COLLABORATIVE RESEARCH: INVESTIGATING HYDROLOGY-DRIVEN MODELS FOR METHANE CYCLING IN NORTHERN PEATLANDS

合作研究：研究北部泥炭地水文驱动的甲烷循环模型

• 批准号: 1044953
• 负责人: Xavier Comas
• 金额: $ 9.04万
• 依托单位: Florida Atlantic University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-03-01 至 2014-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1044953&HistoricalAwards=false
• 关键词: COLLABORATIVE; RESEARCH; INVESTIGATING; HYDROLOGY; DRIVEN

A major contributor to the current uncertainty regarding how carbon cycling in peatlands will respond to climate warming is the incomplete understanding of the production, storage and emission of free phase gas (FPG), a previously under-appreciated source of methane and carbon dioxide emissions to the atmosphere. It is increasingly clear that FPG production, storage and emission are regulated by hydraulic forcing, as well as the mechanical properties of the peat, i.e. that the carbon and water cycles in a peatland are intimately connected. The focus of this project is field-scale hydrological and hydrogeophysical research to further investigate the importance of recently invoked ?shallow? versus ?deep? peat models for the production, storage and emission of FPG in northern peatlands. Specific objectives of the project include [1] quantifying vertical variations in storage and release of methane with depth over a minimum six month time period at each of three locations within a peatland, [2] determining the hydrological forcing mechanisms that drive releases from both deep and shallow gas, [3] estimating spatial variations in storage and release as a function of subsurface heterogeneity, and [4] quantifying relative contributions of shallow versus deep gas to methane emissions from a northern peatland. This research will be conducted by coupling hydrogeological methods with novel chamber, geophysical and geodetic sensing technologies sensitive to FPG production, storage and emissions. The field site is Caribou Bog, a well-studied multi-unit peatland complex in central Maine. Empirical predictive models and simple mechanistic models will be developed to assess the relative importance of key forcing mechanisms on FPG emissions. Time-frequency analysis of time-series datasets will also be employed to improve understanding of likely forcing components regulating production, storage and release of FPG. This research will significantly advance our understanding of hydrological controls on FPG dynamics in northern peatlands, with important implications for the response of peatland carbon dynamics to climate change.Northern peatlands globally cover more than 350 million ha and contain about one third of the terrestrially stored carbon. The fate of this carbon in response to continued climate warming is highly uncertain. Peatlands are also a source of atmospheric methane, a potent greenhouse gas that contributes to climate warming. This research will provide fundamental scientific knowledge needed to advance the understanding of the cycling of methane in peatlands, and how peatland hydrology controls the emission of methane from peatlands to the atmosphere. The work has direct societal relevance given the concerns about the environmental and economical affects of climate warming. In this project, Lois Stokes Alliance for Minority Participation undergraduate students will be exposed to a hands-on interdisciplinary research among three institutions. Furthermore, an international community of graduate students will participate in a student-focused session on methane cycling in northern peatlands at American Geophysical Union meetings. Community outreach in the vicinity of the Caribou Bog will occur via annual guided tours using the Orono Bog Boardwalk that served +30,000 visitors in 2009.

目前关于泥炭地碳循环如何应对气候变暖的不确定性的一个主要因素是对自由相气体（FPG）的生产、储存和排放的不完全了解，这是一种以前被低估的甲烷和二氧化碳排放源。气氛。越来越明显的是，FPG 的生产、储存和排放受到水力作用以及泥炭机械特性的调节，即泥炭地中的碳和水循环密切相关。该项目的重点是现场规模的水文和水文地球物理研究，以进一步调查最近引用的“浅层”的重要性。与？深？北部泥炭地 FPG 生产、储存和排放的泥炭模型。该项目的具体目标包括 [1] 量化泥炭地内三个地点在至少六个月时间内甲烷储存和释放随深度的垂直变化，[2] 确定驱动深层甲烷释放的水文强迫机制和浅层天然气，[3]估计储存和释放的空间变化作为地下异质性的函数，以及[4]量化浅层与深层天然气对北部泥炭地甲烷排放的相对贡献。这项研究将通过将水文地质方法与对 FPG 生产、储存和排放敏感的新型室、地球物理和大地测量传感技术相结合来进行。现场地点是驯鹿沼泽（Caribou Bog），这是缅因州中部一个经过充分研究的多单元泥炭地综合体。将开发经验预测模型和简单的机械模型来评估关键强迫机制对 FPG 排放的相对重要性。时间序列数据集的时频分析也将用于增进对调节 FPG 生产、储存和释放的可能强迫成分的理解。这项研究将显着增进我们对北部泥炭地 FPG 动态水文控制的理解，对于泥炭地碳动态对气候变化的响应具有重要意义。 北部泥炭地全球面积超过 3.5 亿公顷，包含约三分之一的陆地碳储存量。这些碳因气候持续变暖而产生的命运高度不确定。泥炭地也是大气中甲烷的来源，这是一种导致气候变暖的强效温室气体。这项研究将提供必要的基础科学知识，以促进对泥炭地甲烷循环以及泥炭地水文学如何控制甲烷从泥炭地向大气的排放的理解。鉴于人们对气候变暖对环境和经济影响的担忧，这项工作具有直接的社会意义。在这个项目中，路易斯·斯托克斯少数族裔参与联盟的本科生将接触到三个机构之间的跨学科实践研究。此外，国际研究生社区将在美国地球物理联盟会议上参加以学生为中心的关于北部泥炭地甲烷循环的会议。 Caribou Bog 附近的社区外展活动将通过奥罗诺沼泽木板路 (Orono Bog Boardwalk) 进行年度导游活动，2009 年为超过 30,000 名游客提供服务。