Turbulent Generation of Auroral Currents and Fields–A Spectral Simulation of Two-Dimensional MHD Turbulence

  1. T. E. Moore,
  2. J. H. Waite Jr.,
  3. T. W. Moorehead and
  4. W. B. Hanson
  1. Y. Song and
  2. R. L. Lysak

Published Online: 18 MAR 2013

DOI: 10.1029/GM044p0197

Modeling Magnetospheric Plasma

Modeling Magnetospheric Plasma

How to Cite

Song, Y. and Lysak, R. L. (1988) Turbulent Generation of Auroral Currents and Fields–A Spectral Simulation of Two-Dimensional MHD Turbulence, in Modeling Magnetospheric Plasma (eds T. E. Moore, J. H. Waite, T. W. Moorehead and W. B. Hanson), American Geophysical Union, Washington, D. C.. doi: 10.1029/GM044p0197

Author Information

  1. School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455

Publication History

  1. Published Online: 18 MAR 2013
  2. Published Print: 1 JAN 1988

ISBN Information

Print ISBN: 9780875900704

Online ISBN: 9781118664414

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Keywords:

  • Space plasmas—Mathematical models;
  • Magnetosphere—Mathematical models;
  • Ionosphere—Mathematical models

Summary

The nonlinear evolution of large-scale turbulent boundary layer flow with magnetosphere-ionosphere coupling is investigated by a two-dimensional, forced, time-dependent MHD model of the disturbed flux tube. It is suggested that the nonlinear effect, especially the current nonlinear effect, plays an important role in breaking large-scale vortices and currents into medium and small ones. Spectral simulation results show that the large-scale turbulent magnetospheric vortices can be connected with highly structured auroral forms by an energy cascade process. The results are subject to a wavelength-dependent damping rate, which is caused by field-aligned anomalous resistivity and Pedersen conductivity, and fluctuating driving terms (due to, for example, the Kelvin-Helmholtz instability). Our results indicate that the evolution of a disturbed flux tube is determined by the nonlinear effect, the scale length dependence of the damping rate, and the structure of the driving terms.