Magnetospheric convection and magnetopause shadowing effects in ULF wave‐driven energetic electron transport

• Author(s) / Creator(s)

  • Murphy, Kyle
  • Degeling, Alex W.
  • Rankin, Robert
  • Rae, I. Johnathan

• Magnetospheric radiation belt electron transport in the presence of ULF waves and a convection electric field is investigated using a model that includes a nightside plasma sheet source and electron losses by magnetopause shadowing. Narrow-band ULF waves launched from a prescribed dayside magnetopause source are shown to interact with trapped and untrapped equatorially mirroring electrons within the magnetosphere. For magnetic moments less than 8keV/nT and a strong convection electric field (in the order of 5mV/m), we find that a limb of untrapped plasma sheet electrons extending across the dayside magnetosphere into the afternoon sector provides a phase space density (PSD) source for injection to lower L-shells by ULF waves, causing a rapid enhancement in PSD. However, the same ULF wave activity gives rise to a rapid dropout in PSD for electrons with a higher magnetic moment or in the presence of a weaker convection electric field, since in this case the plasma sheet electrons escape through the magnetopause before they reach the afternoon sector. In their place, a lack of PSD, or PSD holes can be periodically injected from the magnetopause to lower L-shells by ULF waves, leading to the rapid depletion in average PSD. In each case, the magnitude and extent in L-shell of the PSD enhancement or depletion is strongly dependent on the amplitude of ULF waves in the afternoon sector, and is significantly augmented by the overlap of drift-resonant islands and an associated stochastic transport layer.

• Date created

  2013

• Subjects / Keywords

  • Fields
  • Storms
  • Mechanisms
  • Radiation Belts
  • Relativistic Electrons
  • Resonances
  • Outer Radiation Belt
  • Ulf Waves

• Type of Item

  Article (Published)

• DOI

  https://doi.org/10.7939/R30V89X86

• License

  © 2013 American Geophysical Union. This version of this article is open access and can be downloaded and shared. The original author(s) and source must be cited.