Calculating scheme for ground freezing depth variations and its application in different landscapes

Abstract

Snow study is important because snow, after the ocean, is the second largest interface between the atmosphere and Earth's surface and it covers considerable part of the land during winter. Changes in snow cover extent and snowpack properties in recent decades in response to warming are ongoing and will likely continue in future. Ground thermal regime, despite the simplicity of measuring the ground temperature, remains an insufficiently studied field of landscapes. For determination of air-temperature influence, snow cover thickness, absolute values and the dynamics on the depth of ground freezing and thawing, a number of ground freezing models have been developed. In this work, the calculation is done with calculating scheme for ground freezing constructed on the basis of three-layer media heat conductivity problem (snow cover, frozen and thawed ground) with phase transition on the boundary of frozen and unfrozen ground. The heat balance equation includes phase transition energy, inflow of heat from unfrozen ground and outflow to frozen ground, snow cover and atmosphere. The heat flux is calculated on basis of Fourier law as a product of heat conductivity and temperature gradient. It is supposed that temperature changes linearly in each media. The calculations of ground freezing depth variations are done for plain and mountain regions. The ground freezing depth calculation results correspond to the observed values. Hence, the influence of the recent climate and weather contrasts and snow cover spatial and temporal variations on underlying ground freezing depth variations are investigated and reviled. This is vital, although climatic norms between 1961–1990 and 1991–2020 did not illustrate significant changes, but some strong weather variation extremes and contrasts (such as hotness in last 2020 year and weather anomalies of this 2020/2021 winter) are present in recent decades causing danger and risks for population and economics.