Effect of snow cover on cooling of the surface layer of the East Grenfjord (Austre Grønfjordbreen) Glacier (Svalbard)

• Published in: Ice and Snow
• Main Authors: A. Sosnovsky V., R. Chernov A., А. Сосновский В., Р. Чернов А.
• Format: Article in Journal/Newspaper
• Language: Russian
• Published: IGRAS 2021
• Subjects: storage of cold; glacier; snow depth; Svalbard; rain-on-snow; thaws; stratigraphy; thermal conductivity; хладозапас; ледник; толщина снега; Шпицберген; зимние дожди; оттепели; стратиграфия; теплопроводность; Austre Grønfjordbreen; Annals of Glaciology; Antarctic and Alpine Research; Arctic; The Cryosphere
• Online Access: https://ice-snow.igras.ru/jour/article/view/871; https://doi.org/10.31857/S2076673421010072

The purpose of this research is to estimate the effect of snow cover on the store of cold of the glacier surface layer. The store of cold is a complex parameter that shows the degree of cooling of the surface layer of the glacier at the end of the cold period. This value is determined with regard for the dynamics of air temperature and snow cover, changes in the density and structure of snow, and the moisture content (water store) in the snow and firn layer by the beginning of the cold period. Analysis of data from measurements of the thermal regime of the upper 11‑meter layer of the East Grenfjord Glacier demonstrated that effect of the snow cover depth (thickness) on the store of cold is ambiguous: when the depth increases, the store of cold can both increase and decrease. For example, in the colder winter of 2013, the store of cold in the upper 11‑meter layer of the glacier was smaller than the similar value in the warmer and snowier winter of 2014. It was found that this was caused by influence of thaws and rains in the winter of 2014. They could produce changes in the structure of the snow cover: an increase in its density and hardness after freezing of ice grains, as well as increase thermal conductivity that could result in more significant cooling of the surface layer of the glacier this winter. Numerical experiments made possible to establish the dependence of the store of cold in the upper layer of the glacier on meteorological conditions and the snow depth. Calculations have shown that with the depth of 50 cm, a rise of winter air temperature by 1 °C reduces the store of cold, on average, by 8.5 MJ/m2, whereas with a snow thickness of 200 cm, the decrease is 6 MJ/m2. Increasing the snow thickness from 50 to 100 cm reduces the store of cold by 11 MJ/m2 at −6 °C, and by 15 MJ/m2 at −10 °C. And growth of snow thickness from 150 to 200 cm decreases the store of cold by 4 MJ/m2 at the temperature of −6 °C, and by 3 MJ/m2 at −10 °C. According to calculations for the compact snow with a thickness of 150 cm ...