August 14, 2023
Arctic Permafrost
Leading the way to improved understanding and communication of fundamental and cutting-edge findings on Arctic permafrost.
The mean annual ground temperature at the top of the permafrost for the Northern Hemisphere at 1 km spatial resolution. The boundary between colored and noncolored areas indicates the 0°C isotherm.
[Reprinted with permission from Boike, J., et al. 2023. "Arctic Permafrost." In: Encyclopedia of Soils in the Environment (Second Edition), 410–18. Elsevier Academic Press, Oxford. DOI:10.1016/B978-0-12-822974-3.00141-5. Adapted from Obu, J., et al. 2019. "Northern Hemisphere Permafrost Map Based on TTOP Modelling for 2000–2016 at 1 km2 Scale." Earth-Science Reviews 193, 299–316. DOI:10.1594/PANGAEA.888600.]
The Science
Permafrost is an important component of the Earth’s cryosphere. It plays a key role in the global carbon cycle, as well as ecosystems and infrastructure in Arctic and sub-Arctic climate zones. Borehole measurements show Arctic permafrost has been warming during the early 21st century. Earth system model simulations demonstrate that carbon release from degrading permafrost due to climate warming represents an important global feedback on climate change. This chapter describes fundamental and cutting-edge findings on permafrost research for constituents, cryo-pedogenetic processes, hydrology, energy, and water balances, as well as snow-vegetation feedbacks and gas transport in permafrost regions.
The Impact
Understanding recent advances in permafrost and its change is vital as permafrost exerts controls on land surface energy, water, and carbon balances across the global climate system. The hydrology of permafrost-affected soils is complex due to seasonal freezing and thawing of the active layer. Snow cover and vegetation exert important controls on energy and water balances of permafrost-affected soils and fluxes. Thawing of ground-ice-rich permafrost leads to subsidence, often with irreversible changes in landscape topography, hydrology, and carbon cycling. As the Arctic warms, permafrost thawing is expected to increase the production and release of carbon dioxide and methane, resulting in potentially deleterious effects worldwide.
Summary
Permafrost encompasses ground (soil, sediments, rocks) that remains at or below 0°C for at least 2 consecutive years. This overview of recent science of global permafrost systems considers the constituents of permafrost (minerals, organic matter, water, ice, and gas) and the presence and importance of ice leading to patterned ground formation. The chapter discusses permafrost degradation and its effects on Arctic energy, water, and carbon balances.
Principal Investigator
Katrina Bennett
Los Alamos National Laboratory
[email protected]
Program Manager
Daniel Stover
U.S. Department of Energy, Biological and Environmental Research (SC-33)
Environmental System Science
[email protected]
Funding
This research was supported by the Biological and Environmental Research program in the U.S. Department of Energy’s Office of Science as a contribution to the Next-Generation Ecosystem Experiments Arctic project.
References
Boike, J., et al. Arctic Permafrost. In: Encyclopedia of Soils in the Environment (Second Edition), 410–18. 2023. Elsevier Academic Press, Oxford.