Strong Hydromagnetic Turbulence Associated with Comet Giacobini-Zinner
- Thomas J. Birmingham and
- Alexander J. Dessler
Published Online: 19 MAR 2013
Copyright 1988 by the American Geophysical Union.
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
- Published Online: 19 MAR 2013
- Published Print: 1 JAN 1988
Print ISBN: 9780875902395
Online ISBN: 9781118668757
- BHX (compressive) component;
- BHZ (transverse) component;
- Bow wave;
- Giacobini-Zinner comet;
- Power spectral density (PSD);
- Strong hydromagnetic turbulence
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.