Articles | Volume 14, issue 8
Atmos. Chem. Phys., 14, 3843–3853, 2014
Atmos. Chem. Phys., 14, 3843–3853, 2014

Research article 17 Apr 2014

Research article | 17 Apr 2014

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

R. Weller1, I. Levin2, D. Schmithüsen2, M. Nachbar2, J. Asseng1, and D. Wagenbach2 R. Weller et al.
  • 1Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Am Handelshafen 12, 27570 Bremerhaven, Germany
  • 2Institut für Umweltphysik, Heidelberg University, Im Neuenheimer Feld 229, 69120 Heidelberg, Germany

Abstract. 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.

Final-revised paper