Solar cycle 25 prediction using length-to-amplitude relations

Abstract

We propose a simple method for prediction of the 11-year solar cycle maximum that is based on two relations. One of them is well known Waldmeier's rule that binds the amplitude of a cycle and the length of its ascending phase. The second rule relates the length of a given cycle from minimum to minimum and the amplitude of the next one. Using corresponding linear regressions we obtain for the amplitide of cycle 25 in the scale of 13-month smoothed monthly total revised sunspot number ${\mathrm{SN}}_{\max }(25)=181\pm 46$ and for the moment of the maximum $T_{\max }(25)=2024.2\pm 1.0$. Therefore, according to the prediction, cycle 25 will be higher than the previous one (${\mathrm{SN}}_{\max }(24)=116$) with probability 0.92.

7 pages, 6 figures; submitted to Solar Physics

References in corpus (1)

• Spotless days and geomagnetic index as the predictors of solar cycle 25