Applying the cold plasma dispersion relation to whistler mode chorus waves: EMFISIS wave measurements from the Van Allen Probes

TitleApplying the cold plasma dispersion relation to whistler mode chorus waves: EMFISIS wave measurements from the Van Allen Probes
Publication TypeJournal Article
Year of Publication2015
AuthorsHartley, DP, Chen, Y, Kletzing, CA, Denton, MH, Kurth, WS
JournalJournal of Geophysical Research: Space Physics
Date Published02/2015
Keywordschorus waves; EMFISIS; energetic electrons; Radiation belts; Van Allen Probes; wave-particle interactions
AbstractMost theoretical wave models require the power in the wave magnetic field in order to determine the effect of chorus waves on radiation belt electrons. However, researchers typically use the cold plasma dispersion relation to approximate the magnetic wave power when only electric field data are available. In this study, the validity of using the cold plasma dispersion relation in this context is tested using Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS) observations of both the electric and magnetic spectral intensities in the chorus wave band (0.1–0.9 fce). Results from this study indicate that the calculated wave intensity is least accurate during periods of enhanced wave activity. For observed wave intensities >10−3 nT2, using the cold plasma dispersion relation results in an underestimate of the wave intensity by a factor of 2 or greater 56% of the time over the full chorus wave band, 60% of the time for lower band chorus, and 59% of the time for upper band chorus. Hence, during active periods, empirical chorus wave models that are reliant on the cold plasma dispersion relation will underestimate chorus wave intensities to a significant degree, thus causing questionable calculation of wave-particle resonance effects on MeV electrons.
URLhttp://doi.wiley.com/10.1002/2014JA020808
DOI10.1002/2014JA020808
Short TitleJ. Geophys. Res. Space Physics


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