Quite generally, and according to the Statement of Work of this study, the term "space weather" refers to the time-variable conditions in the space environment that may affect space-borne or ground-based technological systems and, in the worst case, endanger human health or life. The most important social and economic aspects of space weather are related to being aware of and possibly avoiding the consequences of space weather events either by system design or by efficient warning and prediction systems allowing for preventive measures to be taken. On the climatological time scales there are also potential effects on terrestrial climate.
During the last few years space weather activities have expanded with an increasing pace world-wide and it has become commonly accepted that improved space weather services are important and expected to become much more useful in the near future. At the same time the scientific community has strengthened their efforts toward better understanding of the physical foundations of space weather and many scientists have remarked that without strong emphasis on improved scientific understanding the promises for and dreams of improved space weather products may not be fulfilled. This way the scientific Solar-Terrestrial Physics (STP) community and the users of space-sensitive systems are intimately coupled to each other.
Space weather has many similarities with atmospheric weather thus the design of future space weather activities may be able to utilise the experience from meteorological services, at least concerning real-time operations, input data management, and nowcast and forecast distribution.