Collaborative Research: An Interdisciplinary Investigation of Groundwater-Carbon Coupling in Large Peat Basins and its Relation to Climate Change

合作研究：大型泥炭盆地地下水-碳耦合及其与气候变化关系的跨学科研究

• 批准号: 0628349
• 负责人: Jeffrey Chanton
• 金额: $ 49.34万
• 依托单位: Florida State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-02-01 至 2013-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0628349&HistoricalAwards=false
• 关键词: Collaborative; Research; Interdisciplinary; Investigation; Groundwater

Intellectual Merit: The growth of northern peatlands during the Holocene created a globally important source and sink for greenhouse gases. The response of these large carbon reservoirs to Global Warming, however, remains uncertain. Different mathematical models predict that future warming could alter the carbon balance of peatlands by either increasing the rate of carbon sequestration or accelerating the emissions of greenhouse gases. However, these steady-state analytical models make unrealistic assumptions about natural peatlands, which are spatially and temporally variable ecosystems that are still accumulating carbon. This investigation will therefore develop a transient 3D numerical model that couples multiphase groundwater flow to solute transport, organic matter reactivity, and peat accumulation. The need for such a model is supported by our investigations in large peat basins over the past 25 years that demonstrate the close linkages among climate, groundwater, landscape, and peatland carbon fluxes. This new transient groundwater-peat accumulation model will be calibrated by multiple sets of field, lab, and remote sensing data collected at a range of scales. A sensitivity analysis of this calibrated model should then provide reliable predictions for the response of large peat basins to climate change at the regional level.This approach can best be tested in the Glacial Lake Agassiz Peatlands (GLAP) of northern Minnesota where a regional peat basin developed despite the relatively dry climate and periodic droughts. Recent advances in remote sensing, field instrumentation, geophysical exploration, and computational modeling will be used to develop and calibrate a transient coupled groundwater-peat accumulation model for the GLAP region. This interdisciplinary investigation will focus on several important problems including carbon cycling in the deeper peat and the hydraulics of a deformable media. This study will also determine if methane fluxes from large peatlands are dominated by ebullition (i.e., bubbling) from deep overpressured gas pockets representing a globally important and previously unaccounted for source of atmospheric methane. In addition, this investigation will evaluate whether the configuration of the regional river system amplifies the effects of climate change on peatland ecosystems.Broader Impacts: The broader impacts of this study will be extended by 1) training graduate and undergraduate students in a large interdisciplinary investigation, 2) providing outreach to K-12 schools and the general public, 3) developing 3D computer visualization exhibits for state parks and other interpretive centers, and 4) linking our research results to regional and national educational programs organized by Morin. The visualization exhibits will be specifically designed for a new $1.6 million interpretive center at the Big Bog Recreational Area, which was recently established by the State of Minnesota adjacent to our field area. This exhibit will link results from our field measurements to the role of peatlands in the global carbon cycle for the general public. It will continue the long tradition of close cooperation between the GLAP research group and the officials that manage public land in northern Minnesota and elsewhere.

学术成就：全新世期间北方泥炭地的生长创造了全球重要的温室气体源和汇。然而，这些大型碳库对全球变暖的反应仍然不确定。不同的数学模型预测，未来的变暖可能会改变泥炭地的碳平衡，要么增加碳固存的速度，要么加速温室气体的排放。然而，这些稳态分析模型对自然泥炭地做出了不切实际的假设，自然泥炭地是时空可变的生态系统，仍然在积累碳。因此，这项调查将开发一个瞬态三维数值模型，耦合多相地下水流的溶质运移，有机物的反应，泥炭积累。在过去的25年里，我们对大型泥炭盆地的调查表明，气候、地下水、景观和泥炭地碳通量之间存在密切联系，这支持了对这种模型的需求。这个新的瞬态地下水泥炭积累模型将校准多套现场，实验室和遥感数据收集在一个范围内的尺度。这种校准模型的敏感性分析，然后应提供可靠的预测，在区域一级的气候变化的大型泥炭盆地的响应。这种方法可以最好地测试在冰川湖阿加西泥炭地（Gesi）的北方明尼苏达州的区域泥炭盆地发展，尽管相对干燥的气候和周期性干旱。在遥感，现场仪器，地球物理勘探和计算建模的最新进展将被用来开发和校准一个瞬态耦合地下水泥炭蓄积模型的Gestival地区。这项跨学科的研究将集中在几个重要的问题，包括碳循环在更深的泥炭和水力学的变形介质。这项研究还将确定来自大泥炭地的甲烷通量是否以沸腾为主（即，起泡）来自深过压气袋，其代表全球重要的且先前未考虑的大气甲烷源。此外，本次调查还将评估区域河流系统的配置是否放大了气候变化对泥炭地生态系统的影响。这项研究的更广泛的影响将通过以下方式扩大：1）在大型跨学科调查中培训研究生和本科生，2）向K-12学校和公众提供宣传，3）为州立公园和其他解说中心开发3D计算机可视化展品，以及4）将我们的研究成果与Morin组织的区域和国家教育计划联系起来。可视化展品将专门为位于Big Bog Recommendation Area的新的160万美元的解释中心设计，该中心最近由明尼苏达州毗邻我们的实地区域建立。这个展览将把我们的实地测量结果与泥炭地在全球碳循环中的作用联系起来。它将继续保持甘迺迪研究小组与管理明尼苏达州北方和其他地方公共土地的官员之间密切合作的悠久传统。