Collaborative Research: Constraining the role of chemical transformations in the cycling of mercury at the Arctic Ocean air-sea interface

合作研究：限制化学转化在北冰洋海气界面汞循环中的作用

• 批准号: 1854462
• 负责人: Mark Stephens
• 金额: $ 40.05万
• 依托单位: Florida International University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1854462&HistoricalAwards=false
• 关键词: Collaborative; Research; Constraining; role; chemical

This project will provide new understanding about mercury exchange between the air and sea surface in the Arctic, in conjunction with studies of the forms of mercury in seawater. Results will help predict how increasing ice melt and warming waters will affect mercury levels in polar regions. The investigators will use a novel approach of comparing the dynamics of radon, an unreactive gas, and mercury, which is reactive in all its forms, to understand the importance of chemical and biological reactions influencing mercury levels in seawater. Results will be useful for the international Minamata Convention and resource managers concerned with mercury bioaccumulation in humans and wildlife. The project will train a post-doctoral investigator, who will be involved in all aspects of the research, as well as provide research experience for undergraduate students. The investigators also plan to create outreach publications for non-specialists and highlight the work on their websites.This project will combine shipboard measurements and incubation experiments to improve our understanding of the cycling of inorganic and methylated mercury across the water-air interface and the role of ice cover in affecting this exchange. To separate gas exchange from redox reactions and other transformations in surface waters, the investigators will collect samples for the determination of radon and radium, as the mixed layer deficit in radon can be used as an independent estimate of the gas exchange flux. The investigators will test the hypotheses that: 1) gas evasion of mercury is not the primary sink for water column mercury in the Arctic Ocean, in contrast to other oceans; 2) in situ water column degradation of dimethylmercury is a more important sink than loss to the atmosphere; and 3) the relatively low net production of mercury in the Arctic reflects lower ultraviolet light levels and ice cover, productivity, and bioavailable mercury for reduction. Results will help predict how the bioaccumulation of methylmercury may be altered by a changing climate and an evolving Arctic sea ice regime.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

该项目将与对海水中汞形式的研究一起，对北极空气和海面之间的汞交流有了新的了解。结果将有助于预测冰融化和变暖水的增加将如何影响极地地区的汞水平。研究人员将使用一种新颖的方法来比较ra的动力学，一种不反应性气体和汞，这种动力在其各种形式中具有反应性，以了解影响海水中汞水平的化学和生物反应的重要性。结果对于人类和野生动植物中的汞生物蓄积的国际Minamata公约和资源经理将很有用。该项目将培训一名博士后调查员，他们将参与研究的各个方面，并为本科生提供研究经验。调查人员还计划为非专业人士创建外展出版物，并在其网站上强调工作。该项目将结合船舶测量和孵化实验，以提高我们对水上空气界面上无机和甲基化汞循环的理解，以及冰覆盖在影响这种交流中的作用。为了将气体交换与地表水域中的氧化还原反应和其他转化分开，研究人员将收集样品以测定ra和镭，因为ra中的混合层不足可以用作气体交换通量的独立估计。研究人员将检验以下假设：1）与其他海洋相比，汞气体的气体不是北极海水汞的主要水槽； 2）二甲基汞的原位水柱降解比损失大气更重要。 3）北极中汞的净产量相对较低，反映出较低的紫外线光水平和冰盖，生产力和可生物利用的汞可减少。结果将有助于预测如何通过不断变化的气候和不断发展的北极海冰制度来改变甲基汞的生物积累。该奖项反映了NSF的法定任务，并认为值得通过基金会的知识分子优点和更广泛的影响审查标准通过评估来进行评估。

项目成果

Radon-222 and Radium-226 seawater and ice data from Bering Sea and Chukchi Sea 2021

2021 年白令海和楚科奇海的氡 222 和镭 226 海水和冰数据

• DOI: 10.18739/a23x83n3n
• 发表时间: 2023
• 期刊: Arctic Data Center
• 作者: Stephens, Mark