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Mercury in the atmosphere: Measurements of particulate and gaseous forms in several different ecosystems.

机译：大气中的汞：测量几种不同生态系统中的微粒和气态形式。

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摘要

Mercury (Hg) can exist in the atmosphere as gaseous elemental (Hg 0), reactive gaseous (RGM), and particulate bound mercury (Hg P) with active study including distribution, seasonality, and chemical transformations. Over one year, HgP data was collected using bulk filters, cascade impactors and the Tekran automated speciation unit at a marine site (Appledore Island) and a coastal site (Thompson Farm). This allowed for comparison of size distribution, seasonality, and methods of detection. During summer 2009, HgP was found (50-60%) in coarse fractions composed of sea salt particles at both sites. In winter, HgP was dominated (65%) by fine particles, while in spring and summer 2010, Hg P was distributed across coarse and fine fractions (40% each). Hg" exhibited a diurnal cycle that matched Hg0. Finally, dry deposition rates of HgP were calculated as 1.7-2.8 ngm -2day-1 in summer, 4.6 ngm-2day -1 in winter, and 2.5 ngm-2day-1 in spring.;An instrument was developed for aircraft measurements of total gaseous mercury (TGM) and Hg0 and thus RGM by the difference. The custom-fabricated instrument (UH-Merc) allows for lower detection limits (5 ppqv), lower time resolution (1 minute), and increased accuracy and precision (<3% each) than commercial instruments. First results match data from the Tekran unit during an inter-comparison campaign in Reno, NV as well as previous results for this site. In addition, the instrument recovered 95.5 +/- 1.8% of spiked Hg0. UH-Merc will improve measurements to get a better understanding of Hg in the atmosphere.;Finally, TGM was collected from a forest (Thompson Farm) and a wetland site (Sallie's Fen) where TGM and methane (CH4) stored over the winter was being released into the atmosphere during the thaw. Results showed an increase of 23-28 ppqv TGM in the spring at Thompson Farm and 25-80 ppqv TGM and an increased flux of ~200 mg CH4 m-2day -1 at Sallie's Fen. The different processes forming these TGM and CH4 in the atmosphere become dominant as summer progresses; TGM decreases, while methane increases to a fall maximum. TGM seasonal and diurnal patterns are similar at Thompson Farm and Sallie's Fen; however, TGM is amplified up to 20% at Sallie's Fen.
机译：汞（Hg）可以气态元素（Hg 0），反应性气态（RGM）和颗粒结合汞（Hg P）的形式存在于大气中，并进行了积极的研究，包括分布，季节性和化学转化。一年多来，HgP数据是使用散装过滤器，级联撞击器和Tekran自动化物种形成单位在海洋站点（Appledore岛）和沿海站点（汤普森农场）收集的。这样可以比较大小分布，季节性和检测方法。在2009年夏季，两个地点均发现了HgP（占海盐颗粒的50-60％）。冬季，HgP以细颗粒为主（65％），而在2010年春季和夏季，HgP分布在粗颗粒和细颗粒中（各占40％）。 “汞”的日循环与Hg0相匹配。最后，HgP的干沉降速率计算为夏季为1.7-2.8 ngm -2day-1，冬季为4.6 ngm-2day -1，春季为2.5 ngm-2day-1。 ；开发了一种用于飞机测量总气态汞（TGM）和Hg0并因此测量RGM的仪器定制仪器（UH-Merc）允许较低的检测限（5 ppqv），较低的时间分辨率（1分钟） ），并且比商用仪器提高了准确性和精密度（每种仪器的准确性均低于3％），第一个结果与内华达州里诺市的一次比对活动中Tekran部门的数据以及该地点以前的结果相符。 95.5 +/- 1.8％的加标Hg0.UH-Merc将改善测量结果以更好地了解大气中的汞;最后，TGM是从森林（汤普森农场）和湿地地点（萨利芬）采集的，其中TGM冬季储存的甲烷（CH4）在排放过程中释放到大气中解冻。结果显示，汤普森农场（Thompson Farm）春季的TGM增加了23-28 ppqv，Sallie's Fen的TGM增加了25-80 ppqv，通量增加了〜200 mg CH4 m-2day -1。随着夏季的进行，在大气中形成这些TGM和CH4的不同过程变得占主导地位。 TGM减少，而甲烷增加到最大下降量。 Thompson Farm和Sallie's Fen的TGM季节和昼夜模式相似。但是，萨利芬（Sallie's Fen）的TGM放大了20％。

著录项

  • 作者

    Feddersen, Dara Marina.;

  • 作者单位

    University of New Hampshire.;

  • 授予单位 University of New Hampshire.;
  • 学科 Chemistry.;Atmospheric chemistry.
  • 学位 Ph.D.
  • 年度 2013
  • 页码 108 p.
  • 总页数 108
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

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