Effects of Drift-Shell Splitting by Chorus Waves on Radiation Belt Electrons

Tuesday, 15 December 2015: 16:30
2018 (Moscone West)
Anthony Arthur Chan1, Liheng Zheng2, Thomas Paul O'Brien III3, Weichao Tu4, Gregory Cunningham4, Scot Richard Elkington5 and Jay Albert6, (1)Rice University, Houston, TX, United States, (2)Rice Univ-Physics & Astronomy, Houston, TX, United States, (3)Aerospace Corporation Chantilly, Chantilly, VA, United States, (4)Los Alamos National Laboratory, Los Alamos, NM, United States, (5)Laboratory for Atmospheric and Space Physics, Boulder, CO, United States, (6)Air Force Research Laboratory Albuquerque, Albuquerque, NM, United States
Drift shell splitting in the radiation belts breaks all three adiabatic invariants of charged particle motion via pitch angle scattering, and produces new diffusion terms that fully populate the diffusion tensor in the Fokker-Planck equation. Based on the stochastic differential equation method, the Radbelt Electron Model (REM) simulation code allows us to solve such a fully three-dimensional Fokker-Planck equation, and to elucidate the sources and transport mechanisms behind the phase space density variations. REM has been used to perform simulations with an empirical initial phase space density followed by a seed electron injection, with a Tsyganenko 1989 magnetic field model, and with chorus wave and ULF wave diffusion models. Our simulation results show that adding drift shell splitting changes the phase space location of the source to smaller L shells, which typically reduces local electron energization (compared to neglecting drift-shell splitting effects). Simulation results with and without drift-shell splitting effects are compared with Van Allen Probe measurements.