NGEE Arctic
Next-Generation Ecosystem Experiments
Advancing the predictive power of Earth system models through understanding
of the structure and function of Arctic terrestrial ecosystems
Permafrost promotes shallow groundwater flow and warmer headwater streams
Permafrost promotes shallow groundwater flow and warmer headwater streams
September 13th, 2021
Model-data integration with international partner highlights how thawing permafrost can impact conditions of water discharged to near-by streams.
The Objective:
Use a fully-coupled cryohydrology model (i.e., ATS) to investigate if permafrost thaw could impact flow path depth and possibly influence the temperature of groundwater discharging from hillslopes to streams.
New Science:
The ATS model simulates saturated, unsaturated, and surface flow and energy, and snow processes, for hillslope cases with various permafrost extent.
The Impact:
Hillslopes with continuous permafrost have more shallow flow paths than hillslopes with no permafrost.
The deeper flow paths in permafrost-free simulations buffer seasonal temperature extremes, so that summer groundwater discharge temperatures are highest with continuous permafrost.
Flow path changes will have important effects on water temperature and chemistry and potentially impact fish populations in headwater streams.
Lateral groundwater flux through each soil layer for (a) the permafrost-free, (b) discontinuous permafrost, and (c) continuous permafrost cases.