REFI · REgional core Flow Inversions (REFI) from geomagnetic satellites

Earth's magnetic field is a fundamental but poorly understood part of our planet, generated by the chaotic convection of liquid metal in Earth’s outer core. The geomagnetic field acts as a protective shield against harmful space weather for our network of man-made satellites, vital for modern society, making it essential to model the geomagnetic field and the flow that dictates how it will change. There are two key aspects of the field we cannot explain: why the strength of the magnetic dipole has decreased by nearly 6% per century since the 1800s, and why there is a growing anomalously weak patch of the field in the South Atlantic. Both features are of significant concern in terms of future space weather hazard.These two crucial features of Earth's magnetic field are controlled by regional phenomena inside the core, but they are very difficult to image using the current state of the art global data-driven models of the flow. Because these global models rely on global data, they suffer from the leakage of noisy data near the poles to lower latitudes, and (by design) describe global rather than local features. In this fellowship I propose to create a new paradigm of purely regional data-driven models, REgional core Flow Inversions (REFI), which will resolve local core flow based on only local geomagnetic satellite data. In doing so I will be able to better characterise and understand the local dynamics of the core, leading to a better understanding of the changes in the geomagnetic field and its impact for future space weather hazard. The project is hosted at the University of Leeds in one of the largest and most interdisciplinary deep-Earth research groups in the world, and will be mentored by Prof. Phil W. Livermore.