CorMag: A magnetic model of the corona with upper boundary observational constraints

The Sun’s magnetic field shapes the solar wind and drives space weather, but models of it have long been blind to what actually happens in the corona—the Sun’s outer atmosphere—because there were no direct measurements to check them against. This project fixes that blind spot. The researchers will use coronagraph observations to create tomography maps of the corona, focusing on high-density streamers. These maps let them adjust and optimise global magnetic models, providing constraints both at the Sun’s surface and in the corona itself. The resulting optimised magnetic maps will be shared with the scientific community and integrated into the UK Met Office’s space weather forecasting software. If successful, the work will directly improve space weather forecasts, which protect satellites, power grids, and aviation from solar storms. It will also answer three fundamental questions: at what height the coronal field becomes purely radial (and how that changes with location and solar cycle), what the mean magnetic field is at the unobserved poles, and whether there is an empirical link between coronal field strength and plasma density. These are fundamental science questions, but answering them sharpens the models that underpin practical forecasting.