The article presents quality assessments of using the ensemble approach to produce long-term meteorological forecast in the Western Arctic with a one-month advance. The assessment of retrospective forecasts’ quality of the sea level pressure anomalies field and surface air temperature anomalies has been performed for 2010–2018. The ensemble forecast for the second month was made using two methods. The f irst method is the forecast of the mean field of meteorological parameters for all ensemble members. The second method is the forecast of the mean field made by the best class selected from all ensemble members by the clustering procedure. The best class was selected by comparing macrosynoptic process evolution of the first forecast month of each selected class with the actual observations. In the area considered, which is bounded by coordinates from 20º W to 100º E and from 60º N to 80º N, 108 retrospective forecasts were made. As an independent series, the forecast success for 2018 and 2024 was analyzed using two ensemble forecasting techniques and a synoptic-statistical method (the Wangenheim–Geers macro-circulation method). Three estimates of the forecast quality were obtained — the mean square error, the correlation coefficient between the forecast and actual fields of meteorological parameters, and the coefficient of geometric similarity of the forecast and actual fields of the meteorological parameter. The estimation of quality was made for two parameters — sea level pressure and surface air temperature. The highest quality of forecasts using the best class method is observed in the summer season, and the RMS error of forecasts is minimal at this time. The forecast by the method of all ensemble members is preferable in the winter season. The results show that, in general, the best-class ensemble forecasts are more accurate for forecasting the phase of pressure anomalies, while for forecasting the magnitude of temperature and pressure anomalies, it is preferable to use the forecasts for all ensemble members. For 2018 and 2024, both ensemble forecast methods showed higher forecast quality scores than the synoptic-statistical method.

Estimates are presented for the share of anthropogenic heat flux caused by heating, based on assuming that anthropogenic heat flux depends on outdoor air temperature and that buildings comply with the thermophysical standards specified in the construction regulations. Using the OpenStreetMap web mapping platform, the Yandex Maps service, and GIS housing and communal services, building models were constructed of 12 cities and settlements located in northern Russia. The volumes of all buildings and the surface areas of their enclosing structures were calculated. Three algorithms for estimating the anthropogenic heat flux are considered. The first algorithm uses the concept of normative heat transfer resistance of enclosing structures. The second is based on the normalized value of the specific heat protection characteristic of a building. The third uses the normalized specific characteristic of heat energy consumption for heating and ventilation of the building. It is proposed to use the average anthropogenic heat flux estimate obtained by all algorithms. anthropogenic heat flux is estimated from an administrative and urbanized area. During the heating period the anthropogenic heat flux density from the urbanized area per 1°C difference between indoor and outdoor air temperatures ranges from 0.31 to 1.75 W/(m²·°C). The anthropogenic heat fluxdensity from the urbanized area for the average heating period temperature is located within the range where the lower boundary is estimated between 9.60 and 19.5 W/m², and the upper boundary between 30.0 and 61.2 W/m², depending on the settlement. In this case the total emitted anthropogenic energy (in PJ) from the administrative area is equal to 8.29–20.7 for Surgut; for Yakutsk 9.57–23.6; Arkhangelsk 7.37–15.4; Murmansk — 5.16–11.6; Norilsk — 2.99–9.09; Vorkuta, Apatite and Salekhard — 1.29–4.80; Naryan-Mar — 0.961–1.92; Dudinka — 0.537–1.42; Tiksi and Dixon’s — 0.247–0.681. The anthropogenic heat flux density directed downward toward the underlying surface during the heating season is in the range of 1.20–1.96 W/m². Values of anthropogenic energy averaged over the heating periods 2013–2018 and 2018–2023 are given. Maps of the spatial distribution of the anthropogenic heat f lux density for Vorkuta and Apatite are presented.

