Abstract :
Solar activity forecasting is an important topic for numerous scientific and technological areas, such as space operations, electric power transmission lines and earth environment impact. Nevertheless, the well-known difficulty is how to accurately predict, on the basis of various recorded solar activity indices, the complete evolution of future solar cycles, due to highly complex dynamical processed involved, mainly related to interaction of different components of internal magnetic fields. There are mainly two distinct classes of solar cycle prediction methods: the precursor-like ones and the mathematical-numerical ones. The main characteristic of precursor techniques, both purely solar and geomagnetic, is their physical basis. The non-precursor methods use different mathematical properties of the known temporal evolution of solar activity indices to extract information useful for predicting future activity. For the current solar cycle #23 we obtained quite good performances from both some precursor and purely numerical methods, such as the so-called solar precursor and nonlinear ones. To further check the performances of these prediction techniques, we compared the early predictions for the next solar cycle #24. Preliminary results support the coherence of the prediction methods considered and confirm the actual trend of a reducing solar activity.
