Solar Magnetic Evolution and Complexity: Dundee-Durham Consortium

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This project continues an established and successful collaboration between researchers at the Universities of Dundee and Durham on the structure and dynamics of the Sun's magnetic field. This magnetic field dominates the Sun's atmosphere, controlling both the large-scale structure seen (for example) in total eclipse photographs, and also dynamical events on a wide range of scales. It plays a fundamental role in the celebrated problem of how the solar atmosphere is heated to millions of degrees, and structures not only the low atmosphere of the Sun but also that of the wider "heliosphere", encompassing the Earth.Far from an intellectual curiosity, the Sun's magnetic field has a direct impact on Earth and the near-Earth environment, through space weather events such as flares, coronal mass ejections, or solar energetic particle events. Resulting geomagnetic storms create the Northern and Southern lights, but also have the potential for damaging economic impacts on engineered systems ranging from satellites and communication systems to power grids and pipelines. Our work will address both the underlying magnetic environment - which can change both over the 11-year solar cycle and from one cycle to the next - but also the origins of individual events, which come from magnetic energy releases deep in the solar corona.The overarching aim of the Consortium is to explore the causes and consequences of magnetic complexity in the solar corona - a system that is far from static equilibrium. Can we explain the latest generation of high-resolution observations? Does the small-scale complexity that is being revealed by these observations have consequences even for large-scale outputs such as flares, coronal mass ejections, or the solar wind? The various projects within the consortium will carry out theoretical and numerical modelling for a range of different setups, carefully chosen to model the essential features of the solar corona, including active regions (around sunspots), coronal loops, open magnetic field lines (that extend out into the solar system), and the sources of solar flares, coronal mass ejections and the solar wind. Several of our models will be directly "data-driven", taking input from telescopes, including recently digitized historical data for the past 100 years. A variety of observations from the latest ground-based and satellite telescopes, and Parker Solar Probe, will be used to validate our models. Our study of small-scale behaviour will inform the interpretation of these novel high-resolution observations of the corona. As well as probing fundamental physics relevant more widely to astrophysical plasmas, the insight gained from our simulations will have practical application in the space-weather forecasting community. It is becoming apparent that forecasting the occurrence and impact of space weather events cannot rely on the traditional static extrapolation models, but requires a deep understanding of the dynamical behaviour, and potentially the fine structure, of the Sun's magnetic field.