Continuous 25-years aerosol records at coastal Antarctica: Part 2. Variability and climate implications of 7Be, 10 Be and 210Pb

• Published in: Tellus B: Chemical and Physical Meteorology
• Main Authors: Elsässer, C., Wagenbach, D., Weller, Rolf, Auer, A., Wallner, A., Christl, M.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Wiley-Blackwell 2011
• Subjects: Antarc*; Antarctica
• Online Access: https://epic.awi.de/id/eprint/23185/; https://hdl.handle.net/10013/epic.38268

We investigated the variability of 210Pb, 7Be and 10Be in coastal Antarctica aerosol samples based on continuous, monthly and annually resolved time series which we obtained from Neumayer Station over the period 1983 to 2008. Clear seasonal cycles peaking in the local summer half year stands out in being common to all three radionuclide records. However, MC-SSA time series analyses suggest that significant multi-annual changes are confined to a 4-5 years periodicity resembling that of the SAM circulation index in case of 210Pb and to the expected solar decadal cycle in case of the cosmogenic Be-isotopes. Both, changes in the meridional transport and surface inversion strength appear to drive the seasonal 210Pb cycle which generally peaks in November. In contrast, stratospheric air mass intrusion are proved to be the main reason for the Be-isotopes seasonality as revealed by enhanced 10Be/ 7Be ratios occurring broadly concurrently with the individual Be-isotopes and the 7Be/210Pb ratios during late summer/early autumn. Although both, the (annual) 10Be and the monthly 7Be records reflects the decadal solar modulated production signal the detailed pattern of their decadal changes essentially deviate for unknown reasons, though a substantial excess 7Be production by solar energetic particles could be ruled out.