Abstract Field studies during cruise 50 of the R/V Akademik Sergei Vavilov to monitor the sea surface state using the ship’s navigation radar are described. The spatial scheme of research, development of the method for digitizing, and analyzing data from the ship navigation radar JRC JMA-9110-6XA X-band for reconstructing the characteristics of waves in the open ocean are considered. The results of

Abstract The article considers the primary results of geological, geophysical, geomorphological, and hydrophysical studies in the Barents and Kara seas conducted on cruise 49 of the R/V Akademik Nikolay Strakhov in 2020.

Abstract In the fall of 2018, studies of suspended particulate matter and its organic part in the water column and their lateral flux on the Karelian coast of the White Sea were carried out. The concentration of suspended particulate matter varied from 0.42 to 0.93 μg/L, and the concentration of Corg ranged from 124 to 249 μg/L. In the water column, 25 registration taxa of phytoplankton were recorded;

Abstract The fauna of benthic foraminifers from the northern Laptev Sea has been analyzed to identify the relationship between the distribution of benthic foraminifers and environmental conditions in the eastern and western parts of the sea. The abundance of benthic foraminifer tests in the Laptev Sea is universally low, no more than 3–9 ind./g. Greater foraminifer abundances were found in the west

Abstract Using the example of analysis of 40-year series of vector fields of ice drift in the Arctic Ocean, the features of calculating the parameters of the linear trend of vector processes are considered. The decomposition of acceleration vectors into orthogonal and collinear components relative to the mean vector makes it possible to estimate an increase or decrease in the average velocity and regularity

Abstract The behavior of platinum group elements (PGE = Pt, Pd, Ru, Ir) in separate layers of ferromanganese crusts of the Atlantic Ocean is considered. The studied crusts, in addition to the hydrogenous source of the matter (crusts from the Bathymetrists Seamounts), formed under the variable influence of hydrothermal (MAR, station 2176) and halmyrolytic sources of matter (Angola Basin, station 2179)

Abstract This paper presents a statistical analysis of time series obtained from the Aqualog profiler moored at the upper continental slope off the southeast Russian coast in the northwestern Sea of Japan from mid-April through mid–October 2015. The vertical conductivity, temperature and depth (CTD) profiles with a high resolution (6 hours in time and 1 m in depth) were measured between 64 and 300

Abstract Adding newly processed old marine and land-based wide-angle seismic data to modern geological and geophysical information about the region provides the correct localization and understanding of interaction of the Sinai, Anatolian, and African plates in the Eastern Mediterranean. Wide-angle seismic profile data acquired by ocean bottom and land-based seismometers in 1989–1990 by USSR Academy

Abstract The article discusses advanced technologies, methods, and techniques of diving, which, according to the results of comparative testing, are most suitable for use in in situ oceanographic research by scientific divers, including oceanographers themselves with professional diving training. At the same time, a wider range of scientific problems are being solved, and the methodical level, efficiency

Abstract In this study we explore the origin of the high stability of the Lofoten vortex, persistently observed in the central part of the Lofoten Basin of the Norwegian Sea. It is shown that the higher steepness of the southwestern bottom slopes and a small inclination of the bottom topography towards the region where the Norwegian Current splits into two branches increase the dynamic stability of

Abstract Results of the study of water exchange between the Azov and Black seas based on the data of contact measurements in 2019 are presented. Estimates of the scale of the Sea of Azov plume were obtained under conditions of a strong northeasterly wind (9–10 m/s). The results of field measurements confirmed the determining role of wind in water exchange through the Kerch Strait, which made it possible

Abstract The article presents the data of an comprehensive expedition of the Pacific Oceanological Institute, Far East Branch, Russian Academy of Sciences, performed in the mixing zones of the Uda and Usalgin rivers in July 2016. During the flood period, they occupy most of the catchment basins: Udskaya Bay and Nikolaya Bay. The estimated discharge of the Uda and Usalgin rivers was 4390 and 173 m3/s

Abstract— The results of studies of four coastal lakes with unique hydrological and hydrochemical structure at different stages of isolation from Kandalaksha Bay of the White Sea are reported for 2012–2019. All waterbodies are characterized by a permanent or seasonal stratified structure; as a result, bacterial sulfate reduction and hydrogen sulfide accumulation, toxic for aerobic life forms, become

