  We argue that the most prominent temporal features of the solar dynamo, in
particular the Hale cycle, the Suess-de Vries cycle (associated with variations
of the Gnevyshev-Ohl rule), Gleissberg-type cycles, and grand minima can be
self-consistently explained by double synchronization with the 11.07-years
periodic tidal forcing of the Venus-Earth-Jupiter system and the (mainly)
19.86-years periodic motion of the Sun around the barycenter of the solar
system. In our numerical simulation, grand minima, and clusters thereof, emerge
as intermittent and non-periodic events on millennial time scales, very similar
to the series of Bond events which were observed throughout the Holocene and
the last glacial period. If confirmed, such an intermittent transition to chaos
would prevent any long-term prediction of solar activity, notwithstanding the
fact that the shorter-term Hale and Suess-de Vries cycles are clocked by
planetary motion.
