HR: 0800h
AN: SM51B-0364    [Abstracts]
TI: Auroral Electric Field Generation by Earthward Motion of Hot Plasma
AU: * Lennartsson, O W
EM: lenn@mail.spasci.com
AF: Lockheed Martin ATC, ADCS, B255, 3251 Hanover St, Palo Alto, CA 94304 United States
AB: A neutral plasma beam streaming toward Earth along magnetic field lines has no opposing electric force, and yet electric tensions may arise internal to the beam in association with outer edges and other density gradients, especially when gradient scale lengths are comparable to the ion gyro radii. This is due to differential mirroring of electrons and ions, an effect that occurs even if the electrons and ions both have isotropic velocity distributions about their gyro centers, assuming that the typical electron gyro radii are significantly smaller than those of the ions. The effect has many important implications, one being the generation of auroras. It is easy to imagine that as the beam enters the far topside ionosphere, its positively charged filaments will discharge into the lower ionosphere by releasing local ionospheric electrons from the grip of an ambipolar electric field, thus setting up the normal conditions for accelerating magnetospheric electrons downward. This and other implications are discussed in this paper in the context of simple modeling, using plasma parameters inferred from Polar satellite data.
DE: 2704 Auroral phenomena (2407)
DE: 2712 Electric fields (2411)
DE: 2736 Magnetosphere/ionosphere interactions
DE: 2764 Plasma sheet
DE: 2788 Storms and substorms
SC: SPA-Magnetospheric Physics [SM]
MN: 2004 AGU Fall Meeting