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 paleomagnetic field behavior. Analyzing a suite of 50 geodynamo models, we present here the first numerical simulations known to reproduce the salient aspects of the paleosecular variation and time‐averaged field behavior 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 paleomagnetic field behavior. This dipolarity range agrees well with state‐of‐the‐art statistical field models and represents a testable prediction for next generation global paleomagnetic field model reconstructions.

中文翻译：

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数值发电机模拟重现了古磁场行为

数值地球动力学模拟捕获了历史和全新世时空的时空地磁场可变性的几个特征。但是，最近的分析对这些数值模型遵守长期古磁场行为的能力提出了质疑。通过分析一组50个地球动力学模型，我们在这里展示了第一个数值模拟，该模拟重现了自10 Ma以来的古生物变化和时间平均场行为的显着方面。我们发现，模拟的场特征与芯-地幔边界（偶极）的相对偶极子场强度成正比。仅由对流主导的模型，其埃克曼数（粘滞力与科里奥利力之比）小于10 ^-3双极性在0.34–0.56范围内可以捕获观测到的古磁场行为。这个偶极范围与最新的统计场模型非常吻合，并且代表了下一代全球古磁场模型重建的可检验的预测。