Open AccessThe Day‐Night Difference and Geomagnetic Activity Variation of Energetic Electron Fluxes in Region of South Atlantic Anomaly
Author(s) -
Li L. Y.,
Zhou S. P.,
Wei S. H.,
Yang J. Y.,
Sauvaud J. A.,
Berthelier J. J.
Publication year - 2020
Publication title -
space weather
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.254
H-Index - 56
ISSN - 1542-7390
DOI - 10.1029/2020sw002479
Subject(s) - earth's magnetic field , south atlantic anomaly , anomaly (physics) , morning , dusk , atmospheric sciences , electron , local time , physics , van allen radiation belt , environmental science , magnetosphere , magnetic field , astronomy , statistics , mathematics , quantum mechanics , condensed matter physics
Utilizing the DEMETER observations at 670 km, we examined the day‐night difference of energetic electrons (100–800 keV) in the South Atlantic Anomaly (SAA) region and their dependence on geomagnetic activities in different seasons. Under geomagnetically quiet conditions, the fluxes of higher‐energy electrons (>200 keV) in the dusk and midnight (MLT ~ 19–24 hr) are usually larger than those in the morning (MLT ~ 8–12 hr) in the core region of the SAA ( −50 ≤ λ ≤ − 20deg ) during the northern and southern summers (21 March 2007 to 23 September 2007 and 23 September 2007 to 21 March 2008). The day‐night difference of energetic electrons in SAA region depends not only on the electron energy but also on the geomagnetic activity levels. Enhanced geomagnetic activities increase the energetic electrons in morning and hence weaken their day‐night difference in the SAA region.