On the variability of atmospheric 222 Rn activity concentrations measured at Neumayer, coastal Antarctica

• Published in: Atmospheric Chemistry and Physics
• Main Authors: R. Weller, I. Levin, D. Schmithüsen, M. Nachbar, J. Asseng, D. Wagenbach
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2014
• Subjects: Physics; QC1-999; Chemistry; QD1-999; Antarctic; The Antarctic; Neumayer; Neumayer Station; Antarc*; Antarctica; Sea ice
• Online Access: https://doi.org/10.5194/acp-14-3843-2014; https://doaj.org/article/704160ecbb8a4d9691fda8ff707a4f4f

We report on continuously measured 222 Rn activity concentrations in near-surface air at Neumayer Station in the period 1995–2011. This 17-year record showed no long-term trend and has overall mean ± standard deviation of (0.019 ± 0.012) Bq m −3 . A distinct and persistent seasonality could be distinguished with maximum values of (0.028 ± 0.013) Bq m −3 from January to March and minimum values of (0.015 ± 0.009) Bq m −3 from May to October. Elevated 222 Rn activity concentrations were typically associated with air mass transport from the Antarctic Plateau. Our results do not support a relation between enhanced 222 Rn activity concentrations at Neumayer and cyclonic activity or long-range transport from South America. The impact of oceanic 222 Rn emissions could not be properly assessed but we tentatively identified regional sea ice extent (SIE) variability as a significant driver of the annual 222 Rn cycle.