Mercury Oxidation and Depletion in the Reactive Halogen Enriched Troposphere of the Dead Sea

死海富含活性卤素的对流层中的汞氧化和消耗

• 批准号: 0813690
• 负责人: Daniel Obrist
• 金额: $ 45万
• 依托单位: Nevada System of Higher Education, Desert Research Institute
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-01 至 2012-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0813690&HistoricalAwards=false
• 关键词: Mercury; Oxidation; Depletion; Reactive; Halogen

The aim of this study is to elucidate atmospheric conditions and chemical pathways responsible for recently observed atmospheric mercury depletion events (AMDE) at the Dead Sea in Israel. Hypotheses include: (1) depletion of gaseous elemental mercury (GEM) at the Dead Sea is accompanied by increased levels of reactive gaseous mercury (RGM) and particulate forms (PHg), which would confirm that AMDE at the Dead Sea are analogous to those observed in the polar troposphere; (2) AMDE are correlated with high levels of reactive halogen compounds (RHC), specifically BrOx (Br + BrO); (3) even small concentrations of RHC may initiate GEM oxidation, with implications for other midlatitude marine boundary layer sites with lower RHC levels. These hypotheses will be tested by simultaneous measurement of speciated mercury, halogen oxides, nitrogen oxides, ozone, sulfate aerosols, fine particulates, and meteorological parameters. A modeling study will help identify the mechanisms for reactive halogen chemistry and mercury oxidation.Knowledge of source and sink strengths of atmospheric mercury species is critical for regulatory agencies to protect humans and ecosystems from this potent toxin. The research will involve undergraduate and graduate students from the University of Nevada, Reno. A partnership will be initiated with a local (Nevada) school district to expose teachers and students to this research and expand a current collaboration with their Gifted and Talented Program.

这项研究的目的是阐明大气条件和化学途径负责最近观察到的大气汞耗竭事件（AMDE）在以色列死海。 假设包括：（1）死海气态元素汞（GEM）的消耗伴随着活性气态汞（RGM）和颗粒形式（PHg）水平的增加，这将证实死海的AMDE与极地对流层中观察到的相似;（2）AMDE与高水平的活性卤素化合物（RHC），特别是BrOx相关（3）即使是很低浓度的RHC也可能引发GEM氧化，这对其他RHC水平较低的中纬度海洋边界层站点具有影响。 这些假设将通过同时测量汞、卤素氧化物、氮氧化物、臭氧、硫酸盐气溶胶、细颗粒物和气象参数进行检验。 模拟研究将有助于确定反应性卤素化学和汞氧化的机制。了解大气汞物种的源和汇强度对于监管机构保护人类和生态系统免受这种强毒素的危害至关重要。 这项研究将涉及来自内华达州里诺大学的本科生和研究生。 将与当地（内华达州）学区建立伙伴关系，使教师和学生了解这项研究，并扩大目前与他们的天才计划的合作。