Hartley, Dave and Chen, Yue and Kletzing, C.A. and Denton, Michael and Kurth, William (2015) Applying the cold plasma dispersion relation to whistler-mode chorus waves : EMFISIS wave measurements from the Van Allen Probes. Journal of Geophysical Research: Space Physics, 120 (2). pp. 1144-1152. ISSN 2169-9402
Hartley_et_al_2015_Journal_of_Geophysical_Research_Space_Physics.pdf - Published Version
Available under License Creative Commons Attribution.
Download (1MB)
Abstract
Most 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 the cold plasma dispersion relation in this context is tested using 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.