scholarly journals Spatial analysis of salinity distribution patterns in upper layers of the Black Sea

2020 ◽  
Vol 203 ◽  
pp. 03010
Author(s):  
Denis Krivoguz ◽  
Sergei Mal’ko ◽  
Anna Semenova
Keyword(s):  
Spatial Distribution ◽  
Black Sea ◽  
General Circulation ◽  
Saline Water ◽  
World Ocean ◽  
Distribution Patterns ◽  
The Black Sea ◽  
Marine Environment Monitoring ◽  
Monitoring Service ◽  
The Impact

Salinity is one of the most important factors that primarily determines the level of seawater’s density and, consequently, the movement of water masses in the World Ocean. Spatial distribution of the salinity in different layers of the Black Sea are associated with varying levels of water balance seasonal variability and, general circulation of Black Seas waters and in the surface layer has a seasonal structure. To study spatial distribution of salinity in upper layers of the Black Sea we’ve used data from Copernicus Marine Environment Monitoring Service, that were processed and aggregate by seasons and depth. We found that the most fluctuated layer is a top layer (up to 2.8 m) and the highest values Black Sea salinity reaches near the Bosporus Strait, where more saline water from the Sea of Marmara connected with fresher water of the Black Sea. Also we found that the impact of the river flows, mixing of the water, water regime of the sea decreasing with depth, so in the bottom of the upper layer the spatial fluctuation of the salinity is minimal and reaches about ±3‰, while in the depth of 2.8 m its reaches ±12-15‰.The lowest level of salinity through all of the upper layer (0-50 m) lays around the seashore and north-western part of the sea.

NUMERICAL SIMULATION OF THE SEMIDIURNAL TIDAL WAVE IMPACT ON THE BLACK SEA CLIMATIC CIRCULATION

2017 ◽  
Author(s):  
Anna Lukyanova ◽  
Anna Lukyanova ◽  
Andrei Bagaev ◽  
Andrei Bagaev ◽  
Vladimir Zalesny ◽  
...  
Keyword(s):  
Black Sea ◽  
Time Scale ◽  
General Circulation ◽  
Circulation Model ◽  
The Black Sea ◽  
Marine Hydrophysical Institute ◽  
Wave Impact ◽  
Ecological Processes ◽  
Short Period ◽  
The Impact

The Black Sea is an enclosed deep marine basin, where the structure of tidal movements is dominated by the direct influence of the tidal force on the proper water body. We investigated the spatial structure of its climatic circulation under the impact of tides. We developed a program module extending the numerical general circulation model of the Black Sea which was designed in the Institute of numerical mathematics, Moscow. It allows the lunar semidiurnal harmonics (M_2) influence to be taken into account explicitly via the discrete analogues of the differential equations of motion. Our work reflects the main results of the numerical experiment on the 4x4 km horizontal grid and 40 vertical σ-levels. It was a one-year model run using the CORE atmospheric climatology forcing. We compared the first and the last weeks of simulation and found out that the characteristics of a tidal mode M2 were established at a very short period of time (7 days), which is the estimate of the model’s energy redistribution time scale. The coastal areas where the tidal impact is substantial (~10 cm) were located mainly at the shallow-shelf inlets highly influenced by the climate change. Validation of the cotidal maps showed the reliability of our model at the climatological time scale. In future we will focus on the baroclinic tidal movements and validation with the Marine Hydrophysical Institute database in order to shed new light on physical and ecological processes at the frontal zone along the Rim Current.

NUMERICAL SIMULATION OF THE SEMIDIURNAL TIDAL WAVE IMPACT ON THE BLACK SEA CLIMATIC CIRCULATION

2017 ◽  
Author(s):  
Anna Lukyanova ◽  
Anna Lukyanova ◽  
Andrei Bagaev ◽  
Andrei Bagaev ◽  
Vladimir Zalesny ◽  
...  
Keyword(s):  
Black Sea ◽  
Time Scale ◽  
General Circulation ◽  
Circulation Model ◽  
The Black Sea ◽  
Marine Hydrophysical Institute ◽  
Wave Impact ◽  
Ecological Processes ◽  
Short Period ◽  
The Impact

The Black Sea is an enclosed deep marine basin, where the structure of tidal movements is dominated by the direct influence of the tidal force on the proper water body. We investigated the spatial structure of its climatic circulation under the impact of tides. We developed a program module extending the numerical general circulation model of the Black Sea which was designed in the Institute of numerical mathematics, Moscow. It allows the lunar semidiurnal harmonics (M_2) influence to be taken into account explicitly via the discrete analogues of the differential equations of motion. Our work reflects the main results of the numerical experiment on the 4x4 km horizontal grid and 40 vertical σ-levels. It was a one-year model run using the CORE atmospheric climatology forcing. We compared the first and the last weeks of simulation and found out that the characteristics of a tidal mode M2 were established at a very short period of time (7 days), which is the estimate of the model’s energy redistribution time scale. The coastal areas where the tidal impact is substantial (~10 cm) were located mainly at the shallow-shelf inlets highly influenced by the climate change. Validation of the cotidal maps showed the reliability of our model at the climatological time scale. In future we will focus on the baroclinic tidal movements and validation with the Marine Hydrophysical Institute database in order to shed new light on physical and ecological processes at the frontal zone along the Rim Current.

