Sensitivity of pond methane emissions in the Lena River Delta to climate changes in new model MeEP

Permafrost ponds are a steady source of methane. However, it is difficult to assess the sensitivity of pond methane emissions to ongoing warming and climate-change-induced drainage, because pond methane emissions show large temporal and spatial variability already on local scale.
We study this sensitivity on the landscape level with a new process-based model for Methane Emissions from Ponds (MeEP model), which simulates the three main pathways of methane emissions (diffusion, plant-mediated transport and ebullition) as well as the temperature profile of the water column and the surrounding soils. The model was set up for the polygonal tundra in the Lena River Delta. Due to a temporal resolution of one hour, it is capable of capturing the diurnal, day-to-day and seasonal variability in methane fluxes. MeEP also considers one of the main drivers of spatial variability - ground heterogeneity. Depending on where ponds form in the polygonal tundra, they can be classified as ice-wedge, polygonal-centre or merged-polygonal ponds. In MeEP, each of these pond types is simulated separately and the representation of these ponds was informed by dedicated measurements.
The model performance is validated against eddy-covariance measurements of methane fluxes and against in-situ measurements of the aqueous methane concentration, both obtained on Samoylov Island.  We will present results regarding the sensitivity of modeled methane emissions from ponds to warming and drainage on the landscape scale.