Snow patches of the Lagonaky highlands (Western Caucasus)

The article presents results of investigation of snowfields on the Lagonaky plateau: conditions of their formation, distribution and dynamics. Snow patches are the most characteristic elements of the high-mountain landscapes of the Lagonaky plateau. In warm seasons, they are widely distributed on local flat-topped ridges of the Lagonaky: Abadzeshsh Murzikao, Kamennoe and others, as well as on the mountain masses Fisht, Pshehasu, Oshten, and Nagoychuk. Morphological and climatic conditions of the Lagonaky Highlands are unique and favorable for formation of snow patches and long preservation of them during the spring-summer periods. These conditions are high mountain ridges with flat tops, negative karst forms of the relief as well as a favorable wind regime with long winter snow storms and heavy snowfalls. Snow patches result from snow transport and accumulation after strong snow-drift on the leeward slopes. The avalanche snow patches arise when avalanches release from steep and long slopes of the above mountain ranges. Permanent snow patches are usually formed at the same places, and duration of their existence depends on sizes and a degree of shading. At the same time, even relatively small snow patches (100–200 thousand m3) can be preserved if they are located in narrow fissures (for example, the area of the Maly Fisht Glacier). In the last 3–5 years, the permanent snow patches melt completely, which is probably a result of small amount of solid precipitation during the cold season and the relatively high air temperatures in the warm time (standard deviation is 0.8–1.0 °C above the normal)