Open AccessDrift resonant generation of peaked relativistic electron distributions by Pc 5 ULF waves
Author(s) -
Degeling A. W.,
Ozeke L. G.,
Rankin R.,
Mann I. R.,
Kabin K.
Publication year - 2008
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 - 10.1029/2007ja012411
Subject(s) - physics , ultra low frequency , magnetosphere , van allen radiation belt , computational physics , electron , van allen probes , amplitude , whistler , adiabatic process , magnetohydrodynamics , quantum electrodynamics , magnetic field , optics , quantum mechanics , astronomy
The adiabatic drift‐resonant interaction between relativistic, equatorially mirroring electrons and narrowband, Pc 5 ultra low frequency (ULF) waves in the magnetosphere is investigated using a time‐dependent magnetohydrodynamic (MHD) wave model. Attention is focused on the effect of a ULF wave packet with finite duration on the equatorially mirroring, relativistic electron phase space density (PSD) profile. It is demonstrated that a burst of narrow band ULF waves can give rise to the growth of strong localized peaks in PSD with L ‐shell by nondiffusive radial transport. This contrasts with the diffusive “external source acceleration mechanism” described by Green and Kivelson (2004), a radial transport mechanism often attributed to ULF waves, which cannot produce peaks in PSD that increase with time. On the basis of this paradigm, observations of locally growing PSD peaks are usually attributed to very low frequency (VLF) wave acceleration by resonant interactions with lower‐band chorus (e.g., Horne et al., 2005). However, we show that in situations where large amplitude, narrow bandwidth ULF waves are also observed, these time‐limited coherent ULF waves can also generate growing PSD peaks and under such circumstances may offer an alternative explanation.