Present state and dynamics of glacio-nival systems of Mongun-Taiga and Tavan-Bogdo-Ola mountain massifs

Abstract

Climate-induced variations of glacio-nival systems (snow patches, glaciers, stone-ice formations) of the high-mountain massifs Mongun-Taiga and Tavan-Bogdo-Ola (north slope) were investigated for 1966-2013 period using results of field observations and analysis of aerial photos. Regional 25-year climatic cycles of the variations have been determined. Characteristics of response of glacio-nival objects to the climate changes were obtained. Results of preliminary mass balance calculations made for the 2012/13 glaciological year and values of the mass balance index calculated for the period 1966-2013 for the Seliverstov Glacier together with recorded climate cooling, increase of snow accumulation, and slowing down of glacier snout retreats give evidence to beginning of new 25-year cycle that is expected to be more favorable phase for existence of the above glacio-nival systems. Five-phase scheme of retreats of the valley glaciers happened after the LIA maximum was constructed on the basis of results of field observations performed for many years. Each phase is characterized by different retreat mechanisms as well as by different response to the same climate change that can be used as a basis for forecasting of future glacial dynamics. Rates of the thermokarst processes determined from observations and general mechanisms of dynamics of stone-ice formations are also discussed in the paper.

Keywords

• баланс массы
• каменно-ледовые образования
• колебания климата
• ледники
• снежники
• термокарст.