Report for methane monitoring in Arctic Lakes in Northwest Territories, Canada, August 2015|甲烷监测数据集|北极环境数据集

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 ninemonth
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.