Paleointensity extremes: Dynamic implications and future fields

I propose to use my recently developed modeling techniques to resolve a fundamental disconnect between measurements of the strength of the ancient geomagnetic field (paleointensity) and theories of Earth's core dynamic and use this to answer outstanding questions about how fast Earth's magnetic field can change and how our protective barrier might change in the foreseeable future.

Earth's magnetic field has been protecting our planet for at least 3.4 billion years and, despite being one on the oldest known features of Earth, there remain many aspects of how the field is generated and how it has evolved over time that are poorly understood. This makes is difficult to predict how the field will behave in the future. Currently, our best predications of future variations only extend about 5 years into the future. This is often too short to meet the needs of long terms investments, such as those required for space satellites and ground based power infrastructure, which rely on the shielding provided by the magnetic field.

To predict future changes in the geomagnetic field we have to unravel past changes in the field and the physics that governs them. Understanding the evolution of the deep Earth and the physics behind extreme geomagnetic features, such as rapid field changes, are frontiers in paleomagnetic research that have implications for the predictability of our protective barriers future. However, our ability to understand these phenomena is held back by the uncertain reliability of the paleointensity data needed to understand these key features. To push these boundaries forward, we must ensure the fidelity of our observations, which requires a full understanding of the physical behavior that affects paleointensity data. This is especially important for time periods where the observed paleointensities contradict our most advanced understanding of how the magnetic field works.

This project will use my newly developed tools to bridge the gap between specimen-level paleointensity data and global geomagnetic field reconstructions, and will take a radically different approach that utilizes "big data" analyses of millions of simulated and real results. Much like a surveyor would assess a building based on the quality of the materials and how they were used to construct the building, I will assess the building blocks of paleointensity data to determine the quality of the results.

Armed with this new capability, I will provide a robust assessment of the validity of the Levantine archeomagnetic spikes, which record field intensity changes with rates tens faster than ever observed. Such extreme changes are beyond current dynamo theory and their resolution may have a profound impact on how we understand the dynamics of the outer core. Then, using a next generation geomagnetic field construction spanning the last 4,000 years, I will determine the longevity of the recent decline in dipole field strength and assess how long into the near future the current weakening of Earth's magnetic shield is likely to persist and how it will affect the modern world and the technologies that we all rely on in our daily lives.

The proposed project is broadly "blue skies" in nature and the immediate benefactors will be the Earth science community. In particular, those studying geomagnetic field dynamics and evolution, deep Earth interior processes, and paleointensity methods. However, the ability to achieve more accurate and longer-term forecasts of geomagnetic variations has important societal and economic benefits. Many aspects of modern technology are sensitive to the effects of solar wind radiation that our magnetic field shields against and predictions of variability decades into the future are invaluable to governments and industries seeking to invest in long term projects such as power infrastructure as well as scientific and communication satellites.

This project will establish a robust records of extreme paleomagnetic field variability during the last ~4,000 years, which will have significant impact on current geodynamo theories. Ensuring that the geomagnetic modeling community obtains the maximum benefit from this work will aid their ability to predict the future variability of Earth's magnetic field. A special session at the 2021 AGU Fall meeting, in addition to a domestic UK workshop, will be organized to maximize engagement with the academic beneficiaries. These will ensure the widest attendance by people engaged in all areas of magnetic research and key speakers will be invited to bring together all potential users. General dissemination of project results and information on the uses of magnetism in Earth sciences will be achieved through the Geomagnetism.org website.

A further advantage of the Geomagnetism.org website is the ease with which a wider audience can interact with it. This will provide a medium to engage the general public with the aim of increasing society's appreciation for Earth sciences and science in general. I will participate in NERC training for communicating science to the public, which will be undertaken early in the project so that techniques learned may be immediately implemented to maximize the non-academic impact of the project. These skills will be used to communicate the ideas and benefits of science to the public through university open days, web articles, and other opportunities that may arise during the fellowship.

I will also participate in the Royal Society's MP-Scientist Pairing Scheme. This scheme will allow me to directly communicate the importance of paleomagnetic research in terms of providing constraints on the future geomagnetic field that are necessary to make informed decisions about future investments in key technology and fundamental infrastructure.

The close collaboration with international researchers will be beneficial to the reputation of British science. My extensive experiences working in China will also strengthening Sino-British relations. There are many scientific opportunities in the rapidly developing Chinese scientific community and researchers there are keen to cultivate new international collaborations and expand the impact of their work and the development of Chinese science. This also gives rise to potential opportunities for student exchanges. My reintegration back into British science following several years in China will improve cultural awareness in the UK and will broaden the general public's appreciation of a science as a multinational endeavor.