scholarly journals Results of adaptation and verification of the coupled numerical models set for predicting the variation of oceanographic features in the North-Western part of the Black Sea

2019 ◽  
pp. 95-108
Author(s):  
D. V. Kushnir ◽  
Yu. S. Tuchkovenko ◽  
Yu. I. Popov
Keyword(s):  
Wind Speed ◽  
Black Sea ◽  
Numerical Models ◽  
Forecast Model ◽  
The Black Sea ◽  
Sea Of Azov ◽  
The Sea Of Azov ◽  
The North ◽  
Operational Forecasting ◽  
North Western

In 2014 Ukraine lost the Ukrainian National Automated System of Marine Forecasting for the Black Sea that was created and operated at the premises of Marine Hydrophysical Institute of the National Academy of Sciences of Ukraine located in the Crimea. Within the framework of research works aimed at establishing a new marine forecasting system a possibility of employing the internationally acclaimed set of coupled numerical models Delft3D-FLOW + SWAN (the Simulating WAves Nearshore) for operational forecasting of the short-term (5 to 10 days) spatio-temporal variability of oceanographic features in the Ukrainian part of the Sea of Azov and the Black Sea Basin is considered. To ensure operation of the models set in the forecasting mode it was suggested to use a prediction of variability of meteorological characteristics at the air-sea interface obtained with the help of the numerical weather forecast model GFS (Global Forecast System). This paper presents the results of verification of Delft3D-FLOW and SWAN numerical models which were adapted to the conditions of the North-Western part of the Black Sea and its Odesa area in the version of meteorological data (fields of wind speed and direction, atmospheric pressure) assimilation from the GFS forecast archive. A technique of telescoping the spatial curvilinear computational grids with different resolution capacity was used in the process of models set adaptation to the conditions of the prognostic area. The models were verified by comparing modelling results with observational data on sea level variability in the ports of Odesa area of the North-Western part of the Black Sea (Chornomorsk, Odesa, Yuzhnyi), as well as with data on wind speed and direction, drift currents and characteristics of wind-induced waves recorded over the studied periods by the gauges of stationary hydrometeorological buoy which was mounted in the Bay of Odessa. Based on the analysis of the results of verification of coupled numerical models Delft3D-FLOW + SWAN set it was concluded that the set of coupled models has good prospects of being used in the system of operational forecasting of the variability of oceanographic parameters of the sea environment in the Ukrainian part of the Sea of Azov and the Black Sea Basin in the version of assimilation of meteorological information obtained from the GFS global forecast model.

scholarly journals Differences In Skull Size Of Harbour Porpoises, Phocoena phocoena (Cetacea), In The Sea Of Azov And The Black Sea: Evidence For Different Morphotypes And Populations

2015 ◽  
Vol 49 (2) ◽  
pp. 171-180 ◽  
Author(s):  
P. E. Goldin ◽  
K. A. Vishnyakova
Keyword(s):  
Black Sea ◽  
The Black Sea ◽  
Sea Of Azov ◽  
Phocoena Phocoena ◽  
The Sea Of Azov ◽  
Skull Size ◽  
The North ◽  
North Eastern ◽  
The Difference ◽  
North Western

Abstract There are two porpoise stocks in the northern Black Sea: the north-western (Odessa Gulf) and northeastern (Crimean and Caucasian waters); in addition, another stock is in the Sea of Azov. The Azov porpoises are distinct in their body size and biology. This research was conducted on the skulls of stranded sexually mature porpoises from the north-eastern Black Sea, north-western Black Sea and the Sea of Azov. In the north-eastern Black Sea samples, both present-day and old-time, the sexual dimorphism of the skull size was not significant, whereas in the Sea of Azov the females were significantly larger than males. The Azov skulls were strongly different from those from the Black Sea: they were larger, proportionally wider and had the wider rostra; also, there was no significant chronological variation within the Black Sea. The Azov and Black Sea samples were classified with the 100 % success with four variables. The northwestern Black Sea skulls were somewhat intermediate in their characteristics between the Azov and northeastern Black Sea samples, but they were classify ed together with other Black Sea specimens. The difference between the Azov and Black Sea skulls was greater than between many North Atlantic populations, despite the extreme geographical proximity of the two stocks. The low variation within the Black Sea supports the earlier conclusions on the lack of genetic variation: all the Black Sea stocks are expected to be genetically similar sub-populations, whereas the Azov and Marmara stocks possibly represent the genetically distant populations. The porpoises from the Black Sea and the Sea of Azov equally show the traits which characterize the subspecies Phocoena phocoena relicta, but the Black Sea porpoises appear to be more paedomorphic in terms of ontogenetic trajectories.

