Common Characteristics of the Pulsating Aurora Electrons and Relativistic Electron Microbursts: Satellite Observations and Simulation
Wednesday, 17 December 2014: 8:46 AM
We investigate whether the pulsating aurora and relativistic electron microbursts are caused by a common process. Using Reimei and SAMPEX satellite data, we investigate characteristics of the pulsating aurora electrons and relativistic electron microbursts. Reimei satellite reveals that the pulsating aurora is caused by repetition of tens keV electrons and the internal modulations with a few Hz exist inside the precipitation. Beside intermittent precipitations of a few keV electrons, the stable precipitation of low energy electron ~1 keV is simultaneously observed. SAMPEX satellite confirmed the pulsation of relativistic electron microbursts and the internal modulations embedded in the microburst. We simulate the pitch angle scattering of energetic electrons from ten keV to ~1 MeV, considering the propagation of whistler mode waves along the field line. The simulation shows that the pulsation and internal modulations of electrons are caused by the repetition of chorus bursts and rising tones, respectively, and those are commonly observed in both ten keV electrons (pulsating aurora) and relativistic electron microbursts. Upper band chorus waves cause the stable low energy electron precipitations. The results indicate that the propagating whistler mode chorus waves are the common process to cause both pulsating aurora and relativistic electron microbursts along the field line.