Reasons for Rapid Increase of Water Salinity in the Sea of Azov in the 21st Century

S. V. Berdnikov✉, V. V. Kulygin, L. V. Dashkevich

Federal Research Centre The Southern Scientific Centre of Russian Academy of Sciences (SSC RAS), Rostov-on-Don, Russian Federation

✉ e-mail: berdnikovsv@yandex.ru

Abstract

Purpose. When discussing the Sea of Azov salinization both in the 1970s and in the current period, the reduction of river runoff (primarily in the Don River) is indicated as the main reason for this phenomenon that results in the increased advection of the Black Sea waters. However, this factor alone is not enough to explain salinity decrease in the last quarter of the 20th century as well as its rapid growth in 2007–2020. The paper is purposed at assessing the contribution of water balance components to the change in the Azov Sea salinity for more than 50 years (1966–2020).

Methods and Results. A mathematical model of water-salt balance is used to assess the annual average salinity of the Sea of Azov. The variability of all the water balance components and the sources of its uncertainty are considered. It is shown that the model applied is resistant to variation of the input data. Based on the correlation analysis, it is found that during the salinization period, evaporation plays an important role along with the river runoff. At that in the 1970s, a decisive impact upon evaporation was exerted by the wind speed, whereas at the beginning of the 21st century – by the temperature and humidity regimes.

Conclusions. At the beginning of the 21st century, the reason for rapid salinity increase in the Azov Sea waters consisted in the prolonged period of low-water in rivers coinciding with the period of high water and air temperatures that resulted in an increase of evaporation from the sea surface. The obtained results permit to conclude that at the changed atmospheric processes in the region, the only factor consisting in transition from the low river inflows to the Azov Sea basin to the high ones may be not enough to provide significant decrease of seawater salinity. This circumstance should be taken into account when preparing the plans for adapting the economic activities to the climate changes.

Keywords

Sea of Azov, water salinity, water balance, mathematical model, climatic changes, evaporation

Acknowledgements

The study was carried out within the framework of state assignment of SSC RAS, project No. 122013100131-9, using the equipment of the “Joint Science and Technology Equipment Center of SSC RAS (research, development, testing)”.

Original russian text

Original Russian Text © S. V. Berdnikov, V. V. Kulygin, L. V. Dashkevich, 2023, published in MORSKOY GIDROFIZICHESKIY ZHURNAL, Vol. 39, Iss. 6, pp. 760-778 (2023)

For citation

Berdnikov, S.V., Kulygin, V.V. and Dashkevich, L.V., 2023. Reasons for Rapid Increase of Water Salinity in the Sea of Azov in the 21st Century. Physical Oceanography, 30(6), pp. 714-730.

