HR: 0800h
AN: SA31A-0356    [Abstracts]
TI: Learning Alfvén wave properties from electrons measured by near-earth satellite
AU: * Chen, L
EM: li-jen-chen@uiowa.edu
AF: University of Iowa, Department of Physics and Astronomy, VAN ALLEN HALL, Iowa City, IA 52242 United States
AU: Kletzing, C A
EM: craig-kletzing@uiowa.edu
AF: University of Iowa, Department of Physics and Astronomy, VAN ALLEN HALL, Iowa City, IA 52242 United States
AU: Hu, S
EM: shuanghh@uci.edu
AF: University of California, Irvine, Department of Physics, UC Irvine, Irvine, CA 92697 United States
AB: Inertial Alfvén waves propagating along auroral field lines can produce distinct electron signatures through both resonant and non-resonant interaction with electrons. These signatures vary with observation altitudes. We discuss the cases when there are dc potential drops to produce primary auroral electrons. We show simulation results of electron signatures from below the altitude where Alfvén speed (V_A) peaks to that above it, and compare with Alfvén-wave associated electron energy fluxes that are observed by Freja and FAST satellite. Below the peak V_A altitude, both resonant and non-resonant interaction produce time-dispersed electron fluxes with the non-resonant dispersion a steeper slope. Above the peak V_A altitude, electron signatures due to resonant interaction remain time-dispersed, while those due to non-resonant interaction become dispersionless. We demonstrate in this poster by case examples how to infer the Alfvén wave speed, and the wave parallel electric field from the observed electron energy fluxes. This technique provides a means to quantify the magnetosphere-ionosphere coupling strength through inertial Alfvén waves.
DE: 2407 Auroral ionosphere (2704)
DE: 2451 Particle acceleration
DE: 7867 Wave/particle interactions (2483, 6984)
SC: SPA-Aeronomy [SA]
MN: Fall Meeting 2005