Radiation belt electron transport and energisation in broadband electromagnetic waves

Abstract:

The storm time inner magnetosphere outside the plasmapause is pervaded by a broad spectrum of low frequency electromagnetic fluctuations. In this presentation we discuss the properties of these field variations as observed from the Van Allen Probes. These properties are used to construct a wave model defining how the wave electric and magnetic fields vary along and across the geomagnetic field. This model is then used to explore the manner through which these waves interact with radiation belt electrons. Using a combination of quasi-linear approaches and explicit particle simulations in the model wavefields it is shown how these waves drive fast transport across L-shells while simultaneously forcing electrons into the atmospheric loss cone. It is suggested that these waves may be a driver of electron dropouts during storm main phase and more generally constitute an important player in the modulation of the radiation belts during geomagnetic storms.