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

• Published in: Atmospheric Chemistry and Physics
• Main Authors: Weller, R., Levin, I., Schmithüsen, D., Nachbar, M., Asseng, J., Wagenbach, D.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2014
• Subjects: article; Verlagsveröffentlichung; Antarctic; Neumayer; Neumayer Station; The Antarctic; Antarc*; Antarctica; Sea ice
• Online Access: https://doi.org/10.5194/acp-14-3843-2014; https://noa.gwlb.de/receive/cop_mods_00045062; https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00044682/acp-14-3843-2014.pdf; https://acp.copernicus.org/articles/14/3843/2014/acp-14-3843-2014.pdf

We report on continuously measured 222Rn 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 222Rn activity concentrations were typically associated with air mass transport from the Antarctic Plateau. Our results do not support a relation between enhanced 222Rn activity concentrations at Neumayer and cyclonic activity or long-range transport from South America. The impact of oceanic 222Rn emissions could not be properly assessed but we tentatively identified regional sea ice extent (SIE) variability as a significant driver of the annual 222Rn cycle.