Abstract— The Delft3D Flow model was applied to simulation of the hydrodynamic regime of Voevoda Bay (the southern Primorye, Russky Island, Peter the Great Bay, Russia). The streamflow and distributed inflow from the territories adjacent to the bay was simulated using the SWAT hydrological model. The simulation results were compared with published recommendations on the technology of the off-bottom

Abstract For the visual study of the seafloor and underwater objects and to improve the efficiency of interpreting underwater video data, in some cases it is appropriate to augment it with side-scan sonar data. This article proposes a method for integrating sonar and video data, making it possible to assess the state of underwater objects on the meso- and microscale. Our method is based on creating

The article presents the results of hydrobiological, ichthyological, trophological, acoustic, and genetic research aboard the R/V Professor Levanidov in the Chukchi, East Siberian, Laptev, and Kara seas during August 8–October 2, 2019. The distribution of species-indicators of vulnerable marine ecosystems was studied and the amount of seabed litter was estimated.

Cruise 81 of the R/V Akademik Mstislav Keldysh was organized by Shirshov Institute of Oceanology and took place from August 27 to September 25, 2020 under the Program “Marine Ecosystems of the Siberian Arctic.” Participants included 76 scientists from the institutes of Russian Academy of Sciences, Moscow State University, VNIRO, and the NRC Kurchatov Institute and specialists from the Emergency Situations

Abstract— Field observations were applied to study the macrophytobenthos of the Abrau Peninsula of the Black Sea and the effect of the two most common and largest species of brown algae of the Black Sea sublittoral, Cystoseira bosphorica and Treptacantha barbata (Cystoseira sensu lato), on species richness and phytocenosis biomass, as well as biomass and the occurrence of related macroalgae species

The paper summarizes results on the content and composition of aliphatic hydrocarbons (HCs) in suspended particulate matter (SPM) and bottom sediments in the Kara, Laptev, and East Siberian seas obtained in 2015–2018. It was established that the “losses” in HC concentrations in surface waters in the river (Ob, Yenisei, Lena, Khatanga, Indigirka, Kolyma) and seawater mixing zone in some cases exceeded

Abstract— High-resolution measurements by unmanned aerial vehicles (UAVs), satellite and in-situ data are used to study the optical structure of coastal submesoscale eddies and their influence on the transport of total suspended matter (TSM). It is shown that submesoscale cyclones cause intense cross-shelf TSM fluxes and its subsequent accumulation in their cores, similar to what is observed in large

Abstract The phytoplankton activity was analyzed in June 2015 in Onega Bay of the White Sea. The chlorophyll a concentration, as well as cell abundance and cell biomass, were assessed in natural phytoplankton samples and individually for the picoplankton fraction. These data were compared with the results of additional optical measurements for the same water samples. A strong correlation (R2 = 0.82)

A criterion or index for assessing the hazard of storm-induced coastal erosion is suggested. It is based on comparison of actual beach volume \(~{{V}_{b}}\) and its optimal value \({{V}_{{b^{*}}}}\) sufficient to avoid irreversible beach changes due to severest storm attack over the year. The erosion hazard level is determined taking into account the difference of \(~{{V}_{b}}\) and \({{V}_{{b^{*}}}}\);

Abstract The distribution of heterotrophic bacteria, viruses, and heterotrophic nanoflagellates was studied in the shelf waters of the East Siberian Sea along the meridional transect from the Kolyma River delta in September. The production of heterotrophic bacteria and their mortality as a result of protozoan grazing and lysis of viruses were also determined. The patterns of the spatial distribution

The article deals with deposits exposed in sections along the rivers of the Caspian lowland and on the eastern slope of the Ergenei. The conclusion is made about the lagoonal origin of chocolate clays lying on high-capacity subaerial and alluvial–deltaic deposits. The impact of the Caspian Sea level rise on coastal processes is examined. Taking into account the regularities in the behavior of the coastal

