Hostname: page-component-586b7cd67f-dsjbd Total loading time: 0 Render date: 2024-11-23T06:04:32.873Z Has data issue: false hasContentIssue false
  • English
  • Français

Flux Tubes and Dynamos

Published online by Cambridge University Press:  19 July 2016

M. Schüssler
M. Schüssler*
Affiliation:
Kiepenheuer-Institut für Sonnenphysik Schöneckstr. 6, D-W-7800 Freiburg, Germany

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

The structure of solar surface magnetic fields, the way they erupt from the the convection zone below, and processes like flux expulsion and fragmentation instabilities support the view that magnetic flux in a stellar convection zone is in an intermittent, fragmented state which can be described as an ensemble of magnetic flux tubes. Depending on size and field strength, the dynamics of magnetic flux tubes can strongly differ from the behavior of a passive, diffuse field which is often assumed in conventional mean-field dynamo theory. Observed properties of active regions like emergence in low latitudes, Hale's polarity rules, tilt angles, and the process of sunspot formation from smaller fragments, together with theoretical considerations of the dynamics of buoyant flux tubes indicate that the magnetic structures which erupt in an emerging active region are not passive to convection and originate in a source region (presumably an overshoot layer below the convection zone proper) with a field strength of at least 105 G, far beyond the equipartition field strength with respect to convective flows. We discuss the consequences of such a situation for dynamo theory of the solar cycle and consider the possibility of dynamo models on the basis of flux tubes. A simple, illustrative example of a flux tube dynamo is presented.

Keywords

Flux tubesSolar/stellar magnetic fieldsConvection zone
Type
1. The Solar Dynamo
Information
Symposium - International Astronomical Union , Volume 157: The Cosmic Dynamo , 1993 , pp. 27 - 39
Copyright
Copyright © Kluwer 1993 

