Collaborative Research: Impacts of Recent Climate and Emissions Changes on Mercury Bioaccumulation in Arctic Marine Food-Webs

合作研究：近期气候和排放变化对北极海洋食物网中汞生物累积的影响

• 批准号: 1023213
• 负责人: Daniel Jacob
• 金额: $ 39.66万
• 依托单位: Harvard University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-08-15 至 2014-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1023213&HistoricalAwards=false
• 关键词: Collaborative; Research; Impacts; Recent; Climate

This project aims to improve our understanding of the factors controlling mercury (Hg) concentrations in the Arctic and their trends over the past three decades (1980-2010). It will develop an atmospheric model for mercury in the Arctic, based on the global GEOS-Chem chemical transport model (CTM) simulation for Hg developed at Harvard, and will be calibrated extensively and evaluated with observations. GEOS-Chem includes dynamical coupling of the atmosphere with surface ocean and land reservoirs. Atmospheric oxidation of Hg(0) to Hg(II), driving Hg(II) deposition, is primarily by bromine (Br) atoms. Model representation of Br chemistry in the Arctic will be tested and improved using recent observations from aircraft and satellites. At all stages of this research, the different model components as well as the coupled model will be evaluated in detail with a large body of atmospheric observations.The project will produce the first coupled simulation of atmospheric Hg dynamics in the Arctic with the ocean and land components in the existing GEOS-Chem model. This can be a powerful tool for relating changes in anthropogenic emissions and climate to biological Hg concentrations in the Arctic and its strong physical basis will make it a fundamental vehicle to test different hypotheses for Hg cycling and bioaccumulation in the Arctic. Sensitivity analyses using the model will identify areas of greatest uncertainty and help guide future research. This work will enable scientists and policymakers to better assess the impacts of policy decisions aimed at protecting the arctic environment.

该项目旨在提高我们对北极汞浓度控制因素及其过去三十年（1980-2010年）趋势的认识。它将根据哈佛开发的全球地球观测系统-化学迁移模型（CTM）对汞的模拟，开发一个北极汞大气模型，并将进行广泛的校准和观测评估。GEOS-Chem包括大气层与表层海洋和陆地储层的动力耦合。汞（0）在大气中氧化成汞（II），促使汞（II）沉积，主要是溴（Br）原子。将利用最近的飞机和卫星观测结果对北极溴化学的模型表示进行测试和改进。在这项研究的所有阶段，将利用大量大气观测资料对模型的不同组成部分以及耦合模型进行详细评估，该项目将首次对北极大气汞动态进行耦合模拟，并在现有的全球测地系统-化学模型中纳入海洋和陆地组成部分。这可以成为一个强有力的工具，将人为排放和气候变化与北极的生物汞浓度联系起来，其坚实的物理基础将使其成为检验北极汞循环和生物累积的不同假设的基本工具。使用该模型进行的敏感性分析将确定最不确定的领域，并有助于指导未来的研究。这项工作将使科学家和决策者能够更好地评估旨在保护北极环境的政策决定的影响。