ИСТИНА

Glacier contraction has been observed in recent decades in different parts of the planet. The connection of this process with the ongoing climate warming is no longer in doubt. Moreover, it became possible to talk about the complete disappearance of glaciers in a number of areas in the near future. Glaciers with sizes less than 0.5 km2 are the most vulnerable in this regard. This process occurs with different intensities depending on the regional characteristics of climatic conditions, topography, size and morphology of the glaciers themselves. Information on the dynamics of their state over a sufficiently large time interval plays an important role in understanding the mechanisms of the influence of these factors on glacier changes. The number of glaciers in the world provided by such observations is less than 1%. At the same time, glaciers with sizes less than 0.5 km2 make up more than 80% of the total number of glaciers in mountain ranges of medium and low latitudes. Glaciers of the Polar Urals have the longest series of observations among glaciers located in the polar latitudes of the mountainous regions of mainland Russia and therefore are a unique addition in this regard.The annual glaciological observations of glaciers here began in 1958 under the International Geophysical Year program at the hospital base on Bolshaya Hadata Lake and were carried out until 1981. Currently, ASTER and Sentinal-2 satellite images are used to assess the current state of glacier boundaries. However, changes in the area and length of the glacier do not always adequately reflect the relationship of its state with the climate, since it largely depends on local features of the relief. At the same time, their mass balance is directly related to the climate. To confirm the connection between the reduction in the size of glaciers and the ongoing climate changes, the geodetic balance of the mass of the test glacier IGAN was estimated. To evaluate the changes in its mass balance, different-time digital models of the glacier surface were used, created from archival materials and data from DGPS surveys of 2008 and 2018.The results of studies using satellite data allow us to conclude that the general trend of reducing the size of the glaciers of the Polar Urals, established in the second half of the twentieth century, continues to exist at present. Moreover, compared with 1953–2000. the average annual rate of reduction in the area of glaciers doubled. Since the beginning of the XXI century. glaciers lost 27.7% of the area. The amount of contraction is not the same. For a sample of 30 glaciers, it varies from 7.1% (Terentyev Glacier) to 61.1% (Oleniy Glacier). Small glaciers are particularly sensitive to factors associated with landforms. Between 1963 and 2018, the IGAN glacier lost 19.7 million m3 of ice, of which 3.2 million m3 fell in the last decade. The specific balance of the glacier in 1963–2008 was equal to –317 ± 59 mm / year, and during the period 2008–2018. –336 ± 61 mm / year. The average decrease in surface height was 18.94 ± 3.22 m, and the maximum - 53.5 ± 1.0 m. Based on the results obtained and the ERA-Interim reanalysis data, it can be concluded that the main reason for the currently observed accelerated reduction of glaciers The Polar Urals - an increase in air temperature by 1.5 ºС, to which in the last decade a decrease in the amount of winter precipitation was added.The study of changes in the size of glaciers based on satellite imagery was supported by the RFBR grant No. 18-05-60067 Arctic. Assessment of the geodetic balance of the IGAN glacier was carried out with the support of the RFBR grant No. 17-55-80107-BRICS-a. Logistic support for expeditionary work was carried out with the support of NP Russian Center for Arctic Development