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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
Article

Abstract

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.

Keywords

Flare Solar Flare Convection Zone Faraday Rotation Galactic Disk 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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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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