, steady state electron transport equation includes elastic and inelastic collisions, an inhomogencous magnetic field, and a field-aligned electric field. The case of a self-consistent polarization electric field is considered first. The self-consistent field is derived by solving the continuity equation for all ions of importance, including diffusion of 0(+) and H(+), and the electron and ion energy equations to derive the electron and ion temperatures. The system of coupled electron transport, continuity, and energy equations is solved numerically. Recognizing observations of parallel electric fields of larger magnitude than the baseline case of the polarization field, the effect of two model fields on the electron distribution function in investigated. In one case the field is increased from the polarization field magnitude at 300 km to a maximum at the upper boundary of 800 km, and in another case a uniform field is added to the polarization field. Substantial perturbations of the low energy portion of the electron flux are produced: an upward directed electric field accelerates the downward directed flux of low-energy secondary electrons and decelerates the upward directed component. Above about 400 km the inhomogencous magnetic field produces anisotropies in the angular distribution of the electron flux. The effects of the perturbed energy distributions on auroral spectral emission features are noted.
Document ID
19970014275
Acquisition Source
Headquarters
Document Type
Reprint (Version printed in journal)
Authors
Min, Q.-L.
(Alaska Univ. Fairbanks, AK United States)
Lummerzheim, D.
(Alaska Univ. Fairbanks, AK United States)
Rees, M. H.
(Alaska Univ. Fairbanks, AK United States)
Stamnes, K.
(Alaska Univ. Fairbanks, AK United States)
Date Acquired
August 17, 2013
Publication Date
November 1, 1993
Publication Information
Publication: Journal of Geophysical Research
Publisher: American Geophysical Union
Volume: 98
Issue: A11
ISSN: 0148-0227
Subject Category
Geophysics
Report/Patent Number
NASA-CR-203340
NAS 1.26:203340
Accession Number
97N71157
Funding Number(s)
CONTRACT_GRANT: NAGw-3037
CONTRACT_GRANT: NSF ATM-90-22197
CONTRACT_GRANT: NAG5-1097
Distribution Limits
Public
Copyright
Public Use Permitted.
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