Raimund Muscheler

Cosmogenic radionuclides (e.g., 10Be) from ice cores are a powerful tool for solar reconstructions back in time. However, superimposed on the solar signal, other factors like weather/climate and volcanic influences on 10Be can complicate the interpretation of 10Be data. A comprehensive study of 10Be records over the recent period, when atmospheric 10Be production and meteorological conditions are relatively well-known, can improve our interpretation of 10Be records. Here we conduct a systematic study of the production and climate/volcanic signals in Antarctica and Greenland 10Be records, including a new 10Be record from the East GReenland Ice-core Project site. Greenland and Antarctica records show significant decreasing trends (5%–6.5%/decade) for 1900–1950, which is comparable with the expected production rate inferred from sunspot observations. By comparing 10Be records with reanalysis data and atmospheric circulation patterns, 10Be records from Southern/Southeastern Greenland are significantly correlated with the Scandinavia pattern. Stacking 10Be records from different locations can enhance the production signal. However, this approach is not always straightforward as uncertainties in some records can lead to a weaker solar signal. A strategy can be employed to select records for the bipolar stack by comparing Greenland records with Antarctica records, assuming the shared signal is a production signal. Finally, we observe significant increases (36%–64%) in 10Be depositions in Greenland related to the Agung eruption. This large increase in Greenland 10Be records after the Agung eruption, could be partly explained by the enhanced air mass transport from mid-latitudes coinciding with the decreased precipitation en-route.