Assessment of Changes in Permafrost and Ground Temperature in the Alaskan Arctic and Yamal Peninsula from 1900 to 2100

Authors

Dmitry Nicolsky¹* (djnicolsky@alaska.edu), Vladimir Romanovsky¹, Thomas Wright¹, William Cable², Colleen Iversen³

Institutions

¹University of Alaska–Fairbanks, AK; ²Alfred Wegener Institute, Bremerhaven, Germany; ³Oak Ridge National Laboratory, Oak Ridge, TN

URLs

• https://ngee-arctic.ornl.gov/

Abstract

Thawing and freezing of arctic soils is affected by many factors, with air temperature, vegetation, snow accumulation, and soil moisture among the most significant. Researchers employed the transient permafrost dynamics model developed at the Geophysical Institute Permafrost Laboratory (GIPL) and simulated several high spatial resolution (0.8 km × 0.8 km) scenarios of changes in permafrost characteristics in the Alaskan Arctic Brooks Range and Russia’s Yamal Peninsula in response to projected climate change and land surface disturbances commonly occurring during various construction phases. Impacts of these changes in permafrost on northern ecosystems and infrastructure were assessed and regional maps of the possible impacts developed.

The GIPL-2 model numerically simulates soil temperature dynamics and the depth of seasonal freezing and thawing by solving the one-dimensional, non-linear heat equation with phase change. In this model, the processes of soil freezing and thawing occur in accordance with the volumetric unfrozen water content curve and soil thermal properties. Snow temperature and thickness dynamics were simulated assuming snow accumulation, compaction, and phase change processes. Model simulations were validated by comparison with available active layer, permafrost temperature, and snow depth records from existing permafrost observatories operated by the U.S. Geological Survey and the Geophysical Institute. Properties of surface vegetation, soil type, layering, and moisture content were up-scaled using Sentinel-1 and Sentinel-2 satellite maps of Ecosystems of Northern Alaska, Arctic Network of Parks and Preserves, and Land Cover Classification.