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'Self-consistent' production of ion conics on return current region auroral field lines - A time-dependent, semi-kinetic modelWe describe initial results from a time-dependent, semi-kinetic model of plasma outflow incorporating wave-particle interactions along current-carrying auroral field lines. Electrostatic waves are generated by the current driven ion cyclotron instability (CDICI), causing perpendicular velocity diffusion of ions plus electron heating via anomalous resistivity when and where the relative drift between electrons and ions exceeds certain critical velocities. Using the local bulk parameters we calculate these critical velocities, and so are able to self-consistently switch on and off the heating of the various particle species. Due to the dependence of these critical velocities on the bulk parameters of the species the heating effects exhibit quite complex spatial and temporal variations. A wide range of ion distribution functions are observed in these simulations, including conics with energies of a few electron volts and 'ring' distributions. The rings are seen to be a natural result of transverse heating and velocity filter effects and do not require coherent acceleration processes. We also observe the formation of a density depletion in hydrogen and enhanced oxygen densities at high altitudes.
Document ID
19930031077
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Brown, David G.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Wilson, Gordon R.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Horwitz, James L.
(Alabama Univ. Huntsville, United States)
Gallagher, Dennis L.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Date Acquired
August 15, 2013
Publication Date
October 1, 1991
Publication Information
Publication: Geophysical Research Letters
Volume: 18
Issue: 10
ISSN: 0094-8276
Subject Category
Geophysics
Accession Number
93A15074
Funding Number(s)
CONTRACT_GRANT: NAGW-1550
CONTRACT_GRANT: NAG8-822
Distribution Limits
Public
Copyright
Other

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