Thermal Regime of Frozen Soils with Snow Covers at Combined Radiant and Convective Effects

Abstract

Abstract The paper examines the variability of the temperature profile (including the generation of its inversion by combined radiant and convective action) for the exposed snow cover, which determines the thermal regime of the underlying medium (dense firn or frozen soils and ground of low- and high-lands) in view of heating by a geothermal thermal influx. Experimental and theoretical researches allowed studying the effects daily radiating-conductive heating inside a snow layer (covered the underlying glaciological mediums) at conditions of the external impact by atmosphere convection (together with longwave thermoradiation) and solar shortwave penetrating thermoradiation. The possibility of the formation of heat conductive fluxes redirected to exposed superficial during subsurface radiant overheating - was shown theoretically in order to prevent thawing of the underlying media. For the first time inversion temperature profiles were registered inside snow thickness on the glacier surface near Elbrus at the height ∼ 4000 m. The authors interpreted this effect from the standpoint of scattering media optics. Snow cover was modeled as a semitransparent medium with volumetric albedo, scattering and absorption indices (coefficients), caused by the calculated parameter of internal radiant heat source function, corrected by the experimentally measured temperature profile of the investigated snow layer. It is shown that during the morning hours at intensive insolation and atmospheric negative temperatures, subsurface overheating inside the glacier is produced. This phenomena was observed experimentally on depth up to 5-40 sm using of thermodes of long measure probe. The obtained results are in the consent with theoretical estimations of authors and foreign researchers.