The prediction method of similar cycles

Abstract

The concept of degree of similarity ({\eta}) is proposed to quantitatively describe the similarity of a parameter (e.g. the maximum amplitude Rmax) of a solar cycle relative to a referenced one, and the prediction method of similar cycles is further developed. For two parameters, the solar minimum (Rmin) and rising rate ({\beta}a), which can be directly measured a few months after the minimum, a synthesis degree of similarity ({\eta}s) is defined as the weighted-average of the {\eta} values around Rmin and {\beta}a with the weights given by the coefficients of determination of Rmax with Rmin and {\beta}a, respectively. The monthly values of the whole referenced cycle can be predicted by averaging the corresponding values in the most similar cycles with the weights given by the {\eta}s values. Cycles 14 and 10 are found to be the two most similar cycles of Cycle 24. As an application, Cycle 24 is predicted to peak around January 2013{\pm}8 (months) with a size of about Rmax =83.0{\pm}16.7 and to end around September 2019.