Impact of magnetic complexity in solar and astrophysical plasmas: Dundee-Durham consortium

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This project is a continuation of a successful collaboration between the researchers of the Universities of Dundee and Durham on the behaviour of complex magnetic fields in astrophysical plasmas. Magnetic fields are ubiquitous in astrophysics. Closest to home they are generated inside rotating stars and planets (like the Sun and Earth), but they permeate much of the intervening space - for example, the Earth sits within the magnetised solar wind. Further afield, magnetic fields are observed on scales as vast as that of whole galaxies and as small as that of neutron stars. Where we observe them closely with modern telescopes, such as in the Sun's atmosphere, we find that these magnetic fields are highly complex, having spatial structure down to the smallest observable scales and significant dynamical behaviour. Magnetic fields play a crucial role in determining the behaviour of many of these systems - however, the implications of their ubiquitous complexity remain largely unexplored and poorly understood.The most spectacular impacts of magnetic fields are often found in the tenuous plasma above the visible surface of stars. In the Sun's atmosphere, for example, the magnetic field is responsible for creating long-lived structures such as coronal loops, for heating the corona to its multi-million degree temperatures, and for explosive events such as solar flares and coronal mass ejections. These powerful explosions lead to major space weather events at Earth, creating the Northern and Southern lights but also having the potential for damaging economic impacts on engineered systems, ranging from satellites and communication systems to power grids and pipelines. Yet these solar magnetic explosions are pitifully weak by comparison with the huge bursts observed from distant magnetars; perhaps not surprising given that these have the strongest magnetic fields known in the Universe. The overarching aim of the consortium is to explore the causes of magnetic complexity, and to determine its possible large-scale consequences. Can we explain the latest generation of high-resolution observations? Can this small-scale complexity have a significant effect even when we cannot observe it directly? How does the dynamical behaviour of magnetic fields lead to solar eruptions or magnetar bursts?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 astrophysical plasmas including coronal loops, solar flares, neutron stars, and the sources of coronal mass ejections and the solar wind. Importantly, the modelling will take input from the latest generation of telescopes - several of our solar models will be directly "data-driven", and observations will be used to validate output. Many of our model predictions will be tailored to upcoming new observations, including those from DKIST and Parker Solar Probe. As well as probing the fundamental physics of 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 static extrapolation models but requires a deep understanding of the dynamical behaviour, and potentially the fine structure, of the Sun's magnetic field.