“Extreme Solar Eruptive Events and Their Terrestrial Impacts: Black Swans or Dragon Kings?” with Ilya Usoskin (University of Oulu, Finland)

Solar energetic eruptive processes, such as flares and coronal mass ejections, are relatively well-studied during the past decades of direct observations. Although their maximum strength/energy is not constrained by direct data because of a too-short period of observations, we know that extreme events do occur rarely on the Sun over the last millennia, thanks to cosmogenic-proxy data, and also on sun-like stars, thanks to high-precision stellar photometry. Not only we can estimate their occurrence probability but even reconstruct energy spectra and assess the dramatic terrestrial and societal impacts. However, the nature of such events remains unclear – are they ‘normal’ but just extremely strong solar flares (Black Swans) or do they represent an unknown type of solar events (Dragon Kings)? A summary of the existing pieces of knowledge will be presented along with a try to make a distinction between the Black-swan and Dragon-king scenarios of the extreme events.

Ilya Usoskin graduated from Leningrad Polytechnics in 1988, then worked as a researcher at Ioffe Physical-Technical Institute in St. Petersburg until 1997, a postdoc at INFN Milano from 1997-1999, and head of Oulu Cosmic ray station since 2000. He has Cand.Sci. degree in Astrophysics (1995) and PhD in Space Physics (2000). Full professor of Space Physics since 2012. He has several awards, most honourable are: 1st-class Knight of the Order of Lion of Finland (2013), Julis Bartels medal of EGU (2018), full membership in the Finnish Academy of Sciences and Letters (2019), ISEE Science Award (Nagoya, 2020). He is an expert in Solar, Heliospheric, Cosmic-ray, Solar-terrestrial and Atmospheric physics, a founder of the Space-Climate research discipline, and an actively servant to the community: Vice-President of IAU, member of the C4 commission of IUPAP, editor for several journals, etc.

Webinar was recorded on November 24, 2022