The geomagnetic dipole moment (GDM) modulates the production rates of cosmogenic radionuclides via the shielding of galactic cosmic rays. Therefore, it is possible to use this linkage to reconstruct past changes in the GDM based on cosmogenic radionuclide records from natural archives such as ice cores. Here we present a GDM reconstruction based on ¹⁰Be and ³⁶Cl data from two Greenland ice cores from 11.7 ka to 108 ka b2k (before A.D. 2000). We find that the cosmogenic radionuclide records reflect a mixture of climate and production effects that require separation to evaluate the changes in the GDM. To minimize climate-related variations on isotope data, we applied a multi-linear correction method by removing common variability between ¹⁰Be and ³⁶Cl and climate parameters (accumulation rates, δ¹⁸O and ion data) from radionuclide records. The resulting “climate corrected” radionuclide data are converted to GDM using a theoretical production model. Comparison of “climate corrected” radionuclides based GDM reconstructions with independent paleomagnetic-derived GDM records shows a good agreement. Furthermore, the “climate correction” leads to an improved agreement with GDM reconstructions than simply using radionuclide fluxes, lending support to the validity of our correction method to isolate production rate changes from ice core radionuclide records. With this correction method, we can extend the GDM reconstructions based on the cosmogenic radionuclides in ice cores to a period when there is a strong climate signal in the data.

地磁偶极矩（GDM）通过屏蔽银河系宇宙射线来调节宇宙成因放射性核素的生产率。因此，可以使用这种链接基于自然档案（例如冰芯）的宇宙成因放射性核素记录重建GDM的过去变化。在这里，我们基于从两个格陵兰岛冰芯（从11.7 ka到108 ka b2k）（公元2000年之前）的¹⁰ Be和³⁶ Cl数据提出了GDM重构。我们发现宇宙放射性核素记录反映了气候和生产效应的混合，需要对其进行评估以评估GDM的变化。为了使同位素数据上与气候相关的变化最小化，我们通过消除¹⁰ Be和¹⁰之间的共同变化来应用多线性校正方法。^36个Cl和气候参数（累积速率，δ ¹⁸ O和离子数据）从放射性核素的记录。使用理论生产模型将所得的“气候校正”放射性核素数据转换为GDM。将基于“气候校正”的放射性核素的GDM重建与独立的古磁衍生GDM记录进行比较显示出很好的一致性。此外，与仅使用放射性核素通量相比，“气候校正”导致与GDM重建的一致性得到改善，这为我们校正方法的有效性提供了支持，该校正方法可将冰芯放射性核素记录中的生产率变化隔离出来。通过这种校正方法，我们可以将基于冰芯中的宇宙成因放射性核素的GDM重建扩展到数据中存在强烈气候信号的时期。