Snow cover sublimation on the Svalbard during spring

Snow plays an essential role in mass balance of different water objects on the Arctic archipelagos, such as rivers, glaciers and lakes. Snow cover sublimation has a significant effect on the amount of water stored in the snow. The Arctic and Antarctic research institute (AARI) has been performing sublimation observations on the Svalbard archipelago as a part of mass-balance research since 2021. The aim of the paper is to summarize and process observation results. Estimates of daily sublimation were obtained based on direct observations using GGI-500-6 weighing evaporimeters with an evaporating surface area of 500 cm² and monolithic snow 6 cm thick. It was found that during the spring period the average daily sublimation rate from snow is 0.60 mm w. e., during the day it is 0.43 mm, at night it is 0.17 mm, which is 40 % of the daytime value. There is a strong correlation between daytime sublimation and total daily sublimation, with the correlation coefficient r = 0.924. Between night-time and daytime sublimation rates, the correlation decreases to r = 0.742. The greatest influence on the sublimation process comes from wind speed ( r = 0.822), moisture deficit ( r = 0.670), and air temperature ( r = 0.724). Based on the observations carried out from April to May of 2021–2024, a semi-empirical calculation method and a multiple regression model have been developed. These methods allow one to fill gaps in direct observations or to estimate sublimation when meteorological data are available. The methods were compared with the calculation methodology proposed by P.P. Kuzmin. A significant correlation was established between the results calculated using these methods ( r = 0.776). The average amount of sublimated moisture as determined by these methods near the Barentsburg weather station in pre-spring and spring periods is 35.6 mm, ranging from 30.9 (according to Kuzmin) to 40.2 mm (semi-empirical method). The seasonal sublimation value according to the multiple regression model is close to the average — 35.7 mm. The daily sublimation intensity values, calculated from reconstructed series of 119 days and determined using Kuzmin’s methodology and the multiple regression model, are respectively equal to 0.63 and 0.66 mm/day. The results obtained can be used to assess the contribution of sublimation to the water balance of land surface waters in the Arctic archipelagos and the continental part of the Arctic.