Changes in geocryological conditions in interalas terrain under predicted climate warming, Central Yakutia

Central Yakutia is distinguished by the widespread presence of highly ice-rich permafrost dating back to the Pleistocene epoch, commonly known as the Ice Complex. In the context of global climate warming, it is essential to evaluate the sensitivity and response of permafrost-dominated landscapes to projected climatic changes. The Ice Complex sediments are primarily found in the interalas terrain type. Disruptions to the surface energy balance, particularly those associated with human activities, often lead to destructive cryogenic processes, such as thermokarst and thermal erosion. Alases are prevalent in the region, most of which formed during the Holocene Optimum as a result of the thawing of the Ice Complex. In this study, we analyzed climatic data from weather stations and the thermophysical characteristics of soil samples collected from interalas sites to develop predictive models and compile maps of future soil temperatures under projected climate warming scenarios. Moreover, we conducted model verification. The simulations were based on climatic data from seven meteorological stations and a cryolithological profile representative of the interalas terrain. The study area is a well-drained, forest-covered upland. The simulation results project the dynamics of ground temperatures and active layer thickness in the Ice Complex under three climate warming scenarios for the year 2100: an increase of +2 °C, +3 °C, and +4 °C per century, along with increases in snow cover of 10% and 30%, with no change in precipitation. The findings indicate that thawing of the Ice Complex will commence at a warming of 4 °C with no change in precipitation, at 3 °C with a 10% increase in precipitation, and at 2 °C with a 30% increase in precipitation. Additionally, we classified the terrain into two categories based on susceptibility to Ice Complex degradation due to climate change: unstable and stable. In unstable areas, thawing of the Ice Complex is projected to begin with a +3°C increase in mean annual air temperature.