Particle acceleration and wave emissions associated with the formation of auroral cavities and enhancements

Journal Article · Thu Dec 01 04:00:00 EST 1988 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JA093iA12p14567· OSTI ID:6575137

Winglee, R M; Pritchett, P L; Dusenbery, P B; Persoon, A M; Waite, Jr, J H; Moore, T E; Burch, J L; Collin, H L; Slavin, J A; Sugiura, M; others, and

Observations from DE 1 and electrostatic particle simulations are combined in an effort to provide a unified model for (nightside) auroral particle acceleration and wave emissions and their association with plasma cavities and enhancements. The observations show that enhanced electron precipitation during inverted-V events is associated with broadband electrostatic bursts (BEB), increased upward field-aligned currents, and density enhancements. These regions are flanked by return current regions where the density is depleted (i.e., by plasma cavities). Perpendicular acceleration of ambient plasma ions can occur in both upward and return current regions. It is shown through the simulations that these processes are integrally related and are not independent of each other. The free energy for the auroral particle acceleration can be provided by energetic ion beams in the plasma sheet boundary layer with nonzero perpendicular energy. The perpendicular energy allows charge separation between the beam ions and costreaming electrons to occur. The resultant space charge fields accelerate electrons on the same field lines as the costreaming electrons downward toward the ionosphere, without the beam ions actually propagating down to auroral altitudes. Ambient plasma electrons on adjacent field lines are accelerated upward, forming a return current.

• Research Organization: Department of Astrophysical, Planetary, and Atmospheric Sciences, University of Colorado, Boulder
• OSTI ID: 6575137
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 93:A12; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640201* -- Atmospheric Physics-- Auroral
Ionospheric
& Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AURORAL ZONES
CHARGED-PARTICLE PRECIPITATION
DENSITY
EARTH ATMOSPHERE
EARTH MAGNETOSPHERE
IONOSPHERE
PHYSICAL PROPERTIES
PLANETARY IONOSPHERES
PLASMA SHEET
PLASMA WAVES