Medium-Sized Solar Cycles in Different Epochs of Solar Activity

The study of a reliable series of sunspot observations has allowed formulation of a scenario for the sustainable development of solar cyclicity over the past ~190 years. This scenario predicts a change in the level of sunspot activity in epochs of increased or lowered solar activity with selected transition periods, which gives three different modes of the total magnetic field generation of the Sun with a duration of approximately five cycles. Since January 2020, the 25th solar cycle has begun with the expected average magnitude according to the development of the first 3 years and the Gnevyshev-Ol’ rule. Therefore, an attempt has been made to study the observational characteristics of a family of average solar cycles in different epochs of solar activity, i.e., the 13th, 15th, and 25th epochs of lowered solar activity, the 10th and 20th epochs of increased solar activity, and the 17th and 23rd transitional periods between the epochs.