A new approach to separation small glaciers from perennial snowfields which is based on the data about duration of the continuous existence of glacial and firn objects (on the example of the Kuznetsky Alatau mountains)

To properly assess the changes of geosystems and climate in areas where small forms of glaciation are presented it is necessary to distinguish the objects related to glaciers and objects that associated with snowfields. Overestimation or underestimation of the number of glaciers due to perennial snowfields distorts the true picture of the glacial situation and leads to incorrect climatic and hydrological forecasts. In this article we review principles and approaches to the classification of small glaciers and perennial snowfields and consider the possibility of using the criterion of duration of the continuous existence of glacial and firn objects for solving this problem. The paper also summarizes meteorological measurements data, field records of 30 glaciers and remote sensing methods (repeated photos, satellite images data) to provide an overview of climate and glacier fluctuations in the Kuznetsky Alatau mountains during the last 40 years. The evidence suggests that for the Kuznetsky Alatau mountains, where more than half of all precipitation falls as snow, warming leads to increase of snowing and amount of accumulated snow mass on the leeward slopes. Since 2005 large cirque glaciers have ceased to decline and shown the trend of area and ice thickness increase. It is substantiates the view that large-scale degradation of glaciers that recorded in the area in 2002-2005 can be explained by the fact a large number of perennial snowfields were erroneously classified as glaciers, whereas periodic disappearance of perennial snowfields in unfavorable years is commonplace.

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