Slot region electron loss timescales due to plasmaspheric hiss and lightning-generated whistlers
Article first published online: 31 AUG 2007
Copyright 2007 by the American Geophysical Union.
Journal of Geophysical Research: Space Physics (1978–2012)
Volume 112, Issue A8, August 2007
How to Cite
2007), Slot region electron loss timescales due to plasmaspheric hiss and lightning-generated whistlers, J. Geophys. Res., 112, A08214, doi:10.1029/2007JA012413., , , and (
- Issue published online: 31 AUG 2007
- Article first published online: 31 AUG 2007
- Manuscript Accepted: 6 JUN 2007
- Manuscript Revised: 2 MAY 2007
- Manuscript Received: 22 MAR 2007
- slot region;
- plasmaspheric hiss;
- lightning generated whistlers
 Energetic electrons (E > 100 keV) in the Earth's radiation belts undergo Doppler-shifted cyclotron resonant interactions with a variety of whistler mode waves leading to pitch angle scattering and subsequent loss to the atmosphere. In this study we assess the relative importance of plasmaspheric hiss and lightning-generated whistlers in the slot region and beyond. Electron loss timescales are determined using the Pitch Angle and energy Diffusion of Ions and Electrons (PADIE) code with global models of the spectral distributions of the wave power based on CRRES observations. Our results show that plasmaspheric hiss propagating at small and intermediate wave normal angles is a significant scattering agent in the slot region and beyond. In contrast, plasmaspheric hiss propagating at large wave normal angles and lightning-generated whistlers do not contribute significantly to radiation belt loss. The loss timescale of 2 MeV electrons due to plasmaspheric hiss propagating at small and intermediate wave normal angles in the center of the slot region (L = 2.5) lies in the range 1–10 days, consistent with recent Solar Anomalous and Magnetospheric Particle Explorer (SAMPEX) observations. Wave turbulence in space, which is responsible for the generation plasmaspheric hiss, thus leads to the formation of the slot region. During active periods, losses due to plasmaspheric hiss may occur on a timescale of 1 day or less for a wide range of energies, 200 keV < E < 1 MeV, in the region 3.5 < L < 4.0. Plasmaspheric hiss may thus also be a significant loss process in the inner region of the outer radiation belt during magnetically disturbed periods.