Abstract :
The time series of solar and volcanic activities have been processed to show, mostly by
means of statistical characteristics, the exceptional and recurring pattern of these phenomena in the
intervals of the exceptional and recurring pattern of solar motion, i.e. in the intervals of the Sun’s
motion along the trefoils which reoccur in steps of 178.7 years. Nearly the same sets of five sunspot
cycles have been found in the latest trefoil intervals ( 1730–1780 and 1910–1960), their length being
constant and equal to 10 years (cycles No. 15–19). The steadily attenuated volcanic activity have
been pointed out in the three latest trefoil intervals. The long-term maxima of surface air temperature
occured in the central decades of the trefoil intervals. The results indicate a primary role of solar
motion in a causal chain of ST-relations and a need of taking the Solar System as a whole into account
to explain climatic changes. The solar motion can be computed in advance. Predictive assesments,
so far in form of analogies, have been made: Because the solar motion in the next decades will be
chaotic, lower and longer solar cycles (with irregular length), ocurrence of huge volcanic events and
a decrease of global surface air temperature can be expected.
Keywords :
solar-terrestrial variability , volcanic activity , inertial motion of the sun , Climatic change