Observations of Thermal State of Permafrost in Alaska and Eurasia
Project Personel
Main Contact: Dr. Dmitry Nicolsky
Scientific Personel: V. E. Romanovsky, D.J. Nicolsky, K. Yoshikawa, A.L. Kholodov, L.M. Farquharson, T.C. Wright
Collaborators:
Partner Organizations: various research organizations in Canada and Russia
Project duration:
2019 - 2024
Project Summary
The primary goal of our research is to collect data from existing sites, to maintain existing sites, to instrument new monitoring sites, and to archive and disseminate observations and their implications to the scientific community and public.
Research Goals:
The overarching goal of our research is to obtain a deeper understanding of the temporal (interannual and decadal time scales) and spatial (north to south and west to east) variability and trends in the permafrost temperatures in the North of Eurasia and Alaska to develop more reliable predictive capabilities for the projection of these changes into the 21st century.
| Objective 1: | Continue to maintain and acquire data from the existing Alaskan network of permafrost observatories (including three sites in the Canadian Archipelago) for the period 2019 to 2023. |
| Objective 2: | Continue to develop a sustainable network of permafrost observatories in Russia and participate in the acquisition of a comparable set of standardized data from regional observatories in Russia. |
| Objective 3: | Continue to participate in the implementation of the international TSP project as the U.S. contribution to the GTN-P |
| Objective 4: | Continue to develop and update a joint Alaska-Russian permafrost temperature database and provide data to other data systems such as the NSF Arctic Data Center and GTN-P databases. |
Study Sites:
We have been continuing our efforts to record and archive data on permafrost temperature dynamics at 96 shallow borehole sites and 22 deep boreholes in Alaska. This includes service and downloading data from the real-time and field-based data acquisition systems, data processing and quality control and preliminary data interpretation.
At the beginning of the project, we selected Surface Observation (SO) sites adjacent to the temperature monitoring sites along the Dalton and Elliot Highway. In the current reporting period we continued to collect remote sensing data at the SO locations and started to obtain first results on the ground surface changes. In particular, repeat drone surveys were performed at the selected SO sites and a very high-resolution digital elevation models (DEMs) were developed. Repeat annual drone surveys will allow understanding of relationships between warming rates, ground subsidence and thermokarst development. Some areas are experiencing wide-spread ground subsidence.
Fieldwork:
Alaska: Summer/fall visits to all active Alaskan sites to service data loggers, download data, log borehole temperature and probe active layer depth at our CALM grids. Collect remote sensing data and product to select five Surface Observation (SO) sites. Installation of additional heat flux and soil liquid water content sensors at existing sites along the Alaskan Permafrost Transect.
Russia: Visits to sites to inspect and service dataloggers, collect temperature observations and log boreholes. Continue installation of data loggers into boreholes, extent observations and maintain equipment at the already instrumented sites.
Results:
Our historic observations demonstrate that the ground warming occurs throughout the entire year, but a major part of increase happens in the cold season. As a result, the re-freezing of the active layer takes more and more time. While the complete freeze-up of the active layer on the North Slope in the mid-1980s typically occurred in the first half of October, the typical freeze-up dates in the first half of the 2010s shifted to mid-December. South of the Brooks Range, the active layer freeze-up now occurs much later in the
winter or even in the spring, and thus a layer of perennially thawed material, or so-called subaerial talik, can start to develop.
In late 2010s, sightings of ground collapse and permafrost degradation started to occur in the natural environment at numerous locations in the Interior or Alaska. Indeed, our in-situ ground temperature measurements record novel talik formation (between 2013 – 2020) at 29 sites across a >100,000 km2 region of the discontinuous permafrost zone of Alaska. The talik formation in areas of the high-ice content can indeed lead to the ground failures. The winter of 2018-2019 was the first winter on record when the complete freeze-up did not occur at several sites in the Interior of Alaska and Seward Peninsula (published a manuscript in the Nature Geosciences in 2022).
However, winters of 2019-2020 and 2021-2022 became colder and some taliks that have previously developed ceased to exist. This indicates an unstable situation for permafrost in the Interior of Alaska. As climate variability is near a threshold for the talik formation, taliks can form and disappear almost every other year, until such the threshold is passed in the future.