Effects of Auroral-Particle Anisotropies and Mirror Forces on High-Latitude Electric Fields
- S.-I. Akasofu and
- J.R. Kan
Published Online: 26 MAR 2013
Copyright 1981 by the American Geophysical Union.
Physics of Auroral Arc Formation
How to Cite
Chiu, Y. T., Cornwall, J. M. and Schulz, M. (1981) Effects of Auroral-Particle Anisotropies and Mirror Forces on High-Latitude Electric Fields, in Physics of Auroral Arc Formation (eds S.-I. Akasofu and J.R. Kan), American Geophysical Union, Washington, D. C.. doi: 10.1029/GM025p0234
- Published Online: 26 MAR 2013
- Published Print: 1 JAN 1981
Print ISBN: 9780875900506
Online ISBN: 9781118664360
- Auroras—Addresses, essays, lectures
Auroral arcs result from the acceleration and precipitation of ring current and/or plasma-sheet plasma in narrow regions characterized by strong electric fields both perpendicular and parallel to the earth's magnetic field. The various mechanisms that have been proposed for the origin of such strong electric fields are not mutually exclusive. However, for most proposed mechanisms (with the possible exception of double layers of Debye length parallel scale), the effects of auroral particle anisotropy, of mirror forces due to the inhomogeneous geomagnetic field, of auroral electron backscatter by the atmosphere, and of electron trapping by the combination of magnetic mirroring and electrostatic forces must be taken into account in simulations of auroral electric fields. In addition, the effects of the very strong perpendicular electric field must also be taken into account in a kinetic description of the Poisson equation in order to achieve a unified theory of the auroral electrostatic structure. In this paper, progress in these areas in the past few years will be reviewed. It is shown that particle anisotropies and mirror forces can account for some basic electrostatic features of the quiet arc, while additional effects may be taking place in strong events in which the parallel potential drop exceeds ∼10 kV.