Collaborative Research: Investigating the Rate of Potential Biological in Situ Gas Production of CO and CH4 in Arctic Ice

合作研究：研究北极冰中 CO 和 CH4 的潜在生物原位产气率

• 批准号: 2139295
• 负责人: Edward Brook
• 金额: $ 8.47万
• 依托单位: Oregon State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-03-01 至 2025-02-28
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2139295&HistoricalAwards=false
• 关键词: Collaborative; Research; Investigating; Rate; Potential

Atmospheric gas records developed from polar ice cores are cornerstones of climate change science. The overarching goal of this project is to develop and apply new understanding of high-time-resolution Arctic records of methane and carbon monoxide. Methane is a powerful greenhouse gas and carbon monoxide is linked to the atmospheric lifetime of other greenhouse gases including carbon dioxide. Thus, developing reliable records of both gases is important for understanding past and future atmospheric chemistry and radiative forcing. High-depth-resolution records of carbon monoxide, and to a lesser extent methane, in Arctic ice cores show evidence of non-atmospheric anomalies that are poorly understood. One potential source of such anomalies is biological activity within the ice. Microbes can be active at temperatures well below freezing, and ice cores are subjected to relatively warm temperatures after the ice is extracted from glaciers and ice sheets while they are stored or transported prior to measurement. Special sample handling protocols will be used to evaluate the effects of post-collection ice temperature on methane and carbon monoxide production, and potentially allow development of methane and carbon monoxide records over recent centuries that are free from any artifacts. Funding will support early career investigators, graduate students and undergraduate students who will be involved in field work, laboratory analysis, and data interpretation. The investigators will involve undergraduates from underrepresented groups to foster diversity in earth sciences. Public outreach will be achieved through public lectures, lab tours, and media interactions. The specific goals of this project are to (1) investigate the rate and timing of temperature-dependent in situ biological production of carbon monoxide and methane in an Arctic ice core, (2) develop records of atmospheric carbon monoxide and methane spanning recent centuries that are free of in situ production artifacts, and (3) determine the roles that ice impurity concentration and microbial community structure play in situ gas production. To accomplish these goals, a 150-meter ice core will be collected at Summit, Greenland using the large-diameter Blue Ice Drill. To address goal (1), successive measurements of carbon monoxide and methane will be made in the field on eight parallel longitudinal samples from a 12 meter-long section of the core, with the different samples consistently stored and monitored at temperatures ranging from well below the -31 °C ice sheet temperature at Summit to well above the -26 °C cell vitrification temperature where cellular metabolism is possible. For goal (2), measurements of these two gases will be made in the field on ice that has been kept consistently at -40 °C after extraction. For goal (3), a portion of the entire ice core will be returned to the U.S. for microbial analyses, measurements of a range of elements and chemical species using a well-established, NSF-funded continuous ice core analytical system, and continuous carbon monoxide and methane measurements to complement the field measurements. Microbiological analysis will be conducted on ice samples characterized by high and low in situ gas anomalies to determine what microbes are present that may be responsible for creating the observed gas artifacts.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

从极地冰芯开发的大气气体记录是气候变化科学的基石，该项目的总体目标是开发和应用对甲烷和一氧化碳的高时间分辨率北极记录的新认识，甲烷是一种强大的温室气体和碳。一氧化碳与包括二氧化碳在内的其他温室气体的大气寿命有关，因此，开发这两种气体的可靠记录对于了解过去和未来的大气化学和碳的高深度分辨率记录非常重要。北极冰芯中的一氧化碳，以及较小程度的甲烷，显示了人们知之甚少的非大气异常的证据，这种异常的一个潜在来源是冰内的微生物在远低于冰点的温度下可能活跃。从冰川和冰盖中提取冰后，在测量之前储存或运输冰时，岩心会受到相对温暖的温度。将使用特殊的样品处理协议来评估收集后的冰温度对甲烷和碳的影响。一氧化碳生产，并有可能允许开发近几个世纪以来没有任何人工制品的甲烷和一氧化碳记录。资金将​​支持参与现场工作、实验室分析和数据解释的早期职业研究人员、研究生和本科生。研究人员将让代表性不足的群体的本科生参与进来，以通过公开讲座、实验室参观和媒体互动来促进公众宣传。该项目的具体目标是（1）调查温度变化的速率和时间。依赖原位生物学北极冰芯中一氧化碳和甲烷的产生，(2) 开发近几个世纪以来大气一氧化碳和甲烷的记录，这些记录没有原位生产伪影，(3) 确定冰杂质浓度和微生物群落结构的作用为了实现这些目标，将使用大直径蓝冰钻机在格陵兰萨米特收集 150 米的冰芯，以实现目标 (1)，连续测量一氧化碳和二氧化碳。甲烷将在现场从岩心 12 米长部分的八个平行纵向样本中提取，不同样本的存储和监测温度范围从远低于 Summit 冰盖温度到远高于 -31 °C 冰盖温度对于目标 (2)，将在提取后始终保持在 -40°C 的冰上进行这两种气体的测量。整个冰的冰芯将返回美国进行微生物分析，使用国家科学基金会资助的完善的连续冰芯分析系统测量一系列元素和化学物质，并进行连续一氧化碳和甲烷测量以补充微生物分析。将在具有高和低原位气体异常特征的冰样本上进行，以确定存在哪些微生物可能导致观察到的气体伪影。该奖项反映了 NSF 的法定使命，并被认为值得通过以下方式获得支持：使用基金会的智力价值和更广泛的影响审查标准进行评估。