Study of water exchange in Kerch strait using NEMO model of Black Sea

2021 ◽  
Author(s):  
Roman Sedakov ◽  
Barnier Bernard ◽  
Jean-Marc Molines ◽  
Anastasiya Mershavka
Keyword(s):  
Water Flow ◽  
Black Sea ◽  
Water Exchange ◽  
Discharge Rate ◽  
The Black Sea ◽  
External Forcing ◽  
Sea Of Azov ◽  
The Sea Of Azov ◽  
The North ◽  
Kerch Strait

<p>The Sea of Azov is a small, shallow, and freshened sea that receives a large freshwater discharge. Under certain external forcing conditions brackish water from the Sea of Azov flow into the north-eastern part of the Black Sea through the narrow Kerch Strait and form a surface-advected buoyant plume. Water flow in the Kerch Strait also regularly occurs in the opposite direction, which results in the spreading of an advected plume of saline and dense water from the Black Sea into the Sea of Azov. Using a regional Black Sea Azov Sea model based on NEMO we study physical mechanisms that govern water exchange through the Kerch Strait and analyze the dependence of its direction and intensity on external forcing conditions. We show that water exchange in the Kerch Strait is governed by a wind-induced barotropic pressure gradient. Water flow through the shallow and narrow Kerch Strait is a one-way process for the majority of the time. Outflow from the Sea of Azov to the Black Sea is induced by moderate and strong northerly winds, while flow into the Sea of Azov from the Black Sea is induced by southerly winds. The direction and intensity of water exchange have wind-governed synoptic and seasonal variability, and they do not depend on the variability of river discharge rate to the Sea of Azov on an intraannual timescale.</p>

scholarly journals Water exchange between the Sea of Azov and the Black Sea through the Kerch Strait

Ocean Science ◽  
2020 ◽  
Vol 16 (1) ◽  
pp. 15-30 ◽  
Author(s):  
Ivan Zavialov ◽  
Alexander Osadchiev ◽  
Roman Sedakov ◽  
Bernard Barnier ◽  
Jean-Marc Molines ◽  
...  
Keyword(s):  
Water Flow ◽  
Black Sea ◽  
Water Exchange ◽  
The Black Sea ◽  
External Forcing ◽  
Sea Of Azov ◽  
Buoyant Plume ◽  
The Sea Of Azov ◽  
The North ◽  
Kerch Strait

Abstract. The Sea of Azov is a small, shallow, and freshened sea that receives a large freshwater discharge. Under certain external forcing conditions low-salinity waters from the Sea of Azov flow into the north-eastern part of the Black Sea through the narrow Kerch Strait and form a surface-advected buoyant plume. Water flow in the Kerch Strait also regularly occurs in the opposite direction, which results in the spreading of a bottom-advected plume of saline and dense waters from the Black Sea into the Sea of Azov. In this study we focus on the physical mechanisms that govern water exchange through the Kerch Strait and analyse the dependence of its direction and intensity on external forcing conditions. Analysis of satellite imagery, wind data, and numerical modelling shows that water exchange in the Kerch Strait is governed by a wind-induced barotropic pressure gradient. Water flow through the shallow and narrow Kerch Strait is a one-way process for the majority of the time. Outflow from the Sea of Azov to the Black Sea is induced by moderate and strong north-easterly winds, while flow into the Sea of Azov from the Black Sea occurs during wind relaxation periods. The direction and intensity of water exchange have wind-governed synoptic and seasonal variability, and they do not depend on the rate of river discharge to the Sea of Azov on an intra-annual timescale. The analysed data reveal dependencies between wind forcing conditions and spatial characteristics of the buoyant plume formed by the outflow from the Sea of Azov.

