High frequency sea level fluctuations recorded in the Black Sea since the LGM

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.

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Pleistocene carbonates from Dobrogea (E Romania) and their relationship with Black Sea level fluctuations

10.5194/egusphere-egu2020-10485 ◽

2020 ◽

Author(s):

Virgil Dragusin ◽

Silviu Constantin ◽

Vasile Ersek ◽

Dirk L. Hoffmann ◽

Alex Hotchkies

Keyword(s):

Isotopic Composition ◽

Sea Level ◽

Black Sea ◽

Underground Water ◽

The Black Sea ◽

Sampling Area ◽

Sea Level Fluctuations ◽

Water Tables ◽

Carbonate Deposition ◽

The Town

The eastern part of Romania, bordering on the Black Sea, is generally poor in speleothems and only Piatra Cave has important speleothem occurrences. This cave is positioned close to the present-day shoreline, forcing the local aquifer to completely flood it when it rose synchronously with sea level. The flooding of the cave prevented speleothem formation. Conversely, sub-aerial carbonate deposition took place when the sea level was lower than today and the cave was dry. The study of speleothems from Piatra Cave could bring more insight on past Black Sea level fluctuations, as well as on the isotopic composition of percolating water.Some 50 km to the south of Piatra Cave, around the town of Mangalia, botryoidal calcite has been deposited inside small voids formed between Sarmatian limestone beds. Such calcite formations are considered to form close to the water table, at the contact with the underground atmosphere. If so, they could be used to track the position of past water tables, as well as the isotopic composition of those waters. Moreover, as these samples are found only close to the present-day shoreline, they might have been deposited from underground water whose level was directly controlled by the sea.Here we present the results of &#948;18O and &#948;13C measurements on 75 samples and sub-samples of botryoidal calcite. We explore the implications of their isotopic variability, by comparison with speleothems from Piatra Cave as well as to other speleothems from Romania. Moreover, we explore their isotopic variability across the sampling area, in order to better assess their possible use as sea level markers.

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Sea level changes along the Turkish coasts of the Black Sea, the Aegean Sea and the Eastern Mediterranean

Mediterranean Marine Science ◽

10.12681/mms.285 ◽

2000 ◽

Vol 1 (1) ◽

pp. 141 ◽

Cited By ~ 10

Author(s):

B. ALPAR ◽

E. DOGAN ◽

H. YUCE ◽

H. ALTIOK

Keyword(s):

Sea Level ◽

Black Sea ◽

Eastern Mediterranean ◽

The Black Sea ◽

Marmara Sea ◽

Sea Level Changes ◽

Sea Levels ◽

Sea Level Fluctuations ◽

Short Period ◽

Turkish Straits System

Short, tidal, subtidal, seasonal, secular sea-level variations, sea-level differences and interactions between the basins have been studied, based on the data collected at some permanent and temporary tide gauges located along the Turkish coasts, mostly along the Straits connecting the Marmara Sea to outer seas. Even though the deficiency of sufficient information prevented us to reach the desired results, many pre-existed studies have been improved. Short-period oscillations were clearly identified along the Turkish Strait System and related to their natu-ral periods. The tidal amplitudes are low along the Turkish coasts, except northern Aegean and eastern Mediterranean. The stability of harmonic constants of Samsun and Antalya were examined and most of the long period constituents were found to be unstable. Even the Marmara Sea is not affected from the tidal oscillations of Black and Aegean Seas, some interactions in low frequency band have been detected. Subtidal sea level fluctuations (3-14 day) have relations with the large-scale cyclic atmospheric patterns passing over the Turkish Straits System. Short-term effects of wind on sea level are evident.Seasonal sea-level fluctuations along the Turkish Straits System are in accord with Black Sea's hydrological cycle. The differential range of the monthly mean sea levels between the Black Sea and the Marmara Sea is highly variable; high during spring and early summer and low during fall and winter.On the average, there is a pronounced sea-level difference (55 cm) along the Turkish Straits System. However, the slope is nonlinear, being much steeper in the Strait of Istanbul. This barotrophic pressure difference is one of the most important factors causing the two-layer flow through the system. The topography and hydrodynamics of the straits, the dominant wind systems and their seasonal variations make this flow more complicated. For secular sea level changes, a rise of 3.2 mm/a was computed for Karsiyaka (1935-71) and a steady trend (-0.4 mm /a) has been observed for annual sea levels at Antalya (1935-77). The decreasing trend (-6.9 mm/a) at Samsun is contrary to the secular rising trend of the Black Sea probably because of its rather short monitoring period (1963-77).

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Simulation modelling of wind-induced sea level fluctuations at the ports of the Odesa Region in the North-Western part of the Black Sea

Ukrainian hydrometeorological journal ◽

10.31481/uhmj.23.2019.10 ◽

2019 ◽

pp. 109-120

Author(s):

Yu. S. Tuchkovenko

Keyword(s):

