Session CD3 - Lessons from Space Climate: Extreme solar events

Ilya Usoskin (University of Oulu, Finland), Silvia Dalla (University of Central Lancashire, UK), Florian Mekhaldi (University of Lund, Sweden)

Space Weather studies and tools are largely based on the recent decades of direct and indirect observations of solar/geomagnetic effects, where the strength of the events was not representative of the entire possible range. On the other hand, we know from Space Climate that extreme events, several orders of magnitude stronger than everything we have observed directly during the last 80 years, can take place on the Sun on the secular time scale. This includes extreme solar flares and particle storms, as well as enormous geomagnetic disturbances. The consequences of such extreme events can be dramatic for the modern technological society but this cannot be quantified based upon the existing direct experience. Extreme events are studied by indirect proxy datasets but these measurements are quite robust because of the enormous strength of the events. Here we propose to discuss current knowledge of extreme solar events and their application to modern Space Weather problems, viz. in the context of their parameters, physical origin and consequences. In this session, results related to extremely strong rare events will be presented. This will form new observational constraints and theoretical bounds for the practical Space Weather studies.