Figure 14 shows the evolution of the probability pk(t) for
the different phases of solar cycle 20. While in correspondence
with the activity maximum, the dominant mode is the first mode,
for solar minimum the higher modes (k > 5) are more important.
This suggests that the solar minimum has a more stochastic
character and supports the occurrence of spatio-temporal complexity,
which is caused by the competition between stochastic
fluctuations and regular evolution.