Sunspot count periodicities in different zurich sunspot group classes since 1986

A. Kilcik, A. Ozguc, V. Yurchshn, J. P. Rozelot

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32 Scopus citations


We used two methods to investigate the periodic behavior of sunspot counts in four categories for the time period January 1986 – October 2013. These categories include the counts from simple (A and B), medium (C), large (D, E, and F), and final (final-stage; H) sunspot groups. We used i) the multitaper method with red noise approximation, and ii) the Morlet wavelet transform for periodicity analysis. Our main findings are that 1) the solar rotation periodicity of about 25 to 37 days, which is of obvious significance, is found in all groups with at least a 95 % significance level; 2) the periodic behavior of a cycle is strongly related to its amplitude and group distribution during the cycle; 3) the appearance of periods follows the amplitude of the investigated solar cycles; and that 4) meaningful periods do not appear during the minimum phases of the investigated cycles. We would like to underline that the cyclic behavior of all categories is not exactly the same; there are some differences between these groups. This result can provide a clue for the better understanding of solar cycles.

Original languageEnglish (US)
Article numberA018
Pages (from-to)4365-4376
Number of pages12
JournalSolar Physics
Issue number11
StatePublished - Aug 6 2014

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science


  • Frequency analysis: multitaper method
  • Morlet wavelet analysis
  • Sunspot counts
  • Sunspots groups
  • Sunspots:sunspot classification


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