Abstract
The empirical parameters of functions approximating solar activity cycles 8–23 are used. These parameters show the position of the cycle on the time axis (the start time) and its shape, which is characterized by the extension along the time axes and activity index. A statistical connections was found between two shape parameters of the cycle (the so-called Waldmeier effect) and between the extension of the cycle growth branch and the start time of the following cycle. A connection between the parameters of the given and future cycles has been obtained for a function approximating the “secular” variations in the cycle amplitude. The aforementioned empirical relationships can be stated in the form of three equations that contain the parameters of the current and future cycles. Solving this system, we obtain estimates for three parameters of the function approximating the next cycle. For the 25th cycle, it was found that the maximum of the smoothed Wolf number 116 is expected in March/April 2026; the duration of the activity growth branch is 4.16 years.
Similar content being viewed by others
References
Gnevyshev, M.N. and Ohl, A.I., On the 22-year cycle of solar activity, Astron. Zh., 1948, vol. 25, no. 1, pp. 18–20.
Hathaway, D.H., Wilson, R.M., and Reichmann, E.J., The shape of the sunspot cycle, Sol. Phys., 1994, vol. 151, no. 1, pp. 177–190.
Ishkov, V.N. and Shibaev, I.G., Solar activity cycle: general characteristics and modern forecast frames, Izv. Akad. Nauk Ser. Fiz., 2006, vol. 70, no. 10, pp. 1439–1442.
Nagovitsyn, Yu.A., A nonlinear mathematical model for the solar cyclicity and prospects for reconstructing the solar activity in the past, Astron. Lett., 1997, vol. 23, no. 6, pp. 742–748.
Nagovitsyn, Yu.A., Solar activity during the last two millennia: Solar Patrol in ancient and medieval China, Geomagn. Aeron. (Engl. Transl.), 2001, vol. 41, no. 5, pp. 680–688.
Nagovitsyn, Yu.A., Nagovitsyna, E.Yu., and Makarova, V.V., The Gnevyshev–Ohl rule for physical parameters of the solar magnetic field: The 400-year interval, Astron. Lett., 2009, vol. 35, no. 8, pp. 564–571.
Nagovitsyn, Yu.A. and Kuleshova, A.I., The Waldmeier rule and early diagnostics of the maximum of the current solar cycle, Astron. Rep., 2012, vol. 56, no. 10, pp. 800–804.
Ogurtsov, M.G., Nagovitsyn, Yu.A., Kocharov, G.E., and Jungner, H., Long-period cycles of the Sun’s activity recorded in direct solar data and proxies, Sol. Phys., 2002, vol. 211, pp. 371–394.
Roshchina, E.M. and Sarychev, A.P., Mathematical form of the Waldmeier effect, Sol. Syst. Res., 2014a, vol. 48, no. 3, pp. 239–241.
Roshchina, E.M. and Sarychev, A.P., Appearance and quantitative characteristics of 11 year solar cycles, Sol. Syst. Res., 2014b, vol. 48, no. 6, pp. 460–465.
Stewart, J.O. and Panofsky, H.A., The mathematical characteristics of sunspot variations, Astrophys. J., 1938, vol. 88, pp. 385–407.
Volobuev, D.V., The shape of the sunspot cycle: a oneparameter fit, Sol. Phys., 2009, vol. 258, no. 2, pp. 319–330.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Roshchina, E.M., Sarychev, A.P. Approximation of periodicity in sunspot formation of and prediction of the 25th cycle. Geomagn. Aeron. 55, 892–895 (2015). https://doi.org/10.1134/S0016793215070191
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1134/S0016793215070191