References

Acheson, D.J.: 1978, Solar. Phys. 62, 23 Google Scholar
Bogdan, T.J.: 1985, Astrophys. J. 299, 510 CrossRefGoogle Scholar
Bogdan, T.J., Lerche, I.: 1985, Astrophys. J. 296, 719 CrossRefGoogle Scholar
Byrne, P.B.: 1992, in Thomas, J. H. and Weiss, N. O., ed(s)., Sunspots: Theory and Observations , Kluwer: Dordrecht, 63 Google Scholar
Cattaneo, F., Hughes, D.W.: 1988, J. Fluid Mech. 196, 323 Google Scholar
Choudhuri, A.R.: 1989, Solar. Phys. 123, 217 Google Scholar
Choudhuri, A.R., Gilman, P.A.: 1987, Astrophys. J. 316, 788 Google Scholar
Christensen-Dalsgaard, J.: 1992, in Schmelz, J. T. & Brown, J. C., ed(s)., The Sun: A Laboratory for Astrophysics , Kluwer:Dordrecht, 29 CrossRefGoogle Scholar
D'Silva, S., Choudhuri, A.R.: 1991, Solar. Phys. 136, 201 Google Scholar
D'Silva, S., Choudhuri, A.R.: 1993, Astron. Astrophys. , in press Google Scholar
Durney, B.R., De Young, D.S., Passot, Th.P.: 1990, Astrophys. J. 362, 709 CrossRefGoogle Scholar
Dziembowski, W.A., Goode, P.R.: 1989, Astrophys. J. 347, 540 Google Scholar
Ferriz-Mas, A., Schüssler, M.: 1993, Geophys. Astrophys. Fluid Dyn. , in press Google Scholar
Fisher, G.H., McClymont, N., Chou, D.-Y.: 1991, Astrophys. J. 374, 766 Google Scholar
Galloway, D.J., Weiss, N.O.: 1981, Astrophys. J. 243, 945 CrossRefGoogle Scholar
de la Rosa, J.I. Garcia: 1984, Solar Phys. 92, 161 CrossRefGoogle Scholar
Hale, G.E., Ellerman, F., Nicholson, S.B., Joy, A.H.: 1919, Astrophys. J. 49, 153 Google Scholar
Howard, R.: 1989, Solar. Phys. 123, 271 CrossRefGoogle Scholar
Howard, R.: 1974, Solar. Phys. 38, 283 Google Scholar
Hughes, D.W.: 1992, in Thomas, J. H. and Weiss, N. O., ed(s)., Sunspots: Theory and Observations , Kluwer: Dordrecht, 371 Google Scholar
Mcintosh, P.S.: 1981, in Cram, L. E. & Thomas, J. H., ed(s)., The Physics of Sunspots , Sacramento Peak Observatory: Sunspot, New Mexico/USA, 7 Google Scholar
Moreno-Insertis, F.: 1986, Astron. Astrophys. 166, 291 Google Scholar
Moreno-Insertis, F.: 1992, in Thomas, J. H. and Weiss, N. O., ed(s)., Sunspots: Theory and Observations , Kluwer: Dordrecht, 385 Google Scholar
Moreno-Insertis, F., Schüssler, M., Ferriz-Mas, A.: 1992, Astron. Astrophys. 264, 686 Google Scholar
Nordlund, Å., Brandenburg, A., Jennings, R.L., Rieutord, M., Ruokolainen, J., Stein, R.F., Tuominen, I.: 1992, Astrophys. J. 392, 647 Google Scholar
Parker, E.N.: 1975, Astrophys. J. 198, 205 CrossRefGoogle Scholar
Parker, E.N.: 1982, Astrophys. J. 256, 302 Google Scholar
Parker, E.N.: 1987a, Astrophys. J. 312, 868 Google Scholar
Parker, E.N.: 1987b, Astrophys. J. 321, 984 Google Scholar
Petrovay, K.: 1991, Solar. Phys. 134, 407 Google Scholar
Pidatella, R.M., Stix, M.: 1986, Astron. Astrophys. 157, 338 Google Scholar
Schüssler, M.: 1980, Nature 288, 150 CrossRefGoogle Scholar
Schüssler, M.: 1983, in Stenflo, J. O., ed(s)., Solar and Stellar Magnetic Fields: Origins and Coronal Effects , Reidel: Dordrecht, 213 Google Scholar
Schüssler, M.: 1984, in Guyenne, T. D. & Hunt, J. J., ed(s)., The Hydromagnetics of the Sun , ESA SP–220, 67 Google Scholar
Schüssler, M.: 1987, in Durney, B. R. & Sofia, S., ed(s)., The Internal Solar Angular Velocity , Reidel:Dordrecht, 303 Google Scholar
Schüssler, M., Solanki, S.K.: 1992, Astron. Astrophys. 264, L13 Google Scholar
Schmidt, H.U.: 1968, in Kiepenheuer, K. O., ed(s)., Structure and Development of Solar Active Regions , Reidel:Dordrecht, 95 Google Scholar
Schmitt, D.: 1987, Astron. Astrophys. 174, 281 Google Scholar
Spiegel, E.A., Weiss, N.O.: 1980, Nature 287, 616 Google Scholar
Spruit, H.C.: 1977, thesis, University of Utrecht Google Scholar
Spruit, H.C.: 1981, Astron. Astrophys. 102, 129 Google Scholar
Spruit, H.C., van Ballegooijen, A.A.: 1982, Astron. Astrophys. 106, 58 Google Scholar
Stenflo, J.O.: 1989, Astron. Astrophys. Rev. 1, 3 Google Scholar
Vainshtein, S.I., Zeldovich, Ya.B.: 1972, Sov. Phys. Usp. 15, 159 Google Scholar
Van Ballegooijen, A.A.: 1982, Astron. Astrophys. 106, 43 Google Scholar
Wang, Y.-M., Sheeley, N.R.: 1991, Astrophys. J. 375, 761 CrossRefGoogle Scholar
Zeldovich, Ya.B., Ruzmaikin, A.A., Sokoloff, D.D.: 1983, Magnetic Fields in Astrophysics , Gordon&Breach: New York Google Scholar
Zwaan, C.: 1978, Solar. Phys. 60, 213 Google Scholar
Zwaan, C.: 1987, Ann. Rev. Astron. Astrophys. 25, 83 Google Scholar
Zwaan, C.: 1992, in Thomas, J. H. and Weiss, N. O., ed(s)., Sunspots: Theory and Observations , Kluwer: Dordrecht, 75 CrossRefGoogle Scholar