Planetary beat and solar–terrestrial responses

Abstract

Solar activity changes with time in a cyclic pattern. The origin of those changes may be caused by planetary motion around the Sun, affecting the position of the Sun's motion with respect to the centre of mass and subjecting the Sun to changes in angular momentum and gravitational tidal forces. With modern achievements, this multi-body problem can now be addressed in a constructive way. Indeed, there are multiple criteria suggesting that the solar variability is driven by a planetary beat also affecting a number of terrestrial variables: 14C and 10Be production, Earth's rotation, ocean circulation, paleoclimate, geomagnetism, etc. The centennial changes between grand solar maxima and minima imply that we will soon be in a new solar minimum and, in analogy with past events, probably also in Little Ice Age climatic conditions.