Solar Physics

, Volume 22, Issue 1, pp 3–19 | Cite as

Solar dynamo theory and the models of Babcock and Leighton

  • J. H. Piddington


The dynamo theory of the solar cycle as developed by Parker and others, and the observational models of Babcock and Leighton have been examined, with the conclusion that the dynamo theory is not applicable to the Sun and that the models fail.

An essential part of the theory is an adequate effective diffusion coefficient. Fields are continuously sheared and amplified and, in this theory, these may not be allowed to accumulate; all subsurface fields of an old cycle must be eliminated. Ohmic diffusion is negligible and turbulent diffusion is invoked. However, this requires that all solar fields are tangled to a small scale, which is contrary to observation; for Hale's polarity laws are strictly observed, and large-scale surface features are common at the end of an 11-yr cycle in the same general area where new fields are appearing.

The erupted (sunspot) fields lie generally above the unerupted, toroidal fields so that, even if they are merged as required, the centroid of the new system would be above that of the old. The result is not a steady-state oscillator, as required, but the complete loss of the solar field.

It is concluded that for these and other reasons a shallow, reversing field is unacceptable, and that a deeply penetrating field is required. Reference is made to an alternative theory of the solar cycle based on a deep magnetic field.


Solar Cycle Complete Loss Effective Diffusion Alternative Theory Turbulent Diffusion 
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Copyright information

© D. Reidel Publishing Company 1972

Authors and Affiliations

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

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