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Modeling radiation belt electron acceleration by ULF fast mode waves, launched by solar wind dynamic pressure fluctuations
Author(s) -
Degeling A. W.,
Rankin R.,
Zong Q.G.
Publication year - 2014
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
eISSN - 2169-9402
pISSN - 2169-9380
DOI - 10.1002/2013ja019672
Subject(s) - physics , computational physics , solar wind , electron , van allen radiation belt , magnetohydrodynamics , magnetopause , van allen probes , magnetosphere , kinetic energy , plasma , classical mechanics , nuclear physics
Abstract We investigate the magnetospheric MHD and energetic electron response to a Storm Sudden Commencement (SSC) and subsequent magnetopause buffeting, focusing on an interval following an SSC event on 25 November 2001. We find that the electron flux signatures observed by LANL, Cluster, and GOES spacecraft during this event can largely be reproduced using an advective kinetic model for electron phase space density, using externally prescribed electromagnetic field inputs, (herein described as a “test‐kinetic model”) with electromagnetic field inputs provided by a 2‐D linear ideal MHD model for ULF waves. In particular, we find modulations in electron flux phase shifted by 90° from the local azimuthal ULF wave electric field ( E φ ) and a net enhancement in electron flux after 1.5 h for energies between 500 keV and 1.5 MeV near geosynchronous orbit. We also demonstrate that electrons in this energy range satisfy the drift resonance condition for the ULF waves produced by the MHD model. This confirms the conclusions reached by Tan et al. (2011), that the energization process in this case is dominated by drift‐resonant interactions between electrons and MHD fast mode waves, produced by fluctuations in solar wind dynamic pressure.