Modeling of the Major Baltic Inflow Using a Joint Model of the North and Baltic Seas
N. A. Tikhonova1, 2, ✉, E. A. Zakharchuk1, M. V. Vinogradov1, 2, V. S. Travkin1, 2
1 Saint-Petersburg State University, Saint Petersburg, Russian Federation
2 N.N. Zubov's State Oceanographic Institute, Roshydromet, Moscow, Russian Federation
✉ e-mail: nata-tik@yandex.ru
Abstract
Purpose. The purpose of the work consists in studying the structure and flow routes of the transformed North Sea waters in the Baltic Sea during the formation and spread of the Major Baltic inflow in December 2014 using numerical modeling.
Methods and Results. To achieve the stated aim, a three-dimensional baroclinic hydrodynamic model of the North and Baltic seas with a spherical grid area detailed in the Danish straits has been developed based on the INMOM model. Within the framework of the performed numerical experiment, the oceanological characteristic fields were assessed in the system of two seas for the period from 1 January 2014 to 31 December 2015. Comparison of the model-derived salinity and sea current characteristic values with those measured at the Darss Sill and Arkona stations as well as with the BSPAF regional reanalysis data has shown that in general, the INMOM model reproduces changes both in salinity and characteristics of the average currents better than the reanalysis data. The features of vertical variability of salinity and sea currents in the Danish straits during the Major Baltic inflow formation are described based on the modeling results. The daily average and total volumes of water transported in the Sound, Great Belt and Little Belt straits during the main period of the Major inflow are estimated. The features of distribution of the near-bottom salinity fields during different periods of its formation are described. The Lagrangian modeling made it possible to describe the ways in which the waters of the Major Baltic inflow spread.
Conclusions. The estimates of water exchange obtained due to the INMOM model indicate that during the main period of the Major Baltic inflow (December 2014), a total of 241.4 km3 of the Kattegat waters passed through the Danish straits. The inflow largest part, 170.9 km3, spread through the Great Belt Strait, while only 68.9 km3 passed through the Sound Strait. The effect of the Small Belt Strait on water transport during the Major Baltic inflow was very insignificant – only 1.6 km3. The study of distribution routes of the transformed North Sea waters over the Baltic Sea after the end of the Major Baltic inflow shows that having passed the Danish straits, its waters spread in a wide flow to the Southwestern Baltic, then penetrate to the Gulf of Gdansk, move further along a cyclonic trajectory through the deep-sea areas of the eastern and northern parts of the Gotland Basin without entering the Gulf of Finland and reach the Landsort Deep in the western part of the Gotland basin by the end of December 2015.
Keywords
hydrodynamic modeling, INMOM, Baltic Sea, North Sea, Danish straits, Major Baltic inflow, salinity of the Baltic Sea, currents of the Baltic Sea, regional reanalysis of hydrophysical fields, water exchange, water salinity, sea level, stratification of waters, Lagrangian modeling
Acknowledgements
The study was carried out at financial support of the RSF grant No. 24-27-00412 “Clarifying the mechanisms of generation and non-stationarity of the Major Baltic inflows” https://rscf.ru/project/24-27-00412/.
Original russian text
Original Russian Text © The Authors, 2025, published in MORSKOY GIDROFIZICHESKIY ZHURNAL, Vol. 41, Iss. 2, pp. 185–212 (2025)
For citation
Tikhonova, N.A., Zakharchuk, E.A., Vinogradov, M.V. and Travkin, V.S., 2025. Modeling of the Major Baltic Inflow Using a Joint Model of the North and Baltic Seas. Physical Oceanography, 32(2), pp. 211-237.
References
- Dickson, R.R., 1973. The Prediction of Major Baltic Inflows. Deutsche Hydrographische Zeitschrift, 26, pp. 97-105. https://doi.org/10.1007/BF02232597
- Terziev, F.S., Rozhkov, V.A. and Smirnova, A.I., eds., 1992. Hydrometeorology and Hydrochemistry of the Seas of the USSR. Volume 3. Baltic Sea. Issue 1. Hydrometeorological Conditions. Saint Petersburg: Gidrometeoizdat, 450 p. (in Russian).
- Fischer, H. and Matthäus, W., 1996. The Importance of the Drogden Sill in the Sound for Major Baltic Inflows. Journal of Marine Systems, 9(3-4), pp. 137-157. https://doi.org/10.1016/S0924-7963(96)00046-2
- Matthäus, W., 2006. The History of Investigation of Salt Water Inflows into the Baltic Sea – from the Early Beginning to Recent Results. In: Institut für Ostseeforschung, 2006. Meereswissenschaftliche Berichte = Marine Science Reports. Warnemünde: Institut für Ostseeforschung. No. 65, 73 p. URL: https://doi.io-warnemuende.de/10.12754/msr-2006-0065 [Accessed: 20.02.2025].
