Parameterizing the evolution of active regions from emergence to eruption. Recent results and future work.

Abstract

The emergence of magnetic flux in the Sun can lead to the formation of active regions with highly complex magnetic fields, evident by δ-spots, filaments, and sigmoids. These regions are often the sources of major flares and coronal mass ejections (CMEs) and monitoring their evolution is crucial for a deeper understanding of these phenomena as well as space weather applications. To this end, high-quality observations of the photospheric magnetic field are routinely used to derive parameters and physical magnitudes, and quantify the magnetic complexity of active regions. Thus, we know that eruptive active regions are associated with highly non-potential magnetic field configurations, with strong electric currents and huge amounts of free magnetic energy and helicity. This talk reviews recent efforts to parameterize this non-potentiality of active regions and discusses ongoing and future work on developing new and improved parameters suitable for flare and CME prediction. It further focuses on the evolution of net electric currents in active regions, from their emergence to eruption. The significance of net electric currents on flare and CME prediction and new ways to utilize them in order to produce improved eruptivity parameters and understand solar eruptions will be discussed.