Self-consistent production of ion conics on return current region auroral field lines: A time-dependent, semi-kinetic model

Journal Article · Tue Oct 01 04:00:00 EDT 1991 · Geophysical Research Letters (American Geophysical Union); (United States)

DOI:https://doi.org/10.1029/91GL02244· OSTI ID:5139703

Brown, D G; Wilson, G R; Horwitz, J L ^[1]; Gallagher, D L ^[2]

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1. Univ. of Alabama, Huntsville (United States)
2. NASA/Marshall Space Flight Center, Huntsville, AL (United States)

The authors 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 they 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. They also observe the formation of a density depletion in hydrogen and enhanced oxygen densities at high altitudes.

• OSTI ID: 5139703
• Journal Information: Geophysical Research Letters (American Geophysical Union); (United States), Journal Name: Geophysical Research Letters (American Geophysical Union); (United States) Vol. 18:10; ISSN 0094-8276; ISSN GPRLA
• Country of Publication: United States
• Language: English

Related Subjects

661320* -- Auroral
Ionospheric
& Magnetospheric Phenomena-- (1992-)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ACCELERATION
AURORAL ZONES
CHARGED PARTICLES
CYCLOTRON FREQUENCY
DISTRIBUTION FUNCTIONS
FUNCTIONS
HEATING
INSTABILITY
ION DENSITY
ION WAVE INSTABILITY
IONS
MATHEMATICAL MODELS
PLASMA DRIFT
PLASMA INSTABILITY
PLASMA MICROINSTABILITIES
PLASMA WAVES
TIME DEPENDENCE