HR: 1400h
AN: SM53A-05    [Abstracts]
TI: Global Distribution, Spectral Distribution, and Physical Characteristics of ULF Waves in the Earth's Magnetosphere
AU: * Claudepierre, S G
EM: claudepi@colorado.edu
AF: Laboratory for Atmospheric and Space Physics, 1234 Innovation Dr., Boulder, CO 80303, United States
AU: Elkington, S R
EM: scot.elkington@lasp.colorado.edu
AF: Laboratory for Atmospheric and Space Physics, 1234 Innovation Dr., Boulder, CO 80303, United States
AU: Wiltberger, M J
EM: wiltbemj@hao.ucar.edu
AF: NCAR/HAO, 3080 Center Green Drive, Boulder, CO 80301, United States
AB: Fluctuations in the Earth's magnetic and electric fields on mHz timescales, so-called ultra low frequency (ULF) fluctuations, have been shown to be a major contributing factor in the dynamics of energetic radiation belt electrons. There have been several research efforts undertaken to determine the characteristics of those ULF waves that are the most effective in energizing and transporting radiation belt electrons. These efforts have identified the following properties as the most relevant to the energization and transport of outer zone electrons: (i) spectral distribution at frequencies including mω_d where ω_d is the particle drift frequency and m is (ii) the azimuthal mode structure of the interacting waves; (iii) the global distribution (radial and azimuthal extent) of the waves, which largely determines the rate at which an azimuthally drifting electron will be energized; and (iv) the direction of propagation, which determines whether the particles will effectively interact with the waves. The global nature of these properties makes analysis from single-point, in-situ spacecraft measurements somewhat difficult. This is particularly true for properties (ii), (iii) and (iv). To circumvent this issue, we present results from global, 3-d magnetohydrodynamic simulations of the solar wind/magnetosphere interaction, driven by idealized solar wind conditions. The controlled nature of this experiment allows us to isolate a known solar wind driver of magnetospheric ULF waves, for example shear waves on the flanks driven by high speed solar wind streams, and study the aforementioned characteristics of the ULF waves generated. The results presented here will provide a global context for interpreting results from the upcoming NASA Radiation Belt Storm Probes (RBSP) mission.
DE: 7836 MHD waves and instabilities (2149, 2752, 6050)
DE: 7845 Particle acceleration
DE: 7867 Wave/particle interactions (2483, 6984)
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Joint Assembly