Paleomagnetic records from sediments, archeological artifacts, and lava flows provide the foundation for studying geomagnetic field changes over 0–100 ka. Late Quaternary time‐varying spherical harmonic models for 0–100 ka produce a global view used to evaluate new data records, study the paleomagnetic secular variation on centennial to multimillennial timescales, and investigate extreme regional or global events such as the Laschamp geomagnetic excursion. Recent modeling results (GGF100k and LSMOD.2) are compared to previous studies based on regional or global stacks and averages of relative geomagnetic paleointensity variations. Time‐averaged field structure is similar on Holocene, 100 ky, and million‐year timescales. Paleosecular variation activity varies greatly over 0–100 ka, with large changes in field strength and significant morphological changes that are especially evident when field strength is low. GGF100k exhibits a factor of 4 variation in geomagnetic axial dipole moment, and higher‐resolution models suggest that much larger changes are likely during global excursions. There is some suggestion of recurrent field states resembling the present‐day South Atlantic Anomaly, but these are not linked to initiation or evolution of excursions. Several properties used to characterize numerical dynamo simulations as “Earth‐like” are evaluated and, in future, improved models may yet reveal systematic changes linked to the onset of geomagnetic excursions. Modeling results are useful in applications ranging from ground truth and data assimilation in geodynamo simulations to providing geochronological constraints and modeling the influence of geomagnetic variations on cosmogenic isotope production rates.

中文翻译：

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一百年来的地磁场演化

来自沉积物，考古文物和熔岩流的古磁记录为研究0-100 ka以上的地磁场变化提供了基础。0-100 ka的晚第四纪时变球谐模型产生了一个全局视图，该全局视图用于评估新的数据记录，研究百年至千禧年时间尺度上的古磁长期变化，并研究极端的区域性或全球性事件，例如Laschamp地磁偏移。最近的建模结果（GGF100k和LSMOD.2）与以前基于区域或全球堆栈以及相对地磁古强度变化平均值的研究进行了比较。在全新世，100 ky和百万年时标上，时间平均场结构相似。在0–100 ka范围内，古藻的变异活动变化很大，场强发生较大变化，形态发生明显变化，当场强较低时尤其明显。GGF100k在地磁轴向偶极矩中表现出4倍的变化，而更高分辨率的模型表明，在全球偏移中可能发生更大的变化。有一些迹象表明现时的田间状态类似于当今的南大西洋异常，但这些状态与短途旅行的开始或演变没有联系。评估了将数字发电机模拟定性为“类似地球”的几种属性，并且在将来，改进的模型可能仍会揭示与地磁偏移发生有关的系统变化。