Collaborative Research: Year-round autonomous sampling of methane in Arctic lakes

研究人员建议在整个北极冬季使用自主采样设备连续测量冰冻湖泊中的甲烷浓度，以更彻底地解决从北极湖泊到大气的甲烷通量的变化。甲烷是一种强有力的温室气体，随着气候变暖，北极地区的甲烷排放量将增加。该项目将在一项成功的试点研究的基础上进行扩展，其中包括自动连续流体采样器和传感器系统的初步测试。拟议的扩大将涉及增加能力，并在加拿大北极地区麦肯齐河三角洲沿南北梯度分布的六个小湖中的每一个湖沿着部署一个取样单位，为期九个月，横跨冬季。有了这些数据，研究人员的目标是表征水柱中的物理，化学和微生物条件，以阐明冬季期间的水文，微生物和风化过程，当甲烷在冰盖下的湖水中积累时。研究人员假设，春季洪水和冰盖破裂后，甲烷的释放（周，天，甚至小时）产生了一个独特的大气通量，从北极湖泊，否则将错过，因为大多数合理的采样发生在夏季，此时这些湖泊中的甲烷浓度很低或低于检测值。土壤和小湖泊，虽然这些估计是基于一些具有很大不确定性的直接观测。这项拟议的研究使用现场取样器和传感器，将能够进行广泛的微生物、气体和离子分析方案，并辅之以物理和化学传感器数据网络，以评估冬季月份的时间条件;确认基本过程和速率;确定微生物、地球化学和物理过程之间的相互作用;并制定一项计划，进行一项更具包容性的研究，利用低成本的代理显着的过程，最好的时间方面的湖泊条件的特点。该项目将通过开发新的现场取样，加强北极未来研究的基础设施。该项目将支持一些本科生和研究生，为来自非研究密集型机构的学生提供宝贵的实验室经验。研究人员还将开展两项非正式的外展活动，向小学生宣传北极气候变化的重要性，同时向他们传授设计和工程知识。他们还打算与加拿大因纽维克的奥罗拉学院和奥罗拉研究所密切合作，让第一民族青年参与进来。

The investigators propose to measure methane concentrations in frozen lakes continuously throughout the Arctic winter using autonomous sampling devices, to more thoroughly address the variability in the methane flux from Arctic lakes to the atmosphere. Methane is a potent greenhouse gas, the release of which from Arctic sources is poised to increase with climate warming. This project will expand upon a successful pilot study that included the initial testing of autonomous continuous fluid sampler and sensor systems. The proposed expansion will involve additional capabilities and the deployment of a sampling unit in each of six small lakes along a north-south gradient in the Mackenzie River delta in the Canadian Arctic for a nine-month period, spanning the winter season. With these data the investigators aim to characterize the physical, chemical, and microbial conditions in the water column to elucidate hydrologic, microbial, and weathering processes during the winter season, when methane builds in lake water under the ice cover. The investigators hypothesize that sudden (week, days, or even hours) releases of methane, following spring flooding and ice cover breakup, produce a distinct atmospheric flux from Arctic lakes that would otherwise be missed, since most logistically reasonable sampling occurs in the summer months when methane concentrations in these lakes are low or below detection.The majority of methane flux to the Arctic atmosphere is estimated to come from soils and small lakes, although these estimates are based on few direct observations with large uncertainties. This proposed study, using in situ samplers and sensors, will allow an extensive microbial, gas and ion analytical program coupled with a network of physical and chemical sensor data to assess temporal conditions during winter months; to confirm fundamental processes and rates; to determine the interplay among microbial, geochemical and physical processes; and to develop a plan for a more inclusive study that takes advantage of low cost proxies for significant processes that best characterize temporal aspects of lake conditions. The project will enhance infrastructure for future research in the Arctic through the development of novel in situ sampling. The project will support several undergraduate and graduate students, providing valuable lab-based experience for students from non-research-intensive institutions. The investigators also will conduct two informal outreach activities to communicate the importance of Arctic climate change to primary school students while also teaching them about design and engineering. They also intend to work closely with Aurora College and Aurora Research Institute based in Inuvik, Canada, to engage First Nations youth.