Premium
Revisit of relationship between geosynchronous relativistic electron enhancements and magnetic storms
Author(s) -
Kim HeeJeong,
Lyons Larry,
Pinto Victor,
Wang ChihPing,
Kim KyungChan
Publication year - 2015
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 - 10.1002/2015gl065192
Subject(s) - geosynchronous orbit , physics , solar wind , substorm , magnetopause , electron , storm , geophysics , geomagnetic storm , interplanetary magnetic field , ionosphere , magnetic cloud , atmospheric sciences , magnetic field , magnetosphere , computational physics , meteorology , astronomy , satellite , nuclear physics , quantum mechanics
Abstract We find evidence that magnetic storms are not only unnecessary for geosynchronous relativistic electron enhancements but also not directly relevant to the electron enhancements even if the enhancements are accompanied by magnetic storms. What is crucial for electron enhancements at geosynchronous orbit are sustained south‐oriented or north‐south fluctuating interplanetary magnetic field (IMF) B z that drives sufficiently large substorm activity and small solar wind density N sw that likely leads to low loss rate of relativistic electrons to the ionosphere and/or to the magnetopause for an extended time period. Specifically, almost all the abrupt, large electron increases in our data set took place under the condition of average AE > 235 nT and average N sw ≤ 5 cm −3 . Examination of detailed time profiles clearly shows that electron flux starts to increase quite immediately with arrival of the right IMF and solar wind conditions, regardless of a magnetic storm, leaving the accompanied magnetic storms merely coincident.