The study investigates the spatiotemporal variability of heat content in the North European Basin (NEB) — the Barents, Greenland, and Norwegian Seas. The research is based on the ORAS5 (Ocean ReAnalysis System 5) reanalysis data for the period 1982–2024. The climatic vulnerability of the region, driven by Arctic amplification and the intense advection of warm Atlantic waters, necessitates a detailed investigation of heat redistribution mechanisms. The aim of the work is to quantify interannual changes, taking into account seasonal dynamics, to identify spatial patterns in the distribution of heat content trends for different layers (0–200 m, 200–300 m, 300–400 m, 400–500 m and 500–600 m) and to study the vertical distribution of heat content during the period of modern climate change. The analysis employed methods of linear regression, the coefficient of determination (R2) of the linear trend, and layer-wise averaging; the statistical significance of the trends identified was assessed using Student’s t-test. The most pronounced positive heat content trends (R2 > 0.5) are observed during the winter season in key advection zones of warm Atlantic waters: along the West Spitsbergen Current, over the Mohn Ridge, and within the Bear Island Trough. The Lofoten Basin stands out due to exceptionally high and persistent R2 values (> 0.6 down to a depth of 600 m), explained by the dominant role of mesoscale eddies in deep heat penetration processes. The analysis revealed significant vertical transformations in the thermohaline structure of the NEB waters since the 2000s: in the Fram Strait, the 1.4 °C isotherm descended from ~400 m to ~650 m; in the Boreas Basin, the 0 °C isotherm descended from ~500 m to ~650 m; over the Mohn Ridge, the layer of water warmer than 2 °C thickened from ~200 m to ~300 m. Summer months show minimal R2 values in the central basins, reflecting the strong influence of seasonal stratification and enhanced turbulent mixing processes. The combination of changes observed — weakening of vertical stratification, intensification of meridional heat transport, and the progressive deepening and eastward spread of Atlantic-origin warm waters — serves as a key indicator of the accelerating “Atlantification” process of the NEB, fundamentally altering the regional heat balance. The results obtained highlight the decisive role of complex bathymetry and sustained advection in shaping the spatial patterns of heat accumulation within the basin. The patterns identified are of significant importance for forecasting thermohaline circulation and the sea ice regime of the Arctic under climate change conditions.

The paper study presents a review of synoptic conditions and an analysis of atmospheric radiosonde data collected at the “Ice Base Cape Baranova” research station, operated by the Federal State Budgetary Institution “AARI”. The station is located on the coast of the Shokal’sky Strait at the northern tip of Bolshevik Island (Severnaya Zemlya archipelago). The analysis includes four cases of thunderstorm activity: one case in June 2019, two cases in June 2020 and one case in July 2022. Notably, the first recorded thunderstorm at the station occurred on June 20, 2019. The analysis focused on morning radiosonde data (00:00 UTC) and aimed to construct and evaluate aerological diagrams and calculate various instability indices, including the Boyden Index, K-index, Vertical Totals, Cross Totals and Total Totals. The findings reveal diverse synoptic conditions at the surface, while the upper troposphere consistently exhibited the influence of baric trough from the southwest and height ridges from the southeast. In all the cases analyzed, a temperature inversion was observed in the surface layer, typically indicating stable atmospheric stratification. However, the actual occurrence of thunderstorms suggests alternative factors, such as orographic influences and warm air advection, may give rise to these convective processes.

Although the calculated instability indices generally remained below established thresholds, indicating a low probability of thunderstorms, thunderstorm events were nevertheless recorded. This discrepancy highlights the need to adapt existing criteria for predicting thunderstorm activity in the High Arctic. This study underscores the importance of further research to enhance understanding of atmospheric dynamics in Polar Regions and improve predictive models for convective weather phenomena.

