Driven Alfven waves and electron acceleration: A FAST case study

Abstract

Observations of electric and magnetic field oscillations and accelerated electron distributions within an inverted-V region suggest the propagation of an Alfven wave from the outer magnetosphere into the auroral acceleration region. This hypothesis is tested for a case study event by simulating the propagation of an Alfven wave driven by an oscillating potential in the outer magnetosphere. At the spacecraft altitude the waveform and the associated electron distributions and spectra formed due to acceleration in the Alfven wave field are similar to those observed. The results show that more than 50% of the downgoing wave Poynting flux is dissipated through electron acceleration parallel to the geomagnetic field.