Collaborative Research: RAPID: Quantifying and characterizing the origin of Arctic Ocean methane from the Alaska continental shelf to the North Pole

合作研究：RAPID：量化和表征从阿拉斯加大陆架到北极的北冰洋甲烷的来源

• 批准号: 2226223
• 负责人: Cédric Magen
• 金额: $ 10.44万
• 依托单位: University of Maryland, College Park
• 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: 2022-06-01 至 2025-05-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2226223&HistoricalAwards=false
• 关键词: Collaborative; Research; RAPID; Quantifying; characterizing

Methane is relatively rare in Earth’s atmosphere but plays a significant role in the global carbon cycle and climate change. It is therefore key to better understand the distribution and behavior of natural sources of methane emissions and how both may change in an evolving climate. In the Arctic, large reservoirs of methane are currently trapped as permafrost (frozen soil) or gas hydrates (an ice-like substance that contains methane in its structure) on Arctic Ocean continental shelves. As the Arctic warms, permafrost and gas hydrates may degrade, releasing more methane to the atmosphere. This project, part of the United States’ contribution to the international Synoptic Arctic Survey (SAS), is determining whether rates of Arctic methane release from those natural sources are being affected by the present warming by measuring methane in Arctic Ocean from northern Alaska to the North Pole. The team is focusing especially on how much methane released from the seafloor reaches the water surface and adds to atmospheric methane. The team is sharing methane data and other results with the larger US SAS effort and teaching community college students about seagoing research methods and climate change. This project is testing the hypothesis that a warming Arctic Ocean may have accelerated the release of methane from permafrost and gas hydrate dissociation in shelf and slope sediments. The research team is measuring water column dissolved methane concentrations and stable isotopologues, as well as continuous measurements of methane in air underway along a transect from the Alaska Shelf northward. The team members are investigating the sources and processes controlling the presence of methane using methane 13C and 2H stable isotopes. Clumped isotopes of methane in air are being analyzed on selected samples identified as possible methane endmembers in the Arctic system. The project is a US contribution to the international Synoptic Arctic Survey (SAS) and is providing a baseline for measurements in the future of Arctic conditions. The measurement of the stable isotope 2H-CH4 in the Arctic Basin is the first performed in deep Arctic waters and is greatly improving our understanding of the Arctic methane cycle.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.

甲烷在地球大气中相对罕见，但在全球碳循环和气候变化中发挥着重要作用。因此，更好地了解甲烷排放的自然来源的分布和行为以及两者在不断变化的气候中如何变化是关键。在北极，大量的甲烷储存目前被困在北冰洋大陆架的永久冻土（冻土）或天然气水合物（一种结构中含有甲烷的冰状物质）中。随着北极变暖，永久冻土和天然气水合物可能会降解，向大气中释放更多的甲烷。该项目是美国对国际北极天气调查的贡献的一部分，通过测量从北方阿拉斯加到北极的北冰洋的甲烷，确定这些自然来源的北极甲烷释放率是否受到目前变暖的影响。该团队特别关注从海底释放的甲烷有多少到达水面并增加了大气甲烷。该团队正在与更大的美国SAS项目分享甲烷数据和其他结果，并向社区大学生传授航海研究方法和气候变化。该项目正在检验一种假设，即北冰洋变暖可能加速了永久冻土中甲烷的释放以及陆架和斜坡沉积物中气体水合物的分解。该研究小组正在测量水柱溶解甲烷浓度和稳定同位素，以及沿着沿着阿拉斯加大陆架向北的一个横断面进行的空气中甲烷的连续测量。研究小组成员正在使用甲烷13 C和2 H稳定同位素研究控制甲烷存在的来源和过程。正在对选定的被确定为北极系统中可能的甲烷端元的样本进行空气中甲烷的成团同位素分析。该项目是美国对国际天气北极调查（SAS）的贡献，并为未来北极条件的测量提供基线。在北极盆地对稳定同位素2 H-CH 4的测量是首次在北极深层沃茨进行的测量，极大地提高了我们对北极甲烷循环的理解。该奖项反映了NSF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。