Abstract: Aufeis are a key element in the chain of water exchange processes in the permafrost zone. The hydrological role of aufeis in the formation of river flow can be comparable to that of glaciers. Observations of aufeis during the construction of the Baikal-Amur Mainline showed that the share of aufeis runoff in the annual river flow can reach 35% for watersheds with an area of up to 500 km2. Despite the long history of studying aufeis and the results achieved, there are no methods for predicting the development of aufeis processes, as well as hydrological models that take into account the share of aufeis feeding in river runoff. This is due to the lack of observational data on the dynamics and development factors of aufeis. In the last century, long-term studies were carried out on some aufeis in Siberia and the Far East. One of these unique objects is the giant Anmangynda aufeis, which forms in the upper reaches of the Kolyma River basin. The aim of the research is to study the hydrological regime of the Anmangynda river basin and develop a method for accounting of aufeis runoff (module «Aufeis») in the distributed hydrological model «Hydrograph». The module “Aufeis” takes into account two factors of aufeis destruction – under the influence of solar radiation and thermal erosion destruction. The input data is the area of aufeis at the beginning of the warm season and daily meteorological data. The calculation parameters are the coefficients of ice melting and evaporation from ice, as well as the coefficient of the relative area of aufeis depending on the period of destruction, calculated for the modern climatic period. The result of the calculation is the aufeis runoff and the characteristics of aufeis for a given interval. Based on historical data and materials obtained during own field research, the module «Aufeis» was tested. The deviation of the calculated and observed values was 2—10% and 1—9% for the maximum values of the area and volume of the Anmangynda aufeis, respectively. Results of numerical calculations for the period 1967–2022 revealed the dynamics of the contribution of the Anmangynda aufeis to the river flow in different seasons. The expanded functionality of the Hydrograph model has improved the quality of modeling for rivers where aufeis form. For the river basin Anmangynda average Nash-Sutcliffe coefficient and annual runoff error were 0,57 and 13,0% compared to 0,41 and 18,0% when the module «Aufeis» was not used.

Keywords: Anmangynda river, permafrost, mathematical modeling, Hydrograph model, aufeis regulation, remote sensing, aufeis resources, aufeis, water balance, cryosphere

Abstract: The article is devoted to the first results of monitoring the temperature in the snow cover, the height of the snow cover and the atmospheric air temperature in Irkutsk. The results were obtained on the basis of exploratory scientific and organizational research that began in 2021 at the INRTU sites using an autonomous automatic software and hardware complex developed at the Institute for Monitoring Climatic and Ecological Systems of the SB RAS. It has been established that there is a change in temperature in the snow cover at the same height during the day, while in the height range from 0 to 15 cm (0 cm is the underlying base) temperature fluctuations between min and max are insignificant compared to temperature fluctuations in the upper layers snow cover. It is shown that graphically changes in temperature in the snow cover at altitudes that are closer to the atmospheric surface of the snow cover have more pronounced amplitude daily cycles, in contrast to changes at low altitudes. A linear correlation has been established between air temperature and temperature at various heights in the snow cover; the correlation coefficient decreases with decreasing heights in the snow cover, provided that the maximum height of the snow cover is constant, for example, during the day. The phenomenon of cooling of the surface of the snow cover at certain hours during the day, when the temperature of the snow-atmospheric surface is lower than the air temperature, is shown. We note that actual values obtained in autonomous automatic real-time mode, such as air temperature, temperature and snow depth, may have practical significance and over time, with the development of digitalization, may be in demand for managing the urban ecosystem of the city and/or individual territories

Keywords: software and hardware complex, digitalization, cooling, snow-atmospheric surface, temperature profile, snow cover, depth, temperature, monitoring, Irkutsk

Abstract: Study considers horizontal and vertical sampling directions for pollen analysis of ice wedges, taking into account the special mechanism of wedge ice formation. Pollen spectra from the Late Holocene ice-wedges on high polygonal floodplain of the Lyakkatosyo River are studied. Shrub-lichen-moss-polygonal tundra dominates the site. We accounted for the number of elementary veins. The main research methods are pollen and geochemical analyses. We collected samples for pollen analysis along ice wedges' axis and horizontally at depth of 1.20 m, while we also took samples for chemical analysis along the same axis. The high concentration of pollen and spores in ice wedges made it possible to compare results of horizontal and vertical sampling with sufficient degree of accuracy. Pollen spectra characterizing ice wedge horizontally and vertically showed significant differences in the main components. The main difference between horizontal and vertical pollen spectra in AP is the spruce and birch pollen percentages. Along the ice wedge axis, spruce pollen (2.0–13.0%) and birch pollen (6.0–14.0%) are always visible. However, we only find spruce pollen (2.0–4.0%) up to 0.3 m from the vein axis and birch pollen (2.0–14.0%) up to 0.4m from the vein axis. We detected similar-composition pollen spectra in only one case. The sample that is closest to the center of the ice wedge, located at 0.1 m from axis and at depth of 1.2 m, exhibits approximately the same pollen spectra as the sample that is located at depth of 1.2 m from the central part of ice wedge. It is quite natural that certain pollen taxa do not have a general sequence of culminations. Chemical composition of ice wedge suggests that spruce pollen got into the ice due to flooding of the Lyakkatosyo River.

