Dates and values for sunspot cycle maxima.
Dates and values for sunspot cycle minima. The value is always the value of the 13-month mean of the International sunspot number. The dates differ according to the indicator used.
Dates and values of maxima using the 13-month running mean with sunspot number data, sunspot area data, and 10.7 cm radio flux data.
Dates and values of maxima using the 24-month FWHM Gaussian with sunspot number data, sunspot area data, and 10.7 cm radio flux data as in Table 3.
Cycle maxima determined by the 13-month mean with the International Sunspot Numbers and the Group Sunspot Numbers. The Group values are systematically lower than the International values prior to cycle 12.
Prediction method errors for cycle 19 – 23. The three geomagnetic precursor methods (Ohl’s, Feynman’s, and Thompson’s) give the smallest errors.
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