HR: 14:25h
AN: SM22C-04    [PDF]
TI: Electron Dispersion Below Inverted-V Energies: Resonant Deceleration and Acceleration by Alfv\'en Waves
AU: * Chen, L
EM: li-jen-chen@uiowa.edu
AF: Department of Physics and Astronomy, University of Iowa, Iowa City, IA 52242 United States
AU: Kletzing, C A
AF: Department of Physics and Astronomy, University of Iowa, Iowa City, IA 52242 United States
AU: Hu, S
AF: Department of Physics and Astronomy, University of California, Irvine, Irvine, CA 92697 United States
AB: We report on studies of resonant interactions of inertial Alfv\'en waves with electrons along auroral field lines. The electrons in resonance can be accelerated or decelerated by the parallel electric field of the wave depending on whether the velocity of the electrons is less or greater than the Alfv\'en wave velocity. In this paper, we emphasize the resonant deceleration process and its effects on electrons that have gone through a parallel potential drop (the inverted-V electrons). When the backscattered population is included, a combination of resonant acceleration and deceleration effects accounts well for rocket observations of electron energy dispersion extending from the inverted-V energies to lower energy. Characteristics of the dispersion tail such as the dispersion time scale and the intensity distribution along the tail may be used to deduce the Alfv\'en wave properties and the parent electron spectra. Examples of the model wave signatures and their dependence on the electron population will be shown.
UR: http://alpha.physics.uiowa.edu/~lijen/KAWe.html
DE: 2407 Auroral ionosphere (2704)
DE: 2704 Auroral phenomena (2407)
DE: 2712 Electric fields (2411)
DE: 2736 Magnetosphere/ionosphere interactions
DE: 7867 Wave/particle interactions
SC: SPA - Magnetospheric Physics [SM]
MN: 2003 Fall Meeting