Space climate is the long-term variation in solar activity within the heliosphere, including the solar wind, the Interplanetary magnetic field (IMF), and their effects in the near-Earth environment, including the magnetosphere of Earth and the ionosphere, the upper and lower atmosphere, climate, and other related systems. The scientific study of space climate is an interdisciplinary field of space physics, solar physics, heliophysics, and geophysics. It is thus conceptually related to terrestrial climatology, and its effects on the atmosphere of Earth are considered in climate science.
Space climatology considers long-term (longer than the latitudinally variable 27-day solar rotation period, through the 11-year solar cycle and beyond, up to and exceeding millennia) variability of solar indices, cosmic ray, heliospheric parameters, and the induced geomagnetic, ionospheric, atmospheric, and climate effects. It studies mechanisms and physical processes responsible for their variability in the past with projections onto future. It is a broader and more general concept than space weather, to which it is related like the conventional climate and weather.
In addition to real-time solar observations, the field of research also covers analysis of historical space climate data. This has included analysis and reconstruction that has allowed solar wind and heliospheric magnetic field strengths to be determined from back to 1611.
The importance of space climate research has been recognized, in particular, by NASA which launched a special space mission Deep Space Climate Observatory (DSCOVR) dedicated to monitoring of space climate. New results, ideas and discoveries in the field of Space Climate are published in a focused peer-review research Journal of Space Weather and Space Climate (JSWSC). Since 2013, research awards and medals in space weather and space climate are annually awarded by the European Space Weather Week. Another recent space observatory platform is the Solar Radiation and Climate Experiment (SORCE).
Space climate research has three main aims:
In the early 2000s, when the concept of space weather became common, a small initiative group, led by the University of Oulu in Finland had realized that physical drivers of solar variability and its terrestrial effects can be better understood with a more general and broader view. The concept of Space Climate had been developed, and the corresponding research community formed, which presently includes a few hundred active members around the world. In particular, a series of International Space Climate Symposia (biennial since 2004) was organized, with the first inaugural symposium being held in Oulu (Finland) in 2004, followed by those in Romania (2006), Finland (2009), India (2011), Finland (2013), Finland (2016), Canada (2019), as well as topical space climate sessions are regularly held at the General Assemblies of the Committee on Space Research and Earth Science.