EVALUATION OF THE COMPONENTS OF THE HEAT BALANCE OF THE DJANKUAT GLACIER (CENTRAL CAUCASUS) DURING THE PERIOD OF ABLATION IN 2007–2015
P.A. Toropov1,2, A.A. Shestakova3, A.M. Smirnov1, V.V. Popovnin1
1 Lomonosov Moscow State University, 1, Leninskie Gory, Moscow, 119991, Russia2 Institute of Geography, RAS, 29, Staromonetny per., 119017, Moscow, Russia
3 Obukhov Institute of Atmospheric Physics, RAS, 3, Pyzhevsky per., 119017, Moscow, Russia; tormet@inbox.ru
Analysis of mass-balance data monitoring of the Djankuat Glacier has demonstrated that the severe deglaciation over the past 20 years is associated with the ablation anomaly. We have analyzed the main components of the heat balance during the ablation seasons of 2007–2015 on the basis of meteorological measurements. The quantitative estimates of the accuracy of calculating turbulent heat fluxes using different methods have been presented. It has been revealed that the ‘eddy covariance’ technique can be used as a reference method. The assessment of the temporal variability of the basic components of heat balance has been carried out. The bulk formulas method seems to be the most accurate among other methods. The contribution of various factors to the formation of the melt layer has been estimated: the fraction of the radiation balance is 50–80 %, and that of turbulent heat exchange is 20–40 %. It has been found for the first time for a Caucasus glacier that turbulent heat-moisture exchange plays a more significant role in the formation of the heat balance than it had been previously. Partly, this can be explained by transformation of the heat balance structure associated with climate change.
Glacio-climatology, Djankuat Glacier, glacier heat balance, turbulent flux