Pulsating Auroras Produced By Interactions of Electrons and Time Domain Structures

Previous evidence has suggested that lower band chorus waves or kinetic Alfven waves scatter equatorial kilovolt electrons that propagate to lower altitudes where they precipitate or undergo further low altitude scattering to make pulsating auroras. Recently, time domain structures (TDS) have been shown, both theoretically and experimentally, to efficiently scatter equatorial electrons. To assess the relative importance of these three mechanisms for production of pulsating auroras, eleven intervals of equatorial THEMIS data and a four-hour interval of Van Allen Probe measurements have been analyzed. The conclusion of these studies is that time domain structures caused the most important equatorial scattering of electrons toward the loss cone during these pulsating auroras.