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Title: On the parameter dependence of the whistler anisotropy instability

The evolution of the whistler anisotropy instability relevant to whistler-mode chorus waves in the Earth’s inner magnetosphere is studied using kinetic simulations and is compared with satellite observations. The electron distribution is constrained by the whistler anisotropy instability to a marginal stability state and presents an upper bound of electron anisotropy, which agrees with satellite observations. The electron beta β ∥e separates whistler waves into two groups: (i) quasi-parallel whistler waves for β ∥e ≳ 0.02 and (ii) oblique whistler waves close to the resonance cone for β ∥e ≲ 0.02. Landau damping is important in the saturation and relaxation stage of the oblique whistler wave growth. The saturated magnetic field energy of whistler waves roughly scales with the electron beta β 2 ∥e, shown in both simulations and satellite observations. Lastly, these results suggest the critical role of electron beta β ∥e in determining the whistler wave properties in the inner magnetosphere.
Authors:
ORCiD logo [1] ; ORCiD logo [2] ; ORCiD logo [1] ;  [1] ; ORCiD logo [3] ; ORCiD logo [1]
  1. Univ. of California, Los Angeles, CA (United States)
  2. Univ. of California, Los Angeles, CA (United States); Univ. Corp. for Atmospheric Research, Boulder, CO (United States)
  3. Univ. of California, Los Angeles, CA (United States); Boston Univ., Boston, MA (United States)
Publication Date:
Grant/Contract Number:
SC0010578
Type:
Accepted Manuscript
Journal Name:
Journal of Geophysical Research. Space Physics
Additional Journal Information:
Journal Volume: 122; Journal Issue: 2; Journal ID: ISSN 2169-9380
Publisher:
American Geophysical Union
Research Org:
Univ. of California, Los Angeles, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC)
Country of Publication:
United States
Language:
English
Subject:
79 ASTRONOMY AND ASTROPHYSICS; Whistler anisotropy instability; Whistler‐mode chorus waves; electron anisotropy; electron beta
OSTI Identifier:
1466261
Alternate Identifier(s):
OSTI ID: 1402343