Permafrost warming has the potential to amplify global climate change, because when frozen sediments thaw it unlocks soil organic carbon. Yet to date, no globally consistent assessment of permafrost temperature change has been compiled. Here we use a global data set of permafrost temperature time series from the Global Terrestrial Network for Permafrost to evaluate temperature change across permafrost regions for the period since the International Polar Year (2007–2009). During the reference decade between 2007 and 2016, ground temperature near the depth of zero annual amplitude in the continuous permafrost zone increased by 0.39 ± 0.15 °C. Over the same period, discontinuous permafrost warmed by 0.20 ± 0.10 °C. Permafrost in mountains warmed by 0.19 ± 0.05 °C and in Antarctica by 0.37 ± 0.10 °C. Globally, permafrost temperature increased by 0.29 ± 0.12 °C. The observed trend follows the Arctic amplification of air temperature increase in the Northern Hemisphere. In the discontinuous zone, however, ground warming occurred due to increased snow thickness while air temperature remained statistically unchanged.
The Global Climate Observing System and Global Terrestrial Observing Network have identified permafrost as an ‘Essential Climate Variable,’ for which ground temperature and active layer dynamics are key variables. This work presents long-term climate, and permafrost monitoring data at seven sites representative of diverse climatic and environmental conditions in the western Russian Arctic. The region of interest is experiencing some of the highest rates of permafrost degradation globally. Since 1970, mean annual air temperatures and precipitation have increased at rates from 0.05 to 0.07 °C yr−1 and 1 to 3 mm yr−1 respectively. In response to changing climate, all seven sites examined show evidence of rapid permafrost degradation. Mean annual ground temperatures increases from 0.03 to 0.06 °C yr−1 at 10–12 m depth were observed in continuous permafrost zone. The permafrost table at all sites has lowered, up to 8 m in the discontinuous permafrost zone. Three stages of permafrost degradation are characterized for the western Russian Arctic based on the observations reported.
1 August 2021 in Bulletin of the American Meteorological Society
This paper presents results from long-term active layer monitoring at four CALM sites in the Russian European North. Observational records range from 10 to 24 years in length (1996–2019). The impact of climatic and landscape parameters on active layer thickness has been assessed through linear regression. The temporal dynamics of climatic parameters, responsible for the thaw depth changes, were investigated. The long-term data indicate that the active-layer thickness has increased at all the monitoring sites, in response to changes in both summer and winter climatic parameters. The surface organic layer also serves as a major landscape factor influencing spatial patterns of thaw depth and climate-induced rates of permafrost thawing.
This paper describes the results of ground penetrating radar (GPR) research combined with geocryological data collected from the Circumpolar Active Layer Monitoring (CALM) testing sites in Kashin and Kumzha in August 2015, 2016, and 2017. The study area was located on the Pechora River delta. Both sites were composed of sandy ground and the permafrost depth at the different sites ranged from 20 cm to 8–9 m. The combination of optimum offset and multifold GPR methods showed promising results in these investigations of sandy permafrost geological profiles. According to direct and indirect observations after the abnormally warm conditions in 2016, the thickness and water content of the active layer in 2017 almost returned to the values in 2015 in the Kashin area. In contrast, the lowering of the permafrost table continued at Kumzha, and lenses of thin frozen rocks that were observed in the thawed layer in August of 2015 and 2017 were absent in 2016. According to recent geocryological and geophysical observations, increasing permafrost degradation might be occurring in the Pechora River delta due to the instability of the thermal state of the permafrost.