  Using wavelet analysis approach, we can derive a measure of the disorder
content of solar activity, following the temporal evolution of the so-called
wavelet entropy. The interesting feature of this parameter is its ability to
extract a dynamical complexity information, in terms of frequency distribution
of the energy content, avoiding restrictions, common in the nonlinear dynamics
theory, such as stationarity. The analysis is performed on the monthly time
series of sunspot numbers. From the time behaviour of the wavelet entropy we
found a clear increase in the disorder content of solar activity for the
current 23th solar cycle. This result suggests general low accuracies for
current solar cycleprediction methods. Moreover, we pointed out a possible
connection between wavelet entropy behaviour and solar excursion phases of
solar dipole.
