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±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 down at this point and T R increases further with increasing 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.
