HR: 0800h
AN: SM21A-0311    [Abstracts]
TI: Modeling the Loss of Energetic Ions and Electrons by EMIC Waves
AU: * Jordanova, V K
EM: vania@lanl.gov
AF: Los Alamos National Laboratory, Space Science and Applications, MS D466, Los Alamos, NM 87545, United States
AU: Miyoshi, Y
EM: miyoshi@stelab.nagoya-u.ac.jp
AF: Nagoya University, Solar-Terrestrial Environment Laboratory, Nagoya, 464-8601, Japan
AU: Albert, J M
EM: jay.albert@hanscom.af.mil
AF: Air Force Research Laboratory, Hanscom AFB, Boston, MA 01731, United States
AB: We study the effect of electromagnetic ion cyclotron (EMIC) wave scattering on ring current ions and radiation belt electrons during several geomagnetic storms. We use our global physics-based model, which calculates the evolution of H⁺, O⁺, and He⁺ ions and electrons due to time-dependent earthward transport and acceleration. All major loss processes are included in our kinetic model, which is coupled with a time-dependent plasmasphere model. The anisotropic ring current populations generate plasma waves that accelerate and/or scatter radiation belt particles. The generation and propagation characteristics of the EMIC waves depend strongly on the presence of both cold and energetic heavy ions (mainly He⁺ and O⁺) in the plasmas. We calculate the excitation of EMIC waves self-consistently with the evolving ring current ion populations as the storms progress. We find that the regions of maximum EMIC wave growth are usually located inside plasmaspheric plumes and/or near the plasmapause. In our kinetic model wave-particle interactions are evaluated according to quasi-linear theory using diffusion coefficients for multi-component plasma and including not only field-aligned but also oblique EMIC waves. Pitch angle scattering by these waves cause significant ion precipitation into the atmosphere and generation of detached subauroral proton arcs. Furthermore, EMIC waves cause pitch angle scattering and loss of radiation belt electrons at energies larger than few hundreds keV. Global images of electron precipitating fluxes and first studies of the electron precipitation development with local time are presented.
DE: 2716 Energetic particles: precipitating
DE: 2753 Numerical modeling
DE: 2772 Plasma waves and instabilities (2471)
DE: 2774 Radiation belts
DE: 2778 Ring current
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Fall Meeting