Predicting the solar maximum with the rising rate

TL;DR

This paper investigates how the early growth rate of solar activity can predict the upcoming solar maximum, providing a method to estimate the cycle's peak amplitude and timing with reasonable accuracy.

Contribution

It introduces a correlation-based approach to predict solar maximum using the rising rate of solar activity, with improved accuracy after 20 months from solar minimum.

Findings

Correlation coefficient reaches 0.83 at 20 months after minimum

Prediction error within 20% when 20 months have passed

Cycle 24 predicted to peak around October 2013 with Rmax=84±33

Abstract

The growth rate of solar activity in the early phase of a solar cycle has been known to be well correlated with the subsequent amplitude (solar maximum). It provides very useful information for a new solar cycle as its variation reflects the temporal evolution of the dynamic process of solar magnetic activities from the initial phase to the peak phase of the cycle. The correlation coefficient between the solar maximum (Rmax) and the rising rate ({\beta}a) at {\Delta}m months after the solar minimum (Rmin) is studied and shown to increase as the cycle progresses with an inflection point (r = 0.83) at about {\Delta}m = 20 months. The prediction error of Rmax based on {\beta}a is found within estimation at the 90% level of confidence and the relative prediction error will be less than 20% when {\Delta}m \geq 20. From the above relationship, the current cycle (24) is preliminarily predicted to peak around October 2013 with a size of Rmax =84 \pm 33 at the 90% level of confidence.