The amplitude of sunspot minimum as a favorable precursor for the prediction of the amplitude of the next solar maximum and the limit of the Waldmeier effect

TL;DR

This paper demonstrates that the sunspot minimum amplitude is a reliable precursor for predicting the next solar maximum's strength, introduces a polynomial model for cycle timing, and identifies a limit to the Waldmeier effect that constrains dynamo models.

Contribution

It validates the sunspot minimum amplitude as a predictive tool and reveals a maximum in the rise time cycle amplitude relation, indicating a break in the Waldmeier effect.

Findings

Predicted Cycle 24 maximum amplitude around 85±17.

Cycle 24 expected to peak in the third quarter of 2013.

Identified a minimum in the rise time relation at about 3 to 3.5 years.

Abstract

The linear relationship between the maximum amplitudes (R$_{max}$) of sunspot cycles and preceding minima (R$_{min}$) is one of the precursor methods used to predict the amplitude of the upcoming solar cycle. In the recent past this method has been subjected to severe criticism. In this communication we show that this simple method is reliable and can profitably be used for prediction purposes. With the 13-month smoothed R$_{min}$ of 1.8 at the beginning, it is predicted that the R$_{max}$ of the ongoing cycle will be around 85$\pm$17, suggesting that Cycle 24 may be of moderate strength. Based on a second order polynomial dependence between the rise time (T$_R$) and R$_{max}$, it is predicted that Cycle 24 will reach its smoothed maximum amplitude during the third quarter of the year 2013. An important finding of this paper is that the rise time cycle amplitude relation reaches a minimum at about 3 to 3.5 years corresponding to a cycle amplitude of about 160. The Waldmeier effect breaks at this point and T$_{R}$ increases further with increase in R$_{max}$. This feature, we believe, may put a constraint on the flux transport dynamo models and lead to more accurate physical principles based predictions.