Analysis of Seasonal Energy Characteristics of the Marmara Sea Upper Layer Dynamics

S. G. Demyshev, S. V. Dovgaya✉

Marine Hydrophysical Institute of RAS, Sevastopol, Russian Federation

✉ e-mail: dovgayasvetlana0309@yandex.ru

Abstract

Purpose. The aim of the work is to assess the role of the basic forces in formation of the dynamic structures of the upper layer in the Marmara Sea in different hydrological seasons.

Methods and Results. The numerical model developed in Marine Hydrophysical Institute, Russian Academy of Sciences, was used to calculate the hydrodynamic and energy characteristics of the sea circulation. The horizontal spatial resolution was 1.22 × 0.83 km, 18 horizons were used vertically, and the time step was 0.5 min. The characteristics of the waters inflowing through the Bosporus and Dardanelles straits corresponded to the available observational data. On the sea surface, the daily average fields of tangential wind stress, heat fluxes, precipitation and evaporation for 2008 were preset; these parameters were calculated using the regional atmospheric model MM5. Spatial distributions of the vortex structures and the corresponding energy flows in the upper sea layer for different seasons were considered. Having been analyzed, the average seasonal spatial distributions of the current velocity fields and the components of the kinetic energy budget showed that during the year, the vortices in the upper sea layer were formed mainly by two mechanisms. In the central part of the sea, generation of a large-scale anticyclone and its seasonal variability are basically conditioned by the wind forcing, whereas formation and evolution of coastal cyclonic eddies are caused by the buoyancy force. In the fields where the buoyancy, pressure and friction forcing takes place, the zones of local extremes are distinguished. Two of them are the areas of water inflow through the Bosphorus and Dardanelles straits. The strongest variability is observed in the Bosporus region that is certainly conditioned by the fact that the inflowing Black Sea waters have a decisive influence on seasonal nature of the Marmara Sea circulation. The extreme values in the other zones are the result of the coastline structure heterogeneities, that leads to formation of the coastal eddies, the energy source for which is the available potential energy.

Conclusions. Analysis of the results of the performed numerical experiment makes it possible to conclude that in the upper layer of the Marmara Sea, formation and variability of the central anticyclone are conditioned by the wind forcing, while those of the coastal cyclones – by the buoyancy effect.

Keywords

numerical hydrodynamic model, Marmara Sea, anticyclone, cyclone, kinetic energy, wind forcing, buoyancy forcing

Acknowledgements

The investigation was carried out within the framework of the state task on theme № 0555-2021-0004 "Fundamental studies of oceanological processes determining state and evolution of marine environment under the influence of natural and anthropogenic factors, based on observation and modeling methods".

Original russian text

Original Russian Text © S. G. Demyshev, S. V. Dovgaya, 2021, published in MORSKOY GIDROFIZICHESKIY ZHURNAL, Vol. 37, Iss. 5, pp. 509-524 (2021)

For citation

Demyshev, S.G. and Dovgaya, S.V., 2021. Analysis of Seasonal Energy Characteristics of the Marmara Sea Upper Layer Dynamics. Physical Oceanography, 28(5), pp. 471-485. doi:10.22449/1573-160X-2021-5-471-485

