Latitude-dependent sensitivity of 10Be records to variations in geomagnetic field intensity

The atmospheric production rate of cosmogenic 10Be is inversely related to the geomagnetic field strength. This leads to variable deposition rates of 10Be in environmental archives, such as ice or sediment cores. 10Be records from these archives can, therefore, be used to reconstruct past intensities of the geomagnetic field. Recent 10Be production and atmospheric mixing models, however, suggest that the sensitivity of 10Be records to changes in the geomagnetic field intensity depends on the latitude. This impacts the use of single-site 10Be records for reconstructing global 10Be production rates and, therefore, geomagnetic field intensities.Here, we quantitatively assess the latitudinal sensitivity of 10Be deposition to geomagnetic field changes. We present new authigenic 10Be/9Be data from a sediment core from the Bay of Bengal (IODP U1446) and compile additional 10Be data from ice and sediment cores. Our analysis focuses on 10Be deposition changes during the Laschamps geomagnetic field intensity minimum at different latitudes. We compare 10Be deposition changes with changes in modeled 10Be production from geomagnetic field reconstructions (LSMOD.2, GGFSS70, Black Sea, GLOPIS-75) and the GEOS-Chem atmospheric mixing model.Our findings reveal that 10Be deposition changes are larger in the tropics (tropical enhancement) and diminish at higher latitudes (polar bias), indicating incomplete mixing of cosmogenic beryllium, consistent with atmospheric mixing models. This latitudinal sensitivity needs to be taken into account when reconstructing variations in global geomagnetic field intensity from 10Be.