Evolution of the thermal state of permafrost under climate warming in Central Yakutia

Abstract

The relevance of the problem under review is explained by the need to study the thermal response of permafrost to the modern climate change. Evolution of the thermal state of grounds has been studied with a view to evaluate the effects of modern climate warming on permafrost in Central Yakutia. The leading method to study this problem is the arrangement and performance of long-term monitoring observations of the permafrost thermal state that enable quantitative evaluation of the thermal response of upper permafrost layers to climatic fluctuations of recent decades. The analysis of long-term records from weather stations in the region has clearly revealed one of the highest increasing trends in the mean annual air temperature in northern Russia. Quantitative relationships in the long-term variability of ground thermal parameters, such as ground temperature at the bottom of the active layer, at the bottom of the annual heat exchange layer, and active thaw depth, have been established. The thermal state dynamics of the annual heat exchange layer under climate warming indicates that both warm and cold permafrost are thermally stable. Short-term variability of the snow accumulation regime is the main factor controlling the thermal state of the ground in permafrost landscapes. The active-layer thickness is characterized by low interannual variability and exhibits little response to climate warming, with no statistically meaningful increasing or decreasing trend. The results of ground thermal monitoring can be extended to similar landscapes in the region, providing a reliable basis for predicting heat transfer in natural landscapes.

Monitoring the Permafrost Conditions along Pipeline Routes in Central Yakutia, Russia

“…The active layer thickness varied at the site between 2.4 and 2.8 m depending on the summer air temperature. Our earlier studies in similar settings (sites B-59/87 and B-1601) showed the formation of dry taliks, 20 to 30 m in thickness, in very dry sands (2-4%) [36]. Incipient water erosion features were observed on the slopes of the disturbed site.…”

“…The pipeline routes traverse areas with difficult surface and ground conditions, including the presence of continuous permafrost, suprapermafrost water, massive ground ice, and extensive taliks, as well as the widespread occurrence of frost-related landforms and processes [36,37]. In the study area, the permafrost terrains crossed by the pipelines include a floodplain, sand ridges comprising the middle alluvial terraces, and inter-alas terrain on the upland (Table 1).…”

“…The method of conducting geothermal monitoring showed its reliability and can be successfully used in different natural and climatic conditions. Analysis and summary of observation results at various stages of monitoring are presented in our earlier publications [36,37].…”

Antropogenic Impacts on the Thermal Condition of Permafrost in Central Yakutia

“…Since 1987, observational studies have been conducted along the northern section of the Tommot-Yakutsk Railway to quantitatively assess the spatiotemporal changes in the thermal state of permafrost due to anthropogenic impacts [16][17][18][19][20][21].…”