Mackenzie Delta thermogenic methane distribution, sources, drivers

相对于土壤、湿地和退化的永久冻土中甲烷的地表生物生产，甲烷的地质渗漏还不太清楚。我们知道，大量的甲烷是由自然地质渗漏、泄油气藏或地下天然气水合物排放的。在过去的二十年里，来自省级和联邦科学家的零星研究已经在麦肯齐三角洲发现了巨大的自然渗漏。新的飞机研究表明，地质渗漏热点是控制景观排放的主要因素，而麦肯齐三角洲的水体来源并不是大多数全球陆地表面模型所期望的热点。这使得基于地质的估计与在北极其他地方工作的生态系统科学家的发现之间产生了令人不安的摩擦，他们得出的结论是，气温变暖和活跃层加深导致了甲烷产量的增加，这在很大程度上来自水体。麦肯齐三角洲的甲烷地质排放是否像新研究表明的那样多？这种情况是否也会发生在其他地方？我们是否需要修改研究北极甲烷的方法？******我提出的研究旨在了解地质甲烷分布，来源和驱动因素在麦肯齐三角洲。这项研究将集中于在景观尺度上收集数据，因为争论本质上是关于资源的景观分布。该研究将包括研究生、本科生和研究助理，以及专门研究麦肯齐三角洲甲烷及相关问题（永久冻土退化、石油系统、地球化学、测量工具）的学术、政府和行业合作者。为了确定排放热点，我们将应用景观尺度（100公里）地球化学测量工具，并结合卫星数据。在这些地区，我们将对来源和地球化学进行详细调查，努力了解当地分布、相对速率和地质渗漏和地表生物活动的驱动因素。这项研究是我在油气示踪剂研究、寒冷地区生物土壤气研究（包括最近在麦肯齐三角洲的工作）以及我对景观尺度气体测量方法的浓厚兴趣方面的经验的自然延伸，这些研究将首次在一个项目中结合在一起。******这项跨学科工作的结果将对大气科学家、气候建模者、永久冻土科学家和对石油系统和长期碳循环感兴趣的地质学家有用。由于对识别生物甲烷也有一些关注，因此有可能将这项工作与永久冻土融化和有机物分解、有机负载的水文系统产生的甲烷以及景观变化（由融化引起的滑坡、滑坡）联系起来。这项研究也是为了连接NASA北极寒带脆弱性实验（上图），我在其中扮演了一个持续的角色

Relative to surface biologic production of methane from soils, wetlands, and degrading permafrost, geologic seeps of methane are less well understood. We know that a large amount of methane is emitted from natural geologic seepage, venting oil and gas reservoirs or subsurface gas hydrates. Sporadic studies over the past two decades from provincial and federal scientists have identified huge natural seeps in the Mackenzie Delta. New aircraft studies suggest that geological seepage hotspots are a dominant control on landscape emissions, and that water body sources in the Mackenzie Delta were not the hotspots most global land surface models would expect. This leaves an uncomfortable friction between geologically-based estimates, and the findings of ecosystem scientists working elsewhere in the Arctic who conclude that warming temperatures and a deepening active layer drives increased methane production in large part from water bodies. Are geological emissions of methane in the Mackenzie Delta as prolific as new studies suggest? Could this be happening elsewhere, and do we need to revise our approach to studying Arctic methane?******My proposed research aims to understand geological methane distribution, sources, and drivers in the Mackenzie Delta. The research will focus on collecting data at landscape scales, since the debates are inherently about landscape distribution of sources. The research will involve a mixture of graduate students, undergraduates, and research associates, working alongside identified academic, government, and industry collaborators specialized in Mackenzie Delta methane and related issues (permafrost degradation, petroleum systems, geochemistry, measurement tools). To identify emission hotspots, we will apply landscape-scale (100s km) geochemical survey tools, in combination with satellite data. Within these areas we will undertake detailed investigations of sources and geochemistry, in an effort to understand local distribution, relative rates, and drivers of geological seeps and surface biogenic activity. This research is a natural extension of my experience in oil and gas tracer studies, cold-regions biogenic soil gas studies (including recent work in the Mackenzie Delta), and my keen interest in landscape-scale gas measurement methodologies, which for the first time will come together in a single project.******The results of this interdisciplinary work will be useful for atmospheric scientists, climate modelers, permafrost soil scientists, and geologists interested in petroleum systems and the long-term carbon cycle. Because there is also some focus on identifying biogenic methane, there is the possibility to link this work to permafrost thaw and decomposition of organics, methane from organic-loaded hydrologic systems, and landscape change (thaw-driven landslides, slumps). This research is also designed to connect with the NASA Arctic Boreal Vulnerability Experiment (ABoVE), in which I play a continuing role.**