Evidence for injection of relativistic electrons into the Earth's outer radiation belt via intense substorm electric fields

TitleEvidence for injection of relativistic electrons into the Earth's outer radiation belt via intense substorm electric fields
Publication TypeJournal Article
Year of Publication2014
AuthorsDai, L, Wygant, JR, Cattell, CA, Thaller, S, Kersten, K, Breneman, A, Tang, X, Friedel, RH, Claudepierre, SG, Tao, X
JournalGeophysical Research Letters
Volume41
Issue4
Pagination1133 - 1141
Date Published02/2014
Keywordsradiation belt relativistic electrons; substorm dipolarization; substorm electric fields; substorm injection
AbstractObservation and model results accumulated in the last decade indicate that substorms can promptly inject relativistic ‘killer’ electrons (≥MeV) in addition to 10–100 keV subrelativistic populations. Using measurements from Cluster, Polar, LANL, and GOES satellites near the midnight sector, we show in two events that intense electric fields, as large as 20 mV/m, associated with substorm dipolarization are associated with injections of relativistic electrons into the outer radiation belt. Enhancements of hundreds of keV electrons at dipolarization in the magnetotail can account for the injected MeV electrons through earthward transport. These observations provide evidence that substorm electric fields inject relativistic electrons by transporting magnetotail electrons into the outer radiation belt. In these two events, injected relativistic electrons dominated the substorm timescale enhancement of MeV electrons as observed at geosynchronous orbit.
URLhttp://doi.wiley.com/10.1002/2014GL059228
DOI10.1002/2014GL059228
Short TitleGeophys. Res. Lett.


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