Collaborative Research: The East Siberian Arctic Shelf as a Source of Atmospheric Methane: First Approach to Quantitative Assessment

合作研究：东西伯利亚北极陆架作为大气甲烷的来源：定量评估的第一种方法

• 批准号: 1023444
• 负责人: Samantha Joye
• 金额: $ 54.87万
• 依托单位: University of Georgia Research Foundation Inc
• 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: 2010-09-01 至 2015-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1023444&HistoricalAwards=false
• 关键词: Collaborative; Research; East; Siberian; Arctic

Six investigators from three institutions propose to study methane release over the East Siberian Arctic shelf (ESAS), the largest (about 10% of the world ocean shelf area) and the shallowest (mean depth less than 50 m) continental shelf of the world ocean. The ESAS stores the world?s largest hydrocarbon stocks, mostly as shallow Arctic hydrates, and thus represents a large potential methane atmospheric source that could result from global warming-triggered permafrost degradation. Increased methane fluxes could occur as numerous weak seeps or as strong bubble plumes over large areas. Due to the shallow depth of the ESAS, it is possible that the majority of methane released avoids oxidation and escapes to the atmosphere. The PIs will investigate the migration pathway characteristics and identify the controlling factors of methane flux from the seabed, in the water column, and to the atmosphere. The central hypothesis is that seabed methane fluxes are significant year-round sources while atmospheric fluxes are only significant during ice-free periods. The questions of methane sources, sinks, spatial and temporal variations in fluxes will be addressed through summer and winter expeditions to sample the water column and seabed, and helicopter surveys to sample the atmosphere. The PIs will also assess seafloor direct bubble flux over 6 control and 2 test sites on a nested range of sonar scales and using a combination of bubble video imaging and bubble modeling. Modeling will aim to develop a regional flux model. Broader impacts of the proposed activity include international collaboration, graduate and undergraduate student training, and public outreach.

来自三个机构的六名研究人员提议研究东西伯利亚北极大陆架(ESAS)上的甲烷释放。东西伯利亚北极大陆架是世界上最大的大陆架(约占世界海洋大陆架面积的10%)和最浅的大陆架(平均深度不到50m)。ESAS储存了世界上最大的碳氢化合物储量，主要是北极浅层水合物，因此代表着一个巨大的潜在甲烷大气来源，可能是全球变暖引发的永久冻土退化造成的。甲烷通量的增加可能发生在大量弱渗漏或大范围强气泡羽流的情况下。由于ESAS的深度较浅，可能释放出的大部分甲烷避免了氧化并逃逸到大气中。PIS将研究甲烷从海底、水柱和大气中迁移的路径特征，并确定甲烷通量的控制因素。中心假设是，海底甲烷通量是全年的重要来源，而大气通量只有在无冰期间才是重要的。甲烷源、汇、通量的时空变化问题将通过夏季和冬季对水柱和海床采样的探险以及对大气采样的直升机调查来解决。PIS还将评估6个控制点和2个测试点的海底直接气泡通量，使用气泡视频成像和气泡建模相结合的方式，在声纳尺度的嵌套范围内。建模的目的将是开发一个区域通量模型。拟议活动的更广泛影响包括国际合作、研究生和本科生培训以及公众宣传。