HR: 09:30h
AN: SM21A-06    [PDF]
TI: Generation of electron bursts by Alfven waves in the dayside auroral region
AU: * Su, Y
EM: ysu@lasp.colorado.edu
AF: Laboratory for Atmospheric and Space Physics, University of Colorado, 1234 Innovation Drive, Boulder, CO 80303 United States
AU: Jones, S T
EM: ssjones@colorado.edu
AF: Center for Integrated Plasma Studies, University of Colorado, Department of Physics Campus Box 390 University of Colorado, Boulder, CO 80309 United States
AU: Ergun, R E
EM: ree@lasp.colorado.edu
AF: Laboratory for Atmospheric and Space Physics, University of Colorado, 1234 Innovation Drive, Boulder, CO 80303 United States
AU: Parker, S E
EM: sparker@colorado.edu
AF: Center for Integrated Plasma Studies, University of Colorado, Department of Physics Campus Box 390 University of Colorado, Boulder, CO 80309 United States
AB: Various models have been considered to explain the acceleration of electrons by Alfven waves. Electron time dispersion and electron bursts are often observed in the auroral region. In this presentation, a linear 1-D gyrofluid simulation with finite-gyroradius and electron inertia effects is applied on a dayside auroral field line. A test particle code was constructed under gravitational and mirror forces. The time dispersion of precipitating magnetosheath electrons is generated due to propagating Alfven waves obtained from the gyrofluid code. In order to reproduce the electron burst signature observed from the FAST satellite, the ionospheric density gradient is reduced to maintain the parallel electric field of dispersive Alfven waves at a certain magnitude below the peak of the Alfven speed. Additionally, O+ ions are selected as the dominant species below 6400 km altitudes. Cold background electrons with an initial energy of 2 eV are trapped within the Alfven wave as it propagates toward the ionosphere, and are accelerated by parallel electric field to an energy of hundreds of eV. The energy-time spectrogram and distribution functions of electrons from our simulation will be compared with observations from the FAST satellite.
DE: 2483 Wave/particle interactions
DE: 2487 Wave propagation (6934)
DE: 2704 Auroral phenomena (2407)
DE: 2753 Numerical modeling
DE: 6934 Ionospheric propagation (2487)
SC: SPA - Magnetospheric Physics [SM]
MN: 2003 Fall Meeting