The snow cover plays one of the key roles in the water balance of water objects in Arctic archipelagos. The current climate changes in the Arctic region can have a complex impact on the snow cover of Arctic archipelagos. Since 2000, the Russian Federal State Budgetary Institution “AARI” has been conducting research on the snow cover on the Spitsbergen Archipelago near Barentsburg as part of a hydrological study. The aim of this work is to generalize and analyze the data obtained from the perspective of interannual variability under conditions of climate change. The paper presents results of snow surveys. Gaps in the observations are restored using statistical methods. It was found that during the study period from 2000 to 2024, no statistically significant trends were observed in the main characteristics of the snow cover (height, density, snow water equivalent) — –2.6 cm/10 years, –1.0 kg/m³/10 years and 1.8 mm w. e./10 years respectively. It was shown that the characteristics of the snow cover at similar objects are well correlated with each other and with the maximum height of the snow cover at the Barentsburg weather station, and they can be used to reconstruct the gaps. The climate in the study area during the cold season is becoming slightly warmer, windier, and drier, though the warmest years are also the wettest. The dates of snow disappearance and onset, as well as the duration of snow cover presence, remain largely unchanged. No relationships were found between the meteorological parameters of the cold period and the height or proportion of basal ice in total watershed liquid-water content. Correlation analysis results demonstrate the sensitivity of high-elevation watershed snow cover characteristics (glaciers) to precipitation totals during the cold period, while lowland valley watershed characteristics are sensitive to temperature. Thus, we currently observe an overall stationary period of snow accumulation conditions, where the increase in coldseason temperatures is partially offset by increased precipitation, and the sensitivity of watershed snow cover characteristics depends on their elevation.

This article offers critical comments on the paper “Sustained decrease in inland East Antarctic surface mass balance between 2005 and 2020” by Dr. Danhe Wang and co-authors published on the 11th of June 2025 in the “Nature Geoscience” journal. There is no doubt about the high quality of the data presented in the Wang et al.’s manuscript, but the results of the study are applicable only to a relatively short interval of time and to a small fraction of the East Antarctic Ice Sheet (in particular, to the vicinity of Dome A). In this respect, the paper’s title is to a large extent misleading since there is no evidence of sustained decrease in surface mass balance in inland East Antarctica as a whole, even though there is no disputing the fact that the total mass of the Antarctic Ice Sheet is decreasing due to ablation at the edges.

From the 1970s to the present time, a great deal of field work and analysis has been done on the physical and mechanical properties of sea ice ridges. Sail and keel thicknesses have almost always been measured in the field expeditions. Emphasis is placed on the thickness of the consolidated layer (CL) within the ridge. This paper was motivated by a number of new findings on the distributions of the main morphometric characteristics of ice ridges. The wide range of opinions about the distributions is, apparently, primarily due to the number of ice ridges and stamukhas studied in the different expeditions, i.e., the sample size. This article attempts to systematize the various opinions and add some clarity to the matter. It focuses on the development of approaches to determining the statistical distributions of the main morphometric parameters of first-year ice ridges: sail height, keel depth and consolidated layer thickness. Measurements of ice cover thickness were carried out in 2006–2009 from Russian vessels and icebreakers using a digital television complex. The distribution of first-year ice thickness along the navigation route of vessels shows that Arctic ice is normally distributed with a mathematical expectation of 1.24 m and a standard deviation (RMS) of 0.34 m. The histogram of ridging ice thickness in the Arctic region presented in L. Strub-Klein and D. Sudom’ review and based on a large data set is satisfactorily approximated by the exponential distribution law. It is known from literature sources that sail heights scale with the square root of ice thickness. One of the properties of the exponential distribution is as follows: if a random variable (the thickness of ridging ice) adheres to the exponential distribution, then the random variable “sail height” connected with the thickness of ridging ice has the Weibull–Gnedenko distribution. The ice ridge keel draft can be also shown as adhering to the Weibull–Gnedenko distribution. If we compare the formation process of the sail of ice ridges and stamukhas, it can be concluded that the energy of these processes is similar. Therefore, it can be presumed that the distribution of stamukha sails is also the Weibull–Gnedenko distribution. As for the distribution of the stamukha keel, it also adheres to the Weibull–Gnedenko distribution, since the stamukha draft is determined by the keel draft of an ice ridge which ran aground in shallow water and became its embryo. When considering the distribution of the CL thickness, let us use Høyland's formula, which gives a direct correspondence between the rubble porosity and the CL and level ice thickness. We shall generate an array of pairs of random level ice thickness values normally distributed with a mathematical expectation of 1.24 m and RMS of 0.34 m. We shall assume that the porosity is constant and equal to η = 0.23. For each pair values, we will calculate the CL thickness corresponding to them from Høyland's formula and plot a histogram of the resulting array of values. The best approximation of the histogram is the normal distribution with a mathematical expectation of 1.82 and RMS of 0.88. However, given the gradual reduction of the keel porosity the normal distribution transforms into the Weibull–Gnedenko distribution. Thus, as a result of the simulations performed, a certain pattern of distribution of the sail height, keel draft and the CL thickness of ice ridges has been revealed. The thickness of the ridging ice obeys the exponential distribution law. The height of the sail, the draft of the keel and the thickness of the consolidated layer of ice ridges obey the Weibull–Gnedenko distribution.

