Stochastic Modelling of Thermokarst Lakes

Thermokarst lakes are widespread and dynamic features of ice-rich permafrost landscapes. They accelerate permafrost thaw, enhance methane production, and alter soil hydrology as well as energy and water exchanges between land and atmosphere. These effects can alter local and global climate. But despite their important role in the climate sysem, thermokarst lakes are largely absent from Earth system models (ESMs), because deterministic and physics-based modelling approaches require extensive high-resolution ground-ice data that are not available. To close this gap, we develop a probabilistic modeling framework that represents lake dynamics as stochastic processes and can be parameterized using remote sensing data. The model has the potential to provide evolving Arctic water-area fractions and lake-size distributions that can be coupled to ESMs, improving the representation of permafrost dynamics and high-latitude carbon emissions under climate change.