Abstract:
The Sun’s long-term magnetic variability is the primary driver of space climate. This variability is manifested not only in the longobserved
and dramatic change of magnetic fields on the solar surface, but also in the changing solar radiative output across all
wavelengths. The Sun’s magnetic variability also modulates the particulate and magnetic fluxes in the heliosphere, which determine
the interplanetary conditions and impose significant electromagnetic forces and effects upon planetary atmospheres. All these effects
due to the changing solar magnetic fields are also relevant for planetary climates, including the climate of the Earth. The
ultimate cause of solar variability, at time scales much shorter than stellar evolutionary time scales, i.e., at decadal to centennial
and, maybe, even millennial or longer scales, has its origin in the solar dynamo mechanism. Therefore, in order to better understand
the origin of space climate, one must analyze different proxies of solar magnetic variability and develop models of the solar dynamo
mechanism that correctly produce the observed properties of the magnetic fields. This Preface summarizes the most important
findings of the papers of this Special Issue, most of which were presented in the Space Climate-4 Symposium organized in
2011 in Goa, India.
