Distribution characteristics of 7Be, 210Po and 210Pb in the surface snow of the Arctic Ocean
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摘要: 大气输送的放射性核素7Be、210Po和210Pb,可以作为研究北冰洋大气沉降通量、海洋现代沉积以及海冰中物质传输的重要示踪剂,已被广泛应用于包括气团运动、土壤侵蚀以及水系统中颗粒物循环过程的研究。本文报道了2018年北极高纬度浮冰区表层积雪中7Be、210Po和210Pb的活度特征。7Be、210Po和210Pb的比活度变化范围分别为33.6~632.68 mBq/L、36.2~87.5 mBq/L、30.9~194.49 mBq/L。本文的研究发现,北冰洋表层积雪中7Be和210Pb比活度小于中纬度大陆地区。研究区域表层积雪中7Be的比活度随着纬度的增加而增加。此外,表层积雪中210Po/210Pb活度比值范围为0.70~1.48 (平均为0.93),210Po与210Pb活度已基本达到平衡,表明积雪样品年龄可能较“老”。Abstract: The radionuclides 7Be, 210Po and 210Pb transported by the atmosphere can be used as important tracers for studying the material deposition flux of the Arctic Ocean’s atmosphere, modern ocean sedimentation and the transport of materials into the sea ice. They have been widely used in the study of air mass movement, soil erosion, and particle circulation processes in water systems. This paper reports the activities of 7Be, 210Po and 210Pb in the surface snow of the high-latitude ice floes of the Arctic Ocean in 2018. The activity concentrations of 7Be, 210Po and 210Pb are 33.6−632.68 mBq/L, 36.2−87.5 mBq/L, and 30.9−194.49 mBq/L, respectively. The activity concentrations of 7Be and 210Pb in the surface snow of the Arctic Ocean are lower than those in the mid-latitude continental areas. The results show that the activity concentrations of 7Be in snow increased with the increase of latitude. The activity ratio of 210Po/210Pb ranged from 0.70 to 1.48 (with an average of 0.93), 210Po is almost in equilibrium with 210Pb. It indicates that the age of the surface snow is “older”.
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Key words:
- Arctic Ocean /
- snow /
- 7Be /
- 210Po /
- 210Pb /
- atmospheric deposition
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表 1 不同地区的7Be和210Pb的沉降通量
Tab. 1 Atmospheric deposition flux of 7Be and 210Pb at different area
研究区域 采样时间 纬度 经度 来源 7Be 比活度/(Bq·L−1) 210Pb 比活度/(mBq·L−1) 数据来源 北冰洋 2018年8月 79.22°~84.72°N 169.4°~156.1°W 降雪 0.034~0.63 30.9~194 本文 北冰洋 2011年9月 84.07°~84.39°N 164.2°W~166.4°E 降雪 0.43~2.5 − [13] 新墨西哥州索科罗 1992年12月 − − 降雪 0.37 41.2 [28] 格陵兰岛 1988年11月至1989年2月 65.17°N 40.73°W 降雪 0.23~2.16 4.07~109 [29] 格陵兰岛 1989年6−7月 65.17°N 40.73°W 降雪 0.4~1.04 4.1~110 [30] 格陵兰岛 1989年6−7月 72.33°N 38.75°W 降雪 0.04~1.27 1.85~111.4 [30] 上海 2006−2011年 31.22°N 121.38°E 降雨 1.26 0.31×103 [2] 日本,筑波 2000−2001年 36.05°N 140.13°W 降雨 0.86 0.14×103 [31] 德克萨斯州加尔维斯顿 1988年12月至1992年2月 29.3°N 94.8°W 降雨 0.09~20.7 (0.031~3.6)×103 [32] 德克萨斯州大学城 1988年12月至1992年2月 30.58°N 96.37°W 降雨 0.26~4.96 (0.036~0.428)×103 [32] 西班牙韦尔瓦 2009年4月至2010年8月 37.27°N 6.92°E 降雨 0.03~7.42 (0.005~1.07)×103 [33] 摩纳哥 1998年1月至2010年12月 43.83°N 7.5°E 降雨 0.4~8.6 (0.02~1.9)×103 [34] 加州圣克鲁斯 2009年10月至2010年9月 37°N 122°W 降雨 1.3~4.4 − [35] 纽约石溪 2008年4月至2009年12月 40.9°N 73.12°W 降雨 1.3~4.5 55~255 [36] 注:−表示文献无报道。 -
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