Nonstorm time adiabatic acceleration of radiation belt relativistic electrons
Abstract
Acceleration mechanism of energetica electron is an outstanding question surrounding the Earth's radiation belt dynamics. Here we report an interesting electron acceleration event observed by Van Allen Probes in the dawnside magnetosphere during nonstorm times. Within about 10 h, the multi-MeV electron flux around L=5 increase about one order of magnitude with no chorus waves at corresponding position. Phase space density had a high gradient on radial direction as a result of local acceleration by chorus waves before the event and remained unchanged throughout this case. Meanwhile, a substantial shrinkage of the magnetic field lines occurred in the inner magnetosphere. These observations, together with the data-driven simulations, clearly demonstrate that the adiabatic transport associated with magnetospheric shrinkage was responsible for this acceleration event, indicting that the adiabatic transport can play a dominant role in the acceleration of radiation belt electrons under special conditions during nonstorm times.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2017
- Bibcode:
- 2017AGUFMSM11B2308D
- Keywords:
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- 2740 Magnetospheric configuration and dynamics;
- MAGNETOSPHERIC PHYSICS;
- 2784 Solar wind/magnetosphere interactions;
- MAGNETOSPHERIC PHYSICS;
- 2788 Magnetic storms and substorms;
- MAGNETOSPHERIC PHYSICS;
- 7845 Particle acceleration;
- SPACE PLASMA PHYSICS