As northern regions of the world experience warming climate, scientists look to permafrost, a crucial component of arctic and subarctic ecosystems, as a source and sink of atmospheric carbon.
It is well-known that the thawing of permafrost from above as a result of warming climate is a considerable source of greenhouse gases. However, few studies have considered the production of methane, a potent greenhouse gas, beneath the permafrost. A rugged permafrost bottom is proposed to favor the storage of gas in hollow “pockets” that have been formed through permafrost thaw and degradation from below. Methane can migrate from these pockets to thermokarst lake bottoms through advection and diffusion as a dissolved gas and by movement as an immiscible fluid. These transport mechanisms can occur when connections between the sub-permafrost and supra-permafrost pathways form or when changing permafrost morphology opens pathways from the pocket to an open-talik lake.
A variety of sample analyses and numerical models can be used to study these mechanisms in the Goldstream Valley in Fairbanks, Alaska.