Flickering aurora observations at 500 frames per second

Flickering aurora is thought to be produced when incoming energetic electrons are bunched by Oxygen ion cyclotron waves. The light resulting from the bunched electrons then carry information about the wave particle interactions which cause the bunching. Flickering aurora observed by standard frame rate camera shown a pronounced narrow frequency "flicker" at 3-10 Hz. This frequency matches the ion cyclotron frequency of oxygen ions at altitudes between 2000-5000km. We report on observations of flickering aurora which were obtained at 500 frames per second using an intensified Phantom high speed camera with a 20 degree field of view at magnetic zenith on 2 March 2017. In addition to the narrow frequency results previously reported with standard frame rate imagers, we observe broad band frequencies up to approximately 30 Hz. We report on the spatial distribution of both the narrow and broad band frequency modulations, and compare these to various theoretical models of flickering aurora.