Collaborative Research: Impacts of Global Change on Terrestrial Mercury in the Arctic

合作研究：全球变化对北极陆地汞的影响

• 批准号: 2210173
• 负责人: Elsie Sunderland
• 金额: $ 57.89万
• 依托单位: Harvard University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-01 至 2025-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2210173&HistoricalAwards=false
• 关键词: Collaborative; Research; Impacts; Global; Change

Northern hemisphere permafrost contains a large amount of mercury (Hg) bound to frozen organic matter. The Arctic is warming at two to three times the global average rate. As permafrost thaws, microbial decay of the organic matter will resume, releasing mercury into the environment. The scientific community lacks the process-based terrestrial mercury models needed to understand the impacts of permafrost thaw on the Arctic and global mercury cycles. This project will build such models by leveraging existing models of the terrestrial carbon cycle to advance our understanding of terrestrial mercury processes in permafrost regions at multiple temporal and spatial scales. The project will use these models to predict the pan-Arctic and global impacts of Hg released from thawing permafrost. For the first time, this project will reveal the emergent behavior of two linked components of the Arctic system: the carbon and mercury cycles.This project will leverage and enhance existing models to evaluate how Hg from thawing permafrost will influence the Arctic and global Hg cycles. The project has two objectives: 1) Quantify how different environmental conditions affect Hg accumulation with associated uncertainties; and 2) Quantify how Hg released from thawing permafrost impacts the global Hg cycle with associated uncertainties. This project uses three models of the terrestrial Hg cycle: 1) the full-physics Simple Biosphere Carnegie-Ames-Stanford Approach (SiBCASA) model; 2) the Global Terrestrial Mercury Model (GTMM) coupled to 3-D atmospheric transport and ocean circulation models; and 3) a simple Global Biogeochemical Box Model (GBBM). Simulations from 1400 to 2300 CE using SiBCASA will provide estimates of future Hg releases from thawing permafrost. Simulations with GTMM will quantify global impacts of Hg released from thawing permafrost. Monte Carlo simulations with GBBM will quantify uncertainty. These models require enhancement based on the latest knowledge of Hg uptake and release pathways. These enhancements include new biogeochemical pools such as soil water, new processes such as fire, and new computational techniques such as Monte Carlo simulations. The Broader Impacts of this project include the mentoring of early-career researchers, the organization of a training workshop to bridge the Hg and carbon research communities, and the production of publicly available products, which include an updated Hg emissions dataset, the models themselves, output from the models, and an on-line tool to visualize the model results. This project leverages extensive knowledge of terrestrial carbon pathways to parameterize Hg pathways and couple the terrestrial Hg and carbon cycles.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.

北方永久冻土中含有大量的汞（Hg），这些汞与冻结的有机物结合在一起。 北极正在以全球平均速度的两到三倍变暖。 随着永冻层融化，有机物的微生物腐烂将恢复，汞释放到环境中。 科学界缺乏了解永久冻土融化对北极和全球汞循环影响所需的基于过程的陆地汞模型。 该项目将通过利用现有的陆地碳循环模型来建立此类模型，以促进我们在多个时间和空间尺度上对永久冻土区陆地汞过程的理解。 该项目将利用这些模型预测永冻层融化释放的汞对泛北极和全球的影响。 该项目将首次揭示北极系统中两个相互关联的组成部分----碳循环和汞循环----的紧急行为，并将利用和加强现有模型，评估永冻层融化产生的汞如何影响北极和全球汞循环。该项目有两个目标：1）量化不同的环境条件如何影响汞的积累，并伴有相关的不确定性; 2）量化永冻层融化释放的汞如何影响全球汞循环，并伴有相关的不确定性。 该项目使用了三个陆地汞循环模型：1）全物理学简单生物圈生物-埃姆斯-斯坦福大学方法（SiBCASA）模型; 2）结合三维大气迁移和海洋环流模型的全球陆地汞模型; 3）简单的全球生物地球化学箱模型（GBBM）。 使用SiBCASA进行的公元1400年至2300年的模拟将提供对永久冻土融化后汞释放的估计。 GTMM的模拟将量化永久冻土融化释放的汞的全球影响。 使用GBBM的Monte Carlo模拟将量化不确定性。 这些模型需要根据汞吸收和释放途径的最新知识加以改进。这些增强包括新的地球化学池，如土壤水，新的过程，如火灾，和新的计算技术，如蒙特卡罗模拟。 该项目的“更广泛影响”包括指导早期职业研究人员，组织培训讲习班以沟通汞和碳研究界，以及制作公开产品，其中包括更新的汞排放数据集、模型本身、模型输出以及模型结果可视化在线工具。该项目利用对陆地碳路径的广泛了解，对汞路径进行参数化，并将陆地汞和碳循环结合起来，该奖项反映了国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。