scholarly journals Forecasting sea level fluctuations caused by storm winds at the ports in Odesa Region of the north-western part of the Black Sea

2020 ◽  
pp. 105-114
Author(s):  
Yu. S. Tuchkovenko ◽  
O. S. Matygin ◽  
V. Yu. Chepurna
Keyword(s):  
Sea Level ◽  
Black Sea ◽  
Lead Time ◽  
The Black Sea ◽  
Short Term ◽  
Sea Level Fluctuations ◽  
The North ◽  
Operational Forecasting ◽  
Forecast Lead Time ◽  
North Western

Increasing the draught of ships that may be accepted by ports for loading at their loading berths is one of the main tasks aimed at development and freight turnover enhancement of sea trade ports located in Odesa Region of the north-western part of the Black Sea (cities of Chornomorsk, Odesa and Pivdennyi). An operational forecasting of short-term sea level fluctuations caused by storm winds presents a critical task for ensuring safe navigation across the ports’ water area and approach channels. The article is devoted to analysing and discussing the results of tests of a simplified 2D hydrodynamic model designed for forecasting such phenomena as upsurge and downsurge of the sea level caused by storm winds in the vicinity of sea ports in Odesa Region of the north-western part of the Black Sea. Spatio-temporal variability of wind conditions at the sea-to-atmosphere boundary was set based on the data retrieved from a 10-day synoptic forecast using global atmospheric prediction model GFS (Global Forecast System). The study analyses the results of forecast of significant (the ones exceeding 30 cm) short-term sea level drops and rises at the ports which were observed in 2016, 2017 and 2020. It was established that, in case of use of the GFS forecast data, the pattern of sea level denivellations caused by storm winds and their amplitude in the majority of events start approximating to the observed values provided the forecast has a 4-day lead time. Therefore the accuracy of wind conditions variability forecast with application of the GFS model having a longer lead advance time is not sufficient for forecasting the sea level fluctuations caused by storm winds.  The study made it possible to get an acceptable equivalence between the values of sea level denivellation amplitudes which were forecast with a 1-to-3-day lead time and the ones observed afterwards. In particular, when the forecast lead time is equal to »2 days, in relation to the expected storm conditions, the average absolute error for the forecast of sea level fluctuations amplitude constituted 7-8 cm, while its permissible value was defined as 15 cm, and the average relative error – 16-18%. It allowed making a conclusion that a hydrodynamic model option, applied alongside with the forecasting information on wind conditions variability retrieved with the help of the GFS weather prediction model, may be used for operational forecasting of short-term sea level fluctuations caused by storm winds with the forecast lead time of up to 4 days.

scholarly journals Circulation conditions of strong and elemental wind over southwestern Ukraine

2017 ◽  
pp. 38-48 ◽  
Author(s):  
Н.P. Ivus ◽  
E.V. Agayar ◽  
L.M. Hurska ◽  
А.В. Semergei-Chumachenko
Keyword(s):  
Wind Speed ◽  
Atmospheric Circulation ◽  
Black Sea ◽  
The Black Sea ◽  
Strong Wind ◽  
The South ◽  
The North ◽  
Strong Winds ◽  
The Impact ◽  
North Western

