Abstract 174 snow samples were collected from a 4.5 m snow pit at Dome Argus (Dome A), East Antarctica, during the 2015–2016 austral summer. They covered a period between 1950 and 2016. These samples were measured for iron (Fe) concentrations by the inductively coupled plasma mass spectrometry (ICP-MS). Both the total dissolvable Fe (TDFe) and dissolved Fe (DFe) were measured in order to evaluate the fractional Fe solubility (FFS), an important variable to determine the Fe availability for biological activities. The results show an average TDFe flux of 0.019 mg m−2 a−1 and DFe flux of 2.254 × 10−3 mg m−2 a−1 at Dome A. The mean FFS of 7.27% is consistent with previous studies on the Antarctic ice sheet. Based on the mean value of the TDFe fluxes from both the current and previous studies, the atmospheric TDFe flux in Antarctic modern snow was estimated at 19–140 × 10−3 mg m−2 a−1, potentially supporting 10.5–76.5 Tg C a−1 of primary production. This accounts about 1.21–8.80% of the annual primary production in the seasonal sea ice zone of Southern Ocean (SO), suggesting that atmospheric DFe is a minor component of Fe supply.

中文翻译：

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1950-2016 年间在南极洲东部 Dome Argus 的雪中记录的大气铁变化

摘要 2015-2016 年南半球夏季，从位于南极洲东部 Dome Argus (Dome A) 的 4.5 m 雪坑中收集了 174 个雪样。它们涵盖了 1950 年至 2016 年之间的时期。通过电感耦合等离子体质谱法 (ICP-MS) 测量了这些样品的铁 (Fe) 浓度。测量总可溶解铁 (TDFe) 和溶解铁 (DFe) 以评估分数铁溶解度 (FFS)，这是确定生物活性铁可用性的重要变量。结果显示圆顶 A 处的平均 TDFe 通量为 0.019 mg m-2 a-1 和 DFe 通量为 2.254 × 10-3 mg m-2 a-1。7.27% 的平均 FFS 与之前在南极的研究一致冰盖。基于当前和以前研究的 TDFe 通量的平均值，南极现代雪中的大气 TDFe 通量估计为 19-140 × 10-3 mg m-2 a-1，可能支持 10.5-76.5 Tg C a-1 的初级生产。这约占南大洋季节性海冰区 (SO) 年初级产量的 1.21-8.80%，表明大气 DFe 是 Fe 供应的次要组成部分。