Production of flickering aurora and field-aligned electron flux by electromagnetic ion cyclotron waves

摘要: Recent observations have suggested that flickering aurora is produced by a modulation of the field-aligned component electron flux within an auroral arc. It proposed portion electrons are ionospheric origin and these accelerated their modulated electromagnetic ion cyclotron waves occur below main acceleration region on arc field lines. A model wave shows parallel phase velocity increases as propagates toward ionosphere. test particle calculation trapped or reflected to energies several keV at frequency. The relative amplitudes electric fields consistent with small-scale low-frequency magnetospheric near arcs approximately 10 mV/m 100 mV/m, respectively. large-amplitude also produce ponderomotive force self-consistent ambipolar field. Energy considerations show downward energy in can be percent total flux.