Introduction. Nowadays the problem of storm winds appears to be a very relevant one in those spheres of human activities related to safety of human living, coastal infrastructure, seafaring, aviation etc. One of the conditions for successful forecasting of strong winds is familiarization with wind characteristics of the study area and with synoptic conditions causing them. The below listed results of research form continuation of previous works for search of a better synoptic classification reflecting completeness of macroscale baric processes causing formation of winds, including strong winds, over the South of Ukraine and also providing an opportunity to forecast winds in a more accurate manner. The purpose of this publication consists in analysis of interaction of large-scale atmospheric circulation with formation of unfavorable weather conditions (strong and very strong winds) on the north-west coast of the Black Sea. Methods and results. The impact of storm winds is significant for functioning of the national economic complex of the North-Western Black Sea region. In order to investigate this effect there were fifty seven cases of wind amplification up to criterion of strong ≥ 15 m·s-1 and very strong ≥ 25 m·s-1 selected within the Odessa region during the period from October to March in 2011 – 2014. Indexes of Katz circulation for isobaric surface of 500 hPa were calculated as per the data of synoptic archive for the cases with wind speed of ≥ 15 m·s-1. A more detailed study of the structure of macrocirculation processes under strong winds, except for Katz indexes, is provided by means of classification and calendar of successive change of elementary circulation mechanisms (ECM) in the Northern hemisphere according to Dzerdzeyevskyi B.L. and typification of synoptic processes developed at the Department of Theoretical Meteorology and Meteorological Forecasts of OSENU. It was determined that strong and very strong winds often occur in southern and central regions, particularly at the stations located on the shores of seas and estuaries (Bilgorod-Dnistrovskyi, Ust-Dunaysk, Pivdennyi port). Meridional type of atmospheric circulation (77.2%) creates favourable conditions for wind amplification in the North-Western part of the Black Sea up to the criterion of strong and very strong one, zonal type of circulation constitutes 22.8% from the total number of cases. Meridional type of circulation is mainly represented by mixed and western forms – (24.6%) and (22.8%) respectively. Main types of synoptic situations (5, 6) of Katz typification that used to cause strong winds were revealed. Most frequently strong wind was observed while moving of cyclonic vortexes from the South (ECM type – 12a, 13z) and in the area of cyclones and anticyclones interaction. Conclusion. It was found that wind speed amplification in the South of Ukraine up to the criteria of strong and very strong one mainly occurs due to the meridional type of atmospheric circulation which is dominated by mixed or western forms of circulation as per Katz typification, ECM type 12a and 13z according to Dzerdzeyevskyi B.L. and types 5 (subtype 5.2) and 6 (all subtypes depending on ECM) as per synoptic typification of OSENU. Directions for further research should include the following. The conclusions have preliminary character and need confirmation on the basis of bigger scope of statistical data.

scholarly journals Microalgae of mud volcano of the Bulganak sopochnoe field on the Crimean Peninsula

2020 ◽  
Vol 5 (1) ◽  
pp. 64-77
Author(s):  
L. I. Ryabushko ◽  
A. V. Bondarenko
Keyword(s):  
Species Composition ◽  
Black Sea ◽  
Brackish Water ◽  
Mud Volcano ◽  
General Distribution ◽  
The Black Sea ◽  
Sea Of Azov ◽  
Mud Volcanoes ◽  
The Sea Of Azov ◽  
The World

Mud volcanoes are one of unique natural phenomena widely spread around the world. They can be found in Crimea, including the Bulganak sopochnoe field – the largest cluster of active mud volcanoes on the peninsula (45°25′29.04″N, 36°27′51.64″E). Study of mud volcano microalgae in Crimea, as well as in other regions of Russia, has not been conducted so far. Therefore, scientific interest is caused by need and urgency of the study of these volcanoes. First data on microalgae species composition of active mud volcanoes are presented in this article. Samples collected by O. Yu. Eremin (03.08.2012 and 13.04.2013) in the upper 2–3-cm layer of suspension and in surface water were investigated. The ranges of salinity and water temperature were 27–32 g per L and +28…+31 °C, respectively. Microalgae species composition was determined in water preparations using Axioskop 40 (Carl Zeiss) light microscope at magnification of 10×40 with software AxioVision Rel. 4.6. Totally 16 taxa were found: Cyanobacteria (1), Dinophyta (2), Bacillariophyta (6), and Euglenophyta (7). Of these, cyanobacteria Chamaecalyx swirenkoi (Schirshov) Komárek et Anagnostidis, 1986 was found by us in the mud volcano in August 2012. Pennate species of diatoms were also identified – single living (of genera Cylindrotheca (Ehrenberg) Reimann & J. C. Lewin, Lyrella Karajeva, and Nitzschia Hassall) and colonial species (of genera Berkeleya Greville and Pseudo-nitzschia H. Peragallo). The brackish-water, benthic, boreal-tropical species Nitzschia thermaloides Hustedt was recorded for the algal flora of Crimea, the Black Sea, and the Sea of Azov for the first time. Euglenophytes were also found in the samples – 5 species of the genus Trachelomonas Ehrenberg and 2 species of the genus Strombomonas Deflandre. Of all the species found in the mud volcano ecotope, 7 species are common for the Black Sea, and 9 species, including 3 euglenophytes, are common for the Sea of Azov. It is shown that by characteristics of halobility, species found in the mud volcano belong to freshwater complex (53 %), with a significant share of marine (27 %) and brackish-water (20 %) species. Of the phytogeographic flora elements, boreal species make up 33 %, boreal-tropical – 47 %, and cosmopolites – 20 %. Three species of potentially toxic algae are recorded: diatom Pseudo-nitzschia prolongatoides (Hasle) Hasle, 1993, as well as dinophytes Prorocentrum lima (Ehrenberg) Dodge, 1975 and Alexandrium tamiyavanichii Balech, 1994. The last species is marine, boreal-tropical, and new to the algology of Crimea, the Black Sea, and the Sea of Azov. In the article, own and literary data on morphology, ecology, and phytogeography of species, as well as on their general distribution in different waterbodies of the world, are also presented. Some microalgae species are indicators of saprobity; they are able to participate in purification of water from organic substances. Photos of mud volcanoes and micrographs of some species are presented.