References

  1. Berdnikov, S.V., Dashkevich, L.V. and Kulygin, V.V., 2022. A New State in the Hydrological Regime of the Sea of Azov in the 21th Century. Doklady Earth Sciences, 503(1), pp. 123-128. doi:10.1134/S1028334X22030059
  2. Vorovich, I.I., Gorstko, A.B., Dombrovskii, Yu.A., Zhdanov, Yu.A. and Surkov, F.A., 1981. The Use of a Mathematical Model of the Sea of Azov Ecosystem for the Investigation of the Functioning Regularities and System Structure. Doklady Akademii Nauk SSSR, 259(2), pp. 302-306 (in Russian).
  3. Matishov, D.G., Yaitskaya, N.A. and Berdnikov, S.V., 2018. Temperature and Salinity Variations in Caspian Sea Waters in the 20th Century. Oceanology, 58(6), pp. 786-795. doi:10.1134/S0001437018060103
  4. Dyakov, N.N., Berdnikov, S.V., Kulygin, V.V., Levitskaya, O.V., Dashkevich, L.V. and Lihtanskaya, N.V., 2022. Information Basis for a New Climatic Atlas of the Sea of Azov. In: SOI, 2022. Proceedings of SOI. Moscow. Iss. 223, pp. 33-48 (in Russian).
  5. Gargopa, Yu.M., 2002. Current Desalination of the Sea of Azov and Its Correlation with Long-Term Variations in Atmospheric Circulation. Water Resources, 29(6), pp. 690-697. doi:10.1023/A:1021197316175
  6. Matishov, G.G., Matishov, D.G. and Gargopa, Yu.M., 2008. Climatic Changes of Ecosystems of the Southern Seas under Anthropogenic Impact. Izvestiya Rossiiskoi Akademii Nauk. Seriya Geograficheskaya, (3), pp. 26-34 (in Russian).
  7. Zhukova, S.V., Shishkin, V.M., Karmanov, V.G., Burlachko, D.S., Podmareva, T.I., Lutynskaya, L.A. and Taradina, E.A., 2021. Water and Environmental Problems of the Sea of Azov and Ways to Solve Them. In: Rosvodresources, 2021. Trans-Boundary Water Bodies: Use, Management, Conservation: Proceedings of the All-Russian Theoretical and Practical Conference (Sochi, September 20–25, 2021). Novocherkassk: Lik, pp. 137-143 (in Russian).
  8. Ilyin, Yu.P., Fomin, V.V., Dyakov, N.N. and Gorbach, S.B., 2009. [Hydrometeorological Conditions of the Seas of Ukraine. Vol. 1. The Sea of Azov]. Sevastopol: ECOSI-Gidrofizika, 400 p. (in Russian).
  9. Matishov, G.G. and Grigorenko, K.S., 2017. Causes of Salinization of the Gulf of Taganrog. Doklady Earth Sciences, 477(1), pp. 1311-1315. doi:10.1134/S1028334X17110034
  10. Matishov, G. and Levitus S., eds., 2008. Climatic Atlas of the Sea of Azov 2008. NOAA Atlas NESDIS 65. Washington, D.C.: U.S. Government Printing Office, 148 p.
  11. Matishov, G.G., Sherman, K. and Levitus, S., eds., 2014. Atlas of Climatic Changes in Nine Large Marine Ecosystems of the Northern Hemisphere (1827–2013). NOAA Atlas NESDIS 78.Washington, D.C.: U.S. Government Printing Office, 131 p. doi:10.7289/V5Q52MK5
  12. Matishov, G.G. and Stepanyan, O.V., 2018. Research Vessel Deneb: 10 Years of Marine Scientific Research. Physical Oceanography, 25(6), pp. 501-508. doi:10.22449/1573-160X-2018-6-501-508
  13. Matishov, G.G. and Grigorenko, K.S., 2020. Dynamic Mode of the Azov Sea in Conditions of Salinization. Doklady Earth Sciences, 492(1), pp. 376-381. doi:10.1134/S1028334X20050141
  14. Dashkevich, L.V., Berdnikov, S.V. and Kulygin, V.V., 2017. Many-Year Variations of the Average Salinity of the Sea of Azov. Water Resources, 44(5), pp. 749-757. doi:10.1134/S0097807817040042
  15. Krylenko, V.V., Krylenko, M.V. and Aleynikov, A.A., 2019. Length Coastline Specification of the Azov Sea Using Sentinel-2 Satellite Data. Vestnik SSUGT, 24(4), pp. 78-92. doi:10.33764/2411-1759-2019-24-4-78-92 (in Russian).
