Sun Unleashed: two approaches to predicting solar eruptions
Abstract
The spectacular phenomena known as solar eruptions can impact human infrastructure. As our society becomes more and more sensitive to solar activity due to the technological evolution, solar forecasting is a growing economic stake. The work I am going to present is focused on the link between the eruptivity of a magnetic system and its magnetic helicities. By using magnetohydrodynamic simulations, as well as magnetic data obtained from observational measurements, we have found that the ratio between non-potential helicity and total helicity has a threshold, beyond which an eruption systematically occurs.
However, even if we were able to predict an eruptive flare before it occurs, we would also need to be able to track its propagation and evolution throughout the heliosphere, because not all Coronal Mass Ejections (CMEs) impact Earth, and not all CMEs have the same properties nor the same geoeffectiveness. In the second part of my presentation, I will introduce two space-weather 3D MHD simulations, COCONUT and EUHFORIA, designed with this purpose in mind. COCONUT is a realistic model of the solar corona, which allows us to track the evolution of a CME, from the solar surface to 0.1 AU. On the other hand, EUHFORIA is a time-dependent model of the heliosphere that can be used to track the propagation of the eruption up to Earth and predict its properties.