Abstract

The Sun is a typical G-type star in the middle of its main sequence lifetime. The radiative, magnetic and particle output of the Sun varies at time scales from stellar evolutionary time scales to the decadal time scales of the renowned solar cycle and to the much shorter forms of activity like so... Show moreThe Sun is a typical G-type star in the middle of its main sequence lifetime. The radiative, magnetic and particle output of the Sun varies at time scales from stellar evolutionary time scales to the decadal time scales of the renowned solar cycle and to the much shorter forms of activity like solar flares. Solar variability forces the whole heliospheric environment and all planetary atmospheres, including that of Earth, characterizing what is now known as Space Climate. Space Climate is therefore an interdisciplinary line of research encompassing a vast number of topics ranging from physics of solar variability, solar wind, cosmic rays, and planetary atmospheres to climate, with an emphasis on understanding the long-term evolution and processes that interconnect the heliospheric system. This special issue of the Journal of Atmospheric and Solar - Terrestrial Physics (JASTP) presents 27 papers dealing with the different aspects of Space Climate. Most papers were presented in the Third Space Climate Symposium organized at Saariselkä, Finnish Lapland, in March, 2009. The main results included in these papers, with appropriate background information from the respective subfields of Space Climate, are summarized below. Show less