Hydrophysical factors of coccolithophores Emiliania huxleyi intensive bloom formation in the Abkhazian sector of the Black Sea at the end of May 2013

2019 ◽  
pp. 52-67
Author(s):  
Valeriy G. Yakubenko ◽  
Sergey V. Vostokov ◽  
Vladimir A. Silkin ◽  
Larisa A. Pautova ◽  
Anastasia S. Vostokova
Keyword(s):  
Black Sea ◽  
Elevated Temperatures ◽  
Water Area ◽  
Emiliania Huxleyi ◽  
Horizontal Distribution ◽  
Conditional Density ◽  
The Black Sea ◽  
Winter Period ◽  
The North ◽  
Seasonal Thermocline

At the end of May 2013, in the Abkhazian sector of the north-eastern part of the Black Sea, intensive blooms of Emiliania huxleyi coccolithophores of up to 4,4×106 cells/L were observed. In order to identify the necessary and sufficient hydrophysical conditions for the blooming of this alga at 15 stations of the water area, the spatial distribution of hydrophysical parameters was investigated. It is shown that the vertical distribution of temperature, salinity and density is typical for this time of year and is characterized by the presence of a sharp-gradient seasonal thermocline. The horizontal distribution of the main hydrophysical parameters on the surface water was as follows: at an average temperature of 20,209±1,027°C, the areas of elevated temperatures were located in the coastal zone, for salinity (17,585±0,556 psu) the reverse distribution was observed. Variations of conditional density were 11,477±0,516. A characteristic feature of 2013 was the renewal of the Cold Intermediate Layer (CIL) in the winter period. During the bloom period, the coccolithophores tended to be deepened along the coordinate from the center of the sea to the coast. Variations in the speed of geostrophic currents from 3,58 to 22,43 cm/s did not lead to the destruction of the bloom.

scholarly journals Influence of water area depth on wind waves

2020 ◽  
Vol 36 (4) ◽  
pp. 77-88
Author(s):  
Vitalii V. Yakovlev ◽  
Volodymyr A. Voskoboinick ◽  
Vitalii V. Khomicky ◽  
Viktor O. Tkachenko ◽  
Oleksandr A. Voskoboinyk ◽  
...  
Keyword(s):  
Wind Velocity ◽  
Black Sea ◽  
Wind Wave ◽  
Wind Waves ◽  
Water Area ◽  
Wave Transformation ◽  
The Black Sea ◽  
The North ◽  
Wave Parameters ◽  
North Eastern

A semi-empirical technique for calculating the parameters of wind waves at variable sea depths along the wind acceleration has been developed and presented. This technique allows you to determine the average values of wind wave heights, their length and period depending on the wind velocity, taking into account and without taking into account the heaping of water by wind. Within the framework of the described method, the calculations of wind wave parameters suitable for isobaths d = 20 m were performed for a specific study area of the Bistre (Novostambulske) branch of the Danube estuary, for the north-eastern and eastern wind directions. Numerical simulations were performed for the Black Sea in the location of the protection dam of the Maritime approach channel of the Danube-Black Sea deep-sea navigation. Numerical calculations of wind wave transformation in the water area near the protection dam for the most dangerous wind directions in stormy conditions were performed. For mathematical simulation, the maximum values of wind velocity and wave height were used, which were observed during the whole period of research of the Black Sea water area in the region of the dam. Within the framework of refraction theory, wave transformation calculations have been performed for the most wave-hazardous wind acceleration directions, namely, the north-eastern and eastern wind directions. It is shown that taking into account the heaping of water by wind leads to an increase in the parameters of gravitational waves. The results of numerical simulations have shown that with the increase of wind acceleration exceeding the limit values, the parameters of the waves reach constant values. These values depend on the bathymetry of the seabed, wind velocity and direction. It was found that the increase in the deviation of the free surface of the sea from the undisturbed level significantly depends on the heaping of water by wind. It was found that the relative increase in the wave parameters is observed higher in the east wind direction than in the northeast wind direction in the study area of the Black Sea.

