Complex Vulnerabilities of the Water and Aquatic Carbon Cycles to Permafrost Thaw

The spatial distribution and depth of permafrost are changing in response to warming landscape disturbance across northern Arctic boreal regions. This alters the infiltration, flow, surface subsurface distribution, hydrologic connectivity inland waters. Such changes water cycle consequently alter source, transport, biogeochemical cycling aquatic carbon (C), its role production emission greenhouse gases, C delivery waters Ocean. Responses thaw heterogeneous landscapes will be neither spatially uniform nor synchronous, thus giving rise expressions low medium confidence predicting despite very high projections widespread near-surface disappearance as described 2019 Intergovernmental Panel on Climate Change Special Report Ocean Cryosphere a Changing Climate: Polar Regions. Here, we describe state science regarding mechanisms factors that influence responses thaw. Through synthesis recent topical field modeling studies evaluation influential characteristics, present framework for assessing vulnerabilities specific modes affecting local regional hydrology biogeochemistry transport. Lastly, discuss scaling challenges relevant model prediction these impacts landscapes.