Abstract— The paper proposes a method for assessing the ecological risk, changing throughout the year with the natural functioning of marine ecosystems, and impact of various stressors. The method was applied to ecosystems contrast in productivity of the Arctic shelf. The paper analyses the features of the annual variability of phytoplankton biomass in the Barents, White, Chukchi, Kara, Laptev, and

In this study, we estimated the transport and potential temperature of the Antarctic Bottom Water (AABW) and its variability on intra-annual, interannual, and decadal scales based on eight reanalyses and direct measurements at 26° N in the subtropical North Atlantic. The GLORYS2v4 and GLORYS12v1 reanalyses were selected, which give the closest results of the estimates for average AABW transport, calculated

Abstract —During 79th cruise of R/V Akademik Mstislav Keldysh twelve trawl hauls were collected in Powell Basin and adjacent area at depths 370–3771 m. The structure of the benthic assemblages was highly variable when considered at the macrotaxon level. The main factors shaping the taxonomical structure of the sampled assemblages were depth, near-bottom current velocities and proportion of the hard

The variety of information obtained during scientific research and exploration of seafloor massive sulfide (SMS) deposits include significant data on the morphology of orebodies formed in various geological settings. On the example of hydrothermal vent fields in the Northern Mid-Atlantic Ridge, different hydrothermal ore structures are described, from the most common mound-shaped to rarely encountered

Based on long-term measurements of the concentration of total suspended particulate matter (TSM), particulate organic carbon, chlorophyll a, and the water transparency index for 1978–1998, as well as satellite measurements of the light scattering coefficient for 1998–201, seasonal linear regression equations for the surface layer of the open part of the Black Sea have been obtained. These equations

Abstract— The water exchange between the Black Sea and the Azov Sea is investigated on the base of the marine observations aboard the R/V Deneb in 2018 and 2019. The surveys were conducted under different weather conditions, which led to large variability of the results. The northern wind contributes to the formation of water transfer to the south, which exceeds by five to six times the water transfer

Abstract New data on the geological structure and genesis of relict bottom relief forms, objects of underwater cultural heritage, and the structure of bottom sediments in the Baltic Sea were obtained during cruise 47 of the R/V Akademik Nikolaj Strakhov (June 25–July 4, 2020). Geomorphological features of submerged ancient coastal cliffs have been specified, large sand bodies have been identified at

Abstract—The paper gives brief results of comprehensive studies in the South China Sea obtained from a joint Russian–Vietnamese expedition in November 2019 (cruise 88 of the R/V “Akademik M.A. Lavrentyev”). The set of methods included acoustics, geophysics, geology, mineralogy,geochemistry, paleogeography, geomicrobiology, hydrooptics and hydrology. The seafloor relief, geophysical and gasgeochemical

Abstract During cruise 43 of the R/V Akademik Nikolaj Strakhov (September 21–October 9, 2019), new data were obtained on the bottom relief, sedimentation, and hydrological regime of the Discovery Gap (eastern North Atlantic). It was shown that the upper limit of the Antarctic Bottom Water in the study area follows the 2.05°C isotherm and 34.91 PSU isohaline at depths of 4400–4700 m. A digital elevation

Abstract The multidisciplinary expedition “European Arctic-2020” on board the R/V Akademik Mstislav Keldysh took place from July 31 to August 26, 2020. The investigations were carried out in the Norwegian Sea on the Mohns Mid-Oceanic Ridge (including the hydrothermal activity zone near Jan Mayen), near gas seeps in the Storfjord Trough, on the polar front in the Barents Sea, and on the continental

Abstract Studies have been conducted to assess the functioning of the marginal filter in tidal estuaries of small rivers of the Arctic seas. For this, we used observational data in the White and Barents seas. When extensive tidal drains and thickets of halophytes exist in the mouths of small rivers, biogeochemical processes can differ markedly from the conditions described by the classical marginal

Abstract This work is focused on the river plume generated by the Kodor River which is the largest river of Abkhazia and the northeastern coast of the Black Sea. Based on in situ hydrological data, quadcopter aerial images and satellite observations, hydrophysical structure and circulation in the Kodor plume was studied at different river discharge conditions. Discharge of the Kodor River, which inflows