The influence of submesoscale eddies on hydrochemical parameters and structural and functional characteristics of phytoplankton in the north-eastern part of the Black Sea

2019 ◽  
pp. 24-40
Author(s):  
Sergey B. Kuklev ◽  
Vladimir A. Silkin ◽  
Valeriy K. Chasovnikov ◽  
Andrey G. Zatsepin ◽  
Larisa A. Pautova ◽  
...  
Keyword(s):  
Anticyclonic Eddy ◽  
The Black Sea ◽  
Hydrochemical Parameters ◽  
North East ◽  
The North ◽  
Seasonal Thermocline ◽  
North Eastern ◽  
Quantitative Indicators ◽  
The City ◽  
North Eastern Part

On June 7, 2018, a sub-mesoscale anticyclonic eddy induced by the wind (north-east) was registered on the shelf in the area of the city of Gelendzhik. With the help of field multidisciplinary expedition ship surveys, it was shown that this eddy exists in the layer above the seasonal thermocline. At the periphery of the eddy weak variability of hydrochemical parameters and quantitative indicators of phytoplankton were recorded. The result of the formation of such eddy structure was a shift in the structure of phytoplankton – the annual observed coccolithophores bloom was not registered.

Modeling of ecological conditions in the Euxine Basin in the Sarmatian and Maeotian by methods of diatom analysis

2019 ◽  
pp. 257-261
Author(s):  
Eleonora P. Radionova
Keyword(s):  
Black Sea ◽  
Late Miocene ◽  
The Black Sea ◽  
Subtidal Zone ◽  
Diatom Analysis ◽  
Diatom Flora ◽  
North West ◽  
Ecological Conditions ◽  
The North

The associations and ecological conditions of the existence of modern diatoms of the North-West (Pridneprovsky), Prikerchensky and Eastern regions of the subtidal zone of the Black Sea are considered. Based on the unity of the composition of the Present and Sarmatian-Meotian diatom flora, an attempt has been made to model some of the ecological c situation of the Late Miocene Euxinian basin.

Oscillations of the Black Sea sea level in the north part of the coast

1999 ◽  
Vol 10 (2) ◽  
pp. 123-130
Author(s):  
Yu. I. Goryachkin ◽  
V. A. Ivanov ◽  
Yu. A. Stepanyants
Keyword(s):  
Sea Level ◽  
Black Sea ◽  
The Black Sea ◽  
The North ◽  
North Part

Influence of Currents and Atmospheric Circulation on the Efficiency of European Anchovy Fishing during its Wintering off the Black Sea Coast of the Krasnodar Territory

2021 ◽  
Author(s):  
B. N. Panov ◽  
E. O. Spiridonova ◽  
◽  
Keyword(s):  
Black Sea ◽  
Atmospheric Transport ◽  
Mesoscale Eddy ◽  
The Black Sea ◽  
Short Term ◽  
European Anchovy ◽  
The North ◽  
Daily Data ◽  
Black Sea Coast ◽  
Sea Coast

Russian fishermen harvest European anchovy primarily off the Black Sea coast of the Krasnodar Territory during its wintering and wintering migrations. At wintering grounds, temperature conditions become a secondary factor in determining the behaviour of commercial concentration of European anchovy, with wind and currents being the primary factors. Therefore, the aim of this work is to determine the potential use of daily data on water circulation and local atmospheric transport in short-term (1–7 days) forecasting of European anchovy fishing in the Black Sea. The research used the European anchovy fishery monitoring materials for January – March 2019, as well as daily maps of the Black and Azov Seas level anomalies (from satellite altimetry data) and surface atmospheric pressure and temperature in Europe (analysis) for the mentioned period. The dynamics of the catch rate and its relation to altimetry and atmospheric transport indicators in the north-eastern part of the Black Sea were investigated using graphical and correlation methods. This analysis showed that the main factor contributing to increased catches is intensification of northwest currents in the coastal 60-km zone. The effect of atmospheric transport on fishing efficiency depends on the mesoscale eddy structure of the nearshore current field. In the presence of an intense northwest current in the fishing area, southwest atmospheric transports have a positive effect on fishing, while in the presence of an anticyclonic meander of currents, northeast atmospheric transports become effective. The presence of maximum significant relationships when the determinants of fishing performance are shifted by 1–7 days allows making short-term predictions of fishing efficiency.

