Effects of long-term climate trends on the methane and CO2 exchange processes of Toolik Lake, Alaska ...

• Main Authors: Eugster, Werner, DelSontro, Tonya, Laundre, James A., Dobkowski, Jason, Shaver, Gaius R., Kling, George W.
• Format: Article in Journal/Newspaper
• Language: English
• Published: ETH Zurich 2022
• Subjects: Toolik Lake; long-term ecological research; LTER; methane flux; carbon dioxide flux; piston velocity; arctic trends; quantile regression; Arctic; permafrost; Alaska
• Online Access: https://dx.doi.org/10.3929/ethz-b-000571096; http://hdl.handle.net/20.500.11850/571096

Methane and carbon dioxide effluxes from aquatic systems in the Arctic will affect and likely amplify global change. As permafrost thaws in a warming world, more dissolved organic carbon (DOC) and greenhouse gases are produced and move from soils to surface waters where the DOC can be oxidized to CO2 and also released to the atmosphere. Our main study objective is to measure the release of carbon to the atmosphere via effluxes of methane (CH4) and carbon dioxide (CO2) from Toolik Lake, a deep, dimictic, low-arctic lake in northern Alaska. By combining direct eddy covariance flux measurements with continuous gas pressure measurements in the lake surface waters, we quantified the k600 piston velocity that controls gas flux across the air–water interface. Our measured k values for CH4 and CO2 were substantially above predictions from several models at low to moderate wind speeds, and only converged on model predictions at the highest wind speeds. We attribute this higher flux at low wind speeds to effects on ... : Frontiers in Environmental Science, 10 ...