Keywords: flood plain, pollen grain concentration, spores, pollen, macroelements, permafrost, ice wedge, polygonal landscapes, Lekatosyo River, Yamal Peninsula

Abstract: The article aims to ascertain the qualitative and quantitative ion composition of three massive ices in the central and southern regions of Yamal: a) Bovanenkovo, situated on the shore of Lake Hanikoshito; b) in the upper reaches of the Mordyyakha River; and c) in the Erkutayakha River valley. We compared the results with the ionic composition of the known massive ice of the Yamal Peninsula (Bovanenkovo, Kharasavey, Marre-Sale, Neito, Yuribey, Sabetta) and adjacent territories (Gyda, Tanama, Ust-Port, Ledyanaya Gora) to identify the genetic similarity of the three studied massive ices, thereby establishing a more definitive nature. Samples from all three massive ices are ultra-fresh, with ion concentrations ranging from 20 to 40 mg/l. In the ionic composition of the Bovanenkovo massive ice, sodium cations noticeably predominate, reaching 38.95 mg/l in turbid ice and potassium cations up to 21.76 mg/l in highly bubbly transparent ice. Sodium cations noticeably predominate in the Mordyyakha River valley, reaching 68.51 mg/l in ice with soil and 6.1 mg/l in crystal ice. In the ionic composition of massive ice in the Erkutayakha River, approximately equal amounts of sodium cations are observed, reaching 3.64 mg/l. The average concentration of chlorine anions in the massive ice of the Erkutayakha River valley varies: in crystal and milky white ice, 0.76 mg/l; in gray ice of horizontal layers, 1.46 mg/l; and in vertically layered ice of the central stock, 1.48 mg/l. The ionic compositions found in the three thick massive ice lenses that were studied are most similar to those found in Holocene intrasedimental massive ice lenses near Sabetta village and infiltration-segregation thick ice lenses near Gyda village. This is the basis for the classification of the studied massive ice as intrasedimental massive ice.

Keywords: Bovanenkovo, upper Mordyyakha River, Erkutayakha River valley, chlorine anions, sulfate anions, potassium cations, sodium cations, macroelements, massive ice, permafrost

Abstract: The study's focus is on the distribution of oxygen and hydrogen isotopes in the ice cores of frost blisters in the Chara River valley, Transbaikalia. The Kodar and Udokan mountain ranges surround the Chara Depression. Cryogenic (frosty) heaving is common in high humidity areas with loamy, clay, and peaty sediments. In summer 2023, the authors described two seasonal frost blisters in swampy, forested depressions on the periphery of the Charsky Sands (in the so-called thermosuffusion funnels). Oxygen and hydrogen isotopic compositions of oxygen  (δ18O) and hydrogen (δ2H) in blister ice were analyzed. It has been established that seasonal frost blisters are formed mainly due to downward freezing of the water-saturated active layer sediments, but in some cases, ice was formed as well due to upward freezing from the lower boundary of the active layer. The vertical distribution of the isotope values, as well as the δ2H-δ18O ratio in ice, indicates a relatively rapid freezing of water in closed system conditions during one cycle of freezing. In the ice layers sampled horizontally, very similar isotopic composition values were obtained (for example, in blister ice 1, δ18О values ranged from –17.51 to –17.32‰), which indicates consistent horizontal freezing of ice layers. The slopes of the δ2H-δ18О ratio lines for blister ice are 5.82 (blister ice 1) and 5.95 (blister ice 2). A decrease of the δ2H and δ18О values of blister ice on frost mounds with depth and a slope of the δ2H-δ18O ratio line less than 8–7.3 indicates water freezing under closed system conditions during one cycle without moisture inflow. The distribution of isotopic values in the blister ice of seasonal frost mound 2 may indicate simultaneous bilateral freezing of the water volume.

Keywords: Northern Transbaikalia, Chara basin, seasonal active layer, injected blister ice, segregated blister ice, hydrogen isotope, oxygen isotope, blister ice, seasonal frost mounds, permafrost