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ISRN Astronomy and Astrophysics
Volume 2011 (2011), Article ID 640817, 7 pages
http://dx.doi.org/10.5402/2011/640817
Research Article

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

1A.F. Ioffe Physico-Technical Institute, St. Petersburg 194021, Russia
2Metla, Eteläranta 55, FI-96301, Rovaniemi, Finland

Received 10 February 2011; Accepted 8 March 2011

Academic Editors: P. P. Avelino and M. Richmond

Copyright © 2011 Maxim Ogurtsov and Markus Lindholm. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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 2 ๐‘ and intensity of the odd cycles 2 ๐‘ + 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.