Solar Physics

, Volume 123, Issue 2, pp 357–365 | Cite as

Periodic behavior of solar flare index during solar cycles 20 and 21

  • Atila Özgüç
  • Tamer Ataç


Short-term periodicities of solar activity were studied with the flare index by using Discrete Fourier Transform for the time interval 1966–1986. Two noticeable periodicities (18.5 and 5 months) have been found. The existence of these periodicities comparing with the early findings is discussed.


Fourier Fourier Transform Flare Solar Activity Solar Cycle 
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Copyright information

© Kluwer Academic Publishers 1989

Authors and Affiliations

  • Atila Özgüç
    • 1
  • Tamer Ataç
    • 1
  1. 1.Kandilli Observatory, Bogaziçi UniversityÇengelköy, IstanbulTurkey

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