Earth’s Cryosphere, 2022, Vol. XXVI, No. 6, p. 13-20.
GEOTHERMAL FIELDS AND THERMAL PROCESSES IN CRYOSPHERE
A METHOD FOR EVALUATING THE THERMOPHYSICAL PROPERTIES OF SEASONALLY FREEZING AND SEASONALLY THAWING SOILS UNDER NATURAL CONDITIONS
Ostroumov V.E.1,*, Fedorov-Davydov D.G.1, Komarov I.A.2, Shevchik F.A.2, Koloskov A.M.2, Volokitin M.P.3, Goncharov V.V.1, Bykhovets S.S.1, Shabaev V.P.1, Kholodov A.L.1,4, Eremin I.I.5, Kropachev D.Yu.5, Davydov S.P.6, Davydova A.I.6
1 Institute of Physicochemical and Biological Problems of Soil Science, Russian Academy of Sciences, Institutskaya St. 2, Pushchino, 142290 Russia
2 Lomonosov Moscow State University, Faculty of Geology, Department of Geocryology, Leninskie Gory 1, Moscow, 119991 Russia
3 Institute of Fundamental Problems of Biology, Russian Academy of Sciences, Institutskaya St. 2, Pushchino, 142290 Russia
4 University of Alaska, Geophysical Institute, 2156 Koyukuk Drive, Fairbanks, Alaska, USA
5 JSC SPA Etalon, Lermontov St. 175, Omsk, 644009 Russia
6 Pacific Geographical Institute, Far Eastern Branch of the Russian Academy of Sciences, North-East Scientific Station, Chersky 18, Sakha (Yakutia), 678830 Russia
*Corresponding author; e-mail: v.ostroumov@rambler.ru
Under natural conditions, seasonally freezing and seasonally thawing soils are open systems of variable composition, structure, and properties. However, in engineering projects, to describe their thermal state, the values of thermal properties measured in laboratory on isolated samples of constant composition are used. To take into account the variability of the thermal properties of active layer soils under the influence of external factors, we propose a method for assessing the equivalent indicators of their volumetric heat capacity and thermal conductivity using a combined analysis of dynamics of the temperature and heat flow in soils based on long-term monitoring data. Monitoring of heat flow density and soil temperature is carried out in two areas, one of which characterizes the area of seasonal freezing, the second – the area of seasonal thawing of soils. A method has been developed for calculating the effective coefficients of thermal conductivity and heat capacity from monitoring data on temperature and heat flow in soils. A procedure for processing monitoring data is proposed, which makes it possible to determine the time-averaged effective values of the thermal conductivity coefficients and the heat capacity. The developed technique makes it possible to observe fluctuations in the coefficients of thermal conductivity and heat capacity in time series against the background of changes in the composition and external factors of heat transfer in seasonally freezing and seasonally thawing soils under natural conditions.
Keywords: permafrost, soils, active layer, thermophysical properties, heat flow, temperature regime, geocryological monitoring
Recommended citation: Ostroumov V.E., Fedorov-Davydov D.G., Komarov I.A., Shevchik F.A., Koloskov A.M., Volokitin M.P., Goncharov V.V., Bykhovets S.S., Shabaev V.P., Kholodov A.L., Eremin I.I., Kropachev D.Yu., Davydov S.P., Davydova A.I., 2022. A method for evaluating the thermophysical properties of seasonally freezing and seasonally thawing soils under natural conditions. Earth’s Cryosphere 26 (6), 13–20.