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

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 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 MeVmore » electrons.« less
Authors:
 [1] ;  [2] ;  [3] ;  [4] ;  [3]
  1. Lancaster Univ. (United Kingdom). Physics Dept.
  2. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  3. Univ. of Iowa, Iowa City, IA (United States). Dept. of Physics and Astronomy
  4. Space Science Inst., Boulder, CO (United States)
Publication Date:
OSTI Identifier:
1212475
Report Number(s):
LA-UR-17-20871
Journal ID: ISSN 2169-9380
Grant/Contract Number:
AC52-06NA25396; 1131871; NNG13PJ05I; NAS5-01072; 921647
Type:
Accepted Manuscript
Journal Name:
Journal of Geophysical Research. Space Physics
Additional Journal Information:
Journal Volume: 120; Journal Issue: 2; Journal ID: ISSN 2169-9380
Publisher:
American Geophysical Union
Research Org:
Lancaster Univ. (United Kingdom); Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org:
USDOE; National Science Foundation (NSF); National Aeronautic and Space Administration (NASA); Science and Technology Facilities Council (STFC) (United Kingdom); Royal Astronomical Society (RAS) (United Kingdom); Institute of Physics (IOP) (United Kingdom)
Contributing Orgs:
Univ. of Iowa, Iowa City, IA (United States); Space Science Inst., Boulder, CO (United States)
Country of Publication:
United States
Language:
English
Subject:
79 ASTRONOMY AND ASTROPHYSICS; Van Allen Probes; EMFISIS; chorus waves; wave-particle interactions; radiation belts; energetic electrons