A self-consistent planetary synchronization model of short, medium, and long term cycles of the solar dynamo


A self-consistent planetary synchronization model of short, medium, and long term cycles of the solar dynamo

Stefani, F.; Horstmann, G. M.; Klevs, M.; Stepanov, R.; Weier, T.

In a series of recent papers we have developed a self-consistent explanation of short, medium and long term solar cycles in terms of synchronization by planetary motions. According to this model, the surprisingly phase-stable 22.14-year Hale cycle results from parametric resonance of a conventional α−Ω dynamo with an oscillatory part of the helical turbulence parameter α that is thought to be synchronized by the 11.07-year spring-tide periodicity of the three tidally dominant planets Venus, Earth and Jupiter. The medium term Suess-de Vries cycle (specified to 193 years in our model) emerges as a beat period between the basic 22.14-year Hale cycle and some (yet not well
understood) spin–orbit coupling connected with the motion of the Sun around the barycenter of the solar system that is governed by the 19.86-year synodic period of Jupiter and Saturn. Closely related to this, Gleissberg-type cycles appear as nonlinear beat effects and/or from perturbations of the Sun’s orbital motion due to other synodic periods of the Jovian planets. Finally, the long-term variations on the millennial time-scale (Bond events) arise as chaotic transitions between regular and irregular episodes of the solar dynamo, in close analogy with the super-modulation concept introduced by Weiss and Tobias.

Keywords: solar dynamo; synchronization

  • Lecture (Conference)
    The 12th pamir International Conference on Fundamental and Applied MHD, 04.-08.07.2022, Krakow, Poland

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