Abstract The paper presents new data on concentrations and fluxes of organic carbon, iron, and manganese in waters of the mouth area of the Northern Dvina River. The work was conducted within the project “Northern Dvina River Marginal Filter Observatory” from May 2015 to May 2019 with monthly collection of water samples. Systematic determinations of the concentrations of the main carrier elements of

Abstract Large-scale monitoring of anthropogenic marine litter in the Barents Sea was carried out in 2012–2018. The marine litter composition was estimated by recording by-catch from pelagic and bottom trawling. Litter on the sea surface (floating litter) was also taken into account during visual observations. The contents of 949 pelagic and 1477 bottom trawls were analyzed. Marine litter was recorded

Abstract The OCP and PCB contents in the tissues of beluga whales (Delphinapterus leucas) from the Russian Arctic have been studied for the first time. Skin and subcutaneous adipose tissue samples collected in the White, Kara, and Bering seas in 2012–2017 were analyzed for the animals of different age and sex (n = 22). 4,4'-DDE dominated among the OCPs analyzed; the main PCB congeners were PCB-138+PCB-158

Abstract For the first time, the results of a study of ore sands formed during storm waves and winds on the sea beach of Curonian Spit and in the quieter wind environment on the beach of the Curonian Lagoon are presented. The mineral composition and the sources of their supply to the beaches have been determined. Conclusions are given on the practical and theoretical significance of the ore content

Abstract—Hydrogenetic Fe–Mn crusts in the ocean are enriched in platinum but do not accumulate palladium. The mechanism of platinum input into the crusts remains debatable. There is even less data on ruthenium and iridium. In this article, the distribution of platinum group elements (Pd, Ru, Ir, Pt) in ferromanganese crusts of the Detroit guyot (Northwest Pacific) is studied. Based on correlation analyses

Abstract The article presents the results of hydrochemical studies of the rivers of the Abkhazian coast of the Black Sea in April 2019. The Kodor River with its plume was the main object of the study, and additional samples were drawn from the small rivers of Kelasur, Mokva, and Galizga. Kodor River water was shown to contain nutrients at high concentrations (1.35 µM phosphates, 128.5 µM silicates

Abstract At the Black Sea research site Gelendzhik of the Shirshov Institute of Oceanology (IO RAS), a technique has been established for joint current velocity profile measurements using towed ADCP and periodic CTD soundings from on board of the mini R/V Ashamba with high spatiotemporal resolution. In this case, CTD soundings are taken from the sea surface to the bottom layer according to an original

Abstract— The study examines changes in the abundance (density) and distribution of European Sprattus sprattus (Linnaeus, 1758) eggs and larvae, as well as the phenology of its spawning depending on hydrologic factors and abundance of gelatinous macroplankton in the Black Sea in November 2016–2017. An increase in temperature of the sea surface layer observed since the beginning of the century and the

Abstract The effects of oceanic and biotopic factors on the size and age at maturity of sea urchins Strongylocentrotus intermedius alongside the northwestern coast of Primorsky krai are discussed. The growth rate and body size of the sea urchin at 50% maturity of the population corresponds to 30–35 mm in clusters with high growth rates and to 20–22 mm in clusters with low growth rates. In populations

Abstract The geological-structural, magmatic, seismic, and thermometric models of the Earth’s crust and upper mantle of the Sea of Japan region are considered in relation to three-dimensional rheological gravity models reflected in horizontal and vertical sections of density contrast of the tectonosphere. In the crust and the upper mantle, formal manifestations of a right-lateral strike-slip duplex

Abstract On cruise 76 in 2019, the R/V Akademik Mstislav Keldysh completed the Gulf of Ob–Kara Sea slope transect. Samples of bottom water and two sediment layers 1 cm thick were obtained with a multicorer. The silicon, mineral and total phosphorus, and organic nitrogen concentrations were measured in them. The magnitude of fluxes of these nutrients at the water–bottom boundary along the transect was

Abstract Herein we provide information on the sedimentological and paleoceanographic research on the Argentine Patagonian continental slope during cruise 79 of the R/V Akademik Mstislav Keldysh in March 2020. The preliminary scientific results are discussed.

