Abstract: This article examines the reliability of ice data presented in the HadISST1 database (Hadley Centre Sea Ice and Sea Surface Temperature data set) of Hadley Meteorological Center (Hadley Centre for Climate Prediction and Research, Met Office, UK). The criterion for the reliability of HadISST1 database on the Northern hemisphere serves the average multiyear annual course of insolation in the Northern Hemisphere and the average multiyear annual course of insolation in 5-degree latitudinal zones at the upper boundary of the atmosphere, phase-shifted by two and three months to the past. It is revealed that the representative criterion for assessing the reliability of the business database is the average multiyear course of insolation in 5-degree latitudinal zones shifted by two months to the past. Evaluation of the data array on the Northern Hemisphere on the basis of the selected criterion demonstrates the overall high reliability of ice data reflected therein. However, there are two areas that differ in the degree of reliability of the presented data: 1) pack, drift ice with high negative values of the correlation coefficient; 2) coastal zone, in which the correlation is virtually absent (shore ice and flaw leads). The weak (or absent) correlation is observed over a significant length of the coastal zone in the Arctic Ocean, as well as in the straits and bays of the Canadian Arctic Archipelago. It is established hat the correlation coefficient of the annual course of the ice flow in the cells of the array of size 1 with the annual course of insolation of the Northern Hemisphere and the corresponding 5-degree latitudinal zones increases from the past to the present. This indicates the need for the correction of ice data in the early time range of the array (1901–1978), which precedes the time of the beginning of satellite observations.

Keywords: Arctic Ocean, The Arctic, Arctic seas, insolation contrast, insolation of the Earth, changing the area, sea ice, insolation, atmosphere, Earth

Abstract: The object of this research is the reconstruction of the climatic conditions of the Late Pleistocene summer seasons based on the pollen spectra of syngenetic ice wedges and inclosing Yedoma deposits. For quantitative assessment of summer temperatures and phenological relationships, the author applies the total annual thaw index, since namely the sum of positive temperatures is the only indicator that determines the beginning of pollen emission in majority of plant species. The relationship between the composition of pollen spectra and the total annual thaw index is deterministic, although it cannot be formulated strictly mathematically. Yedoma is a unique object for research by many parameters, which allows acquiring paleogeographic information on two components, such as ice wedges and deposits, because the accumulation of pollen and spores occurs differently therein. The structure of vegetation cover during the accumulation of Yedoma deposits during the Late Pleistocene differed significantly from the Holocene and modern periods, which is recorded in the pollen spectra of syngenetic deposits and ice wedges. It is established that in certain periods, the diversity of species of Late Pleistocene vegetation was higher compared to modern vegetation of tundra and forest tundra due to the large number of ecological niches and peculiarity of temperature regime of the summer season.

Keywords: long distance transported pollen, vegetation, paleorecostructions, pollen spectra, ice wedge, yedoma, spores, pollen, verification, total annual thawing index

Abstract: Massive ice beds are unique natural formations of cryolithozone, as well as important objects of research in the area of reconstruction of paleogeographic conditions and solution of the tasks of engineering geology. On the plains of Chukchi Peninsula, massive ice beds are common and represent regional geological peculiarity. The article traces the dynamics of recession of the edge of thermocirque and the evolution of the morphology of ice bed outcrop in 7 km south of the village of Lavrentia (Chukotka Autonomous Okrug) over the period from 2018 to 2021. The results of field observations indicate the active development of thermocirque over 4 years: its back wall in both corridors receded by 50-60 meters, increasing the area of the thermocirque by 3-4 times. The shape of the outcropping massive ice bed changed over time: in 2018, its main part was exposed in the northern part, in subsequent years, the bed was outcropped mainly in the northern part from the side of the deposits remnant (southern side) and in the southern part. The width of the bed varied from 5 m in 2018 to 15-20 m in 2019 and 2021. The ice thickness also varied in the northern part of the thermocirque from 2 m in 2018 to 6 m in 2019, while in the southern corridor it remained stable in 2020-2021 (about 5 m). A hypothesis has been put forward on the mechanism and time of ice bed formation. The acquired results suggest that the ice bed may have heterogeneous segregation-injectional genesis. It is revealed that the ice bed under review is part of a larger ice body and was outcropped as a result of the cyclic fluctuations of climatic characteristics that determine the depth of seasonal thawing of the soil.

Keywords: permafrost dynamics, cryolithological analysis, permafrost zone, climate change, thermocircus, Chukotka, massive ice, permafrost, cryogenic landslides, paleocryology

Abstract: The research of peat and peat-mineral frost mounds was carried out in September – October 2021 in the northeast of Yamal Peninsula, 50 km north of the village of Tambey. Morphometric data was acquired om ten frost mounds. The wells with the depth of up to 1 m were drilled in 4 out of 10 mounds using electric drill, which outcropped the upper horizons of permafrost. Descriptions were given to seasonally thawed layer and drilled permafrost. Diameter of the mounds located in various landscape conditions varied from 4.5 to 9.8 m, and their heights ranged from 0.5 to 1.5 m. The thickness of seasonally thawed layer on these mounds varied from 28 to 131 cm, while the maximum depth of seasonal thawing was reached on the slope of the hillock, with rare exceptions when it was observed on the top of the hillock, or 1 meter from it. The steepness of hillocks rarely reached 10°, averaging from 3°to 5°. The seasonally thawed layer consisted mostly of the layers of lignite of varying degree of decomposition, rarely replaced by light gray loam (including peaty). Permafrost rocks were also represented by peat with high content of ice.

Keywords: Late Holocene, loam, peat, seasonal thawing layer, tundra, peat-mineral heaving mounds, permafrost, Tambey River, Yamal Peninsula, northwest Siberia

Abstract: The subject of this research is the historical data on the origin, geographical distribution, seasonal and long-term variability of giant aufeis ice sills in the Russian Far East. Ice sills are the ice fields, the thickness and area of which reach up to 10-12 m and several tens of sq. km respectively. They are formed in severe climatic conditions as a result of layer-by-layer freezing of groundwater poured onto the surface. This is a distinct form of seasonal, and at times, long-term glaciation, which regulates the processes of water and energy exchange in low temperature cryolithozone, as well as determines the extent of permafrost intermittency and developmental challenges. Assessment is given on the role of aufeis ice sills in the formation of river and underground runoff, transformation of terrain, morphological structure of landscape, and development of dangerous cryogenic phenomena. This article is first to review the data on aufeis ice sills in the Russian Far East that have accumulated over the past two centuries. Three author highlights the three research periods: until 1900, since 1900 to 1950, after 1950. The latter period is the most effective, indicate the creation of the map and cadastre of giant aufeis, including more than 7,000 ice fields based on the data of aerial photography. The article establishes the key patterns of their distribution, factors and conditions of formation, relation to permafrost-hydrogeological structures, forms of terrain and climate; as well as determines the peculiarities of seasonal and long-term variability.

Keywords: aufeis regulation, river streamflow, underground waters, aufeis hazard, mapping of aufeis, distribution of aufeis, aufeis resources, aufeis, permafrost, ice cover