scholarly journals Long term trends in the sea surface temperature of the Black Sea

Ocean Science ◽  
2010 ◽  
Vol 6 (2) ◽  
pp. 491-501 ◽  
Author(s):  
G. I. Shapiro ◽  
D. L. Aleynik ◽  
L. D. Mee
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Black Sea ◽  
Sea Surface ◽  
The Black Sea ◽  
The North ◽  
Sst Variability ◽  
Long Term Trends ◽  
Cooling Trend

Abstract. There is growing understanding that recent deterioration of the Black Sea ecosystem was partly due to changes in the marine physical environment. This study uses high resolution 0.25° climatology to analyze sea surface temperature variability over the 20th century in two contrasting regions of the sea. Results show that the deep Black Sea was cooling during the first three quarters of the century and was warming in the last 15–20 years; on aggregate there was a statistically significant cooling trend. The SST variability over the Western shelf was more volatile and it does not show statistically significant trends. The cooling of the deep Black Sea is at variance with the general trend in the North Atlantic and may be related to the decrease of westerly winds over the Black Sea, and a greater influence of the Siberian anticyclone. The timing of the changeover from cooling to warming coincides with the regime shift in the Black Sea ecosystem.

The northern Black Sea and North Caucasus

2018 ◽  
Author(s):  
Valenina Mordvinceva ◽  
Sabine Reinhold
Keyword(s):  
Black Sea ◽  
Iron Age ◽  
Seventh Century ◽  
The Black Sea ◽  
North Caucasus ◽  
The North ◽  
Long Time ◽  
History Of ◽  
Northern Shore ◽  
Greek Colonization

This chapter surveys the Iron Age in the region extending from the western Black Sea to the North Caucasus. As in many parts of Europe, this was the first period in which written sources named peoples, places, and historical events. The Black Sea saw Greek colonization from the seventh century BC and its northern shore later became the homeland of the important Bosporan kingdom. For a long time, researchers sought to identify tribes named by authors such as Herodotus by archaeological means, but this ethno-deterministic perspective has come under critique. Publication of important new data from across the region now permits us to draw a more coherent picture of successive cultures and of interactions between different parts of this vast area, shedding new light both on local histories and on the role ‘The East’ played in the history of Iron Age Europe.

scholarly journals Engineering geophysical studies in the Black Sea from onboard the R/V Ashamba during 2017

2019 ◽  
Vol 59 (2) ◽  
pp. 319-320
Author(s):  
N. N. Dmitrevskiy ◽  
R. A. Ananyev
Keyword(s):  
Transition Zone ◽  
Continental Slope ◽  
Black Sea ◽  
Water Area ◽  
The Black Sea ◽  
Echo Sounder

In May and October 2017, expeditionary research was carried out in the area of Gelendzhik in the Black Sea at the R/V «Ashamba». The main tasks were the mapping of the seabed and the search for small-sized objects at the bottom of the water area using a WASSP WMB-3250 multibeam echo sounder. Surveys included areal surveying and drawing up bathymetric maps of test sites in Gelendzhik Bay and in the transition zone from the shelf to the continental slope. In addition, the echo sounder was used to search and determine the exact coordinates of the bottom seismograph installed at the seabed near the Divnomorskoye village in May 2016. The article presents the results of the work carried out.

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