Collaborative Research: P2C2: Contributions of northern cold-climate peatlands and lakes to abrupt changes in atmospheric methane during the last deglaciation

合作研究：P2C2：北部寒冷气候泥炭地和湖泊对末次冰消期大气甲烷突变的贡献

• 批准号: 1304823
• 负责人: Katey Walter Anthony
• 金额: $ 45.98万
• 依托单位: University of Alaska Fairbanks Campus
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-06-01 至 2018-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1304823&HistoricalAwards=false
• 关键词: Collaborative; Research; P2C2; Contributions; northern

The proposed research integrates studies in a range of disciplines (paleoecology, climate, biogeochemistry, geomorphology, geology) to understand the timing, magnitude, and overall contribution of northern cold-climate peatlands and lakes to rapid increases in atmospheric methane (CH4) concentrations (AMC) during the last deglaciation. The study will use comprehensive paleoecological records of northern peatland and lake development to document their past spatial and temporal patterns of CH4 emission. This will enable better prediction of future emissions from northern ecosystems, particularly as surface permafrost thaws under scenarios of climate warming. Specifically, the PIs propose to: (1) Synthesize new and existing peatland, thermokarst-lake, kettle-lake and other post-glacial lake initiation data, as well as compiling such data from regions that no longer support peatlands or permafrost, such as on formerly exposed continental shelf and along southern margins of ice sheets, to gain knowledge of timing of these AMC sources during the last deglaciation; (2) analyze new and existing peat macrofossil data to estimate past CH4 flux from northern high latitude peatland regions as they evolved from high- CH4 emitting fens to lower- CH4 emitting bogs during the Holocene; (3) use novel stable isotope approaches and 14C dating to constrain the magnitude and timing of permafrost-derived hydrogen and carbon in CH4 from northern peatlands and lakes that formed when ground ice melted; and (4) compare their bottom-up reconstructions of past CH4 emissions and their isotope values from peatlands and thermokarst lakes with top-down modeling of global atmospheric CH4 sources based on recent, higher resolution data of interhemispheric CH4 isotope (13C, D, 14C) gradients recorded in Greenland and Antarctic ice cores.Methane is a potent greenhouse gas. Its global warming potential is many times that of carbon dioxide. Therefore, in order to develop scenarios of future climate change, it is important to be able to estimate how much methane will be released to the atmosphere due to permafrost degradation. This project will constrain that number.

该研究整合了一系列学科（古生态学、气候、生物地球化学、地貌学、地质学）的研究，以了解最后一次冰消期间北方寒冷气候泥炭地和湖泊对大气甲烷（CH4）浓度（AMC）快速增加的时间、幅度和总体贡献。该研究将利用北部泥炭地和湖泊发展的综合古生态记录来记录其过去CH4排放的时空格局。这将使我们能够更好地预测北方生态系统未来的排放，特别是在气候变暖的情况下，随着地表永久冻土的融化。具体而言，PIs建议：(1)综合新的和现有的泥炭地、热岩溶湖、壶湖和其他冰期后湖泊形成数据，并汇编来自不再支持泥炭地或永久冻土的地区（如以前暴露的大陆架和冰盖南缘）的数据，以获得这些AMC源在末次冰消期间的时间知识；(2)分析新的和现有的泥炭宏观化石资料，估算全新世北纬高纬度泥炭地由高排放沼泽向低排放沼泽演变过程中的CH4通量；(3)利用新的稳定同位素方法和14C测年技术，对北部泥炭地和湖泊在地下冰融化时形成的永久冻土中CH4中氢和碳的大小和时间进行了限制；(4)将他们对泥炭地和热岩溶湖过去CH4排放及其同位素值的自下而上重建与基于最近在格陵兰和南极冰芯记录的半球间CH4同位素（13C， D, 14C）梯度的更高分辨率数据的自上而下的全球大气CH4源模拟进行比较。甲烷是一种强有力的温室气体。它的全球变暖潜力是二氧化碳的许多倍。因此，为了发展未来气候变化的情景，重要的是能够估计由于永久冻土退化将向大气释放多少甲烷。这个项目将限制这个数字。

项目成果

Spatiotemporal patterns of northern lake formation since the Last Glacial Maximum

• DOI: 10.1016/j.quascirev.2020.106773
• 发表时间: 2021-02
• 期刊: Quaternary Science Reviews
• 影响因子: 4
• 作者: L. Brosius;K. W. Anthony;C. Treat;J. Lenz;Miriam C. Jones;M. Bret-Harte;G. Grosse