Van Allen Probes Observations of Direct Wave Particle Interactions
Abstract
We present observations of wave-particle interactions observed on the Van Allen Probes during an interval of sporadic increases or bursts of 20-30 keV electron fluxes observed in conjunction with bursts of chorus activity. The electron flux and chorus burst occurred on a nearly one for one basis during an hour interval on January 13, 2013. The electron angular distributions changed during the burst events such that flux increases evolved from Sinn(α) type angular distributions to form maxima in the electron angular distributions at 75-80° local pitch angle with the fluxes at 90° and <60° remaining the same as in the pre and post burst distributions. These events occurred well outside the plasmasphere following a minor plasma injection. They were observed on both Van Allen Probes spacecraft, which were relatively close together. The plasma density, electron gyro-frequency and pitch angle of peak flux in a burst was used to estimate the resonant electron energy. The result of ~25 keV is consistent with the energies of the electrons showing the flux enhancements observed by the ECT/MagEIS and ECT/HOPE spectrometers. These results will be described in detail and questions concerning the source of such events will be discussed.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2013
- Bibcode:
- 2013AGUFMSM23C..03F
- Keywords:
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- 2774 MAGNETOSPHERIC PHYSICS Radiation belts;
- 2772 MAGNETOSPHERIC PHYSICS Plasma waves and instabilities;
- 2788 MAGNETOSPHERIC PHYSICS Magnetic storms and substorms