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.

该项目将结合对海水中汞形态的研究，为北极空气和海面之间的汞交换提供新的认识。结果将有助于预测冰融化的增加和海水变暖将如何影响极地地区的汞含量。研究人员将使用一种新颖的方法来比较氡（一种惰性气体）和汞（各种形式的活性气体）的动力学，以了解影响海水中汞含量的化学和生物反应的重要性。研究结果将对国际水俣公约和关注人类和野生动物体内汞生物累积的资源管理者有用。该项目将培养一名博士后研究员，参与研究的各个方面，并为本科生提供研究经验。研究人员还计划为非专业人士制作外展出版物，并在他们的网站上重点介绍这项工作。该项目将结合船上测量和孵化实验，以提高我们对无机汞和甲基化汞在水-空气界面上的循环及其作用的理解。冰盖影响这种交换。为了将气体交换与地表水中的氧化还原反应和其他转化分开，研究人员将收集样品来测定氡和镭，因为氡的混合层缺陷可以用作气体交换通量的独立估计。研究人员将测试以下假设：1）与其他海洋相比，汞的气体逃逸并不是北冰洋水柱汞的主要汇； 2) 二甲基汞的原位水柱降解是比流失到大气中更重要的汇； 3) 北极的汞净产量相对较低，反映出紫外线水平和冰盖、生产力和生物可利用汞的减少程度较低。结果将有助于预测气候变化和北极海冰状况的变化可能如何改变甲基汞的生物累积。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

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