scholarly journals High resolution modelling of severe wind patterns over the north-west Black Sea Region

2020 ◽  
pp. 5-16
Author(s):  
R. V. Zazimko ◽  
S. E. Romanenko ◽  
I. G. Ruban ◽  
S. V. Ivanov ◽  
Yu. S. Tuchkovenko ◽  
...  
Keyword(s):  
Wind Velocity ◽  
Spatial Resolution ◽  
Black Sea ◽  
Wind Direction ◽  
Wind Field ◽  
The Black Sea ◽  
Model Output ◽  
The North ◽  
Gfs Model ◽  
Wind Patterns

The research studies the performance of the convective-permitting Harmonie model in reproducing mesoscale features of the wind regime over the north-western part of the Black Sea. It allowed establishing the optimum configuration, projection and geometry of the model's high spatial resolution area over Ukrainian part of the Black Sea, preparing a digital format for a coastline based on the resolution and conducting numerical experiments to verify informativeness and stability of computations. It also presents a detailed description of the forecasting procedure which includes a data flow from the Meteorological Archiving and Retrieving System (MARS) of the European Center, creating boundary conditions, forecast computations and a model output composition for the particular region and domain resolution. The results have shown that the Harmonie model with the 2.5 km spatial resolution and the 60 second time step is able to reproduce detailed spatial variability of a near-surface wind field and its evolution to the corresponding scales. In particular, the model is able to simulate mesoscale circulation features of approximately ten km over a homogeneous sea surface and to track their evolution; to monitor the position of convergence zones; to highlight the spatial characteristics of a lee-side wind attenuation band along the coast line when wind blows from the shore; to specify mesoscale wind patterns in bays and along the coastline with complex orography; to reproduce the weakening of a wind velocity over an urban area due to increased surface roughness. Two operational forecasting systems, GFS-WRF and ARPEGE/IFS-Harmonie are compared by the following components: numerical solvers, sub-grid parameterizations, efficiency of computer resources and intellectual potential. The GFS model output with the 25 km spatial resolution is able to correctly reproduce over the region only large-scale atmospheric patterns. However, for rapid changes in the atmospheric circulation accompanied by changes in the wind direction to the opposite and wind increase, the model simulations are delayed in terms of wind field evolution. Additionally, because of crude spatial resolution, the GFS model is unable to describe mesoscale atmospheric features due to differences in surface types, orography, thermal contrasts, etc. Comparison of the both model outputs versus observations from Odesa, Chornomorsk and Yuzhnyi port during severe wind conditions has shown that the discrepancy between the models and observations within the allowable error value (5 m/s) occurred only for Odesa port with regard to the Harmonie model for weak wind velocity. The difference partially increases for moderate wind from the shore, while for strong wind from east and south directions indicates disagreement between the model results and observations and achieves critical values of 20-25 m/s. Such values are mainly determined by the discrepancy in wind direction (up to 180°). The comparison results clearly indicate the doubtful representativeness of wind observations at Chornomorsk and Yuzhnyi stations in general, and at Odesa station in particular.

NUMERICAL SIMULATION OF MESO- AND SUBMESOSCALE FEATURES OF THE NORTH-WESTERN BLACK SEA SHELF CIRCULATION USING HIGH SPATIAL RESOLUTION

2017 ◽  
Author(s):  
Natalia Evstigneeva ◽  
Natalia Evstigneeva ◽  
Sergey Demyshev ◽  
Sergey Demyshev
Keyword(s):  
Spatial Resolution ◽  
Black Sea ◽  
Open Boundary ◽  
The Black Sea ◽  
Marine Hydrophysical Institute ◽  
Shelf Circulation ◽  
The North ◽  
Mesoscale Structure ◽  
Deep Layers ◽  
North Western

A numerical experiment on reconstruction of currents was conducted with real atmospheric forcing data in autumn period of 2007 on the basis of Marine hydrophysical institute (MHI) hydrodynamic model, which was adapted to the coastal area of the Black Sea with an open boundary (north-western shelf). A high resolution (horizontal grid 500500 m and 44 verti-cal layers from 1 m to 49 m) and detailed bathymetry with resolution ~1.6 km were used in the calculation. A higher spatial resolution allowed to get a detailed mesoscale and sub-mesoscale structure of currents in the upper and deep layers of the north-western shelf and to obtain quantitative and qualitative characteristics of the eddies and jets more accurately in comparison with previous calculations.

