Astrophysics and Space Science

, Volume 35, Issue 2, pp 389–402

Open and closed magnetospheric tail configurations and their stability

  • J. Birn
  • R. Sommer
  • K. Schindler
Article

DOI: 10.1007/BF00637005

Cite this article as:
Birn, J., Sommer, R. & Schindler, K. Astrophys Space Sci (1975) 35: 389. doi:10.1007/BF00637005

Abstract

The asymptotic theory valid for magnetospheric tail configurations that vary only weakly in the antisolar direction is used to derive a number of explicit properties. The conditions under which the magnetopause converges to form a closed magnetosphere or diverges (open magnetosphere) are identified and discussed. It is shown that the presence of the high latitude low pressure tail lobes guarantees the open solution. The large value of the Mach-number of the unperturbed solar wind is the reason for the slow variation of the plasma and field quantities along the tail. Criteria for (two-dimensional) stability are discussed and it is shown that they can be expressed in terms of simple topological properties of the equilibria. Closed magnetopheres turn out to be stable, open magnetospheres with sufficiently stretched field lines are subject to an instability which — as shown earlier —may be the cause of magnetospheric substorms.

Copyright information

© D. Reidel Publishing Company 1975

Authors and Affiliations

  • J. Birn
    • 1
  • R. Sommer
    • 1
  • K. Schindler
    • 1
  1. 1.Ruhr-Universität BochumBochumGermany