One of the aims of space meteorology is to reliably predict solar flares, in the same way meteorological services forecast storms on Earth, so that we may better guard against their effects. At present, the probability of forecasting a major flare one day in advance is less than 40% - and yet the most powerful flares can lead to major disruptions, causing interference with telecommunications and knocking out electrical power grids across the world. Using 3D 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.
For their study, the researchers carried out computer simulations of two scenarios, one with an eruption and the other without. Using a complex mathematical approach based on the separation of the magnetic field into several components, the researchers successfully obtained a proxy capable of predicting eruptions. The proxy (which compares two helicities in the potentially eruptive region) remains low in non-eruptive scenarios; whereas in every other case it increases significantly before the eruption.
The study, carried out as part of the HéliSol3 program, opens the way to more effective forecasting of solar flares. The theoretical findings now need to be confirmed by analyzing observations of active solar regions. This is being done as part of the European Flarecast project, which aims to set up an automatic system for forecasting flares.
Source Reference: CNRS, Courtesy of https://watchers.news/2017/05/23/new-approach-to-forecasting-solar-flares/
Credit for image at top of page: Artist's impression of a solar flare and the twisted magnetic field that carries away the ejected solar material. © G.Valori, M. Berger & NASA SDO