Sea Level ◽

Black Sea ◽

Hydrodynamic Model ◽

Temporal Variability ◽

The Black Sea ◽

Sea Level Fluctuations ◽

The North ◽

Allowable Error ◽

Spatio Temporal ◽

North Western

The paper is devoted to discussion of the prospects of simplified 2D hydrodynamic model use aimed at forecasting the wind-induced sea level fluctuations within the area of sea ports (Chornomorsk, Odesa and Yuzhnyi) of the Odesa Region in the North-Western part of the Black Sea. Spatio-temporal variability of wind conditions at the sea-atmosphere division is specified based on the data of the global numerical weather prediction model of the Global Forecast System (GFS). The research includes the description of the mathematical structure of the hydrodynamic model and the results of its adaptation to the conditions of the simulated sea area. It presents the results of model verification in the version which implies adoption of wind data from the archives of GFS-analysis and GFS-forecasts for 2010, 2016 and 2017. The verification was performed by comparing wind-induced denivellations of the sea level at the ports of Chornomorsk, Odesa and Yuzhnyi calculated over the course of modelling and those established on the basis of observational data (with the discreteness of 6 hours). A quantitative assessment of the calculation accuracy was performed for the cases where, according to the observational data, level denivellations exceeded the value of the standard deviation for the entire series. New series of the observed and calculated model-based significant wind-induced denivellations of sea level were formed for each of the ports from the sets of samples that met this condition. Using these series estimates of the mean square error of the calculations, allowable error of calculations, correlation coefficient between the actual and calculated values of the level denivellations, the probability of the calculation method under the allowable error were obtained. It was established that in the case of use of the data from wind GFS-analysis (with spatial resolution of 0.5° both latitudinally and longitudinally) over the course of modelling the probability of calculation of significant sea level denivellation constitutes 84-85%, and in case of using the data from the GFS-archive of wind forecasts (with spatial resolution of 0.25°) – 88-91%. This allowed making a conclusion that the model has good prospects of use for operational forecast of the sea level fluctuations caused by storm wind in the version implying assimilation of the predicted information on the spatio-temporal variability of wind conditions obtained by means of the GFS global weather forecast model.

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Detailed reconstructions of Holocene climate and environmental changes in the Taman Peninsula (Kuban River delta region) and their correlation with rapid sea-level fluctuations of the Black Sea

Quaternary International ◽

10.1016/j.quaint.2017.08.013 ◽

2018 ◽

Vol 465 ◽

pp. 22-36 ◽

Cited By ~ 4

Author(s):

N.S. Bolikhovskaya ◽

А.V. Porotov ◽

K. Richards ◽

M.D. Kaitamba ◽

S.S. Faustov ◽

...

Keyword(s):

Sea Level ◽

Black Sea ◽

Environmental Changes ◽

River Delta ◽

The Black Sea ◽

Taman Peninsula ◽

Delta Region ◽

Holocene Climate ◽

Sea Level Fluctuations ◽

Kuban River

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Tendencies of long-term changes of temperature fields, salinity and water level of the North-Western part of the Black Sea

Ukrainian hydrometeorological journal ◽

10.31481/uhmj.23.2019.08 ◽

2019 ◽

pp. 84-94

Author(s):

N. Berlinsky ◽

R. Gavriluk ◽

O. Danilenko

Keyword(s):

Water Temperature ◽

Sea Level ◽

Black Sea ◽

Temperature Increase ◽

The Black Sea ◽

Sea Level Fluctuations ◽

The North ◽

Long Term Changes ◽

North Western

The paper analyzes the variability of hydrological characteristics of the North-Western part of the Black for different temporal scales: long-term, seasonal and synoptic. The traditional methods of geographic investigations, such as comparative-geographic, retrospective and cartographic methods, were used. When analyzing sea level data packages and thermohaline characteristics mathematical methods, including statistical, correlation and regression analysis, were used. As a result of the conducted research quantitative estimates of tendencies of long-term changes of the thermohaline characteristics and level in the North-Western part of the Black Sea were received. Over the period of 1982-2005 an increase of water temperature in the North-Western part of the Black Sea was observed: in winter water temperature in the surface layer increased by 2оC, in the bottom layer – by more than 2оC. Over the period of 1990-2005 an increase of an average annual water temperature in Odesa area constituted 1,2°C. The most considerable and statistically significant temperature increase took place during the summer hydrological season: an average summer temperature increased during this period by 2,7оC. During transitional seasons (autumn and spring) there was also a tendency of temperature increase, however, statistically significant trend was observed only during the autumn period. There is a statistically significant negative trend observed for long-term changes of salinity. For the period of 1990-2005 an average annual salinity decreased by 1.36 ‰. A tendency of salinity decrease was observed for all seasons of the year, however, statistically significant trends are observed only in winter and summer. A close relationship between long-term changes in water salinity and runoff of the Dnieper River was also established. A sea level rise is observed at all stations of the North-Western part of the Black Sea. Over the period of 1947-2012 an average annual sea level in Odesa increased by 14 cm. An analysis of climatic changes of wind-induced sea level fluctuations showed that the frequency of surges of varying intensity remained almost unchanged, however, the frequency of sweeps changed significantly. Over the period of 1980-2012, as opposed to the period of 1947-1979, the frequency of minor sweeps (no more than 30 cm) increased, and the frequency of significant (more than 30 cm) and very significant (more than 50 cm) sweeps, on the contrary, decreased by about 5%-6%. Changes of wind-induced sea level fluctuations' character harmonize with wind direction and wind speed over the North-Western part of the Black Sea.

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CORRELATION OF THE BLACK, MARMARA AND AEGEAN SEAS DURING THE HOLOCENE

Proceedings of International Conference "Managinag risks to coastal regions and communities in a changinag world" (EMECS'11 - SeaCoasts XXVI) ◽

10.21610/conferencearticle_58b4315c686d6 ◽

2017 ◽

Author(s):

Nikolay Esin ◽

Vladimir Ocherednik ◽

Vladimir Ocherednik

Keyword(s):

Mathematical Model ◽

Sea Level ◽

Black Sea ◽

Aegean Sea ◽

The Black Sea ◽

Sea Level Changes ◽

The Holocene

A mathematical model describing the change in the Black Sea level depending on the Aegean Sea level changes is presented in the article. Calculations have shown that the level of the Black Sea has been repeating the course of the Aegean Sea level for the last at least 6,000 years. And the level of the Black Sea above the Aegean Sea level in the tens of centimeters for this period of time.

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