We have set up an International Team of ten researchers with expertise on the structure and evolution of the global magnetic field in the Sun’s corona. This is a timely problem: our modern technological society is becoming increasingly vulnerable to severe space weather events, yet operational forecasts are based on traditional potential-field extrapolations of the coronal magnetic field. Potential-field models cannot account for the distribution and evolution of free magnetic energy in the low corona, which is responsible for driving violent eruptions and variations in the interplanetary magnetic field. At the same time, modern satellite observations are revealing indirect evidence of this non-potential structure.
Our focus will be to compare different non-potential modelling approaches that are currently under development. We are meeting at ISSI (Bern) with the specific goal of undertaking a direct comparison of the results from different numerical codes, driven by the same satellite observational data. The team includes experts in solar magnetic field observations to assist both with the boundary conditions for the simulations and with the validation of the simulation results. The expected outcome of the research will be a clearer understanding of non-potential magnetic fields in the low solar corona. It will also result in a better understanding of the strengths/weaknesses of the models and lead to improved models for the global magnetic field and space weather prediction.