The Sun is a variable star whose magnetic, radiative and particulate output varies over multiple timescales ranging from stellar evolutionary timescales to centennial, decadal and daily timescales; variability across this range of timescales seamlessly couple space climate to space weather. This session will focus on the physical mechanisms that drive solar-stellar variability and create phenomena which eventually impact the Earth and other planets.

Solar activity affects the heliosphere and the terrestrial system on different time scales. In our session, we propose to consider long-term processes with characteristic scales from several years to millions of years. Moreover, activity on the young Sun and its possible influence on the origin of life on Earth will also be discussed. Special attention will be paid to extreme situations (superflares, grand minima). At the same time, the selection of effective and physically justified indices of solar activity becomes important. Finally, the prospects for the upcoming cycle will be discussed.

Short-term solar variability such as coronal mass ejections, high-speed solar wind streams (corotating interaction regions), and interplanetary shocks are the main drivers affecting the terrestrial geospace environment. The space weather effects of these solar transients range from atmospheric to magnetospheric regions surrounding the Earth. This session solicits presentations that address geospace response to these solar drivers from a space weather perspective. Recent missions such as Arase, and Van Allen Probes provide measurements of geospace, interplanetary spacecraft at L1 measure solar driver parameters, both in great detail and of high quality. Both observational as well as model studies that address the space weather impact of short-term solar variability of the geospace system are welcome.

The Earth's atmosphere exhibits a large range of variability which is partly due to intrinsic processes, but also due to forcing from outside, for example by the Sun. At the same time, the atmosphere introduces significant variability of the plasma, electromagnetic field, and neutrals in geospace regions. This session focuses on the geospace and middle atmosphere response to the variability of the lower atmosphere, including effects by the propagation of gravity waves, tides, and planetary waves from the lower atmosphere to the thermosphere and ionosphere, as well as their connection to the inner and outer magnetosphere. Presentations on the impact of longer term variability of the atmosphere such as ENSO, QBO, and trends of greenhouse gases are encouraged. Reports on modeling and observational approaches are welcome.

This session calls on focused campaign study of Sun-Earth connection events that are of specific significance in science understanding and/or of strong geoeffectiveness. The session fosters inter-disciplinary collaboration in understanding the full chain of activity from Sun to Earth. The known events of interest (arrival at Earth) are 2012/07/14, 2013/03/17, 2013/05/31, 2015/03/17, 2017/09/07 events.

A rigorous data management is of upmost importance to allow interoperability between databases, development of tools and interdisciplinary science from the Sun to the Earth. In recent years, projects and research infrastructures have been created to facilitate the access and handling of heterogeneous datasets by scientists. At the same time, International Scientific Instances and Organizations (RDA) are issuing guides and advices on good practices for data life cycle [(i) create, acquire, collect; (ii) check, curate, process, analyze; (iii) ingest, save, preserve; (iv) discover; (v) access, download; (vi) use, cite; (vii) re-use] towards scientific communities, whereas certification of data repositories (ISC-WDS, CoreTrustSeal) is becoming an important concern. Altogether, these initiatives make it possible for users to easily access huge archives of disparate data and metadata in a secure and reliable manner. This session solicits contributions on various data archiving efforts, data repositories mutual links as well as possible related topics as development of visualization tools and plotting software.

PreSTo (Predictability of the variable Solar-Terrestrial Coupling), the Next Scientific Program of SCOSTEP, will address the predictability of the Sun-Earth System on a wide range of timescales. This session will present the overall structure of PreSTo and the scientific orientation of its main pillars.