Vol 65, No 2 (2025)

Historical materials, including photographic records, play an important role in the study of glacier dynamics. Archives scattered around the world contain collections of glacier images from the mid-19^th century to the present day. In Russia, until recently, such systematized and accessible data were practically absent. For the first time work on compiling such a collection in Russia was started at the Institute of Geography of the Russian Academy of Sciences with the support of the Russian Geographic Society. Images of glaciers were searched in the archives of Institute of Geography RAS, Tomsk State University, Moscow State University, Institute of Volcanology and Seismology FEB RAS, Institute of Limnology SB RAS, the library of the Russian Geographical Society, scientific publications, personal archives, and the Internet. Special attention was paid to the availability of historical documents dating back to the mid-19^th – early 20^th century. For comparison with historical images, modern photographs of the beginning of the 21^st century taken from the same points were selected. As a result of the project, time series of images of glaciers of the Caucasus, Altai, Kamchatka, Kodar, Eastern Sayan, Baikal, Barguzinsky, Verkhneangarsky, Koryak Plateau, Kuznetsk Alatau, Novaya Zemlya, Severnaya Zemlya ranges were created. Analysis of the data obtained confirms the stable trend of glacier fronts retreat in all represented areas. But there are some exceptions. These are dynamically unstable glaciers and glaciers of volcanic areas of Kamchatka. In the Caucasus, the surging Kolka glacier is recovering after the catastrophe of 2002. The surge of the Vavilov Ice Cap outlet glacier on Severnaya Zemlya continues. Access to the data is a website (https://sites.google.com/view/images-of-russian-glaciers). As of the beginning of 2025, more than 1500 glacier images have been placed on the site. The data can be used both in scientific research for detailed analysis of glacier changes and for a wide audience actively interested in the nature of mountain and polar regions of Russia. It is planned to expand and replenish the archive of images of Russian glaciers.

The processes of river flow formation in the glacier basin were studied using stable isotope geochemistry methods. During the ablation period, isotopic and hydrochemical characteristics of the components involved in the formation of river runoff were determined for the Mizhirgi River within the glacial basin, and isotopic dissection of the hydrograph was performed. The study was performed for a short observation period at a hydrological post in the middle of the ablation season from July 6^th to July 16^th of 2021. Samples of Mizhirgi River water at gouge in 750 m from the glacier tongue were collected as well as precipitation and glacial ice samples on the tongue. Samples of glacial ice were also collected near the Katyn-Tau summit at an altitude of 4750 m in the upper part of the Bezengi Wall, obtained by ice core drilling. The use of two isotopic and one hydrochemical tracer showed the promise of using these methods to study glacier melt patterns. The share of glacial ice melt ranged from 39 to 59%, the share of snow melt water near the feeding boundary varied from 8 to 27%, and an insignificant contribution was made by direct precipitation, which entered the river flow mainly by infiltration through the ground.

The article analyzes the results of measurements of the aerosol count concentration in the surface air in the range from 0.3 to 20.0 μm in 15 intervals. The measurements were carried out using a Grimm 1.108 aerosol spectrometer installed at the Fonovaya observatory (IAO SB RAS, Tomsk). The calculation of the statistical parameters of the distribution of surface aerosol fractions was carried out using a sample compiled on the basis of a continuous series of measurements within the time interval from 11/17/2022 to 01/30/2023. The sample size was 1799 hourly observations. A service program was written to work with the sample, as well as to visualize the calculations. The features of the effect of photophoretic forces on the average daily dynamics of the fractional distribution of aerosol particles in the surface layer were assessed in conjunction with the analysis of reverse trajectories of transport of moisture-bearing air masses and taking into account the time intervals of snow accumulation at the Fonovaya observatory in the first half of winter 2022/23. A certain relationship was established between the increase in the number concentration of particles in the range of 0.3–2.0 μm and the effect of photophoretic forces in different phases of snow cover growth associated with the fall of stratigraphically significant snowfalls. It is postulated and proven that the cause of this phenomenon is the levitation of particles in the field of infrared radiation leaving the surface of the snow, caused by the action of “snow” photophoresis. Obviously, this circumstance should be taken into account when constructing transport models of vertical transport of aerosols in the lower troposphere. In addition, “snow” photophoresis during breaks between snowfalls and during anticyclonic weather conditions can be considered as one of the potentially significant mechanisms for increasing the concentration of pollutants on the snow surface and in the ground air.