Coastal zone dynamics - as a result of changes at the border of three environments

2021 ◽  
Author(s):  
Oleksii Batyrev ◽  
Olga Andrianova ◽  
Radomir Belevich ◽  
Michael Skipa
Keyword(s):  
Sea Level ◽  
Coastal Zone ◽  
Black Sea ◽  
World Ocean ◽  
The Black Sea ◽  
Western Coast ◽  
The World ◽  
The Mediterranean ◽  
The Impact ◽  
Coastal Land

<p>Coastal zone research is becoming increasingly important because the impact of climate change is most significant here. The state of coastal regions is determined by the variability in three contact media (geological, water, and air). Evaluation of level changes on the coasts of various parts of the World Ocean (the Mediterranean, Black, Baltic and North Seas, and the Atlantic coasts in Brazil and France) over a long period of time shows various fluctuations with an upward trend in recent decades.</p><p>To highlight the factors that determine the seashores' level fluctuations, three contact media parameters were considered on the example of the western part of the Black Sea. Calculations, analysis, and comparison of trends in the variability of hydrometeorological characteristics (air and water temperatures, precipitation, and river discharge) and sea level over a period of more than 100 years have been carried out.</p><p>To assess the intensity of fluctuations of the coastal land along the western coast of the Black Sea, the series of level heights were considered at 6 Ukrainian stations: Vylkove, Chornomorsk (Ilyichevsk), Odesa-port, port Yuzhne, Ochakiv and Sevastopol (partially used as a benchmark), at 2 stations on the Romanian coast: Constanta and Sulina, and 2 stations on the Bulgarian coast: Burgas and Varna. Estimates of the dynamics of the land for the stations of this region's coastal zone for more than a 100-year period are calculated, and it is shown in which way changes in sea level are a consequence of the processes occurring in the coastal land and at the bottom.</p><p>Comparison of the years with extreme fluctuations in the sea level with the years of the global El Niño phenomenon showed that one of the causes of the observed disturbances in the water and air environments is the distant manifestations of this phenomenon.</p><p>Level fluctuations, both in the Black Sea and in the World Ocean, are synchronous at low-frequency scales (their period is more than 5 years) since global climatic processes on our planet influence them; short-term fluctuations are distinguished by regional features and are created under the influence of local factors (tectonic, geophysical, hydrostatic, etc.).</p><p>Modeling and predicting changes in the coastal zone of various parts of the World Ocean requires continuation of systematic observations of sea-level fluctuations, hydrometeorological characteristics, and seismic conditions in regions with the longest data series; it's crucial for the Black Sea as well for the Mediterranean, Baltic, North Seas, and Atlantic shores.</p>

Influx of streaming methane into anoxic waters of the Black Sea basin

2019 ◽  
Vol 59 (6) ◽  
pp. 952-963
Author(s):  
Yu. G. Artemov ◽  
V. N. Egorov ◽  
S. B. Gulin
Keyword(s):  
Spatial Distribution ◽  
Black Sea ◽  
The Black Sea ◽  
Gas Bubble ◽  
Dissolved Methane ◽  
Anoxic Waters ◽  
Deep Waters ◽  
Methane Budget

Based on data on the spatial distribution and fluxes of streaming (bubbling) methane within the Black Sea, the rate of dissolved methane inflow to Black Sea deep waters was assessed. Calculations showed that gas bubble streams annually replenish the methane budget in the Black Sea by 1.2 109 m3, or 0.9 Tg, which is considerably less than determined by known biogeochemical estimates of components of methane balance in the Black Sea.

scholarly journals Multi-Criteria Analysis of the Mass Tourism Management Model Related to the Impact on the Local Community in Constanta City (Romania)

Inventions ◽  
2021 ◽  
Vol 6 (3) ◽  
pp. 46
Author(s):  
Catalin Anton ◽  
Angela-Eliza Micu ◽  
Eugen Rusu
Keyword(s):  
Black Sea ◽  
Seasonal Cycle ◽  
Local Community ◽  
Local Economy ◽  
Management Model ◽  
The Black Sea ◽  
Mass Tourism ◽  
Tourism Management ◽  
The Impact ◽  
The City

Traditionally and socially, the tourism in Constanta is considered to be important to the local economy. Sun and beach locations are both a draw for locals and tourists to the city, on the Black Sea. However, vacation-oriented activities in the city only have a seasonal cycle. In this paper, we proposed to analyze the mass tourist activity in Constanta, taking into account economic, social, and environmental conditions. Additionally, we attempted to build a model based on the data available. The model was developed using a PESTEL analysis to determine the supportability factor of the indicators identified. We also set out to create a projection of the activities proposed for analysis by 2050. To create a model for coastal areas, the data used in this research must be accurate and consistent. Furthermore, correctly identifying indicators and their relationships is a critical step in conducting a thorough study. Last but not least, finding the calculation coefficient for the activity in question is critical, as collecting data from various activities might be challenging when trying to find a feasible model.

