Continuously measured 222Rn activity concentrations (daily means) in near surface air at Neumayer Station in the period 1995 through 2011@en

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.本研究报道了1995-2011年间诺伊迈尔站（Neumayer Station）近地表空气中氡-222（222Rn）活度浓度的连续监测数据。该17年监测序列未呈现长期趋势，整体均值±标准差为(0.019 ± 0.012) Bq/m³。序列具有显著且稳定的季节变化特征：1月至3月为浓度高峰期，对应值为(0.028 ± 0.013) Bq/m³；5月至10月为浓度低谷期，对应值为(0.015 ± 0.009) Bq/m³。氡-222活度浓度升高的现象通常与来自南极高原的气团输送相关。本研究结果表明，诺伊迈尔站观测到的氡-222活度浓度升高，与气旋活动或来自南美洲的长距离气团输送不存在关联。海洋源氡-222排放的影响尚未得到准确评估，但本研究初步判定，区域海冰范围（Sea Ice Extent, SIE）的变化是驱动年度氡-222浓度周期的关键因素。