资源环境科技发展态势分析平台

Numerical geodynamo simulations capture several features of the spatial and temporal geomagnetic field variability on historical and Holocene timescales. However, a recent analysis questioned the ability of these numerical models to comply with long‐term palaeomagnetic field behaviour. Analysing a suite of 50 geodynamo models, we present here the first numerical simulations known to reproduce the salient aspects of the palaeosecular variation and time‐averaged field behaviour since 10 Ma. We find that the simulated field characteristics covary with the relative dipole field strength at the core‐mantle boundary (dipolarity). Only models dominantly driven by compositional convection, with an Ekman number (ratio of viscous to Coriolis forces) lower than 10⁻³ and a dipolarity in the range 0.34 − 0.56 can capture the observed palaeomagnetic field behaviour. This dipolarity range agrees well with state‐of‐the‐art statistical field models and represent a testable prediction for next generation global palaeomagnetic field model reconstructions.