Sunspot Count Periodicities in Different Zurich Sunspot Group Classes Since 1986

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KILÇIK A., Ozguc A., Yurchyshyn V., Rozelot J. P.

SOLAR PHYSICS, vol.289, no.11, pp.4365-4376, 2014 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 289 Issue: 11
  • Publication Date: 2014
  • Doi Number: 10.1007/s11207-014-0580-0
  • Journal Name: SOLAR PHYSICS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.4365-4376
  • Keywords: Frequency analysis: multitaper method, Morlet wavelet analysis, Sunspots: sunspot classification, Sunspots groups, Sunspot counts, SHORT-TERM PERIODICITIES, SOLAR-ACTIVITY, FLARE INDEX, WAVELET ANALYSIS, VARIABILITY, CYCLES, IRRADIANCE, 1.3-YEAR, MAXIMUM, 154-DAY
  • Akdeniz University Affiliated: Yes


We used two methods to investigate the periodic behavior of sunspot counts in four categories for the time period January 1986 -aEuro parts per thousand 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.