The inter-annual variability of the dates of formation of the highest intensity of snowmelt and the maximum spring flood discharge is considered on the example of the Inva River basin for the period 2010–2020. Meteorological and catchment factors have a key influence on the duration of snowmelt, the amount of snow melted per day, water discharge and, accordingly, the levels of water outlets on the floodplain. The applied geo-information model of snowmelt takes into account spatially distributed meteorological information and the characteristics of the floodplain meteorological information and catchment underlying surface features. Model allowed obtaining daily values of the melted snow layer, snowpack and the proportion of remaining snow cover. The basin time which characterizes the period between the peak of the runoff layer and the corresponding peak of water discharge, the peak of the runoff layer and the corresponding peak of water discharge. The results of comparison of snow reserves and frequency of water level exceedance of the adverse event (AE) mark at the gauging station of Inva-Kudymkar for the multi-year period 1970–2020 showed that for the period 2010–2020 the snow reserves were on average 10% higher, and the frequency of exceedance of the AE mark is on average once in 2 years. The application of GIS-technologies allowed visualization of the process of snowmelt and flooding of urban areas. The snowmelt factors of 2017 resulted in flooding of 2.0 km² of the territory of Kudymkar town, including 52 households.

This paper presents the results of a study of the bottom sediments of the northern margin of the Barents Sea shelf, carried out within the framework of the Transarctic 2019 expedition. The exposed bottom sediments with a thickness of 11 to 18 cm began to form approximately 300–400 years ago. The sedimentary strata are composed of pelite and siltstone fractions with local periodic inclusions of coarse-grained particles. After the Little Ice Age (LIA), sedimentation rates in the area of the northern margin of the Barents Sea shelf varied in time and space from 0.04 to 0.19 cm/year, with average values of 0.04–0.1 cm/year. The main factor of sedimentation north of the strait between Spitsbergen and Franz Josef Land is ice and iceberg spread of terrigenous sediments. Chronostratigraphic studies indicate a significant impact of global climate change on the sedimentation regime in the northern Barents Sea shelf after the end of the LIA in the late 18^th – early 19^th centuries. The periodicity of changes is close to climatic periods of 50–60 years. However, in the direction from southwest to northeast, there is a lag of peaks of approximately 20 years (according to our observations of the structure of the sedimentary cover and the intensity of sedimentation). Due to local changes in the sedimentation regime after the LIA, three areas have been identified that differ in the response of sedimentogenesis to climate change: 1) the high response area – the northeast of the Spitsbergen archipelago; 2) the moderate response zone – the northern shelf of the Franz Josef Land archipelago; 3) the low response zone – Franz Victoria Trench area.

As a result of applying the principle of symmetry and the similarity property to the glacial cycles of the Late Pleistocene, an analogy was found in the climate dynamics of the Milankovich glacial cycles. This made it possible to outline the future glacial cycle, determine its configuration and duration.

Aufeis are widespread in the permafrost zone, including the Selenga River basin. They are considered as indicators of dynamic groundwater reserves and often cause damage to settlements and infrastructure. In this study, a representative set of aufeis in the Selenga River basin was compiled based on a previously developed GIS dataset. Landsat and Sentinel-2 satellite images for 1990–2024, acquired immediately after snowmelt, were used to estimate the aufeis area and its multi-year changes. Changes in aufeis area were compared with meteorological parameters derived from the weather station data and ERA5 reanalysis. We found that the average aufeis area decreases by 3.5% per 10 years. At the same time, interannual variations of the area of individual aufeis are generally poorly correlated. The aufeis area has a negative correlation with air temperature in December, March and April, as cold weather in these months favours increase of ice-covered area. A significant increase in air temperature in April in recent decades may be one of the reasons for the overall decrease in the aufeis area. A correlation has also been found with the amount of precipitation in the previous year and particularly in the period from June to September. The largest aufeis area has been observed in 1995–1996, after 1993–1994 which was the wettest year of the period. The lowest aufeis area corresponds to the driest years 2014–2016. On average, the meteorological variables explain 52% of the interannual variability of the aufeis area, but for individual aufeis this value ranges from 7 to 63%. Such differences are due to the different origin of the considered aufeis and possible changes in the hydrogeological conditions, the identification of which requires field studies.

The size and shape of the ice cuttings influence the choice of drilling regimes, as well as the design of drilling heads, augers, chip chambers, and internal drilling channels. To collect ice chips, two boreholes, VK-22 (30 m) and VK-23 (40 m), were drilled at Vostok station. Sieving was used to analyze the particle size distribution of the ice cuttings at full depth in both boreholes. The shape of the ice particles was examined microscopically at drilling depths of 5, 10, 15, 20, 25, 30, and 35 m of VK-23. The density of the snow-firn layer and the bulk density of ice cuttings were measured. The ice cuttings became finer-grained as the borehole depth increased. The prevailing fraction changes from 1.6–3 mm to 0.4–0.63 mm, the average particle diameter reduces from 1.55 mm to 0.06 mm, and the D10, D50, and D90 values decrease more than twice. The shape analysis revealed that the ice chips are dominated by equant and elongated particles, with medium shape projections described by parameters FF = 0.74 and ER = 0.67. A visual comparison of microscopic images shows that the thickness of the ice cuttings decreases as the depth of the well increases.