Influence of the snow–soil contact conditions on the depth of ground freezing (based on observations in the Kursk region)

• Published in: Ice and Snow
• Main Authors: V. Kotlyakov M., A. Sosnovsky V., R. Chernov A., В. Котляков М., А. Сосновский В., Р. Чернов А.
• Other Authors: Mathematical modeling was carried out with the financial support of the RFBR grant 18-0560067, numerical experiments and their analysis was carried out according to the framework of fundamental scientific studies within the project reg. № 0148-2019-0004 (АААА-А19-119022190172-5), experimental field studies and experimental data processing were carried out according to the RFBR 17-55-80107 BRICS_a project, Математическое моделирование проводилось при финансовой поддержке гранта РФФИ 18-05-60067, численные эксперименты и их анализ в рамках темы Государственного задания № 0148-2019-0004 (АААА-А19-119022190172-5), экспериментальные исследования в полевых условиях и обработка экспериментальных данных – по проекту РФФИ 17-55-80107 БРИКС_а
• Format: Article in Journal/Newspaper
• Language: Russian
• Published: IGRAS 2019
• Subjects: air gap; landscape conditions; mathematical modeling; snow cover; ground freezing; thermal conductivity; thermal regime; the snow– soil interface; воздушный зазор; граница снег–почва; ландшафтные условия; математическое моделирование; промерзание почвы; снежный покров; теплопроводность; Downfall; Arctic; The Cryosphere
• Online Access: https://ice-snow.igras.ru/jour/article/view/559; https://doi.org/10.15356/2076-6734-2019-2-407

The results of measurements of the ground freezing under a snow cover do not always agree with the calculations. The reason for this may be variability of thermal characteristics of the snow cover which properties depend on the landscape features. One of probable reasons may be also the incomplete contact between the snow cover and the soil. In autumn, the ground surface is usually covered with fallen leaves or withered grass. Estimates show that, in the presence of such layer on the soil surface, the air gap between snow and soil with the 1 cm thickness has a thermal protection capacity equal to the value of a 10‑centimeter thick layer of snow. Sometimes the presence of local gaps in the snow-soil interface can also be caused by other reason, for example, the spontaneous downfall of a depth hoar layer. The results of field measurements of snow cover characteristics, ground freezing depths and investigation of the contact conditions at the snow-soil interface carried out in different landscapes are presented. The results of mathematical modeling showed that when the air gap between snow and soil is taken into account the calculated values of depth of ground freezing are in a good agreement with data of the measurements. This consideration is especially important for small thicknesses of snow cover with high density and thermal conductivity. Numerical experiments did also show that the snow hardness is the necessary characteristic for analysis of the snow cover state. This provides more accurate estimating of the snow thermal conductivity that is closely connected with its hardness. Приводятся результаты полевых измерений параметров снежного покрова, глубины промерзания почвы и анализа условий на границе снег–почва в разных ландшафтах. Проведено сравнение данных измерений и расчётов по влиянию зазора на границе снег–почва на термический режим почвы и глубину промерзания. Изоляционный слой на границе снег–почва из растительности, опавших листьев и воздуха снижает поток тепла из почвы в атмосферу, что ...