  16. Gershanovich, D.E., Goptarev, N.P., Zatuchnaya, B.M. and Simonov, A.I., eds., 1991. Hydrometeorology and Hydrochemistry of the Seas in the USSR. Vol. 5. The Azov Sea. Saint Petersburg: Gidrometeoizdat, 236 p. (in Russian).
  17. Evstigneev, V.P., Mishin, D.V. and Ostroumova, L.P., 2018. Calculation of Precipitation Layer as a Water Balance Component of the Sea of Azov. Russian Meteorology and Hydrology, 43(8), pp. 520-529. doi:10.3103/S1068373918080046
  18. Dashkevich, L.V. and Kulygin, V.V., 2019. The Average Temperature Assessment of the Surface Layer of the Sea of Azov Based on Satellite Imagery and Observations at Coastal Hydrometeorological Stations. In: MGU, 2019. InterCarto. InterGIS. GI Support of Sustainable Development of Territories: Proceedings of the International Conference. Moscow: Moscow University Press. Vol. 25, part 2, pp. 112-120. doi:10.35595/2414-9179-2019-2-25-112-120 (in Russian).
  19. Legeais, J.-F., Meyssignac, B., Faugère, Y., Guerou, A., Ablain, M., Pujol, M.-I., Dufau, C. and Dibarboure, G., 2021. Copernicus Sea Level Space Observations: A Basis for Assessing Mitigation and Developing Adaptation Strategies to Sea Level Rise. Frontiers in Marine Science, 8, 704721. doi:10.3389/fmars.2021.704721
  20. Mikhailov, V.N. and Mikhailova, M.V., 2015. Effect of Long-Term Changes of Marine Factors on River Mouths. Water Resources, 42(4), pp. 420-431. doi:10.1134/S0097807815040089
  21. Dashkevich, L.V., 2020. Long-Term Trends in Changes in Meteorological Parameters of the Sea of Azov Region. Ecology. Economy. Informatics. System Analysis and Mathematical Modeling of Ecological and Economic Systems, 1(5), pp. 130-137. doi:10.23885/2500-395X-2020-1-5-130-137 (in Russian).
  22. Lur’e, P.M. and Panov, V.D., 1999. An Influence of Climate Changes on Hydrological Regime of the Don River in the Early 21st Century. Russian Meteorology and Hydrology, 4, pp. 62-68.
  23. Kostyanoyi, A.G., Ginzburg, A.I. and Lebedev, S.A., 2014. Climatic Variability of Hydrometeorological Parameters of the Seas of Russia in 1979-2011 Years. Proceedings of Voeikov Main Geophysical Observatory, 570, pp. 50-87 (in Russian).
  24. Babkin, V.I. and Postnikov, A.N., 2000. The Role of Cyclonic Activity in the Formation of the Runoff of the Volga, Don, and Dnieper Rivers. Water Resources, 27(1), pp. 95-97.
  25. Shlygin, I.A., 1980. Evaluation of the Error in the Components of the Water Balance of the Sea of Azov. Trudy GOIN, 153, pp. 14–23 (in Russian).
  26. Luts, N.V., 2001. Long-Term Variability of Wind Speed in the Eastern Azov Region. Russian Meteorology and Hydrology, (2), pp. 98-102.
  27. Albul, I.P., 2012. SHI Formula Application for Water Evaporation Assessment under Different Composition of Initial Parameters Photos. Vestnik Saint-Petersburg University. Series 7. Geology. Geography, (3), pp. 125-136 (in Russian).
  28. Simonov, A.I. and Altman, E.N., eds., 1991. Hydrometeorology and Hydrochemistry of Seas in the USSR. Vol. 4. Black Sea. Issue 1. Hydrometeorological Conditions. Saint Petersburg: Gidrometeoizdat, 429 p. (in Russian).
  29. Zavialov, I.B., Osadchiev, A.A., Zavialov, P.O., Krementskiy, V.V. and Goncharenko, I.V., 2021. Study of Water Exchange in the Kerch Strait Based on Historical Data and Contact Measurements in 2019. Oceanology, 61(3), pp. 329-337. doi:10.1134/S0001437021030176
  30. Zavialov, I., Osadchiev, A., Sedakov, R., Barnier, B., Molines, J.-M. and Belokopytov, V., 2020. Water Exchange between the Sea of Azov and the Black Sea through the Kerch Strait. Ocean Science, 16(1), pp. 15-30. doi:10.5194/os-16-15-2020

Download the article (PDF)