Lithological characteristics and fossil assemblages of planktic and benthic foraminifers, ostracods and macrobenthos/macroplankton were investigated with high resolution in sediment core KD12-03-10С retrieved from the water depth of 2200 m on the eastern Mendeleev Ridge slope. The downcore alternation of 8 peaks in the abundance of coarse-grained ice- and iceberg-rafted material (IRD) and several peaks in the abundance of planktic and benthic fossils, together with the changes in species composition and the presence of stratigraphically indicative species give evidence for temporally consistent sediment accumulation of the core sequence. This allowed estimating the age range of the sequence as the whole Neopleistocene and probably slightly older and establishing several interglacial, glacial and deglacial epochs. The reconstructed paleoenvironmental changes correspond to the growth and decay of continental ice sheets, variations in sea ice cover extent, progressive Neopleistocene cooling trend, decreasing connection with the Pacific Ocean and growing influence of the Atlantic Ocean.

Long-term regime of extreme values of the surface horizontal wind speed (V) was studied for the open part of the Barents Sea basing on the ERA-Interime reanalysis data for 1981-2010. Empirical distribution functions of V were estimated. Spatial and temporal analysis of the median and extreme V (95th, 99th and 99.9th percentiles) variability was carried out. No long-term trend was revealed for the whole period, but in the 1990s wind speed extreme values tended to be higher. The latter is in agreement with the increase of the southern type of meridian circulation (according to Dzerdzeevsky’s classification). Sea level pressure patterns for the days with high V (99%) were classified into four circulation types. It is shown that the majority of such cases were characterized by active cyclones passing over the sea, and wind direction in different sea parts depended on the cyclone center position. The year-to-year variability was studied for every circulation type. Quantitative description of sea level pressure patterns for high wind speed values allowed processing the long-term data set and creating a basis for the future evaluation of projected extreme patterns under possible climate changes.

A winter cyclone that crossed the Barents Sea on 10–15 February, 2015, was studied. The wind speed was 30 m/s and wave heights reached 12 m (satellite measurements). The wind waves modeling during the cyclone was made using the SWAN model and NCEP/CFSR wind data. Wind speed values from reanalysis are validated by comparing with AMSR2 microwave radiometer wind data. The wave data from the AltiKa altimeter were used for wave model validation. In general wave heights are well modeled with the RMSE=1 m and the correlation = 0.9. The reanalysis wind speed is underestimated by 0,63 m/s on the average.

The characteristics and specific features of storm surges formation in the White Sea are investigated basing on the observations at the stations located in the Gorlo (Neck), Dvina Bay, Kandalaksha Bay and on the Solovetsky archipelago. It was found that in some cases the passing cyclones generate a pressure wave in the Barents Sea that penetrates into the White Sea, and induces the surge. The crest of the surge wave first passes the Sosnowiec station, then in about 7 h the Severodvinsk station and after 2 h more reaches the Solovki. The maximum height of surge wave (0.9 m) was observed on December 12, 2013. In the absence of significant effects of the wind in the White Sea, the height of the surge is practically constant during the passage of the wave. Wind action results in the transformation of wave surges. The wind factor reached its maximum in the Dvina Bay, where on November 6, 2010, the highest ever surge was recorded (1.08 m at Severodvinsk and 1.22 m at Solombala station). Under the northwesterly wind this surge came first in the Dvina Bay, and then reached other parts of the sea. In most cases, pressure forces made the major contribution. Herewith, as a rule, there was a high negative correlation (-0.8) between the average daily values of surface atmosphere pressure and the residual sea level at the Sosnowiec station. Only during the maximum wind surge in the Dvina Bay of November 6, 2010 the contribution of pressure forces was relatively small. Wind component in this case was the highest (56%). The down-surge is quite usual phenomenon before the surge. The most significant one was recorded on 27 November, 2013, when the residual sea level fell 0.54 m below average at the Severodvinsk station. The residual level range in this case was 1.35 m, which is comparable with tide magnitude.

The area under investigation is the Arctic region of the European part of Russia. According to the information from 74 hydrological gauging stations on 65 rivers, the characteristics of ice regime from 1961 to 2013 are described. Dates of first ice on the rivers, formation of seasonal winter ice cover, ice breakup and ice clearance were analyzed, as well as the duration of the autumn and spring ice run, freezing-up and ice-clearing periods, complete freezing period and that with ice phenomena on the rivers; characteristics of water level regime (maximum levels during the spring ice run, levels of the first ice and the complete freezing) etc. are described. The most pronounced problems for people and economy in relation to ice phenomena on the rivers are inundations (because of ice-dam or ice-jam development), damage of hydraulic engineering structures during heavy ice run at high water levels, and also the organization of navigation and ice crossings of rivers. Ice hazards were evaluated using such indicators as frequency of floodplain flooding during the spring ice run; return period of the maximum annual water level accompanied by the ice phenomena; characteristics of ice-damming (frequency, maximum levels of water and contribution of ice-dams to their formation); actual duration of navigation, characteristics of freezing-up and ice-clearing periods.

