Mercury deposition in a polar desert ecosystem.
Mercury deposition in a polar desert ecosystem.
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DOI：
10.1021/es800022g
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发表时间：
2008-05
影响因子：
11.4
通讯作者：
Rebecca A. Witherow;W. Lyons
中科院分区：
文献类型：
--
作者：
Rebecca A. Witherow;W. Lyons
痕量金属由于其潜在的毒性性质，在最近几十年中受到了相当大的关注。冰川雪和冰已被广泛用于阐明微量金属和其他化合物的大气成分的历史变化。南极冰中的汞浓度描述了从末次盛冰期到全新世过渡期间大气汞沉积的变化，但南极现代汞沉积的记录有限。在这里，我们提出了一个记录的净汞沉积到南极雪在过去的二十年。在十年的时间里，汞被保存在积雪中，并依赖于区域海洋来源。雪中的年度至次年度汞浓度在一定程度上得到保存，并显示出与海洋气溶胶的协方差，这一点可以通过钙浓度得到证明。来自裸露岩石和土壤的风成输入物在汞沉积到南极雪中也起着关键作用。这种识别与以前的数据一起沿着说明，直接从冰川迁移的汞可能占冰前河流和常年冰封湖泊的表面沃茨中总汞浓度的25-65%。
Trace metals have received considerable attention in the recent decades due to their potential toxic nature. Glacial snow and ice have been used extensively to elucidate historical changes in the atmospheric composition of trace metals and other compounds. Mercury concentrations in Antarctic ice have described changes in atmospheric mercury deposition during the transition from the Last Glacial Maximum to the Holocene, however the record of modern mercury deposition in Antarctica is limited. Here we present a record of net mercury deposition to Antarctic snow over the past two decades. Over decadal periods, mercury is conserved in the snowpack and is dependent on a regional oceanic source. Annual to subannual mercury concentrations in snow are to some extent preserved and show covariance with marine aerosols as evidenced by calcium concentrations. Aeolian inputs from exposed rock and soil also play a critical role in depositing mercury to Antarctic snow. Such identifications along with previous data illustrate that mercury transport directly from the glaciers may account for 25-65% of the total mercury concentration in proglacial streams and the surface waters of perennially ice-covered lakes.