Open AccessRapid rebuilding of the outer radiation belt
Author(s) -
Glocer A.,
Fok M.C.,
Nagai T.,
Tóth G.,
Guild T.,
Blake J.
Publication year - 2011
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2011ja016516
Subject(s) - van allen radiation belt , physics , electron , van allen probes , magnetosphere , computational physics , radiation , flux (metallurgy) , geophysics , ionosphere , space weather , spacecraft , plasmasphere , magnetic field , astronomy , nuclear physics , materials science , quantum mechanics , metallurgy
Recent observations by the radiation monitor (RDM) on the spacecraft Akebono have shown several cases of >2.5 MeV radiation belt electron enhancements occurring on timescales of less than a few hours. Similar enhancements are also seen in detectors on board the NOAA/POES and TWINS 1 satellites. These intervals are shorter than typical radial diffusion or wave‐particle interactions can account for. We choose two so‐called “rapid rebuilding” events that occur during high speed streams (4 September 2008 and 22 July 2009) and simulated them with the Space Weather Modeling Framework configured with global magnetosphere, radiation belt, ring current, and ionosphere electrodynamics model. Our simulations produce a weaker and delayed dipolarization as compared to observations, but the associated inductive electric field in the simulations is still strong enough to rapidly transport and accelerate MeV electrons resulting in an energetic electron flux enhancement that is somewhat weaker than is observed. Nevertheless, the calculated flux enhancement and dipolarization is found to be qualitatively consistent with the observations. Taken together, the modeling results and observations support the conclusion that storm‐time dipolarization events in the magnetospheric magnetic field result in strong radial transport and energization of radiation belt electrons.