Integration of Ground-based and Airborne Measurements Shows Substantial Methane Emissions from Freshwater Ecosystems in the Yukon-Kuskokwim Delta, Alaska

Freshwater ecosystems are known to substantially contribute to the methane budget of arctic and subarctic regions, however small lakes and ponds have generally been overlooked due to difficulties identifying them with satellite imagery because of their small areal extent. Recent pan-arctic and global syntheses show an inverse relationship between dissolved methane and lake surface area, suggesting small ponds and lakes may contribute disproportionately to Arctic methane emissions. The work presented here investigates the relationship between lake surface area and methane emissions, in order to better constrain freshwater methane emissions for the Yukon-Kuskokwim Delta, Alaska. We measured methane flux from 13 lakes and ponds of a range of size classes using floating chambers deployed on each lake for 5-24 h. Additionally, spatial and temporal variations in methane emissions were examined …