MI2021 - 01 Andy Biggin: Integrating paleomagnetic data with dynamo simulations
Channel: MagNetZ
Date: 18/02/2021

What can be achieved by integrating paleomagnetic datawith numerical dynamo simulations?

Andy Biggin, University of Liverpool, UK

Palaeomagnetic datasets have the potential to provide critical observational constraints on numerical models that seek to realistically simulate the dynamo process occurring in Earth’s outer core. Conversely, in providing high-resolution, dynamically self- consistent, synthetic datasets with global coverage, geodynamo simulations have huge potential to inform and synthesize diverse palaeomagnetic studies.Here we will report on efforts led by the DEEP (Determining Earth Evolution from Palaeomagnetism) group at Liverpool to realize these avenues of potential through measuring palaeomagnetic behaviour during intervals of Earth history where little data previously existed, running geodynamo simulations that attempt to accurately reproduce primary features of observed palaeomagnetic variability, and utilizing outputs from geodynamo simulations to inform us about ancient magnetic field morphology.In the last 5 years, we have successfully measured more than 100 new site mean estimates of palaeomagnetic field intensity and roughly trebled the amount of data in the 300-1000 Ma time interval. We have also developed and applied new palaeomagnetic criteria for geodynamo simulations and have run the first simulations that reproduce the main features of palaeomagnetic variability observed in the last 10 Myr. Finally, by assessing dozens of dynamo simulations, we have developed an improved statistical field model for the last 10 Myr. We have further shown that for much, but possibly not all, of its history, the palaeomagnetic field has maintained a morphology that was, on average, dominated by an axial dipole. By continuing to obtain high-quality palaeomagnetic measurements and integrating these with numerical dynamo simulations in the future, there is scope for considerable mutual benefit and advances in our understanding of the long-term behaviour of the geodynamo.