The Arctic seas are subdivided by the characteristic features of the ice regime into natural areas identified in the course of many years of observations and research by various scientists. At present, the ice cover of the Arctic seas is traditionally determined relative to such areas, identified in 1972 at the Arctic and Antarctic Research Institute. The ice-free period has some advantages over ice cover; for example, its start and end dates are an important ice characteristic. However, it is not always possible to determine the ice-free period for a large area of the sea since ice rarely disappears over its entire water area. In addition, climate change has led to the boundaries of some previously identified areas not fully corresponding to parts of the sea with uniform ice conditions. Warming in the Arctic has led to the southern waters of the Laptev Sea and the southwest of the East Siberian Sea becoming free of ice almost every year in recent decades, while in their northern part the ice-free period does not occur in some years. Therefore, for a more accurate dating of the ice-free period for the Laptev and East Siberian seas, this article proposes making some additions to the traditional zoning. The increase in the duration of the ice-free period in different parts of the seas began at different times, on average around 2000. To describe this process in the article, the time period from 1991 to 2023 was divided into three equal eleven-year periods. For each of them, the values of the duration of the ice-free period were calculated. The data analysis showed that the duration of the ice-free period in all parts of the Arctic seas in the second period (2002–2012) increased significantly compared to the first period (1991–2001). The increase ranged from 13 to 88 days, depending on the area of the sea. Over the past 11 years (2013–2023), the duration of the ice-free period in the Kara, Laptev, and northwestern part of the East Siberian Sea has increased by 8–18 days compared to the second time interval (2002–2012). In the southwestern and eastern parts of the East Siberian Sea, as well as in the Chukchi Sea, the ice-free period has not increased over the past 11 years, although compared to the first time period (1991–2001), it remains quite large.

In view of the continuing human expansion in Antarctica, it is crucial to implement a wide range of measures to effectively protect the natural environment and uphold the fundamental principles of the Antarctic Treaty system. Soil is the most important component of all terrestrial ecosystems, which plays a crucial role as the spatial basis of ecosystems. Despite the considerable research performed in different sectors of Antarctica, soils and soil-like bodies of Antarctica remain poorly investigated. The aim of this study is to investigate the processes of biogenic accumulation of substances and biogenic-abiogenic interactions in the soils of the Pravda Coast and the Haswell Archipelago, East Antarctica — vicinities of the Antarctic station Mirny. Field observations and laboratory analyses were conducted, focusing on determining the chemical composition and levels of organic matter in the soils. It was found that the soils exhibit a moderately acidic to near-neutral pH. High levels of organic carbon accumulation were recorded on Haswell Island, influenced by ornithogenic factors. Unlike most soils in East Antarctica, these soils display a presence of humus-like plasma. The soils studied are characterized by low (or moderate) levels of contamination, according to Igeo (geoaccumulation index); however, an increase in pollutant accumulation rates is observed in ornithogenic habitats and on the surfaces of peat horizons.

The problem of conservation and study of small urbanized water bodies in the Arctic regions of Russia is quite acute, given their economic, biological and recreational significance. The article is devoted to the study of the hydrobiological features of Lake Kontokki, on the eastern coast of which the single-industry town of Kostomuksha (northern Karelia) is located, the main industrial enterprise of which, the Kostomuksha Mining and Processing Plant, makes a significant contribution to the economic development of the Republic of Karelia and north-west Russia. To solve the problem, a study of the current state of zooplankton communities, macrozoobenthos and ichthyofauna of the reservoir was conducted in 2024. The main dynamic factors affecting the ecosystem of the reservoir are associated with population growth and expanding urban infrastructure. These include increasing recreational load, as well as an increase in municipal, storm water runoff and melt water from the city. The object of the study is a small urban reservoir located within the Arctic zone of Russia. To achieve the goal, comprehensive hydrobiological studies were conducted using generally accepted laboratory techniques. The quantitative characteristics and species composition of the planktofauna, benthofauna and ichthyofauna of the reservoir under modern conditions were determined. Features of the development of the plankton fauna and macrozoobenthos of Lake Kontokki are primarily due to the geographical location of the object, its hydrological features, and the influence of anthropogenic factors. According to the level of quantitative development of zooplankton and macrozoobenthos, Lake Kontokki is characterized as an oligotrophic reservoir. The zooplankton biomass fluctuates within 0.6–0.8 g/m3, benthos 0.6–2.0 g/m2. The zooplankton community is formed by representatives of two dominant groups (rotifers, crustaceans), which in equal shares form the species richness (44 taxa). A significant number of oligochaetes and chironomid larvae tolerant to habitat conditions were found in the lake sediments. More than 70 % of the macroinvertebrate taxa in the benthos are represented by insect larvae (Ephemeroptera, Diptera, Trichoptera). According to the species composition of the ichthyofauna (8 species), the lake belongs to the water bodies of the first fishery category. The results obtained can provide additional information for complex environmental monitoring of urbanized water bodies in the northern regions of the taiga zone.