The Characteristics of Valley Phase as Predictor of the Forthcoming Solar Cycle

TL;DR

This study analyzes the valley phase of solar cycles to identify predictive correlations with subsequent cycle features, revealing that valley characteristics can forecast cycle strength and duration, aiding solar activity prediction.

Contribution

It introduces a quantitative partitioning method of solar cycle phases and uncovers significant correlations between valley phase properties and future cycle characteristics.

Findings

Valley phase length negatively correlates with cycle maximum.

Cycle maximum positively correlates with cycle minimum.

Cycle period negatively correlates with valley variation.

Abstract

Is Solar Cycle 24 anomalous? How do we predict the main features of a forthcoming cycle? In order to reply such questions, this work partitions quantitatively each cycle into valley, ascend, peak, and descend phases, statistically investigate the correlations between valley phase and the forthcoming cycle. We find that the preceding valley phase may dominate and can be predictor of the forthcoming cycle: (1) The growth rate in ascend phase strongly negatively correlates to valley length and strongly positively correlates to cycle maximum. (2) The cycle maximum strongly negatively correlates to valley length, and strongly positively correlates to cycle minimum. (3) The cycle period strongly negatively correlates to the valley variation. Based on these correlations, we conclude that the solar cycle 24 is a relatively weak and long cycle which is obviously weaker than Cycle 23. The similarity analysis also presents the similar result. The Cycle 25 is also inferred possibly to be a weak cycle. These results can help us understanding the physical processes of solar cycles.