The Fuzzy Classification of the Solar Cycle and the Prediction for the 22nd Solar Cycle

In this paper, on the basis of fuzzy set theory the classification and the prediction of solar cycles are discussed. By using the method of fuzzy cluster analysis, a prediction for the 22nd solar cycle has been made. The results are as follows:The length of the declining time for the 21st cycle is 8 or 9 years; the begining time for the 22nd cycle is the year 1987 or 1988; the first minimum of the year, s mean value of the relative number is 4.3; the length of the ascending duration for the 22nd cycle is 4 years; the maxima of the year, s mean value of the relative number is 118.9; the length of the declining duration for the 22nd cycle is 6.5 or 8 years.