Multi-Mode Kink Instability as a Mechanism for δ-Spot Formation

  • M. G. Linton
Conference paper
Part of the Astrophysics and Space Science Library book series (ASSL, volume 259)

Abstract

δ-spot active regions are a special class of active regions where a sunspot umbra of opposite polarity exist within the same penumbra (Zirin 1988). It is commonly held that active regions are the manifestation in the photosphere of a magnetic flux tube which arches up into the corona from the convection zone. The two opposite polarity spots of a bipolar active region are created by the intersection with the photosphere of the two legs of this arched flux tube. The close proximity of the opposite polarity spots of a δ-spot active region indicate that something forces the legs of the flux tube to remain close together. Other commonly observed properties of δ-spots, namely that the two spots rotate about each other as they evolve and that they develop magnetic shear along the magnetic neutral line between them, indicate that these active regions may be caused by kinked flux tubes, as first suggested by Tanaka (1991).

Keywords

Convection Peri Rium Sulem 

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References

  1. Alfvén, H. 1950: Tellus 2, 74.MathSciNetADSCrossRefGoogle Scholar
  2. Dahlburg, R. and Norton, D.: 1995, in M. Meneguzzi, A. Pouquet, and P. Sulem (eds.),Small Scale Structures in Three-Dimensional Hydrodynamic and Magnetohydrodynamic Turbulence, Springer, Heidelberg, 317.Google Scholar
  3. Fan, Y., Zweibel, E., Linton, M., and Fisher, G.: 1998, ApJ 505, L59.ADSCrossRefGoogle Scholar
  4. Galsgaard, K. and Nordlund, A.: 1997, JGR 102, 219.ADSCrossRefGoogle Scholar
  5. Linton, M.G., Dahlburg, R.B., Longcope, D.W., and Fisher, G.H.: 1998, ApJ 507, 404.ADSCrossRefGoogle Scholar
  6. Linton, M.G., Fisher, G.H., Dahlburg, R.B., and Fan, Y.: 1999, ApJ 522, 1190.ADSCrossRefGoogle Scholar
  7. Linton, M.G., Longcope, D.W., and Fisher, G.H.: 1996, ApJ 469, 954.ADSCrossRefGoogle Scholar
  8. Matsumoto, R., Tajima, T., Chou, W., Okubo, A., and Shibata, K.: 1998, ApJ 493, L43.ADSCrossRefGoogle Scholar
  9. Priest, E.R.: 1982, Solar Magnetohydrodynamics, Reidel, Boston.CrossRefGoogle Scholar
  10. Tanaka, K.: 1991, Solar Phys. 136, 133.ADSCrossRefGoogle Scholar
  11. Zirin, H.: 1988, Astrophysics of the Sun, Cambridge Univ. Press, Cambridge.Google Scholar

Copyright information

© Springer Science+Business Media Dordrecht 2001

Authors and Affiliations

  • M. G. Linton
    • 1
  1. 1.Space Sciences DivisionNaval Research LaboratoryUSA

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