Abstract：
The Arctic region forms a unique environment with specific physical, chemical, and biological processes affecting mercury (Hg) cycles and limited anthropogenic Hg sources. However, historic global emissions and long range atmospheric transport has led to elevated Hg in Arctic wildlife and waterways. Continuous atmospheric Hg measurements, spanning 20 years, and increased monitoring sites has allowed a more comprehensive understanding of how Arctic atmospheric mercury is changing over time. Time-series trend analysis of TGM (Total Gaseous Mercury) in air was performed from 10 circumpolar air monitoring stations, comprising of high-Arctic, and sub-Arctic sites. GOM (gaseous oxidised mercury) and PHg (particulate bound mercury) measurements were also available at 2 high-Arctic sites. Seasonal mean TGM for sub-Arctic sites were lowest during fall ranging from 1.1 ng m-3 Hyytiälä to 1.3 ng m-3, Little Fox Lake. Mean TGM concentrations at high-Arctic sites showed the greatest variability, with highest daily means in spring ranging between 4.2 ng m-3 at Amderma and 2.4 ng m-3 at Zeppelin, largely driven by local chemistry. Annual TGM trend analysis was negative for 8 of the 10 sites. High-Arctic seasonal TGM trends saw smallest decline during summer. Fall trends ranged from -0.8% to -2.6% yr-1. Across the sub-Arctic sites spring showed the largest significant decreases, ranging between -7.7% to -0.36% yr-1, while fall generally had no significant trends. High-Arctic speciation of GOM and PHg at Alert and Zeppelin showed that the timing and composition of atmospheric mercury deposition events are shifting. Alert GOM trends are increasing throughout the year, while PHg trends decreased or not significant. Zeppelin saw the opposite, moving towards increasing PHg and decreasing GOM. Atmospheric mercury trends over the last 20 years indicate that Hg concentrations are decreasing across the Arctic, though not uniformly. This is potentially driven by environmental change, such as plant productivity and sea ice dynamics.
摘要：
北极地区形成了一个独特的环境，具有特定的物理，化学,和影响汞（Hg）循环和有限的人为汞来源的生物过程。然而,历史性的全球排放和远距离大气传输导致北极野生动物和水道中汞含量升高。连续大气汞测量，跨越20年,增加的监测点可以更全面地了解北极大气汞随时间的变化。从10个环极空气监测站进行了空气中TGM（总气态汞）的时间序列趋势分析，包括高北极地区，和亚北极地区。GOM（气态氧化汞）和PHg（颗粒结合汞）测量也可在2个北极高地点获得。秋季，亚北极地区的季节平均TGM最低，范围从1.1ngm-3Hyytiälä到1.3ngm-3，小狐狸湖。高北极地区的平均TGM浓度表现出最大的变异性，春季最高的每日平均值在Amderma的4.2ngm-3和齐柏林飞艇的2.4ngm-3之间，主要由当地化学驱动。10个站点中的8个站点的年度TGM趋势分析为阴性。高北极季节性TGM趋势在夏季下降幅度最小。下降趋势从-0.8%到-2.6%yr-1。在亚北极地区，春季出现了最大的显着下降，yr-1在-7.7%至-0.36%之间，而下降一般没有显著趋势。Alert和Zeppelin的GOM和PHg的高北极形态表明，大气汞沉积事件的时间和组成正在发生变化。警惕GOM趋势全年都在增加，而PHg趋势下降或不显著。齐柏林看到了相反的情况，朝着增加PHG和减少GOM的方向发展。过去20年的大气汞趋势表明，整个北极的汞浓度正在下降，虽然不是统一的。这可能是由环境变化驱动的，如植物生产力和海冰动态。
