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Rapid Injections of MeV Electrons and Extremely Fast Step‐Like Outer Radiation Belt Enhancements
Author(s) -
Kim H.J.,
Lee D.Y.,
Wolf R.,
Bortnik J.,
Kim K.C.,
Lyons L.,
Choe W.,
Noh S.J.,
Choi K.E.,
Yue C.,
Li J.
Publication year - 2021
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2021gl093151
Subject(s) - electron , van allen radiation belt , physics , substorm , radiation , atomic physics , tracking (education) , computational physics , nuclear physics , plasma , magnetosphere , psychology , pedagogy
Rapid injection of MeV electrons associated with strong substorm dipolarization has been suggested as a potential explanation for some radiation belt enhancement events. However, it has been difficult to quantify the contribution of MeV electron injections to radiation belt enhancements. This paper presents two isolated MeV electron injection events for which we quite precisely quantify how the entire outer‐belt immediately changed with the injections. Tracking detailed outer‐belt evolution observed by Van Allen Probes, for both events, we identify large step‐like relativistic electron enhancements (roughly 1 order of magnitude increase for ∼2 MeV electron fluxes) for L ≳ 3.8 and L ≳ 4.6, respectively, that occurred on ∼30‐min time scales nearly instantaneously with the injections. The enhancements occurred almost simultaneously for 10s keV to multi‐MeV electrons, with the lowest L of enhancement region located farther out for higher energy. The outer‐belt stayed at these new levels for ≳several hours without substantial subsequent enhancements.