We present a high-resolution historical analysis of the atmosphere over the North Atlantic for the period from January 1979 to December 2018. The dataset was obtained using the nonhydrostatic atmospheric model WRF-ARW version 3.8.1 and contains two experiments that differ in spatial resolution: 14 km (HiRes) and 77 km (LoRes). Except for the spatial resolution, the configuration remained identical

Abstract This article presents a data set on ash, proteins, lipids, carbohydrates, chitin, organic carbon (OC), total nitrogen (TN) and total phosphorus (TP) contents, macronutrients ratio (C, N, and P) and energy content of zooplankton (size fraction >500 μm) from the Kara Sea. Zooplankton samples were collected at 22 stations during the 76th interdisciplinary cruise of the R/V “Akademik Mstislav

Abstract The research is based on the materials collected during cruise 66 of R/V Akademik Mstislav Keldysh in the Yenisei estuary and over the adjacent Kara Sea shelf in the latitudinal range from 71°50.5′ to 75°55.0′ N. The studies were performed from July 25 to 27, 2016, three weeks after the end of the flood period. Two hundred fifty species of plankton algae were recorded. Well-pronounced latitudinal

Abstract The seasonal occurrence and distribution of the pelagic larvae of large burrowing shrimps of infraorders Gebiidea and Axiidea, leading a hidden lifestyle, were studied in the Vostok Bay (Peter the Great Bay, the Sea of Japan) from May through September 2014. Zoea of the burrowing shrimps were found from the end of May to the end of September, at a water temperature of 12.3–23.4оС, reaching

Abstract Transformation of the chemical composition of seawater upon interaction with loess, an analog of natural terrigenous aerosols of the Pleistocene, was studied experimentally. It was shown that this process leads to a change in the concentrations of major ions (K, Ca, SO4, and HCO3), nutrients (Si and P), and fluorine, while the chloride, sodium, and magnesium contents do not vary due to their

The article is devoted to the development of an autonomous profiling system for measuring the aquatic environment under ice. The system moves up and down in the water column along a cable with a load at the lower end, which is lowered into a lane in the ice. The system carrier is designed for transporting an acoustic Doppler current profiler and a salinity, temperature, and pressure probe. The system

The paper presents data from a granulometric analysis based on the results of studying of 44 surface (0–5 cm) sediment samples obtained on cruise 67 of the R/V Akademik Mstislav Keldysh (2016) from different parts of the Barents Sea. Pebble and gravel material is found in surface sediments as an admixture scattered throughout the sea. Such a chaotic distribution pattern is apparently associated with

Abstract— The results of an analysis of wave observations in Dvoinaya Bay at the southern part of Matua Island (Kuril Ridge) are reported. Experimental studies were carried out in order to determine the probability of amplifying the incoming waves in the coastal zone of the island. The observations provided the records of waves at two points of the bay located at depths of ~10 and 20 m, with a discreteness

Abstract— Interannual variability (2002–2018) of primary production, surface seawater temperature (T0), photosynthetically active radiation (PAR) and ice cover area in the East Siberian Sea (ESS) was studied based on the data of the MODIS-Aqua ocean color scanner. The annual total primary production (PPtot) decreased by 1.7 TgC over 17 years. The multi-year negative trend in PPtot was 0.1 TgC y–1 (1

We have summarized the results of studies of bottom rock material in Quaternary sediments in the polar seas of the Arctic, North Atlantic, and Antarctica, obtained by sieve washing on expeditions of the Shirshov Institute of Oceanology, Russian Academy of Sciences. We have compiled maps of the quantitative distribution of this material over water areas and created pie charts of the petrographic composition

Abstract This study was based on data obtained during the cruise 63 of the R/V Akademik Mstislav Keldysh in September 2015. We examine the features of the hydrochemical structure of the Lena River–Laptev Sea mixing zone. The studies were carried out in the eastern part of the Laptev Sea on a quasi-meridional transect, with the length of 710 km along 130°30' E. The distribution of dissolved oxygen,

A new area of oceanography, operational oceanography, involves a comprehensive assessment and forecast of the variability of the state of the marine environment. This requires systematic study of numerous natural parameters, the creation of integrated measurement systems for the properties of the water column and seafloor, rapid data collection and transmission systems, assimilation of new data in