Vol 59, No 4 (2019)

Investigation of the interaction between oceanic heat fluxes and fields of the spatial gradient of the geopotential in the middle troposphere has been carried out by means of linear correlation analysis when meridional and zonal processes are active. Analysis of the spatial distribution of the correlation coefficients demonstrated that the structure of the interaction between heat fluxes in the North Atlantic and the geopotential gradient field in the middle troposphere over the Atlantic–European sector differs in periods with predominant meridional and zonal forms of circulation, which provides evidence on the significant contribution of ocean heat flux to the formation and development of atmospheric circulation regimes.

The authors study how the spectral shape of irregular surface waves affects the bottom sediment suspension. The features of the frequency distribution of the energy of synchronous fluctuations of water flow velocity series and the concentration of suspended particles are analyzed. It is shown that the maximum mutual energy of synchronous oscillations of the velocity and concentration series can occur at both low and at high frequencies in a wide range of passing waves. In a narrow spectrum, synchronous oscillations dominate in the region of the main energy-carrying frequency. It is also shown that the geometric shape of wave groups has a direct impact on the resuspension intensity. In groups of waves with a symmetrical profile, the suspension is more intense compared to groups with pronounced spatial asymmetry. In the groups of waves with a symmetrical profile, the bottom sediments are suspended more intensely than in groups with pronounced spatial asymmetry.

Particulate organic carbon is one of the major components of the carbon cycle in the ocean. In this study, an attempt to has been made construct a pattern of the distribution and fluxes of particulate organic carbon in the Arctic Ocean with account for its exchange with the Pacific and Atlantic oceans. The specificity of this construction is associated with the irregular distribution of measurements of particulate organic carbon and with the complicated structure and hydrodynamics of the water masses. To overcome these difficulties, multiple linear regression analysis was applied for testing the correlation between the particulate organic carbon concentration, temperature, and salinity, as well the depth, horizon, latitude, and distance from shore. As a result, maps of the distribution of particulate organic carbon and its fluxes were compiled for 38 horizons from 5 to 4150 m (with a resolution of resolution of 1° × 1°). The data on the temperature, salinity, meridional, and latitudinal components of current velocities were obtained from the ORA S4 database (Integrated Climate Data Center, http://icdc.cen.uni-hamburg.de/las). According to these estimates, the import of particulate organic carbon in the Arctic Ocean was estimated to be 38 ± 8 Tg C year^–1, and the export was 9.5 ± 4.4 Tg C year^–1.

The article presents the results of studies on the grain size distribution of aerosols and surface waters (cruise 31 of the R/V Akademik Nikolay Strakhov in December 2015–January 2016 and cruise 42 of the R/V Akademik Boris Petrov in January–April 2017). It was found that the average quantity of 0.3–0.5-µm aerosol particles per L decreased during 2017 as follows: Bab El-Mandeb Strait (135 190) > Gulf of Aden (102 854) > Red Sea (91 612) > North and Baltic seas (76 468) > Indian Ocean (64 113) > Malacca Strait (46 491)> Mediterranean Sea (28 397) > East Atlantic Ocean (14 803). The biotic factor prevails in the distribution of particulate matter and organic compounds in open waters of the Indian Ocean and in the northeast Atlantic Ocean, as well as in areas of high productivity (the Arabian Sea). Circumcontinental zoning results in a prevalent terrigenous component in particulate matter of coastal waters. The transformation from the winter (2016) to the spring (2017) phytoplankton community resulted in a decrease in particulate matter content by an average factor of 8. The lack of a correlation between the concentrations of particulate matter and organic compounds in some regions points to different sources of their formation. Despite the high concentrations of hydrocarbons in several samples in 2016 (up to 50–70 µg/L), the average concentrations were practically unchanged: 10.5 and 8.7 µg/L in 2016 and 2017, respectively. The presence of weathered oil alkanes in the composition of hydrocarbons points to the influence of oil pollutants.

