Climate warming changes heat fluxes within the atmosphere-surface cover-soil system and affects the thermal state of permafrost. A comparison of heat fluxes from the atmosphere to the soil during the period with positive air temperatures and from the soil to the atmosphere during the cold period makes it possible to assess the stability of permafrost. Snow and moss cover are important factors influencing heat flows. The influence of surface fluxes on heat fluxes is estimated based on mathematical modeling and numerical experiments on the model. The processing of data from field measurements of soil temperature made it possible to determine the heat fluxes for the cold and partially warm periods of the year. A comparison of the data from model calculations and measurements of heat fluxes showed a satisfactory agreement. The difference between them from December to February did not exceed 4%, and in November and March-9% and 8%, respectively. In 2023/24, during the period with negative air temperatures lasting 255 days with an average air temperature of-7 degrees C, soil heat losses amounted to 76.5 and 92.3 MJ/m(2) with snow thickness of 1.14 m and 0.63 m, respectively, and the average values of heat fluxes from October to March were 4.9 and 5.9 W/m(2). According to model calculations, with an average daily positive air temperature of 6.8 degrees C, the loss by the soil in winter is 10 MJ/m(2) less than the heat flow into the soil in summer, leading to permafrost degradation. At snow cover depth of 0.5 m, heat input into the soil in summer coincides with heat loss in winter. With a higher snow cover depth, the heat flow from the soil to the atmosphere decreases, soil cooling decreases and permafrost degradation will occur. The same processes will occur when the snow cover is 1 m depth and the moss cover is less than 3 cm thick. For a moss cover of greater thickness, the thermal stability of permafrost rocks remains. Numerical experiments on the model estimated the heat fluxes and the thickness of the active layer for different snow and moss cover thicknesses and atmospheric air temperatures.

Borehole temperature measurements at the Dasan station were made by Baroo-Diver geothermal datalogger. During September 28, 2002 - August 12, 2003 three temperature data (at the depth of 0.25m, 0.5m, and 0.75m) were obtained by Environ Mon every thirty minutes. The thermal dynamics of active layer at the Dasan Korea Arctic Research Station, Svalbard (78 degrees 55.5'N, 11 degrees 56.0'E) is represented in the soil temperature which can be measured with high accuracy and high temporal resolution. Using the continuous data over a period of 318 days at the Dasan site, Svalbard, we deduce and quantify the processes which constitute the thermal dynamics. Conductive heat flow, migration of water vapor, and heat generation from phase transition are analyzed. Average thermal diffusivity indicates the range of thermal diffusivity 4x10(-7) similar to 6x10(-7)m(2)s(-1). The Dasna experiment is a good test of the geothermal method of climate reconstruction because the permafrost is a valuable recorder of climate change.