Astrophysics and Space Science

, Volume 24, Issue 1, pp 259–267 | Cite as

Dynamo theories of the solar and galactic magnetic fields

  • J. H. Piddington


Earlier criticisms of solar and galactic dynamo theories are extended to answer Parker's rebuttal, and the major modification made to his models to include Sweet's magnetic field annihilation mechanism as invoked in some theories of solar flares. His kinematic and weak-field analyses appear irrelevant because they ignore magnetic stresses which are of major importance and whose effects are evident in sunspots and elsewhere. It is shown that, even if Sweet's mechanism is effective under the most favourable conditions, these conditions are most unlikely in the solar convection zone or galactic disk.

The problem is resolved by observational data which show that the fields are not tangled down to the scales required for dissipation byany known mechanism in the times available. Spot groups and many other patterns show that the solar fields are much too ordered to be products of a region of turbulence or to be dissipated by turbulence; the toroidal field must leave the Sun entirely to complete each 11-yr cycle. Faraday rotation, H I gas observations and extra-galactic fields provide strong evidence against a galactic dynamo and for a primordial field.


Flare Solar Flare Convection Zone Faraday Rotation Galactic Disk 
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  1. Allen, C. W.: 1963,Astrophysical Quantities, Univ. London Press., p. 163.Google Scholar
  2. Burton, W. B.: 1972a,The Large-Scale Distribution of Neutral Hydrogen in the Galaxy, U.S. National Radio Astronomy Obs. Rep.Google Scholar
  3. Burton, W. B.: 1972b,Astron. Astrophys. 19, 51.Google Scholar
  4. Harvey, J.: 1971,Publ. Astron. Soc. Pacific 83, 539.Google Scholar
  5. Howard, R. and Stenflo, J. O.: 1972,Solar Phys. 22, 402.Google Scholar
  6. Jokipii, J. R. and Lerche, I.: 1969,Astrophys. J. 157, 1137.Google Scholar
  7. Kiepenheuer, K. O.: 1953, in G. P. Kuiper (ed.),The Sun, Chicago University Press, p. 322.Google Scholar
  8. Kopecký, M.: 1971,Bull. Astron. Inst. Czech. 22, 343.Google Scholar
  9. Kuperus, M.: 1969,Space Sci. Rev. 9, 713.Google Scholar
  10. Mathewson, D. S. and Ford, V. L.: 1970,Astrophys. J. Letters 160, L43.Google Scholar
  11. Newkirk, G., Trotter, D. E., Altschuler, M. D. and Howard, R.: 1972,Solar Phys. 24, 370.Google Scholar
  12. Osterbrock, D. E.: 1961,Astrophys. J. 134, 347.Google Scholar
  13. Parker, E. N.: 1972,Astrophys. J. 174, 499.Google Scholar
  14. Parker, E. N.: 1973,Astrophys. Space Sci. 22, 279.Google Scholar
  15. Piddington, J. H.: 1969,Cosmic Electrodynamics, Wiley-Interscience, New York.Google Scholar
  16. Piddington, J. H.: 1970,Australian J. Phys. 23, 371.Google Scholar
  17. Piddington, J. H.: 1971,Proc. Astron. Soc. Australia 2, 7.Google Scholar
  18. Piddington, J. H.: 1972a,Solar Phys. 22, 3.Google Scholar
  19. Piddington, J. H.: 1972b,Cosmic Electrodyn. 3, 60.Google Scholar
  20. Piddington, J. H.: 1972c,Cosmic Electrodyn. 3, 129.Google Scholar
  21. Piddington, J. H.: 1973,Monthly Notices Roy. Astron. Soc.,162, 73.Google Scholar
  22. Reinhardt, M. and Thiel, M. A. F.: 1970,Astrophys. Letters 7, 101.Google Scholar
  23. Spitzer, L.: 1962,Physics of Fully Ionized Gases, Wiley, New York.Google Scholar
  24. Sweet, P. A.: 1969,Ann. Rev. Astron. Astrophys. 7, 149.Google Scholar
  25. Weiss, N. O.: 1966,Proc. Roy. Soc. London A,293, 310.Google Scholar
  26. Yeh, T. and Axford, W. I.: 1970,J. Plasma Phys. 4, 207.Google Scholar
  27. Zirin, H.: 1972,Solar Phys. 22, 34.Google Scholar

Copyright information

© D. Reidel Publishing Company 1973

Authors and Affiliations

  • J. H. Piddington
    • 1
  1. 1.CSIRO Division of PhysicsNational Standards LaboratorySydneyAustralia

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