scholarly journals Vertical turbulent exchange features in the layer of seasonal pycnocline in the northwestern part of the Black Sea

2018 ◽  
Vol 1128 ◽  
pp. 012148
Author(s):  
A S Samodurov ◽  
A M Chukharev
Keyword(s):  
Black Sea ◽  
Turbulent Exchange ◽  
The Black Sea ◽  
Northwestern Part

SHORT-TERM DYNAMICS OF THE ANAPA BAY-BAR SHORELINE

2017 ◽  
Author(s):  
Marina Krylenko ◽  
Marina Krylenko ◽  
Alexandr Aleynikov ◽  
Alexandr Aleynikov ◽  
Viacheslav Krylenko ◽  
...  
Keyword(s):  
Black Sea ◽  
Satellite Images ◽  
The Black Sea ◽  
Northwestern Part ◽  
Short Term ◽  
Shoreline Position ◽  
Local Dynamics ◽  
Average Displacement ◽  
Local Erosion

The Anapa bay-bar is located in the northwestern part of the Black Sea. With the goal in mind to determine the short-term dynamics of the Anapa bay-bar we analyzed satellite images from 2003 to the present. Depending on the hydro-lithodynamical situation the shoreline configuration during storm can vary from a rectilinear to sinusoidal forms. There are regions of local erosion or accumulation whose formation is related to the alongshore motion of sediments and dynamics of underwater bars. Comparison of the data on 1965 and 1966 showed that in this period the amplitude of the shoreline position was more than 20 m but average displacement of the shoreline for 13 months was only 0.8 m. This study showed that for the analysis of changes in the shoreline position is necessary to consider the configuration of the coastline at the time of each observation and the local dynamics.

Meiobenthos as indicator of gaseous hydrocarbons reservoirs existing under the seabed of the Black Sea

2021 ◽  
Author(s):  
Valentina Yanko ◽  
Anna Kravchuk ◽  
Irina Kulakova ◽  
Tatiana Kondariuk
Keyword(s):  
Black Sea ◽  
Abiotic Factors ◽  
Taxonomic Composition ◽  
The Black Sea ◽  
Northwestern Part ◽  
Hydrocarbon Gases ◽  
The Sustainable Development ◽  
Dual Analysis ◽  
Gaseous Hydrocarbons ◽  
Physical And Chemical

<p>This <span>presentation</span> represents a case study that reviews research into the relationship between meiobenthos distribution and concentrations of hydrocarbon gases (HG), primarily methane, in the sediments of the northwestern part of the Black Sea, including gases released by mud volcanoes and gas seeps. Evidence forming the basis of this research comes from meiobenthos here represented by 29 species of benthic foraminifers, 7 species of ostracods, and 44 species of nematodes. The potential use of these meiobenthic organisms as indicators of gaseous hydrocarbons reservoirs existing under the seabed is evaluated according to two linked axes, namely the dual analysis of abiotic factors (physical and chemical parameters of the water column, gasmetrical, geochemical, lithological, and mineralogical properties of the sediments) and biotic characteristics (quantitative and taxonomic composition of foraminifers, nematodes, and ostracods). Studies of this kind have been directed toward developing interdisciplinary methods to improve the search for HG accumulations, especially methane, under the seabed. Development of such methods might have substantial socio-economic importance for the economy of Ukraine as well as that of other Black Sea countries, and such methods might also contribute to the sustainable development of Black Sea ecosystems.</p>

Vertical turbulent exchange in the Black Sea pycnocline and its relation to water dynamics

Oceanology ◽  
2017 ◽  
Vol 57 (4) ◽  
pp. 492-504 ◽  
Author(s):  
O. I. Podymov ◽  
A. G. Zatsepin ◽  
A. G. Ostrovsky
Keyword(s):  
Black Sea ◽  
Turbulent Exchange ◽  
Water Dynamics ◽  
The Black Sea

scholarly journals Basic Regularities of Vertical Turbulent Exchange in the Mixed and Stratified Layers of the Black Sea