Anthropogenic Impact on the Lithodynamics of the Coastal Zone of the Southern and Western Black Sea Coast (Review)

2021 ◽  
Author(s):  
T. V. Efremova ◽  
Yu. N. Goryachkin ◽  
◽  
Keyword(s):  
Coastal Zone ◽  
Black Sea ◽  
Bottom Sediments ◽  
Anthropogenic Impact ◽  
River Flow ◽  
The Black Sea ◽  
Negative Consequences ◽  
Coastal Zones ◽  
Natural Dynamics ◽  
The Impact

Anthropogenic impact on lithodynamics of the coastal zone changes the natural dynamics of bottom sediments, which leads to increased abrasion and swelling of beaches, activation of landslide processes creating a threat of destruction of the coastal infrastructure. The article aims at providing an overview of the scientific literature on the anthropogenic impact on lithodynamics of the coastal zone of the southern and western coasts of the Black Sea (shores of Romania, Bulgaria and Turkey). The work shows that with all the differences in the natural conditions of the coastal zones of these countries the types of anthropogenic effects they undergo are almost the same. These include: hydrotechnical construction without regard to the impact on the neighbouring coast sections; reduction of solid river flow due to river regulation by reservoirs; construction of capital facilities directly on the beaches; illegal extraction of sand from beaches and river beds; dredging with sale of the extracted material to construction companies; covering of cliffs by various structures; destruction of coastal dunes, etc. The main negative consequences of these actions are reflected in disruption of natural dynamics and shortages of bottom sediments, changes in the coastline, reduced aesthetic attractiveness and accessibility of shores, destruction of coastal ecosystems. The article also provides information on the legislation of these countries regarding environmental management in the coastal zone

scholarly journals Drivers, mechanisms and long-term variability of seasonal hypoxia on the Black Sea northwestern shelf – is there any recovery after eutrophication?

2013 ◽  
Vol 10 (6) ◽  
pp. 3943-3962 ◽  
Author(s):  
A. Capet ◽  
J.-M. Beckers ◽  
M. Grégoire
Keyword(s):  
Organic Matter ◽  
Spatial Distribution ◽  
Interannual Variability ◽  
Black Sea ◽  
Sea Surface ◽  
The Black Sea ◽  
Northwestern Shelf ◽  
Bottom Waters ◽  
Seasonal Hypoxia ◽  
Bottom Hypoxia

Abstract. The Black Sea northwestern shelf (NWS) is a shallow eutrophic area in which the seasonal stratification of the water column isolates the bottom waters from the atmosphere. This prevents ventilation from counterbalancing the large consumption of oxygen due to respiration in the bottom waters and in the sediments, and sets the stage for the development of seasonal hypoxia. A three-dimensional (3-D) coupled physical–biogeochemical model is used to investigate the dynamics of bottom hypoxia in the Black Sea NWS, first at seasonal and then at interannual scales (1981–2009), and to differentiate its driving factors (climatic versus eutrophication). Model skills are evaluated by a quantitative comparison of the model results to 14 123 in situ oxygen measurements available in the NOAA World Ocean and the Black Sea Commission databases, using different error metrics. This validation exercise shows that the model is able to represent the seasonal and interannual variability of the oxygen concentration and of the occurrence of hypoxia, as well as the spatial distribution of oxygen-depleted waters. During the period 1981–2009, each year exhibits seasonal bottom hypoxia at the end of summer. This phenomenon essentially covers the northern part of the NWS – which receives large inputs of nutrients from the Danube, Dniester and Dnieper rivers – and extends, during the years of severe hypoxia, towards the Romanian bay of Constanta. An index H which merges the aspects of the spatial and temporal extension of the hypoxic event is proposed to quantify, for each year, the intensity of hypoxia as an environmental stressor. In order to explain the interannual variability of H and to disentangle its drivers, we analyze the long time series of model results by means of a stepwise multiple linear regression. This statistical model gives a general relationship that links the intensity of hypoxia to eutrophication and climate-related variables. A total of 82% of the interannual variability of H is explained by the combination of four predictors: the annual riverine nitrate load (N), the sea surface temperature in the month preceding stratification (Ts), the amount of semi-labile organic matter accumulated in the sediments (C) and the sea surface temperature during late summer (Tf). Partial regression indicates that the climatic impact on hypoxia is almost as important as that of eutrophication. Accumulation of organic matter in the sediments introduces an important inertia in the recovery process after eutrophication, with a typical timescale of 9.3 yr. Seasonal fluctuations and the heterogeneous spatial distribution complicate the monitoring of bottom hypoxia, leading to contradictory conclusions when the interpretation is done from different sets of data. In particular, it appears that the recovery reported in the literature after 1995 was overestimated due to the use of observations concentrated in areas and months not typically affected by hypoxia. This stresses the urgent need for a dedicated monitoring effort in the Black Sea NWS focused on the areas and months concerned by recurrent hypoxic events.

