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The content of pollutants in the bottom sediments of coastal waters with limited water exchange characterize the total load on the water area and catchment of bays. This paper presents the definition of the total content of trace elements such as Cr, Co, Ni, Pb, Zn, V, Sr (mg/kg) and metal oxides TiO2, MnO, Fe2O3 (%). Samples were taken in the surface layer of bottom sediments of the Sevastopol Bay in 2016. The bottom sediments of the Sevastopol bays accumulate a wide range of organic and inorganic pollutants entering the bays from industrial, domestic, agricultural, stormwater, and also from ships. According to the concentration of individual toxicants, bottom sediments of some areas of the Sevastopol Bay are classified as highly polluted, for example, South Bay: the lead content is 534 mg/kg. In comparison with the data obtained in 2002, the content of lead, cobalt, chromium and iron in the water area of South Bay increased. The content of chromium and iron in the area of the central part of the bay, on the contrary, decreased in 2016 in comparison with the data obtained earlier. Also, according to the data of 2016, the maximum concentrations of lead content (756 mg/kg) were detected in the Artillery Bay area. The dynamics of the Sevastopol Bay bottom sediments pollution was assessed by examining the physical (particle size) and chemical (trace element content: Ti, Pb, Zn, Ni, Co, Cr, V, Sr, Fe, Mn), characteristics that determine the anthropogenic press on the water area. As a result of the research, features of the spatial distribution of trace metals were revealed, zones of increased content of Ti, Pb, Zn, Ni, Co, Cr, V, Sr, Fe, Mn in the surface layer of bottom sediments were identified. It was noted that as a result of the intensification of various natural and anthropogenic processes in the water area of the Sevastopol Bay from 2002 to 2016, the ratio of important geochemical parameters significantly changed. [ABSTRACT FROM AUTHOR]

Aerosol particles, despite their small size, have a great influence on climate change and on human health. Aerosol optical depth (AOD) is one of the main parameters characterizing the scattering and absorbing effects of solar radiation in the atmosphere, therefore creating a methodology for researching the AOD variability is a very current task. Nowadays, the AERONET solar photometer database for the Black Sea is represented by 2 functioning stations: Galata_Platform (Bulgaria) and Gloria (Romania), which is not enough for the full spatial and temporal coverage of aerosol characteristics over the researched region. The purpose of this work is a comparative analysis of AOD by data from several sources: the database of the AERONET network, the satellite data CALIPSO and MODIS over the western part of the Black Sea region. To assess the similarity of the obtained optical characteristics the Euclidean distance between the model results and the AOT in-situ vector (the values of the SPM portable photometer, measured on the Crimean coast) was used. [ABSTRACT FROM AUTHOR]

An important indicator of the existing and possible pollution of any water area is the content of trace metals in bottom sediments that can characterize the level of anthropogenic load. Analysis of the content of metals in bottom sediments in different parts of the water area made it possible to establish the features of distribution of toxic metals in dependence on natural geochemical processes and to identify the areas that experience the most intensive anthropogenic load. In the paper, estimates of the spatial distribution of the investigated parameters were obtained, and correlations between bottom sediment fractions and elevated concentrations of heavy metals were found. Analysis of the quantitative characteristics of granulometric composition and the features of spatial distribution of the bottom fractions showed that over the past ten years an increase in the fraction of fine-grained material has been noted, and the areas of its accumulation are located in places of active anthropogenic development. The content of clay material in the sediments of the Balaklava bay for all samples on average increased from 58.2 to 65.9%, and its maximum values still concentrate in the western and northwestern parts of the bay. Pollution of the bottom sediments of the Balaklava bay by metals is of polyelement nature and is determined primarily by metals such as Pb, Cr, Zn, Cu, As, Sr. Specific features variability in the content of the elements and localization of their inputs to the ecosystem were determined. Maximum metal concentrations are observed near local pollution sources. The obtained results allowed to evaluate the modern ecological state of the investigated regional object, to develop recommendations for its rational economic use. [ABSTRACT FROM AUTHOR]

Tsunami in the Black Sea is a relatively rare phenomenon. Because of its rare occurrence and small volume of full-scale data, tsunami hazard of the Black Sea region has not been sufficiently studied. However, the chance of tsunami waves is still on. In the XX century, four known tsunami phenomena were recorded by marigraphs. These include two events that occurred in 1927, events of 1939 and 1966. Vertical sea level fluctuations were recorded in several points on the Black Sea coast. However, true sea level heights cannot be estimated by the gauge, because the amplitudes of the longwave oscillations on the record are less than those of the real oscillations in the sea. Given the lack of information about tsunami in the Black Sea today, this phenomenon remains, although rare, but quite unsafe for the coast of this region. Therefore, it becomes necessary to perform numerical calculations to determine the possible wave heights as tsunami propagates in the coastal zone of the Black Sea. Numerical modeling of evolution of tsunami caused by the Yalta earthquake on 12 September, 1927 in the Black Sea basin is made. The study is performed in the framework of the nonlinear long wave model. Local elevation caused by bottom movements is transformed into a ring wave that propagates throughout the Black Sea. As a result, the tsunami wave approaches the coast as a flat wave. The level oscillations for a number of points at the coast are calculated and compared with the records of marigraphs. The maximum heights of the waves on the shore are analyzed. The calculated marigrams for several points of the Crimean and Caucasian coasts allow us to estimate the character of oscillations and the amplitude of tsunami waves. The study showed that coastal areas under the greatest influence of waves are those closest to tsunami generation source. So, the most intense waves are observed in Yalta. Such waves can cause significant damage to the population and economy of the Black Sea coast. This study helps to assess the dangers of such events and identify areas of the coast that are exposed to the destructive effects of tsunami waves in the Black Sea. [ABSTRACT FROM AUTHOR]

The study of sediment transport in the coastal zone under the influence of waves and currents makes it possible to predict changes in the ecosystem of the coastal zone under various hydrometeorological conditions and anthropogenic influences. River runoff and abrasion processes are one of the main sources of solid matter entering the coastal zone, as well as one of the factors determining the changes in the granulometric composition of bottom sediments. Since the rivers of the Western Crimea are heavily regulated, the combined effect of wind waves and river flow has a significant influence on the formation of the fractional composition of bottom sediments. In the present work, a study of the dynamics of the bottom sediments granulometric composition in the coastal zone of the Crimean Peninsula near the mouth of the river Belbek using XBeach model were conducted. The XBeach model was applied in a 2D setting with a constant grid step 10 m. All calculations were carried out for a storm period of 24 h. A series of numerical experiments were conducted to study the mechanism of redistribution of sediments of different sizes under the influence of river runoff separately, as well as the combined effect of river runoff and wind waves of various directions and intensities. The wave period and the direction of the wave action, as well as flow rate were used as main input parameters, which changed in numerical experiments. As for coarse and medium-grained material, the distribution of the finely dispersed fraction differs significantly for the central part of the investigated area, primarily determined by the influence of river flow, and for the periphery where the influence of the river is less pronounced, and the greater effect is exerted exclusively by wind waves. In the work, some quantitative characteristics were obtained and the relationship between the influence of the bottom relief and hydrodynamic processes in the study water area on the dynamics of sand material of various sizes was investigated. It is shown that as the storm develops, the material begins to accumulate at lower values of the angle of inclination. There is also a relationship between the angle of inclination and the wave period. [ABSTRACT FROM AUTHOR]