Ebinghaus Ralf, Kock Hans H, Temme Christian, Einax Jürgen W, Lowe Astrid G, Richter Andreas, Burrows John P, Schroeder William H
Institute for Coastal Research/Physical and Chemical Analysis, GKSS Research Centre Geesthacht, Germany.
Environ Sci Technol. 2002 Mar 15;36(6):1238-44. doi: 10.1021/es015710z.
Unlike other heavy metals that are inherently associated with atmospheric aerosols, mercury in ambient air exists predominantly in the gaseous elemental form. Because of its prolonged atmospheric residence time, elemental mercury vapor is distributed on a global scale. Recently, Canadian researchers have discovered that total gaseous mercury levels in the lower tropospheric boundary layer in the Canadian Arctic are often significantly depleted during the months after polar sunrise. A possible explanation may involve oxidation of elemental mercury, followed by adsorption and deposition of the oxidized form, leading to an increased input of atmospheric mercury into the Arctic ecosystem. Here we present the first continuous high-time-resolution measurements of total gaseous mercury in the Antarctic covering a 12-month period between January 2000 and January 2001 at the German Antarctic research station Neumayer (70 degrees 39' S, 8 degrees 15' W). We report that mercury depletion events also occur in the Antarctic after polar sunrise and compare our measurements with a data setfrom Alert, Nunavut, Canada. We also present indications that BrO radicals and ozone play a key role in the boundary-layer chemistry during springtime mercury depletion events in the Antarctic troposphere.
与其他天然与大气气溶胶相关的重金属不同，环境空气中的汞主要以气态单质形式存在。由于其在大气中的停留时间较长，单质汞蒸气在全球范围内分布。最近，加拿大研究人员发现，在极地日出后的几个月里，加拿大北极地区对流层低层边界层中的总气态汞水平常常显著降低。一种可能的解释可能涉及单质汞的氧化，随后是氧化形式的吸附和沉积，导致大气汞向北极生态系统的输入增加。在此，我们展示了在德国南极研究站诺伊迈尔（南纬70度39分，西经8度15分）对2000年1月至2001年1月期间南极地区总气态汞进行的首次连续高时间分辨率测量。我们报告称，极地日出后南极地区也会发生汞消耗事件，并将我们的测量结果与加拿大努纳武特地区阿勒特的数据进行了比较。我们还表明，溴氧自由基和臭氧在南极对流层春季汞消耗事件期间的边界层化学过程中起关键作用。
