Editorial

Long-term solar activity and its implications to the heliosphere, geomagnetic activity, and the Earth’s climate

Preface to the Special Issue on Space Climate

¹ Leading Guest Editor, Department of Physics, University of Oulu, 90014 Oulu, Finland
² Guest Editor, Radio Astronomy Centre, Tata Institute of Fundamental Research, Ooty 643001, India
³ Guest Editor, Department of Physical Sciences and CESSI, Indian Institute of Science Education and Research, Kolkata, Mohanpur 741252, India
⁴ Guest Editor, Earth Observation, Finnish Meteorological Institute, 00101 Helsinki, Finland

^* Corresponding author: e-mail: Kalevi.Mursula@oulu.fi

Received: 1 April 2013
Accepted: 24 April 2013

Abstract

The Sun’s long-term magnetic variability is the primary driver of space climate. This variability is manifested not only in the long-observed 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.