Strong Hydromagnetic Turbulence Associated with Comet Giacobini-Zinner

  1. Thomas J. Birmingham and
  2. Alexander J. Dessler
  1. Bruce T. Tsurutani and
  2. Edward J. Smith

Published Online: 19 MAR 2013

DOI: 10.1029/SP027p0077

Comet Encounters

Comet Encounters

How to Cite

Tsurutani, B. T. and Smith, E. J. (1988) Strong Hydromagnetic Turbulence Associated with Comet Giacobini-Zinner, in Comet Encounters (eds T. J. Birmingham and A. J. Dessler), American Geophysical Union, Washington, D.C.. doi: 10.1029/SP027p0077

Author Information

  1. Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109

Publication History

  1. Published Online: 19 MAR 2013
  2. Published Print: 1 JAN 1988

ISBN Information

Print ISBN: 9780875902395

Online ISBN: 9781118668757

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Keywords:

  • BHX (compressive) component;
  • BHZ (transverse) component;
  • Bow wave;
  • Giacobini-Zinner comet;
  • Power spectral density (PSD);
  • Strong hydromagnetic turbulence

Summary

The turbulence surrounding comet Giacobini-Zinner reached intensities three orders of magnitudes above that of “intermediate” solar wind conditions, was characterized by Δ B/Bo almost equal to one, and extended to cometocentric distances beyond 106 km. The strong spectral peak at f ∼ 10−2 Hz and the general intensity profile of the turbulence (a lack of emissions close to the nucleus [< 2.5×104 km], peak intensities near the bow wave, and a spatial extend > 106 km) are in excellent agreement with generation by plasma instabilities associated with the pickup of H2O+ group ions.

The total energy of the magnetic turbulence near f ∼ 10−2 Hz is estimated to be ∼5×1015 joules and that of ion energization due to solar wind pickup ∼6×1013 watts. It thus takes a minimum of ∼100 s to build up the magnetic turbulence. This scale is approximately the linear growth rate of the ion pickup instability, giving a consistent picture of the energy source of the turbulence.