Resistive Instability

  1. C. T. Russell,
  2. E. R. Priest and
  3. L. C. Lee
  1. Karl Schindler and
  2. Antonius Otto

Published Online: 21 MAR 2013

DOI: 10.1029/GM058p0051

Physics of Magnetic Flux Ropes

Physics of Magnetic Flux Ropes

How to Cite

Schindler, K. and Otto, A. (1990) Resistive Instability, in Physics of Magnetic Flux Ropes (eds C. T. Russell, E. R. Priest and L. C. Lee), American Geophysical Union, Washington, D. C.. doi: 10.1029/GM058p0051

Author Information

  1. Ruhr-Universät Bochum, Bochum, Federal Republic of Germany

Publication History

  1. Published Online: 21 MAR 2013
  2. Published Print: 1 JAN 1990

ISBN Information

Print ISBN: 9780875900261

Online ISBN: 9781118663868

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Keywords:

  • Solar photosphere;
  • Magnetic flux;
  • Astrophysics

Summary

The concept and the relevance of resistive instabilities in cosmic plasmas is discussed from a general point of view. The discussion emphasizes qualitative changes that occur by proceeding from simple cases where symmetry allows ignoring one or two space coordinates to the general three-dimensional process. The prototype of resistive instability, the tearing mode of a plane sheet, already exhibits important aspects. Particularly, the instability occurs on a time scale that can be much faster than magnetic diffusion for large values of the Lundquist number. This speed-up is due to a strong localization of the resistive effects.

The step from one- to two- or three-dimensional systems brings about large scale consequences of the instability. Such resistive instability processes are found to be powerful mechanisms for releasing previously stored magnetic energy in cosmic plasma configurations and for initiating the magnetic opening of surfaces separating regions of different topological structure. A further important aspect is the occurrence of structures resembling magnetic flux ropes.

The step from two to three dimensions bears on the concept of magnetic reconnection. An analysis of resistive instability processes has demonstrated the necessity for a revision of that concept. It is shown that the recently suggested notion of general magnetic reconnection is adequate to describe three-dimensional resistive instability processes. This includes cases where the magnetic field has no singularity such as magnetic nulls.

A three-dimensional process that illustrates these properties is a model of flux transfer events at the earth's magnetopause. By a 3D-MHD simulation this model analyses the dynamic consequences of a sudden appearance of a localized spot of resistivity at the magnetopause. The results are discussed in the light of general magnetic reconnection.