NUMERICAL SIMULATION OF MESO- AND SUBMESOSCALE FEATURES OF THE NORTH-WESTERN BLACK SEA SHELF CIRCULATION USING HIGH SPATIAL RESOLUTION

2017 ◽  
Author(s):  
Natalia Evstigneeva ◽  
Natalia Evstigneeva ◽  
Sergey Demyshev ◽  
Sergey Demyshev
Keyword(s):  
Spatial Resolution ◽  
Black Sea ◽  
Open Boundary ◽  
The Black Sea ◽  
Marine Hydrophysical Institute ◽  
Shelf Circulation ◽  
The North ◽  
Mesoscale Structure ◽  
Deep Layers ◽  
North Western

A numerical experiment on reconstruction of currents was conducted with real atmospheric forcing data in autumn period of 2007 on the basis of Marine hydrophysical institute (MHI) hydrodynamic model, which was adapted to the coastal area of the Black Sea with an open boundary (north-western shelf). A high resolution (horizontal grid 500500 m and 44 verti-cal layers from 1 m to 49 m) and detailed bathymetry with resolution ~1.6 km were used in the calculation. A higher spatial resolution allowed to get a detailed mesoscale and sub-mesoscale structure of currents in the upper and deep layers of the north-western shelf and to obtain quantitative and qualitative characteristics of the eddies and jets more accurately in comparison with previous calculations.

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.

scholarly journals Past and recent trends in the western Black Sea storminess

2012 ◽  
Vol 12 (4) ◽  
pp. 961-977 ◽  
Author(s):  
N. N. Valchev ◽  
E. V. Trifonova ◽  
N. K. Andreeva
Keyword(s):  
Wind Velocity ◽  
Black Sea ◽  
Wave Energy ◽  
Human Life ◽  
Public Awareness ◽  
Coastal Hazards ◽  
The Black Sea ◽  
The North ◽  
Decadal Scale ◽  
Storm Duration

Abstract. Storms are one of the most important phenomena producing coastal hazards and endangering human life and activities. In recent decades storm climate has become a subject of increased public awareness and knowledge of this issue can help the society to meet future challenges related to extreme storm manifestation. Therefore, the goal of this study is to assess trends in past and recent storminess in the western Black Sea. The analysis of storm climate is based on a continuous hindcast dataset covering a substantial historical time-span of 63 yr (1948–2010). It was used to create a storm population and to estimate properties describing storminess (proxies). This was done by introduction of criteria allowing separation of events with low probability of occurrence and at the same time keeping the information on their pattern, i.e. properties of storm phases. Eleven storminess proxies were analysed and the most indicative appeared to be storm duration; integral, mean and specific storm wave energy; and wind velocity and direction, which were obtained for each storm season. While experiencing significant variability on a quasi-decadal scale, no significant upward or downward trends in storminess were detected. For almost all proxies, an increasing trend until the 1980s or the 1990s and a return to average or even calm conditions in the late 2000s are traceable. On this background, a steady although not significant increase of wind velocity was detected. Results also indicate an alteration of storm pattern, manifested as shortening of storm duration due to a shift of the prevailing direction of storm forcing winds to the north. Nevertheless, incident wave energy in the storms' most intense phase remains significant. The obtained results are discussed with regard to the influence of the North Atlantic Oscillation on the hydrometeorological pattern of the Black Sea region as a part of the European-Atlantic area, in particular with respect to the cyclonic activity.

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.

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