Wet and dry deposition fluxes of mercury in Japan
Wet and dry deposition fluxes of mercury in Japan
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DOI：
10.1016/j.atmosenv.2005.01.049
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发表时间：
2005-06
影响因子：
5
通讯作者：
M. Sakata;K. Marumoto
中科院分区：
文献类型：
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作者：
M. Sakata;K. Marumoto
从2002年12月至2003年11月，在日本的10个地点同时测量了汞的湿沉降通量和干沉降通量（9个地点用于干沉降测量）。降水和干沉降（气体和颗粒物）收集每半个月使用自动干湿沉降采样器。该采样器由降水采样器和干沉降水面采样器组成。结果表明，随着降水量的增加，夏季汞的湿沉降通量普遍增加。与此相反，干沉降通量的季节变化是非常小的湿沉降通量相比。结果发现，湿沉降在日本汞沉降中起主导作用，贡献的通量范围为0.99至2.2倍（1.6倍，平均在9个站点）的干沉降通量。汞的年湿沉降通量与年降水量呈高度相关（r2= 0.73，P <0.01）。因此，约70%的汞湿沉降在日本的变化是由降水量解释。这可能是因为汞的湿沉降主要是通过氧化气相和水相中的气态元素汞（Hg0）沉淀来清除活性气态汞（RGM）。此外，在北美地区的汞沉降网络（MDN）观测点，年湿沉降通量与降水量之间也存在类似的关系（r2= 0.55，P <0.001），表明汞湿沉降的方差约有55%是由降水量引起的。
Wet and dry deposition fluxes of mercury were measured concurrently from December 2002 to November 2003 at 10 sites in Japan (nine sites for dry deposition measurements). Precipitation and dry deposition (gases and particles) were collected every half-month using an automatic wet and dry deposition sampler. This sampler is composed of a precipitation sampler and a water surface sampler for dry deposition. The results showed that wet deposition fluxes of mercury increase generally during summer when the precipitation amount increases. In contrast, the seasonal variations of the dry deposition fluxes were very small compared to those of the wet deposition fluxes. It was found that wet deposition plays a dominant role in mercury deposition in Japan, contributing fluxes ranging from 0.99 to 2.2 times (1.6 times on average at nine sites) those of the dry deposition fluxes. There was a high correlation between the annual wet deposition flux of mercury and annual precipitation amount (r2=0.73, P<0.01). Thus, about 70% of the variance of mercury wet deposition in Japan is explained by precipitation amount. This is probably because mercury wet deposition is dominated by the scavenging of reactive gaseous mercury (RGM) by precipitation via oxidation of gaseous elemental mercury (Hg0) in the gas and aqueous phases. In addition, a similar relationship between the annual wet deposition flux and precipitation amount (r2=0.55, P<0.001) was observed at the Mercury Deposition Network (MDN) sites in North America, suggesting that about 55% of the variance of mercury wet deposition is due to precipitation amount.