Award: PLR-1114485

Methane, a greenhouse gas, contributes to global warming. Methane emissions from the Arctic may be particularly important because the Arctic is a large reservoir for methane. Methane concentrations are very high in Arctic soil, permafrost and groundwater. One way by which methane can be transported to the atmosphere is if groundwater delivers methane to lakes and the coastal ocean. In this study we show that methane-rich groundwater from the seasonally thawed active layer in the Arctic flows into Toolik Lake, and into both the North Pacific (Kasitsna Bay) and Arctic Ocean (Barrow) coastal zones. This may be an important previously unrecognized conduit for methane transport and emissions in the Arctic. The controls on methane input from the active layer are fundamentally different than those affecting methane production within lakes or the coastal ocean water, and the response of these processes to climate and environmental change is also distinct. The accuracy of predictions of methane emissions and ultimately the extent of climate change that can be expected in the Arctic depend on a better understanding of methane dynamics in the region, including the controls over methane production and transport processes within the active layer. Therefore better understanding of the processes affecting methane concentrations in groundwater and their discharge to water bodies is needed. Last Modified: 04/05/2016 Submitted by: Adina Paytan