Abstract
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.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Akioka, M., Kubota, J., Suzuki, M., Ichimoto, K., and Tohmura, I.: 1987, Solar Phys. 112, 313.
Ataç, T.: 1987, Astrophys. Space Sci. 135, 201.
Bai, T.: 1987a, Astrophys. J. 314, 795.
Bai, T.: 1987b, Astrophys. J. 318, L85.
Bai, T. and Sturrock, P. A.: 1987, Nature 327, 601.
Belmont, A. D., Dartt, D. G., and Ulstad, M. S.: 1966, J. Atmos. Sci. 23, 314.
Bogart, R. S. and Bai, T.: 1985, Astrophys. J. 229, L151.
Hoyng, P.: 1976, Astron. Astrophys. 47, 449.
Ichimoto, K., Kubota, J., Suzuki, M., Tohmura, I., and Kurokawa, H.: 1985, Nature 316, 422.
Kiplinger, A. L., Dennis, B. R., and Orwig, L. E.: 1984, Bull. Amer. Astron. Soc. 16, 891.
Kleczek, J.: 1952, Publ. Centr. Inst. Astron. No. 22, Prague.
Knoška, S. and Petrášek, J.: 1984, Contr. Astron. Obs. Skalnate Pleso 12, 165.
Knoška, S. and Letfus, V.: Catalogue of Activity of the Solar Flares 1950–1965 (unpublished).
Landscheidt, T.: 1986, Solar Phys. 107, 195.
Mayfield, E. B. and Lawrence, J. K.: 1985, Solar Phys. 96, 293.
Raychaudhuri, P.: 1986, Solar Phys. 106, 421.
Rieger, E., Share, G. H., Forrest, D. J., Kanbach, G., Reppin, C., and Chupp, E. L.: 1984, Nature 312, 623.
Rušin, V., Rybanský, M., and Zverko, J.: 1987, Bull. Astron. Inst. Czech. 38, 181.
Shapiro, R. and Ward, F.: 1962, J. Atmos. Sci. 19, 506.
Vitinskii, Y. I.: 1962, Solar Activity Forecasting, Academy Sci. USSR, Leningrad.
Wolff, C. L.: 1983, Astrophys. J. 264, 667.
Yakob, A. and Bhargava, B. N.: 1968, J. Atmos. Terr. Phys. 30, 1907.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Özgüç, A., Ataç, T. Periodic behavior of solar flare index during solar cycles 20 and 21. Sol Phys 123, 357–365 (1989). https://doi.org/10.1007/BF00149111
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF00149111