HR: 14:55h
AN: SM43D-06    [Abstracts]
TI: Dynamics of ULF wave attenuation inferred through the optical aurora
AU: * Semeter, J
EM: jls@bu.edu
AF: Boston University, 725 Commonwealth Ave., Boston, MA 02215 United States
AU: Zettergren, M
EM: mattzett@gmail.com
AF: Boston University, 725 Commonwealth Ave., Boston, MA 02215 United States
AU: Kamalabadi, F
EM: farzadk@uiuc.edu
AF: University of Illinois, 1301 West Main St., Urbana-Champaign, IL 61801 United States
AB: During prolonged periods of steady southward IMF Bz, solar wind-magnetosphere coupling is often characterized by a dynamic equilibrium between dayside merging and nightside reconnection. One manifestation of this equilibrium is ULF pulsations in the Pi2 range which are well correlated with dynamical behavior of auroral forms along the nightside polar cap boundary. The soft, but intense, electron fluxes responsible for these subvisual auroras result from wave-particle coupling in the near-Earth magnetosphere and, hence, the attenuation of Alfven waves. The energetics of this process is revealed indirectly in the altitude distribution and spectral content of optical emissions-in particular those associated with neutral and ionized oxygen in the ionospheric F-region. An analysis of multi-spectral observations and modeling of dynamic auroras associated with ULF pulsations is presented. We focus on a particularly interesting discrepancy suggesting the presence of small-scale parallel electric fields at ionospheric altitudes.
DE: 2704 Auroral phenomena (2407)
DE: 2736 Magnetosphere/ionosphere interactions (2431)
DE: 2752 MHD waves and instabilities (2149, 6050, 7836)
SC: SPA-Magnetospheric Physics [SM]
MN: Fall Meeting 2005