Using Dynamo Theory to predict the sunspot number during Solar Cycle 21


  • Kenneth H. Schatten,

  • Philip H. Scherrer,

  • Leif Svalgaard,

  • John M. Wilcox


On physical grounds it is suggested that the sun's polar field strength near a solar minimum is closely related to the following cycle's solar activity. Four methods of estimating the sun's polar magnetic field strength near solar minimum are employed to provide an estimate of cycle 21's yearly mean sunspot number at solar maximum of 140 ± 20. We think of this estimate as a first order attempt to predict the cycle's activity using one parameter of physical importance based upon dynamo theory.