Probing the magnetosphere via observations of electron flux oscillations associated with broadband ULF waves
Abstract
Electron flux oscillations are produced in the magnetosphere in association with broadband Ultra Low Frequency (ULF) waves. These oscillations are observed in the form of drift-periodic flux fluctuations, but are not associated with drift echoes following storm- or substorm-related energetic particle injections. They are observed in particular during quiet times, and could be used as indicators of ongoing radial transport processes caused by ULF waves. The amplitudes of such flux oscillations is dependent on a number of parameters, such as the local phase space density gradient, the amplitude of ULF waves and the width of electron energy channels. In particular, the latter is a critical parameter affecting the observed amplitude of flux oscillations, with narrower energy channel widths enabling the observation of higher-amplitude flux oscillations; this potentially explains why such features were not observed regularly before the Van Allen Probes era, as previous spacecraft generally had lower energy resolution. We present simulation and observation results quantitatively associating the observed flux oscillations with the electron detector width; we also present associations of the observed flux oscillations with the local phase space density gradient and the amplitude of electric and magnetic fluctuations in the ULF range, both of which are expected to also affect radial transport rates.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMSM010..01S
- Keywords:
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- 2772 Plasma waves and instabilities;
- MAGNETOSPHERIC PHYSICS;
- 2774 Radiation belts;
- MAGNETOSPHERIC PHYSICS;
- 2784 Solar wind/magnetosphere interactions;
- MAGNETOSPHERIC PHYSICS;
- 7867 Wave/particle interactions;
- SPACE PLASMA PHYSICS