scholarly journals Recent Sea Ice Decline Did Not Significantly Increase the Total Liquid Freshwater Content of the Arctic Ocean

2018 ◽  
Vol 32 (1) ◽  
pp. 15-32 ◽  
Author(s):  
Qiang Wang ◽  
Claudia Wekerle ◽  
Sergey Danilov ◽  
Dmitry Sidorenko ◽  
Nikolay Koldunov ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Sea Ice ◽  
Arctic Ocean ◽  
Ocean Circulation ◽  
General Circulation ◽  
The Arctic ◽  
Sea Ice Decline ◽  
The Arctic Ocean ◽  
Eurasian Basin ◽  
The Impact

Abstract The freshwater stored in the Arctic Ocean is an important component of the global climate system. Currently the Arctic liquid freshwater content (FWC) has reached a record high since the beginning of the last century. In this study we use numerical simulations to investigate the impact of sea ice decline on the Arctic liquid FWC and its spatial distribution. The global unstructured-mesh ocean general circulation model Finite Element Sea Ice–Ocean Model (FESOM) with 4.5-km horizontal resolution in the Arctic region is applied. The simulations show that sea ice decline increases the FWC by freshening the ocean through sea ice meltwater and modifies upper ocean circulation at the same time. The two effects together significantly increase the freshwater stored in the Amerasian basin and reduce its amount in the Eurasian basin. The salinification of the upper Eurasian basin is mainly caused by the reduction in the proportion of Pacific Water and the increase in that of Atlantic Water (AW). Consequently, the sea ice decline did not significantly contribute to the observed rapid increase in the Arctic total liquid FWC. However, the changes in the Arctic freshwater spatial distribution indicate that the influence of sea ice decline on the ocean environment is remarkable. Sea ice decline increases the amount of Barents Sea branch AW in the upper Arctic Ocean, thus reducing its supply to the deeper Arctic layers. This study suggests that all the dynamical processes sensitive to sea ice decline should be taken into account when understanding and predicting Arctic changes.

scholarly journals Hydrology and circulation in the North Aegean (eastern Mediterranean) throughout 1997 and 1998

2002 ◽  
Vol 3 (1) ◽  
pp. 5 ◽  
Author(s):  
V. ZERVAKIS ◽  
D. GEORGOPOULOS
Keyword(s):  
Surface Layer ◽  
Black Sea ◽  
Sea Water ◽  
Saline Water ◽  
Eastern Mediterranean ◽  
Late Summer ◽  
Cyclonic Circulation ◽  
The Black Sea ◽  
The North ◽  
North Aegean

The combination of two research projects offered us the opportunity to perform a comprehensive study of the seasonal evolution of the hydrological structure and the circulation of the North Aegean Sea, at the northern extremes of the eastern Mediterranean. The combination of brackish water inflow from the Dardanelles and the sea-bottom relief dictate the significant differences between the North and South Aegean water columns. The relatively warm and highly saline South Aegean waters enter the North Aegean through the dominant cyclonic circulation of the basin. In the North Aegean, three layers of distinct water masses of very different properties are observed: The 20-50 m thick surface layer is occupied mainly by Black Sea Water, modified on its way through the Bosphorus, the Sea of Marmara and the Dardanelles. Below the surface layer there is warm and highly saline water originating in the South Aegean and the Levantine, extending down to 350-400 m depth. Below this layer, the deeper-than-400 m basins of the North Aegean contain locally formed, very dense water with different θ /S characteristics at each subbasin. The circulation is characterised by a series of permanent, semi-permanent and transient mesoscale features, overlaid on the general slow cyclonic circulation of the Aegean. The mesoscale activity, while not necessarily important in enhancing isopycnal mixing in the region, in combination with the very high stratification of the upper layers, however, increases the residence time of the water of the upper layers in the general area of the North Aegean. As a result, water having out-flowed from the Black Sea in the winter, forms a separate distinct layer in the region in spring (lying between “younger” BSW and the Levantine origin water), and is still traceable in the water column in late summer.

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