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The Efficiency of Coronal Mass Ejection With Different IMF Preconditions on the Production of Megaelectronvolt Electron Content in the Outer Radiation Belt
Author(s) -
Yuan C.J.,
Zong Q.G.
Publication year - 2019
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
eISSN - 2169-9402
pISSN - 2169-9380
DOI - 10.1029/2018ja026263
Subject(s) - physics , coronal mass ejection , plasmasphere , solar wind , electron , shock wave , magnetopause , van allen radiation belt , geophysics , computational physics , astrophysics , plasma , nuclear physics , magnetosphere , mechanics
Fifty‐two coronal mass ejections (CMEs) from 2012 to 2017 are categorized into four types according to different interplanetary magnetic field (IMF) preconditions, and behaviors of 1.8‐, 3.4‐, 5.2‐, and 7.7‐MeV electrons are quantitatively investigated using an Radiation Belt Content (RBC) index improved for nondipolar geomagnetic field configuration due to interaction with CMEs. Statistical analyses show that CMEs with continuous southward IMF from upstream of shock front to CME leading edge are the most efficient in the production of megaelectronvolt electron content, with RBC five times larger after shock arrival for 1.8‐MeV channel, seven times larger for 3.4‐MeV channel, and three times larger for 5.2‐MeV channel; the 7.7‐MeV channel also experiences less pronounced enhancements. For CMEs with continuous northward IMF from upstream of shock front to CME leading edge, clear dropouts of RBC are revealed. The depletion is the most significant for 1.8 MeV, and the magnitude of depletion gradually decreases when the electron energy goes higher. It is suggested that the location of magnetopause and plasmapause, and thus magnetopause shadowing and magnetopsheric waves like whistler mode chorus, contributes to the dynamics of megaelectronvolt electrons in the outer radiation belt, with energy dependence, in response to CMEs with different preconditions.