Time-Dependent Electron Transport I: Modelling of Supra-Thermal Electron Bursts Modulated at 5–10 Hz With Implications for Flickering Aurora

Abstract

A time-dependent multi-stream electron transport model, AURORA, has been developed for studies of auroral emission-rates during precipitation with large variations on sub-second time-scales. The transport-code accurately takes time-of-flight, energy degradation, scattering and production of secondary electrons into account. AURORA produces ionospheric electron-flux as a function of energy, altitude, time and pitch-angle, with a time-resolution of 3.33 ms. AURORA has been used to simulate flickering aurora by modulating field-aligned bursts (FAB) of electrons modulated at frequencies between 5 and 10 Hz. Intensity modulations of auroral emissions at 4,278, 6,730, 7,444, and 8,446 Å have been calculated, time-shifts on the order of 10 ms between the maxima of the emissions were found.