- Mohrholz, V., Naumann, M., Nausch, G., Krüger, S. and Gräwe, U., 2015. Fresh Oxygen for the Baltic Sea – An Exceptional Saline Inflow after a Decade of Stagnation. Journal of Marine Systems, 148, pp. 152-166. https://doi.org/10.1016/j.jmarsys.2015.03.005
- Tikhonova, N.A. and Sukhachev, V.N., 2017. Wave Interpretation of Major Baltic Inflows. Russian Meteorology and Hydrology, 42(4), pp. 258-266. https://doi.org/10.3103/S1068373917040069
- Zakharchuk, E.A., Litina, E.N., Klevantsov, Yu.P., Sukhachev, V.N. and Tikhonova, N.A., 2017. Nonstationarity of the Hydrometeorological Processes in the Baltic Sea under Changing Climate. Proceedings of State Oceanographic Institute, (218), pp. 6-62 (in Russian).
- Leppäranta, M. and Myrberg, K., 2009. Topography and Hydrography of the Baltic Sea. In: M. Leppäranta and K. Myrberg, 2009. Physical Oceanography of the Baltic Sea. Berlin; Heidelberg: Springer, pp. 41-88. https://doi.org/10.1007/978-3-540-79703-6
- Zakharchuk, E.A., Kudryavtsev, A.S. and Sukhachev, V.N., 2014. On the Resonance-Wave Mechanism of Major Baltic Inflows. Russian Meteorology and Hydrology, 39(2), pp. 100-108. https://doi.org/10.3103/S1068373914020058
- Wyrtki, K., 1953. Die Dynamik der Wasserbewegungen im Fehmarnbelt. Kieler Meeresforschungen, 9(2), pp. 155-170 (in German).
- Madsen, K.S. and Højerslev, N.K., 2009. Long-Term Temperature and Salinity Records from the Baltic Sea Transition Zone. Boreal Environment Research, 14, pp. 125-131.
- Gräwe, U., Friedland, R. and Burchard, H., 2013. The Future of the Western Baltic Sea: Two Possible Scenarios. Ocean Dynamics, 63(8), pp. 901-921. https://doi.org/10.1007/s10236-013-0634-0
- Stigebrandt, A., 1983. A Model for the Exchange of Water and Salt between the Baltic and the Skagerrak. Journal of Physical Oceanography, 13(3), pp. 411-427. https://doi.org/10.1175/1520-0485(1983)013%3C0411:AMFTEO%3C2.0.CO;2
- Meier, H.E.M., Kjellström, E. and Graham, L.P., 2006. Estimating Uncertainties of Projected Baltic Sea Salinity in the Late 21st Century. Geophysical Research Letters, 33(15), L15705. https://doi.org/10.1029/2006GL026488
- Neumann, T., 2010. Climate-Change Effects on the Baltic Sea Ecosystem: A Model Study. Journal of Marine Systems, 81(3), pp. 213-224. https://doi.org/10.1016/j.jmarsys.2009.12.001
- Hordoir, R., Dieterich, C., Basu, C., Dietze, H. and Meier, H.E.M., 2013. Freshwater Outflow of the Baltic Sea and Transport in the Norwegian Current: A Statistical Correlation Analysis Based on a Numerical Experiment. Continental Shelf Research, 64, pp. 1-9. https://doi.org/10.1016/j.csr.2013.05.006
- Burchard, H., Lass, H.U., Mohrholz, V., Umlauf, L., Sellschopp, J., Fiekas, V., Bolding, K. and Arneborg, L., 2005. Dynamics of Medium-Intensity Dense Water Plumes in the Arkona Basin, Western Baltic Sea. Ocean Dynamics, 55(5), pp. 391-402. https://doi.org/10.1007/s10236-005-0025-2
- Umlauf, L., Arneborg, L., Burchard, H., Fiekas, V., Lass, H.U., Mohrholz, V. and Prandke, H., 2007. Transverse Structure of Turbulence in a Rotating Gravity Current. Geophysical Research Letters, 34(8), L08601. https://doi.org/10.1029/2007GL029521
- Lehmann, A. and Myrberg, K., 2008. Upwelling in the Baltic Sea – A Review. Journal of Marine Systems, 74(1), pp. S3-S12. https://doi.org/10.1016/j.jmarsys.2008.02.010
- Fennel, W., Seifert, T. and Kayser, B., 1991. Rossby Radii and Phase Speeds in the Baltic Sea. Continental Shelf Research, 11(1), pp. 23-36. https://doi.org/10.1016/0278-4343(91)90032-2
- Reißmann, J.H., 2006. On the Representation of Regional Characteristics by Hydrographic Measurements at Central Stations in Four Deep Basins of the Baltic Sea. Ocean Science, 2(1), pp. 71-86. https://doi.org/10.5194/os-2-71-2006
