The Minimum Activity Epoch as a Precursor of the Solar Activity
Abstract
This paper considers the indices characterizing the minimum activity epoch, according to the data of large-scale magnetic fields and polar activity. Such indices include: dipole-octopole index, area and average latitude of the field with dominant polarity in each hemisphere, polar activity seen in polar faculae and Ca II K line bright points, coronal emission line intensity (5303 Å) and others. We studied the correlation between these indices and the amplitude of the following sunspot cycle, and the relation between the duration of the cycle of large-scale magnetic fields and the duration of the sunspot cycle. The obtained relationships allow us to presume that the polar field is formed from the sources of both preceding and the current activity cycles during the decay phase and at the activity minimum. The balance in these sources would therefore determine the features of the following sunspot cycle. The prediction for the 24th activity cycle using these results leads to W=102±13.
- Publication:
-
Solar Physics
- Pub Date:
- December 2009
- DOI:
- 10.1007/s11207-009-9451-5
- Bibcode:
- 2009SoPh..260..465T
- Keywords:
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- Large-scale magnetic field;
- Solar activity cycle