Warming and Thawing Permafrost in Alaska


Vladimir E. Romanovsky1* (veromanovsky@alaska.edu), Dmitry J. Nicolsky1, Alexander L. Kholodov1, Louise M. Farquharson1, Thomas C. Wright1, Colleen Iversen2


1University of Alaska–Fairbanks, AK; 2Oak Ridge National Laboratory, Oak Ridge, TN



The impact of climate warming on permafrost and the potential of climate feedbacks resulting from permafrost thawing have recently received a remarkable attention. Climate warming promotes an increase in permafrost temperature and active layer thickness, which in turn affect the stability of northern ecosystems, threaten infrastructure, and cause the release of carbon dioxide and methane into the atmosphere. The timing and rate of permafrost degradation are two of the major factors in determining the anticipated negative impacts of climate warming on the Arctic ecosystems and infrastructure. This project presents the results of almost 40 years of permafrost and active layer temperature observations in Alaska. Most of the sites in Alaska show substantial warming of permafrost since the 1980s. The magnitude of warming has varied with location, but was typically from 0.5 to 4°C. However, this warming was not linear in time and not spatially uniform. While permafrost warming was more or less continuous on the north slope of Alaska with a rate between 0.2 to 1°C per decade, permafrost temperatures in the Alaskan interior started to experience a slight cooling in the 2000s that has continued during the first half of the 2010s. The warming resumed in the mid-2010s. By 2020, new record highs for the entire period of temperature measurements at 15 m and 20 m depth were recorded at all locations. This warming has triggered near-surface permafrost degradation and talik development in many locations in the Alaskan interior and in the northwest of Alaska with adverse consequences for ground surface stability. The talik starts to form when the depth of potential seasonal ground thawing exceeds the depth of potential freezing. To enhance the understanding of possible future rates and pathways of permafrost degradation and to predict the local, regional, and global consequences to human society, accurate high spatial resolution permafrost models are needed. Establishment of these models is possible only by integrating available high-resolution environmental data and by assimilation of existing field and remote sensing data and observations into these models. A Geophysical Institute Permafrost Laboratory (GIPL2) model, a high-resolution stand-alone permafrost dynamics model, will be used to illustrate how changes in climate together with further industrial development of the north slope of Alaska will affect permafrost and ecosystems in this region.