Physical-geographical aspects of formation of artificial firn-ice massives
The paper presents results of analysis of diurnal and potentially possible efficiency of water freezing aimed at construction of artificial infiltration (firn-ice) masses on the Russia's territory. A method of jet ice-formation (winter sprinkling) developed in Institute of Geography of the Russian Academy of Sciences is used for freezing of the artificial firn-ice masses. The method applies far-reaching (long-distance) sprinkler installations for spraying of water and formation of thick (more than 7 m for a day) masses of artificial firn. In winter the sprinkler allows freezing of both the monolithic ice and artificial firn. A practical implementation of this method is licensed and realized for construction of ice passages, bridges, and winter automobile roads. Testing of the method demonstrated that the artificial firn can be used for desalination and purification of polluted salt waters with high efficiency. That is stipulated by both, the high productivity of the method (about 1500 tons of artificial firn for a day at the air temperature of -20 °С, and low mineralization of the firn relative to initial salt water. Winter sprinkling is carried out when mean daily air temperature drops below -5 °С. Estimating of productivity of the artificial firn and monolithic ice under present-day climatic conditions was made over the Russia's territory. Analysis of the climate conditions for periods 2001-2010 and 1961-2000 have shown that reduction of the firn productivity changed from 5-10% in Siberia up to 20-40% in central and southern regions of the European Russia. At the present time, a potentially possible volume of the artificial firn freezing being produced in cold seasons changes from 500 thousand tons in northern areas of Yakutia down to 10 thousand in center of European Russia. Productivity of the monolithic ice freezing by a method of thin-layer water pouring is twice lower in central areas of Yakutia than on the Arctic seashores that is explained by differences in wind speeds. Potentially possible monolithic ice productivity made by means of thin-layer water pouring changes from 56 m of ice thickness in Northern Siberia down to 10 m in center of European Russia. The Northern Yakutia and the River Ob' mouth are two areas of maximal productivity of this method.