Multidecadal‐ to Centennial‐Scale 10Be Variations in Holocene Sediments of Huguangyan Maar Lake, South China.

We report a new high‐resolution Holocene 10Be record from Huguangyan Maar Lake in subtropical‐tropical South China, aimed to detect the atmospheric 10Be production signal in low‐latitude regions. After minimizing climatic effects by regression analyses between 10Be concentration and climatic proxies from the same archive, we successfully distinguished variations in geomagnetic field intensity and solar activity using 2,000‐year low‐ and high‐pass filtering, respectively, of the residual 10Be record (a proxy of the atmospheric 10Be production rate). The resulting 10Be‐derived record of geomagnetic field intensity is generally comparable with geomagnetic models, and the solar‐modulated 10Be signal shows significant correlations with solar activity proxies. The preservation of 10Be production signal in the sediments of this low‐latitude maar lake highlights the largely unexplored potential as well as limitations of 10Be as a tool to reconstruct variations in solar activity and geomagnetic field intensity. Plain Language Summary: The atmospheric production rate of cosmogenic 10Be depends on the cosmic ray flux penetrating the atmosphere, a process that is mainly controlled by the geomagnetic field strength and solar activity. The geomagnetic imprint on 10Be has been well established in previous studies of ice cores and marine sediments. The relationship between solar activity and 10Be has also been studied in ice cores and high‐latitude lakes. Here we for the first time present a high‐resolution 10Be record from Huguangyan Maar Lake in subtropical‐tropical South China over the Holocene. We successfully separated the atmospheric 10Be production signal from climatic effects that contribute to up to ~52% of the variance in 10Be concentration. After eliminating the climatic effects, variations in both geomagnetic field intensity and solar activity signals were reconstructed from the residual 10Be record, using 2,000‐year low pass, and high‐pass filtering, respectively. The geomagnetic‐ and solar‐modulated 10Be production signals are evaluated by comparisons with independent records. This result unambiguously indicates that the 10Be‐derived solar activity signal at a low‐latitude subtropical site can be obtained, even when the 10Be signal is dominated by regional climate, in our case, accounting for up to ~65% of the variance in the record during the early‐middle Holocene. Key Points: We for the first time report on a multidecadal to centennial‐scale 10Be record throughout the Holocene in subtropical‐tropical South ChinaWe separated atmospheric 10Be production signal from regional environmental effects that account for ~52% of variance in 10Be concentrationGeomagnetic‐ and solar‐derived 10Be signals were reconstructed by 2,000‐year low‐ and high‐pass filtering, respectively, of the residual record [ABSTRACT FROM AUTHOR]