Reconstructions of the global production rate of the cosmogenic isotope ¹⁰Be from sedimentary records of authigenic ¹⁰Be/⁹Be ratios have been successfully used to obtain independent estimates of geomagnetic dipole moment variations caused by field excursions or reversals. In this study, we assess the reliability of ¹⁰Be/⁹Be as a proxy for the cosmogenic ¹⁰Be production rate by evaluating two potential biasing sources represented by sediment composition and climatic modulation. For this purpose, we compare five high-resolution ¹⁰Be/⁹Be records of the Matuyama-Brunhes (M-B) field reversal from sediment cores of the Indian, West Pacific, and North Atlantic oceans. Significant increase of ¹⁰Be/⁹Be ratios at $\sim$774 ka is explained in terms of the dominant control of geomagnetic modulation during the M-B reversal. Results do not support the existence of a direct proportionality between measured sedimentary ¹⁰Be/⁹Be ratio and cosmogenic ¹⁰Be production rate, as shown by ¹⁰Be/⁹Be records that offset relative to each other during and outside the M-B reversal.

Residual differences between offset-corrected rescaled records do not appear to be related to an incomplete correction of variable sediment scavenging efficiencies by ⁹Be normalization. Instead, these differences can be explained by a common climatic modulation model, assuming a linear relation between ¹⁰Be/⁹Be and the global ¹⁰Be production rate with site- and time-dependent additive and multiplicative coefficients. These coefficients are linear functions of a single global climate proxy identified with the benthic ${\delta }^{18}$O record. Additive coefficients are almost constant in time and can represent up to $\sim$60% of the average ¹⁰Be/⁹Be value during periods of stable field polarity. Multiplicative coefficients are also site-specific, with mean values representing the bulk scavenging efficiency of the site, and variations about this mean expressing a multiplicative climatic modulation of the ¹⁰Be production rate. The amplitude of this modulation amounts to 10–15% of the maximum variations recorded during the M-B reversal and is sufficiently large to mask minor variations of the dipole moment during stable polarity periods. Reconstructions of the geomagnetic dipole intensity can benefit from the information about climatic modulation effects gained with our modelling approach. Best suited sites for magnetic field reconstructions should be characterized by minimal Be-recycling contributions from ancient ¹⁰Be reservoirs and minimal climatic modulation, as far as it can be determined from relative comparisons with other records. These conditions are most likely encountered in open basins at sites (1) with $<$ 2.8 km water depth, (2) $>$ 200 km offshore, and (3) located underneath a large current system extending over regions with minimum terrigenous inputs. Scaling all records with respect to a chosen reference enables to produce ¹⁰Be/⁹Be stacks with reduced noise and short-term local environmental effects. Differences between stacks obtained in this manner highlight global climatic effects that need to be considered when generating calibrated reconstructions of the geomagnetic dipole moment.

已根据自生的¹⁰ Be / ⁹ Be的沉积记录重建了宇宙成因同位素¹⁰ Be的全球生产率，已成功地获得了由磁场偏移或逆转引起的地磁偶极矩变化的独立估计。在这项研究中，我们通过评估以沉积物成分和气候调节为代表的两个潜在的偏置源，评估了¹⁰ Be / ⁹ Be作为宇宙成因¹⁰ Be生产率的可靠性。为此，我们比较了五个高分辨率的¹⁰ Be / ⁹记录下印度，西太平洋和北大西洋沉积岩心中的Matuyama-Brunhes（MB）油田逆转。¹⁰ Be / ⁹ Be比显着增加$〜$关于MB反转期间的地磁调制的主要控制来说明774ka。结果不支持所测量的沉积物¹⁰ Be / ⁹ Be比率与宇宙成因¹⁰ Be产生率之间存在直接比例关系，如¹⁰ Be / ⁹ Be记录所示，它们在MB反转期间和外部相互抵消。

经偏移校正的重新定标记录之间的残留差异似乎与通过⁹ Be归一化对可变的泥沙清除效率的不完全校正无关。取而代之的是，这些差异可以通过常见的气候调制模型来解释，假设¹⁰ Be / ⁹ Be与总体¹⁰ Be生产率之间存在线性关系，并具有与时间和地点有关的累加系数和乘法系数。这些系数是由底栖生物识别的单个全球气候代用品的线性函数。${\delta }^{\mathrm{18岁}}$O记录。加性系数在时间上几乎是恒定的，最多可以表示$〜$在稳定的电场极性期间，平均¹⁰ Be / ⁹ Be值的60％。乘数系数也是特定于站点的，平均值代表站点的整体清除效率，并且该平均值的变化表示¹⁰的乘积气候调制。是生产速度。这种调制的幅度等于MB反转期间记录的最大变化的10％至15％，并且足够大，可以掩盖稳定极性期间偶极矩的微小变化。地磁偶极子强度的重构可以受益于通过我们的建模方法获得的有关气候调制效应的信息。只要可以从与其他记录的相对比较中确定，那么最合适的磁场重建地点应以古老的¹⁰ Be储集层的Be-recycling贡献和最小的气候调制为特征。这些情况最有可能发生在站点（1）的开放盆地中$<$ 2.8公里的水深，（2） $>$离岸200公里，并且（3）位于大电流系统下方，该系统在最小陆源输入范围内延伸。相对于选定参考，按比例缩放所有记录可以产生^10个Be / ⁹ Be烟囱，并减少噪音和短期局部环境影响。以这种方式获得的烟囱之间的差异突出了全球气候效应，在生成地磁偶极矩的校正重建时需要考虑这些气候效应。