EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Evaluating empirical models of lake methane emissions and concentrations in hemiboreal and subarctic regions

Jonathan Schenk, Anna Katarzyna Sieczko, David Rudberg, Gustav Pajala, Henrique Oliveira Sawakuchi, and David Bastviken
Jonathan Schenk et al.
  • Department of Thematic Studies – Environmental Change, Linköping University, Linköping, Sweden

Lakes are responsible for substantial emissions of methane (CH4) to the atmosphere globally, but their contribution is poorly constrained and current estimates vary widely. One of the reasons for this large uncertainty lies in the practical challenges involved in collecting CH4 concentration and flux data at the suitable temporal and spatial scales to capture their natural variability. Here, we present the results of an attempt to account for the spatial and temporal variability of CH4 concentrations and fluxes when deriving whole-lake and yearly average values. We used these average values to investigate the main environmental drivers of CH4 concentrations in the surface water of lakes and CH4 emissions from lakes. We made surface water CH4 concentration and CH4 fluxes measurements using headspace equilibration and floating chambers, respectively, in a set of boreal lakes located in different parts of Sweden and with various morphological and biogeochemical properties. Measurements covered different periods of the open-water season at multiple locations covering various depths/distances to shore in each lake. Individual CH4 flux measurements (150-300 measurements per lake) were interpolated based on relationships with local spatial and temporal variables. Relationships between mean open water season CH4 concentrations and emissions, and one to three independent environmental variables were tested as different models. The results suggest that the frequency and spatial coverage of the measurements is critical for identifying reliable quantitative empirical models of CH4 concentrations and emissions from lakes.

How to cite: Schenk, J., Sieczko, A. K., Rudberg, D., Pajala, G., Sawakuchi, H. O., and Bastviken, D.: Evaluating empirical models of lake methane emissions and concentrations in hemiboreal and subarctic regions, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-1794,, 2022.