Solar dynamo modes of oscillations and the long- term prediction of solar activity

Abstract

We verify that the values and dates of occurrence of sunspot maxima during Schwabe sunspot cycles ##19 to 24 as predicted by Derek Justin Schove in 1955 coincide with the actually observed ones with a high degree of accuracy. A question arises from this result: why is such a deterministic behavior apparent in a system, like the solar dynamo, that is in principle stochastic. We find that solar activity related data may be well represented by the addition of a constant level and eight modes of oscillation. The repetitive behavior and the relationships that appears to exist between these modes, opens the possibility for a long-term prediction of solar activity. In that line, we forecast the Gleissberg cycle for the forthcoming two centuries and data on sunspot maxima for the next century. Thus, we predict the values and dates of occurrence of sunspot maxima ##25 to 35 and find that the new Episode of solar activity that started during polar cycle #24, as a follow-up of the 20th century Grand Maximum, is of the Regular type and, as the ongoing Hallstatt oscillation will pass through zero from negative to positive around the year 2036, it will last for the remainder of the present millennium. We also find that modes of oscillations are mutually related through a forced non-linear oscillator with a persistent asymmetry. A brief discussion of the origin of this behavior on the excitation of solar dynamo motions by solar-planetary forces is presented.