The article deals with the river mouth sites of the Southern Island of the Novaya Zemlya archipelago and their classification according to the hydrological and morphological characteristics. The classification is based on the visual interpretation of satellite images and topographic maps. Five basic types of river mouths and their occurrence within the island are characterized. Deltaic forms typical for different types of river mouths are described. Using the rich body of literature the authors evaluated the impact of different environmental conditions on the formation of solid discharge and sedimentation conditions in river mouth areas.

The results of detailed studies of hazardous hydrological processes in the mouth of the Northern Dvina river are presented. The focus is on the ice jams, inundations from both pure maximum stream flow and peak discharges with ice jams, storm surges and surge-induced flooding, dangerous wind-induced down-surges and low-water periods. The updated and new information on the location, frequency and magnitude of hydrological hazards, long-term variability of their characteristics are given. Long-term changes of hazardous hydrological processes in the mouth of the Northern Dvina river in the period 1900–2013 are analyzed. During this analysis, the features and patterns of long-term variations in water runoff and hydrological regime of the river, of the regime of the White sea, of the regional climatic conditions are taken into account. New estimates of the parameters of the hydrological regime river in its mouth are obtained. Conclusions on the spatial and temporal variability of these characteristics, the causes of variability are justified. Detailed information about the damages into the mouth of the Northern Dvina river caused by floods, about list and effectiveness of the measures of prevention and protection against ice jams and river flooding, new data on the structure and parameters of the mouth of the Northern Dvina are given.

The results of studying the problems of socio-economic development of the Arctic zone of Russia are presented. The focus is on the development of approaches to the assessment of additional costs of the economy caused by both the state of natural complexes of the Arctic, and their changes over time, as well as the consequences of arising anomalies. In this context, the impact of permafrost degradation on the housing sector of the Russian Arctic settlements is discussed more in detail. Another topic line of research in the Arctic, particularly for the purposes of planning the economic activities in the region and forecast of their development, is the assessment of municipalities in terms of their vulnerability to socio-economic and environmental changes. The results of our study prove that the global warming and its effects, combined with social and economic processes at the global and regional level, lead to divergent trends of costs and increase the vulnerability of territorial systems.

The article deals with the distribution and chronology of recent geomorphologic processes, mainly in the Khibiny tundras. New evidences about the respective relief transformation and the manifestation of both well known (water-snow flows) and «exotic» for the Kola Peninsula processes (landslides) are presented. The processes were typical for the whole second half of the Holocene, although there were periods of their activation and weakening. A main factors of their development is the climate change, therefore, the principal trends of fluctuations of air temperature and precipitation in the Kola Peninsula were analyzed. Over the past 100 years the air temperature changes were quasi-cyclic, with a distinct linear trend of increasing annual average air temperature at a rate of about 1oC over 100 years. This could be attributed to the changes in the atmospheric circulation - the duration of northern longitudinal circulation combined with southern one increases throughout the year. There is a positive linear trend in precipitation, i.e. a slight increase of moisture index of the territory. Since a geomorphologic system is very inert, it needs much longer climate changes than 30–50 year long warming-cooling cycles to manifest any transformation.

The main morphological and physical-chemical characteristics of soils (the mineral and elemental composition, pH, carbon organic matter content and its fractional-group composition, the radiation condition) were investigated in the arctic tundra landscapes of the Novaya Zemlya archipelago. Quartz and feldspars dominate in soils, pedogenetic illite and kaolinite are formed in the acid environment, and medium to high quantity of humus of humate-fulvate composition is typical. Soil-forming rocks of the Abrosimov and Stepovoy bays coasts are enriched in Fe, Ti, Cr, V, Ni, As, and depleted in P, S, Rb, Sr, Ba, Th, Nb and Cl. Plants of the arctic tundra landscapes accumulate S, P, Cl, Sr and Zn. The activity of natural isotopes ( ₂₂₆Ra, ₂₃₂Th, ₄₀K) increases from the vegetation to soils and finally bottom sediments. ₁₃₇Cs activity varies inbetween 10–350, 1–310 and 0–26 Bq kg^-1 in plants, soils and sediments, respectively.

 

Rare geochemical phenomena within the polygon landscapes, namely the brackish ice wedges with marine and continental type of mineralization are described. The marine type of mineralization of the Holocene syngenetic ice wedges in the mouth of the Mongatalangyakha River in the north-western Siberia represents local (within the laida fragment) changes of water migration class from neutral hydrogen sulfidechloride to weakly acidic and neutral gley. The continental mineralization of the Late Pleistocene syngenetic ice wedges in the Mamontova Gora section in Central Yakutia is indicative of the local (within the alas depression) changes of water migration class from slightly alkaline gley to acidic gley. Both radial and lateral variability of the chemical composition of the ice wedges was revealed.

The centrographical method is suggested for the analysis of indigenous minorities’ settlement. Application of the method showed that in recent decades the centers of settlement of the indigenous minorities of the North, Siberia and the Far East remained almost unchanged. However the changing nature of the traditional way of life, and demographic and migration processes are likely to change the geography of their settlement, and shift the centers of the peoples’ living.