DOI

10.22449/1573-160X-2021-5-471-485

References

  1. Beşiktepe, T.S., Sur, H.I., Özsoy, E., Latif, M.A., Oguz, T. and Unluata, U., 1994. The Circulation and Hydrography of the Marmara Sea. Progress in Oceanography, [e-journal] 34(4), pp. 285-334. https://doi.org/10.1016/0079-6611(94)90018-3
  2. Demyshev, S.G., Dovgaya, S.V. and Ivanov, V.A., 2012. Numerical Modeling of the Influence of Exchange through the Bosporus and Dardanelles Straits on the Hydrophysical Fields of the Marmara Sea. Izvestiya, Atmospheric and Oceanic Physics, 48(4), pp. 418-426. doi:10.1134/S0001433812040056
  3. Chiggiato, J., Jarosz, E., Book, J.W., Dykes, J., Torrisi, L., Poulain, P.-M., Gerin, R., Horstmann, J. and Beşiktepe, Ş., 2012. Dynamics of the Circulation in the Sea of Marmara: Numerical Modeling Experiments and Observations from the Turkish Straits System Experiment. Ocean Dynamic, 62(1), pp. 139-159. doi:10.1007/s10236-011-0485-5
  4. Zalesny, V.B., Gusev, A.V. and Fomin, V.V., 2016. Numerical Model of Nonhydrostatic Ocean Dynamics Based on Methods of Artificial Compressibility and Multicomponent Splitting. Oceanology, 56(6), pp. 876-887. https://doi.org/10.1134/S0001437016050167
  5. Sannino, G., Sözer, A. and Ozsoy, E., 2017. A High-Resolution Modelling Study of the Turkish Straits System. Ocean Dynamic, 67(3), pp. 397-432. https://doi.org/10.1007/s10236-017-1039-2
  6. Stanev, E., Grashorn, S. and Zhang, Y., 2017. Cascading Ocean Basins: Numerical Simulations of the Circulation and Interbasin Exchange in the Azov-Black-Marmara-Mediterranean Seas System. Ocean Dynamic, 67(8), pp. 1003-1025. https://doi.org/10.1007/s10236-017-1071-2
  7. Aydoğdu, A., Pinardi, N., Özsoy, E., Danabasoglu, G., Gürses, Ö. and Karspeck, A., 2018. Circulation of the Turkish Straits System under Interannual Atmospheric Forcing. Ocean Science, 14(5), pp. 999-1019. https://doi.org/10.5194/os-14-999-2018
  8. Aydoğdu, A., Hoar, T.J., Vukicevic, T., Anderson, J.L., Pinardi, N., Karspeck, A., Hendricks, J., Collins, N., Macchia, F. and Özsoy, E., 2018. OSSE for a Sustainable Marine Observing Network in the Sea of Marmara. Nonlinear Processes in Geophysics, 25(3), pp. 537-551. https://doi.org/10.5194/npg-25-537-2018
  9. Demyshev, S.G., 2004. Energy of the Black Sea Climatic Circulation. Part I: Discrete Equations of the Time Rate of Change of Kinetic and Potential Energy. Meteorology and Hydrology, (9), pp. 65-81 (in Russian).
  10. Demyshev, S.G., Dovgaya, S.V. and Shokurov, M.V., 2016. Effect of Heat Flow, Precipitation and Evaporation on the Dynamics of the Marmara Sea Surface Water. Physical Oceanography, (3), pp. 3-13. doi:10.22449/1573-160X-2016-3-3-13
  11. Demyshev, S.G., Dovgaya, S.V. and Shokurov, M.V., 2019. Energy Characteristics of the Marmara Sea Water Circulation in 2008. Physical Oceanography, 26(4), pp. 275-287. doi:10.22449/1573-160X-2019-4-275-287
  12. Jordà, G., von Schuckmann, K., Josey, S., Caniaux, G., García-Lafuente, J., Sammartino, S., Özsoy, E., Polcher, J., Notarstefano, G., Poulain, P.-M., Adloff, F., Salat, J., Naranjo, C., Schroeder, K., Chiggiato, J., Sannino, G. and Macías, D., 2017. The Mediterranean Sea Heat and Mass Budgets: Estimates, Uncertainties and Perspectives. Progress in Oceanography, 156, pp. 174-208. https://doi.org/10.1016/j.pocean.2017.07.001
  13. Oguz, T., Özsoy, E., Latif, M.A., Sur, H.I. and Ünlüata, U., 1990. Modeling of Hydraulically Controlled Exchange Flow in the Bosphorus Strait. Journal of Physical Oceanography, 20(7), pp. 945-965. https://doi.org/10.1175/1520-0485(1990)020%3C0945:MOHCEF%3E2.0.CO;2
  14. Zapevalov, А.S., 2005. Seasonal Variability of Vertical Temperature and Salinity Distribution in the Sea of Marmara. Meteorology and Hydrology, (2), pp. 78-84 (in Russian).
  15. Beşiktepe, S.T., 2003. Density Currents in the Two-Layer Flow: an Example of Dardanelles Outflow. Oceanologica Acta, 26(3), pp. 243-253. https://doi.org/10.1016/S0399-1784(03)00015-X
  16. Kamenkovich, V.M., Koshlyakov, M.N. and Monin, A.S., 1986. Synoptic Eddies in the Ocean. Amsterdam: Springer, 444 p. doi:10.1007/978-94-009-4502-9
  17. Sarkisjan, A.S. and Ivanov, V.F., 1971. Joint Effect of Baroclinicity and Bottom Relief as an Important Factor in Dynamics of Sea Currents. Izvestiya, Atmospheric and Oceanic Physics, 7(2), pp. 173-188 (in Russian).
  18. Sarkisyan, A.S., 2006. Forty Years of JEBAR – the Finding of the Joint Effect of Baroclinicity and Bottom Relief for the Modeling of Ocean Climatic Characteristics. Izvestiya. Atmospheric and Oceanic Physics, 42(5), pp. 534-554. https://doi.org/10.1134/S0001433806050021

Download the article (PDF)