Mercredi 4 novembre 2026 à 11h00 ; salle des séminaires IRPHE
Abstract: Earth's magnetic field, sustained by dynamo action in the liquid outer core, has existed for at least 3.5 billion years. Understanding the geodynamo requires combining numerical simulations with geomagnetic observations. This talk presents our recent efforts to constrain core dynamics from two complementary fronts: state-of-the-art numerical simulations and high-precision satellite magnetic data. First, I will show dynamo simulations that achieve viscosity-independent behavior at extremely low viscosity (very low Ekman number), demonstrating the negligible role of fluid viscosity in our dynamo models as we approach core conditions relevant to the deep past. Second, I will introduce a novel framework for reconstructing time-dependent 3-D core flows based on inertial mode representation and physics-informed neural networks (PINNs). Using high-precision magnetic data from the Swarm constellation and the Macau Science Satellite-1 (MSS-1), we present a 3-D core flow model within Earth's outer core spanning the past two decades.
Yufeng LIN - Department of Earth and Space Sciences at SUSTech (China)