Solar wind conditions leading to efficient radiation belt electron acceleration: A superposed epoch analysis

TitleSolar wind conditions leading to efficient radiation belt electron acceleration: A superposed epoch analysis
Publication TypeJournal Article
Year of Publication2015
AuthorsLi, W, Thorne, RM, Bortnik, J, Baker, DN, Reeves, GD, Kanekal, SG, Spence, HE, Green, JC
JournalGeophysical Research Letters
Date Published09/2015
KeywordsChorus wave; Electron acceleration; solar wind conditions; Van Allen Probes
AbstractDetermining preferential solar wind conditions leading to efficient radiation belt electron acceleration is crucial for predicting radiation belt electron dynamics. Using Van Allen Probes electron observations (>1 MeV) from 2012 to 2015, we identify a number of efficient and inefficient acceleration events separately to perform a superposed epoch analysis of the corresponding solar wind parameters and geomagnetic indices. By directly comparing efficient and inefficient acceleration events, we clearly show that prolonged southward Bz, high solar wind speed, and low dynamic pressure are critical for electron acceleration to >1 MeV energies in the heart of the outer radiation belt. We also evaluate chorus wave evolution using the superposed epoch analysis for the identified efficient and inefficient acceleration events and find that chorus wave intensity is much stronger and lasts longer during efficient electron acceleration events, supporting the scenario that chorus waves play a key role in MeV electron acceleration.
URLhttp://onlinelibrary.wiley.com/wol1/doi/10.1002/2015GL065342/abstract
DOI10.1002/2015GL065342
Short TitleGeophys. Res. Lett.


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