2021 ◽  
Vol 28 (4) ◽  
Author(s):  
A. S. Samodurov ◽  
A. M. Chukharev ◽  
D. A. Kazakov ◽  
◽  
◽  
...  
Keyword(s):  
Experimental Data ◽  
Black Sea ◽  
Dissipation Rate ◽  
Turbulent Exchange ◽  
The Black Sea ◽  
Buoyancy Frequency ◽  
Exchange Coefficient ◽  
Semi Empirical ◽  
Turbulence Generation ◽  
Turbulent Exchange Coefficient

Purpose. The purpose of the study is to assess the coefficient of vertical turbulent exchange for different layers of the Black Sea basin based on the experimental data on microstructure of the physical fields obtained for the period 2004–2019 in the Black Sea and using the semi-empirical models. Methods and Results. For the upper mixed layer, the turbulent energy dissipation rate ɛ and the exchange coefficient were calculated using the velocity fluctuation spectra based on the Kolmogorov hypotheses on the turbulence spectrum inertial range. In the stratified layers, the turbulence coefficient and the dissipation rate were experimentally determined both from the spectra of the velocity horizontal fluctuations’ gradients and the vertical spectra of temperature fluctuations using the concept of the effective scale of turbulent patches. Depending on the features of the hydrological regime and the prevailing energy contributors to turbulence generation, five layers were identified and described (including their characteristic power dependences of the vertical turbulent diffusion coefficients K on the buoyancy frequency N) using the 1.5D-model of vertical turbulent exchange for the basin under study. For the stratified layers, the 1.5D-model results were comparatively analyzed with those of the other semi-empirical and theoretical models describing the most probable hydrophysical processes in each specific layer; the relations for the vertical turbulent exchange coefficient were obtained depending on the buoyancy frequency. Conclusions. Comparison of the experimental data collected under different hydrometeorological conditions with the simulations resulted from the known turbulence models for the sea upper layer showed that the best agreement between the simulation and measurement data was provided by a multiscale model taking into account three basic mechanisms of turbulence generation: current velocity shear, instability of wave motions, and wave breaking. The turbulent exchange coefficient dependencies on depth are conditioned by the effect of the turbulence dominant source at a given level. In the stratified layers, the exchange coefficient dependence on buoyancy frequency is determined by the hydrophysical processes in each layer; the relations obtained for individual layers indicate intensity of the contributions of vertical advection, internal wave breakings, turbulence diffusion and geothermal flux.

scholarly journals Peculiarities of Pollution by Some Persistent Organic Pollutants of the Marine Environment of the Northwestern Part of the Black Sea

2020 ◽  
Keyword(s):  
Black Sea ◽  
Marine Environment ◽  
Bottom Sediments ◽  
Sea Water ◽  
Marine Pollution ◽  
Marine Organisms ◽  
The Black Sea ◽  
Northwestern Part ◽  
Marine Biota ◽  
Ecological State

Purpose. The study is aimed at estimation of marine pollution in the northwestern part of the Black Sea by some persistent organic pollutants (POPs), in particular polychlorinated biphenyls (PCBs) and hexachlorobenzene (HCB). Methods. Peculiarities of marine pollution were determined on the basis of research conducted at the Ukrainian Scientific Center of Ecology of the Sea (UkrSCES). The content of PCBs and HCB was determined on a gas chromatograph Agilent 7890B with a capillary column and an electronic capture detector using the methods of the US Environmental Protection Agency (EPA-3545A, 3630C, 8081, 8082A, 8275A). The ecological state of the marine environment was determined using developed in UkrSCES the “Ecological standards of marine environment quality”, which allow us to assess the quality status of such components of the marine environment (sea water, bottom sediments and biota). Results. The methodology of environmental standards has been adapted to assess the pollution of the marine environment of POPs. The ecological state of sea water and bottom sediments of the northwestern part of the Black Sea is determined according to the established values of Maximum Concentration Limit (MCL) and Ecological Standards (ES). The ecological state of marine biota was assessed by HCB pollution according to the established Ecological Standard. The European analogue of MCL (MAC-EQS) for industrial marine organisms was used to assess the ecological state of marine organisms for PCBs pollution (but it should be noted that the assessment was performed only for non-dioxin-like PCBs. Standard for the content of PCBs in marine organisms, in particular, – of industrial importance, must be implemented in Ukraine at the legislative level. For integral assessment of the ecological state of the marine environment and the specifics of POPs pollution in the northwestern part of the Black Sea, it is necessary to introduce a comprehensive monitoring system that would analyze marine pollution by all POPs required by the Stockholm Convention. Conclusions. The ecological state of the sea water of the northwestern part of the Black Sea by POPs pollution in most cases corresponds to the category "very good". The state of marine biota in most cases corresponds to the quality classes "good" and "very good", but in Ukraine there are no clear standards that would regulate the content of PCBs in marine biota, in particular – for industrial important species of marine organisms. The ecological condition of bottom sediments is mainly classified as "satisfactory" and "poor", which under certain natural conditions can be a source of secondary pollution of sea water and biota. For integral assessment of the ecological state, it is necessary to take into account all POPs, which can significantly change the results of the assessment of the quality of the marine environment of the northwestern part of the Black Sea.