The article presents findings of recent ecological investigations into marine waters in Sevastopol region and overviews the main sources of water pollution in Sevastopol Bay and other parts of the coastal zone between capes Lukull and Foros. The work involved assessment of the position of Sewage Treatment Plant submarine outfalls, the volume of wastewater discharge, and the degree of its treatment. Side-scan sonar served to examine the condition of headwalls of sewage treatment plants in the region. The work considers the spatial distribution patterns of hydrological characteristics and currents and rising of effluent to the sea surface using autonomous buoys and mathematical simulation. Concentrations of nutrients, total petroleum hydrocarbons, and organic matter by biological oxygen demand BOD₅ are determined based on historical data and results of recent research expeditions in 2016–2017. Nutrients do not exceed the Maximum Allowable Contamination levels, and no significant differences have been identified between different parts of Crimean coastal waters by the majority of indicators. Nonetheless, Yalta sea waters are recorded to contain larger quantities of silicates, while levels of petroleum hydrocarbons and organic matters exceed the standards on multiple occasions in Sevastopol district and in the Kerch Strait.

Data on benthic harpacticoid copepods from the Voronin Trench (central part of the Kara Sea) are reported for the first time. Harpacticoids accounted for 1–25% of total meiofauna, their abundance varied from 6 to 102 ind./10 cm² and decreased with depth. I total, 42 nominal species have been found, 15 species are new for the Kara Sea, and at least 8 species are new for science. Several species have been recorded for Arctic waters for the first time: Cylindronannopus bispinosus, Haloschizopera clotensis, H. bathyalis, Metauntemannia pseudomagniceps, Mesocletdemus duosetosus, M. parabodini, Proameira echinipes, and Cletodes tuberculatus. The most species-rich families are Ameiridae, Argestidae, Pseudotachidiidae, Miraciidae, and Ectinosomatidae. Comparative analysis including the data obtained at shallow-water stations from the Yenisei Gulf (southern Kara Sea) revealed three assemblages occupying different habitats. The assemblage inhabiting shallow-water silts (20–62-m depth) was the poorest in regard to species diversity; shallow-water sands were richer in species number, while the deepest stations (92–698 m) were the richest. The latter assemblage had the composition of families typical for the deep-sea areas. The fauna of the Kara Sea includes by now 82 harpacticoid species, most of which have been also reported from North Atlantic and/or western Arctic waters.

The paper presents mineralogical analysis data on very-fine- and fine-grained sand in the composition of Quaternary sediments in the southern part of the Chukchi Plateau. The associations and downcore distribution of rock-forming and accessory minerals in relation to other characteristics are considered. The established climatically controlled mineralogical features, i.e., periodicity of warmings and coolings, can be used to solve a number of genetic problems, stratigraphic subdivision of sediments, and paleoreconstructions.

Within the East Canadian continental margin, three oil and gas bearing regions have been identified from north to south: the Labrador Sea shelf, the margin of the Grand Banks of Newfoundland, and the Nova Scotia continental margin. In each of these regions, a number of sedimentary basins are distinguished and completely submerged. The following large sedimentary basins are distinguished on the Labrador Sea shelf: the Saglek, Hopdale, and Havke; on the margin of the Grand Banks of Newfoundland, the following basins are known: the Jeanne d’Arc, Flemish Pass, and Orphan. The Scotian Shelf distinguishes the Nova Scotia and Sable basins. It is noteworthy that at high latitudes, such as the Labrador Sea region, the age of productive sediments begins with more ancient rocks (since the Paleozoic) than in the basins to the low latitude (since the Mesozoic), due to which the stratigraphic range of oil and gas bearing in the high latitude basins is much wider. The oil and gas bearing potential in the entire region is mainly related to the continental slopes and turbidite deposits occurring within them. Late Jurassic and Early Cretaceous reservoirs will be the target sediments during deep drilling. Widespread Late Cretaceous and Early Tertiary formations with oil and gas potential are quite realistic, since they do not lie at deep horizons. The oil and gas bearing potential on the margins of basins is associated with Late Cretaceous and Tertiary sediments, alluvial fan deposits, and salt diapirs.

During the 39th cruise of RV Professor Logachev, ecological studies of the Russian exploration area in the central part of the Northern Mid-Atlantic Ridge were conducted. New data on the composition and structure of benthic communities as well as composition and distribution of ichthyofauna were obtained.