Abstract :
Solar activity is studied using a cluster analysis of the time-fluctuations of the sunspot number. It is shown that in an Historic period the high activity components of the solar cycles exhibit strong clustering, whereas in a Modern period (last seven solar cycles: 1933–2007) they exhibit a white-noise (non-)clustering behavior. Using this observation, it is shown that in the Historic period, emergence of the sunspots in the solar photosphere was strongly dominated by turbulent photospheric convection. In the Modern period, this domination was broken by a new more active dynamics of the inner layers of the convection zone. Then, it is shown that the dramatic change of the sun dynamics at the transitional period (between the Historic and Modern periods, solar cycle 1933–1944) had a clear detectable impact on the Earth’s climate. A scenario of a chain of transitions in the solar convective zone is suggested in order to explain the observations, and a forecast for global warming is suggested on the basis of this scenario. A relationship between the recent transitions and solar long-period chaotic dynamics has been found.
