厦门近岸^(210)Po和^(210)Pb的大气沉降通量

Atmospheric deposition of ^(210)Po and ^(210)Pb near the coast of Xiamen

为揭示中国东南沿海地区^(210)Po和^(210)Pb的大气沉降时空变化特征,探讨该地区气溶胶的停留时间,于2013年1月至2014年12月对厦门地区^(210)Po和^(210)Pb的大气沉降通量进行了时间序列研究。结果发现,^(210)Po和^(210)Pb的平均日沉降通量分别为(65.38±4.79)mBq/(m^2·d)(n=54)和(0.78±0.09)Bq/(m^2·d)(n=54),表现出明显的周年变化。东北季风期间,^(210)Po和^(210)Pb的沉降通量较高,而西南季风期间其通量较低。2013年和2014年,^(210)Po的年沉降通量分别为19.29 Bq/(m^2·a)和9.25 Bq/(m^2·a),^(210)Pb的年沉降通量分别为159.2 Bq/(m^2·a)和189.6 Bq/(m^2·a)。两核素的年沉降通量表现出不同程度的年际差异。^(210)Po与^(210)Pb沉降通量之间存在显著的线性正相关关系,揭示了大气中^(210)Po和^(210)Pb具有相同的迁出机制,降雨和大气中核素含量是影响^(210)Po和^(210)Pb沉降通量的主要因素。该研究结果可以为探求台湾海峡海水中^(210)Po与^(210)Pb的收支平衡提供大气来源项。

Atmospheric deposition of 210Po and 210Pb were measured at a time-series station in the southeast of China (Xiamen) from 2013 to 2014.The daily deposition fluxes of 210Po and 210Pb are (65.38±4.79)mBq/(m^2·d) and ( 0.78 ±0.09)Bq/(m^2·d),respectively,and the flux values present a significant annual variation.High fluxes occur in months with northeast monsoon,and low values are observed in the southwest monsoon prevailing months.In 2013 and 2014,the yearly deposition fluxes of 210Po are 19.29 Bq/(m^2·a) and 9.25 Bq/(m^2·a),and 210Pb fluxes are 159.2 Bq/(m^2·a) and 189.6 Bq/(m^2·a),respectively.The deposition fluxes of 210Po and 210Pb show inter-annual variations.There is a significant linear positive correlation between the 210Po and 210Pb fluxes.In addition,good positive correlations between rainfall and the deposition fluxes of the two nuclides are observed.These results reveal that the predominant removal passage of 210Po and 210Pb is precipitation along with rainfall,providing insights into understanding the transport of aerosol via 210Po and 210Pb.The datasets would provide an atmospheric source term for budgeting 210Po and 210Pb in waters of the western Taiwan Strait.