HR: 0800h
AN: SM21A-0330    [Abstracts]
TI: Calculation of Path-integrated Growth of Whistler-mode Chorus Waves With the HOTRAY Code Based on CRRES Observation
AU: * Li, W
EM: moonli@atmos.ucla.edu
AF: Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, 405 Hilgard Ave., Los Angeles, CA 90095, United States
AU: Thorne, R M
EM: rmt@atmos.ucla.edu
AF: Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, 405 Hilgard Ave., Los Angeles, CA 90095, United States
AU: Bortnik, J
EM: jbortnik@gmail.com
AF: Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, 405 Hilgard Ave., Los Angeles, CA 90095, United States
AU: Meredith, N P
EM: nmer@bas.ac.uk
AF: British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge, CB3 0ET, United Kingdom
AU: Horne, R B
EM: r.horne@bas.ac.uk
AF: British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge, CB3 0ET, United Kingdom
AB: Whistler-mode chorus waves are excited in the low-density region outside the plasmapause by the injection of plasmasheet electrons into the inner magnetosphere. During substorm injection, electron anisotropy increases as electrons move from the plasmasheet to lower L shells conserving the first adiabatic invariant. On the other hand, electron scattering by chorus waves reduces the electron anisotropy. We fit 5 minute-averaged CRRES data of the electron phase space density (PSD) at different equatorial pitch-angles for various energy channels (between 0.1 keV and 20 keV) with an analytical distribution function to calculate the hot electron density and anisotropy. The path-integrated growth of chorus waves is simulated with the HOTRAY code by tracing chorus waves in a hot magnetized plasma. The results show that substorm-injected electrons are responsible for the intensification of the whistler-mode chorus and higher electron anisotropy than that obtained from the 5 minute- averaged electron PSD data is needed to reproduce the observed wave intensity by CRRES during a substorm injection event. We also suggest that the electron anisotropy is reduced due to pitch-angle scattering by the enhanced chorus waves within the 5 minutes interval over which the CRRES data are analyzed.
DE: 2483 Wave/particle interactions (7867)
DE: 2716 Energetic particles: precipitating
DE: 2730 Magnetosphere: inner
DE: 2753 Numerical modeling
DE: 2774 Radiation belts
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Fall Meeting