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ON THE INTERPRETATION OF MAGNETIC HELICITY SIGNATURES IN THE DISSIPATION RANGE OF SOLAR WIND TURBULENCE

Journal Article · · Astrophysical Journal Letters
 [1];  [2]
  1. Department of Physics and Astronomy, University of Iowa, Iowa City, IA 52242 (United States)
  2. Department of Astronomy, University of California, Berkeley, CA 94720 (United States)
Measurements of small-scale turbulent fluctuations in the solar wind find a non-zero right-handed magnetic helicity. This has been interpreted as evidence for ion cyclotron damping. However, theoretical and empirical evidence suggests that the majority of the energy in solar wind turbulence resides in low-frequency anisotropic kinetic Alfven wave fluctuations that are not subject to ion cyclotron damping. We demonstrate that a dissipation range comprised of kinetic Alfven waves also produces a net right-handed fluctuating magnetic helicity signature consistent with observations. Thus, the observed magnetic helicity signature does not necessarily imply that ion cyclotron damping is energetically important in the solar wind.
OSTI ID:
21301393
Journal Information:
Astrophysical Journal Letters, Journal Name: Astrophysical Journal Letters Journal Issue: 1 Vol. 709; ISSN 2041-8205
Country of Publication:
United States
Language:
English

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