The World Atlas of Snow and Ice Resources: A Review

Summary

Kotlyakov reviews the World Atlas of Snow and Ice Resources through its classification and regionalization of snow–ice phenomena and quantitative assessments of their water-resource and climatic roles. He distinguishes four levels of nival-glacial systems and explains the Atlas's six-level regionalization, based on latitude, continentality, moisture sources, and terrain. Calculations using Atlas materials estimate perennial surface ice on continents and islands at 25.8 million km³ water equivalent, seasonal snow reserves at approximately 20,000 km³, and glacial runoff at 3,450 km³, about 8% of surface runoff entering the ocean. The article examines continental snow accumulation and redistribution of moisture between ocean basins, alongside glacier accumulation patterns associated with latitude, ocean proximity, atmospheric circulation, and mountain relief. It describes a snow-resource assessment method combining climatic, hydrological, and snow-gauging observations with glacier alimentation-boundary data; determining snow-cover boundaries and timing enabled mapping across virtually all snow-covered areas. Mountain runoff estimates use relationships between runoff and basin elevation, snow-cover limits, and glacioclimatic maps. Kotlyakov concludes that the meltwater share of river runoff increases with continentality and emphasizes glacier runoff's value in summer and low-water years. He also estimates the climatic effects of glacier albedo, turbulent heat exchange, and iceberg melting. He describes the Atlas as condensing worldwide information gathered over 20–25 years and supporting assessments from river basins to the atmosphere–ocean–land–glaciation system. A glaciological GIS based on its materials was under development at the Russian Academy of Sciences' Institute of Geography.