scholarly journals Estimation of the Vertical Turbulent Exchange Intensity in the Main Pycnocline Layer in the Prikerchensky Area of the Black Sea Shelf

2021 ◽  
Author(s):  
D. A. Kazakov ◽  
A. S. Samodurov ◽  
◽  
Keyword(s):  
Black Sea ◽  
Measurement Data ◽  
Water Area ◽  
Turbulent Exchange ◽  
The Black Sea ◽  
Buoyancy Frequency ◽  
Turbulent Diffusion Coefficient ◽  
Shelf Slope ◽  
Sigma 1 ◽  
Deep Water Area

The paper investigates the seasonal variability of the vertical turbulent exchange coefficient in the upper stratified layer of the Black Sea. The expedition data used in this work containing information on the microstructure of physical fields were obtained in different hydrological seasons covering the northeastern part of the Black Sea in the Prikerchensky area of the shelf slope. The data were collected during cruises of r/v “Professor Vodyanitsky” in 2016–2019 using “Sigma-1” sounding complex. Based on the semi-empirical methods of assessment of vertical turbulent exchange in the deep-water area of the Black Sea, the dependence of the vertical turbulent diffusion coefficient K on the buoyancy frequency N in the studied layer was established from the flow fluctuation characteristics, with the corresponding graphs and their approximating power-law dependences K  A  N  plotting. In addition, the vertical distribution of the K coefficient with depth was analyzed. Comparative analysis of the obtained dependences with the results of the 1.5D model was carried out. The analysis of the measurement data showed that the results obtained in this work do not contradict the original model. The results can also be used to assess the vertical fluxes of heat, salt and other dissolved chemical and biological substances depending on stratification in the studied part of the Black Sea for different seasons.

scholarly journals HAZARDOUS MARINE HYDROLOGICAL PHENOMENA IN THE NORTHWESTERN PART OF THE BLACK SEA

2019 ◽  
Vol 24 (2(35)) ◽  
pp. 26-39
Author(s):  
Р. В. Гаврилюк ◽  
М. А. Берлінський
Keyword(s):  
Black Sea ◽  
The Black Sea ◽  
Northwestern Part

SHORT-TERM DYNAMICS OF THE ANAPA BAY-BAR SHORELINE

2017 ◽  
Author(s):  
Marina Krylenko ◽  
Marina Krylenko ◽  
Alexandr Aleynikov ◽  
Alexandr Aleynikov ◽  
Viacheslav Krylenko ◽  
...  
Keyword(s):  
Black Sea ◽  
Satellite Images ◽  
The Black Sea ◽  
Northwestern Part ◽  
Short Term ◽  
Shoreline Position ◽  
Local Dynamics ◽  
Average Displacement ◽  
Local Erosion

The Anapa bay-bar is located in the northwestern part of the Black Sea. With the goal in mind to determine the short-term dynamics of the Anapa bay-bar we analyzed satellite images from 2003 to the present. Depending on the hydro-lithodynamical situation the shoreline configuration during storm can vary from a rectilinear to sinusoidal forms. There are regions of local erosion or accumulation whose formation is related to the alongshore motion of sediments and dynamics of underwater bars. Comparison of the data on 1965 and 1966 showed that in this period the amplitude of the shoreline position was more than 20 m but average displacement of the shoreline for 13 months was only 0.8 m. This study showed that for the analysis of changes in the shoreline position is necessary to consider the configuration of the coastline at the time of each observation and the local dynamics.

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