Statistical Effects in the Solar Activity Cycles during AD 1823–1996

Maxim Ogurtsov,Markus Lindholm

doi:10.5402/2011/640817

Abstract

General statistical properties of solar activity cycles during the period AD 1823–1996—including the Gnevyshev-Ohl and Waldmeier effects as well as an amplitude-period effect—were analyzed using Wolf number, group sunspot number, and extended total sunspot area series. It was found out that the Gnevyshev-Ohl effect GO2 (the positive correlation between intensity of the even cycles 2N and intensity of the odd cycles 2N+1) and the Waldmeier effect W2 (the anticorrelation between rise times of sunspot cycles and their amplitudes) are the most universal and robust features of the solar cycle. Other statistical relations were found appreciably sensitive to the selection of solar index, the interval of analysis, and the way of the cycle feature determination.

Highlights

IntroductionThe presence of a link between the Sun’s activity and processes in circumterraneous space (atmosphere and magnetosphere), which form space weather, has been reliably established (see [1, 2])
The presence of a link between the Sun’s activity and processes in circumterraneous space, which form space weather, has been reliably established
The 11-year cycle is the major characteristic of solar activity

Summary

Introduction

The presence of a link between the Sun’s activity and processes in circumterraneous space (atmosphere and magnetosphere), which form space weather, has been reliably established (see [1, 2]). Dikpati et al [6] analyzed the Waldmeier effect (anticorrelation between the peak in sunspot number of a cycle and the rise time) in sunspot area for cycles 12–22 (1878– 1996) using mainly data of the Royal Greenwich Observatory. They found out that the Waldmeier effect is not present in the spot area data; that is, the corresponding coefficient of linear correlation Rl is close to zero. Karak and Choudhuri [8], presented some evidence for Waldmeier relations in different solar indices including sunspot area These authors reported that coefficient of correlation between rise times of sunspot area cycles and their strengths Rl = −0.31. Eddy [12] considered Wolf numbers RZ reliability as good during 1818– 1847 and fully reliable after 1848

General Statistical Effects of Solar Cycles

Datasets

Findings

Discussion and Conclusion