Braided Flux Ropes and Coronal Heating

  1. C. T. Russell,
  2. E. R. Priest and
  3. L. C. Lee
  1. Mitchell A. Berger

Published Online: 21 MAR 2013

DOI: 10.1029/GM058p0251

Physics of Magnetic Flux Ropes

Physics of Magnetic Flux Ropes

How to Cite

Berger, M. A. (1990) Braided Flux Ropes and Coronal Heating, 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/GM058p0251

Author Information

  1. Department of Mathematical Sciences, University of St Andrews, Fife, Scotland

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

We model a coronal loop as a set of N flux tubes braided about each other. The braiding is generated by random motions of the photospheric foot points. For one or two tubes the magnetic energy grows linearly with time as the motions proceed. For three or more tubes, however, energy grows quadratically with time. A method is given which provides a qualitative description of the flux rope structure for N = 3.

In Parker's (1983) coronal heating model, randomly braided fieldlines undergo reconnection; the magnetic energy associated with the braiding structure is then released as a source of heat. Calculating the energy storage and release is a difficult problem. Using a simple model for the structure of three braided flux tubes, a Monte Carlo simulation yields an average energy growth rate significantly smaller than that estimated in the Parker model. However, higher values of N will be needed before reliable comparisons can be made.