scholarly journals Amphipod (Crustacea, Amphipoda) Communities in the North-Western Part of the Black Sea

2016 ◽  
Vol 50 (5) ◽  
pp. 387-394
Author(s):  
S. A. Kudrenko
Keyword(s):  
Species Composition ◽  
Community Composition ◽  
Black Sea ◽  
The Black Sea ◽  
Published Data ◽  
Amphipod Species ◽  
Quantitative Parameters ◽  
The North ◽  
North Western

Abstract The data about the community composition, number and biomass of amphipods in three gulfs of the North-Western Black Sea are presented. The amphipod communities of the gulfs of Yahorlyk, Karkinit, and Tendra were studied and the species composition was compared with the previously published data. For each particular gulf, the list of amphipod species was composed. The quantitative parameters of the amphipod communities in the studied localities in different years were described.

Organic Matter of Bottom Sediments of the Crimean and Caucasian Coasts (Azov and Black Seas)

2021 ◽  
Author(s):  
E. A. Tikhonova ◽  
Keyword(s):  
Organic Matter ◽  
Black Sea ◽  
Bottom Sediments ◽  
Petroleum Hydrocarbons ◽  
Water Area ◽  
The Black Sea ◽  
Pollution Level ◽  
Sea Of Azov ◽  
The Caucasus ◽  
The Sea Of Azov

As part of the 113th cruise of the R/V “Professor Vodyanitsky”, research was conducted on organic pollution of bottom sediments in the coastal areas of Crimea and the Caucasus, as well as the water area in front of the Kerch Strait. Concentration of chloroformextractable substances was determined by the weight method and that of petroleum hydrocarbons was determined using infrared spectrometry. Both in 2020 and 2016 (the 83d cruise of the R/V “Professor Vodyanitsky”), properties of the bottom sediments of the Crimean and Caucasian coasts were typical of the marine soils of this region. This indicates that the studied water areas are generally in good condition. In accordance with the regional classification of bottom sediment pollution, the maximum concentrations of chloroform-extractable substances obtained for both the Black Sea and the Sea of Azov coast indicate pollution level III (23% of analysed samples). These values were found in bottom sediments in the Sevastopol water area (225 mg·100 g-1), in the coastal area of Cape Tarkhankut (120 mg·100 g-1) and Karadag (120 mg·100 g-1), the southern part of the Sea of Azov (125 mg·100 g-1) and Tuapse (110 mg·100 g-1). The content of chloroform-extractable substances in bottom sediments off the Black Sea coast of the Caucasus and the Sea of Azov coast is slightly lower than that off the Crimean coast. Pollution level II is assigned to bottom sediments in 46 % of the samples, with an average concentration of 72 mg·100 g-1 of air-dry solids. The rest (31 %) of the studied area was classified as conditionally clean (pollution level I, i. e. less than 50 mg·100 g-1). There has been a slight increase in the concentration of petroleum hydrocarbons in the bottom sediments of both the Black Sea and the Sea of Azov and their share in the total amount of chloroformextractable substances. In general, the level of pollution of bottom sediments by organic matter remained unchanged if compared with previous years, in particular with the data from 2016

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