One of the main causes of sea-level rise is the melting of ice and, above all, the Antarctic ice sheet. Over the past three decades, the loss of ice sheet mass has more than tripled. Some researchers propose reducing ice melting through large-scale geoengineering interventions that change the processes of heat transfer in coastal oceanic waters and the parameters of the ice sheet, or slow down the flow and change the basal hydrology of ice shelves and ice streams. Methods of solar geoengineering have also been proposed to control the amount of solar radiation reaching the Earth’s atmosphere and reduce the surface temperature of the ice sheet. Despite some progress made towards the theoretical and technological validation of these interventions, there are fundamental problems with their technical feasibility, uncertainty and high risks. The potential environmental consequences of geoengineering interventions are extraordinary. At present, our understanding of glacier geoengineering is not sufficiently advanced to support the deployment and implementation of glacial geoengineering technologies.

Authigenic mineral formation in permafrost environments represents a scientifically significant yet little understood field of cryolithology. This study provides the first comprehensive documentation and analysis of authigenic barite discovered in frozen sediments of thermocirques on the Yamal Peninsula, with a particular focus on its potential as a novel indicator of cryogenic processes. The research methodology combines advanced analytical techniques including high-resolution scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and comprehensive geochemical characterization of ice-ground systems. A key methodological innovation is the development and application of specialized polymer replica techniques that enable precise preservation of primary cryogenic textures and microstructures in frozen samples, overcoming the limitations of conventional sample preparation methods. The results obtained demonstrate that authigenic barite forms distinctive rosette-shaped micro-aggregates within ice-ground micro-pores, with the crystal morphology indicating in situ growth under cryogenic conditions. Detailed geochemical analysis reveals that barite formation is fundamentally controlled by freeze-induced solute redistribution processes, where specific ionic ratios (particularly elevated SO₄²⁻/Ca²⁺) and neutral pH conditions preferentially promote barium sulfate precipitation over calcium sulfates. These findings show authigenic barite as a sensitive paleoindicator of cryogenic processes including thermodenudation, segregation ice formation, and freeze-thaw solute concentration. The study provides crucial new insights into low-temperature geochemical processes operating in permafrost environments, with important implications for understanding cryosphere evolution under contemporary climate change scenarios.

The warming of the Arctic climate in the Atlantic has led to a significant reduction in the glaciation of Spitsbergen. The numerous periglacial lakes formed on the ice-free areas among the moraines, their banks and adjacent areas have become the suitable habitat for the birds. The current stage of deglaciation of Western Spitsbergen began about 100 years ago, and the first to be freed from ice were those land areas that lie at low hypsometric levels. Over the past 100 years (since the 1920s), the large glaciers of Grønfjord Bay (Nordenschöld Land) have retreated 2.1–2.8 km from the coast, freeing up significant land with a total area of about 14 km2. Numerous lakes of various sizes (52 lakes) with a total size of 1.9 km2 have formed on these moraines. The shores of Grønfjord Bay were surveyed during August 2022–2024 and 26 bird species were identified. Among them, 9 bird species were found within the “new land” — in the areas of glacial moraines. We noted that the following bird species were often observed or found nesting on the moraines: the red-throated loon, fulmar, bean goose, barnacle goose, rock ptarmigan, purple sandpiper, glaucous gull, Arctic tern and snow buntings. The bird species, their status and numbers were registered at a visible distance during a field survey in various habitats, by counting or photographing the birds by camera or “digiscoping”. All the bird species encountered were recorded within the visibility range, without a fixed counting strip. As a result, differences in the bird composition and numbers were found for moraines of the Austre, Vestre GrØnfjordbreen and Aldegondabreen glaciers: the most preferred habitats for birds were the gentle or flat areas of young moraines covered by pioneer vegetation near the periglacial lakes. These are the areas, which became free of glaciers at an early stage of deglaciation more than 50–60 years ago. Despite the diversity of bird species in the bay, they occupy the new periglacial areas relatively slowly.