- Osiński, R., Rak, D., Walczowski, W. and Piechura, J., 2010. Baroclinic Rossby Radius of Deformation in the Southern Baltic Sea. Oceanologia, 52(3), pp. 417-429. http://dx.doi.org/10.5697/oc.52-3.417
- Kurkin, A., Kurkina, O., Rybin, A. and Talipova, T., 2020. Comparative Analysis of the First Baroclinic Rossby Radius in the Baltic, Black, Okhotsk, and Mediterranean Seas. Russian Journal of Earth Sciences, 20(4), ES4008. https://doi.org/10.2205/2020ES000737
- Zhang, Y.J., Stanev, E.V. and Grashorn, S., 2016. Unstructured-Grid Model for the North Sea and Baltic Sea: Validation against Observations. Ocean Modelling, 97, pp. 91-108. https://doi.org/10.1016/j.ocemod.2015.11.009
- Zalesny, V.B., Marchuk, G.I., Agoshkov, V.I., Bagno, A.V., Gusev, A.V., Diansky, N.A. Moshonkin, S.N., Tamsalu, R. and Volodin, E.M., 2010. Numerical Simulation of Large-Scale Ocean Circulation Based on the Multicomponent Splitting Method. Russian Journal of Numerical Analysis and Mathematical Modelling, 25(6), pp. 581-609. https://doi.org/10.1515/rjnamm.2010.036
- Diansky, N.A., 2013. [Modeling the Ocean Circulation and Study of Its Response to Short- and Long-Period Atmospheric Influences]. Moscow: Fizmatlit, 272 p. (in Russian).
- Brydon, D., Sun, S. and Bleck, R., 1999. A New Approximation of the Equation of State for Seawater, Suitable for Numerical Ocean Models. Journal of Geophysical Research: Oceans, 104(C1), pp. 1537-1540. https://doi.org/10.1029/1998JC900059
- Pacanovsky, R.C. and Philander, G.H., 1981. Parametrization of Vertical Mixing in Numerical Models of Tropical Oceans. Journal of Physical Oceanography, 11(11), pp. 1443-1451. https://doi.org/10.1175/1520-0485(1981)011%3C1443:POVMIN%3D2.0.CO;2
- Yakovlev, N.G., 2009. Reproduction of the Large-Scale State of Water and Sea Ice in the Arctic Ocean from 1948 to 2002: Part II. The State of Ice and Snow Cover. Izvestiya, Atmospheric and Oceanic Physics, 45(4), pp. 478-494. https://doi.org/10.1134/S0001433809040082
- Hunke, E.C. and Dukowicz, J.K., 1997. An Elastic-Viscous-Plastic Model for Sea Ice Dynamics. Journal of Physical Oceanography, 27(9), pp. 1849-1867. https://doi.org/10.1175/1520-0485(1997)027%3C1849:AEVPMF%3E2.0.CO;2
- Hordoir, R., Axell, L., Löptien, U., Dietze, H. and Kuznetsov, I., 2015. Influence of Sea Level Rise on the Dynamics of Salt Inflows in the Baltic Sea. Journal of Geophysical Research: Oceans, 120(10), pp. 6653-6668. https://doi.org/10.1002/2014JC010642
- Pemberton, P., Löptien, U., Hordoir, R., Höglund, A., Schimanke, S., Axell, L. and Haapala, J., 2017. Sea-Ice Evaluation of NEMO-Nordic 1.0: A NEMO-LIM3.6-Based Ocean-Sea-Ice Model Setup for the North Sea and Baltic Sea. Geoscientific Model Development, 10(8), pp. 3105-3123. https://doi.org/10.5194/gmd-10-3105-2017
- Nerger, L., Hiller, W. and Schröter, J., 2005. A Comparison of Error Subspace Kalman Filters. Tellus A: Dynamic Meteorology and Oceanography, 57(5), pp. 715-735. https://doi.org/10.3402/tellusa.v57i5.14732
- Prants, S.V., Uleysky, M.Yu. and Budyansky, M.V., 2017. Lagrangian Oceanography: Large-Scale Transport and Mixing in the Ocean. Physics of Earth and Space Environments. Cham: Springer, 273 p. https://doi.org/10.1007/978-3-319-53022-2
- Mattsson, J., 1996. Some Comments on the Barotropic Flow through the Danish Straits and the Division of the Flow between the Belt Sea and the Öresund. Tellus A: Dynamic Meteorology and Oceanography, 48(3), pp. 456-464. https://doi.org/10.3402/tellusa.v48i3.12071
- Liblik, T., Naumann, M., Alenius, P., Hansson, M., Lips, U., Nausch, G., Tuomi, L., Wesslander, K., Laanemets J. [et al.], 2018. Propagation of Impact of the Recent Major Baltic Inflows from the Eastern Gotland Basin to the Gulf of Finland. Frontiers in Marine Science, 5, 222. https://doi.org/10.3389/fmars.2018.00222