Simulation of Bounce Resonance ULF Wave-Particle Interactions

Poloidal mode ultra-low-frequency (ULF) waves with high azimuthal mode number (high-m) are common throughout Earth's magnetosphere. The electric fields in these waves are on the order of tens of millivolts per meter, and are large enough to energize ions and electrons via drift- and drift-bounce wave-particle resonance. In this article, we present full orbit test-particle simulations of drift-bounce resonance using a numerical model of ULF waves. The model uses a dipole magnetic field and can accommodate a realistic ionosphere with height-resolved Pedersen and Hall conductivity. It is demonstrated that second-harmonic poloidal mode waves can energize ions to tens of keV depending on the wave amplitude. The test-particle simulations also predict ion flux oscillations that have energy dispersion similar to many satellite observations. It will be shown that features in the energy dispersion are in agreement with theoretical considerations.CPCI-S(ISTP)rrankin@ualberta.ca; qgzong@pku.edu.cn956-95