The emerging discipline of space meteorology aims to reliably predict solar flares so that we may better guard against their effects. Using 3-D numerical models, an international team headed by Etienne Pariat, a researcher at LESIA (Observatoire de Paris / CNRS / Université Paris Diderot / UPMC), has discovered a proxy that could be used to forecast an eruptive event. The proxy is associated with magnetic helicity, which reflects the extent of twist and entanglement of the magnetic field. The study is published in the journal Astronomy and Astrophysics dated 17 May 2017.