Radiation Belt Scattering in Electromagnetic Turbulence

Observations from the Van Allen Probes have revealed the occurrence of low frequency electromagnetic turbulence pervading the outer radiation belt during intervals of enhanced geomagnetic activity. In this presentation it is shown how the spatial distribution of this turbulence in MLT and L-shell is similar to statistical distributions of relativistic electron precipitation observed from low altitude spacecraft. A case study conjunction connecting these turbulent fields to precipitation will be discussed. It is shown how these fields have the impedance characteristics of a broad spectrum of kinetic Alfven waves with extended length scales along the geomagnetic field often in the form of field-line eigenmodes. It is demonstrated how these field variations are composed of an array of field-aligned filamentary currents and flow vortices on scales across the geomagnetic field that encompass the gyro-radii of radiation belt electrons. These features can be expected to scatter radiation belt electrons. By combining the observed wave-field properties with a fluid-kinetic model it is demonstrated how these features may drive electron scattering leading to precipitation and losses to the atmosphere.