Articles | Volume 18, issue 3
https://doi.org/10.5194/os-18-857-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/os-18-857-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
09 Jun 2022
Research article |
| 09 Jun 2022
| 09 Jun 2022
Quasi-steady circulation regimes in the Baltic Sea
Taavi Liblik
CORRESPONDING AUTHOR
Department of Marine Systems, Tallinn University of Technology, Tallinn, Estonia
Germo Väli
Department of Marine Systems, Tallinn University of Technology, Tallinn, Estonia
Department of Marine Systems, Tallinn University of Technology, Tallinn, Estonia
Jaan Laanemets
Department of Marine Systems, Tallinn University of Technology, Tallinn, Estonia
Madis-Jaak Lilover
Department of Marine Systems, Tallinn University of Technology, Tallinn, Estonia
Urmas Lips
Department of Marine Systems, Tallinn University of Technology, Tallinn, Estonia
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Cited articles
Berden, G., Charo, M., Möller, O. O., and Piola, A. R.: Circulation and Hydrography in the Western South Atlantic Shelf and Export to the Deep Adjacent Ocean: 30∘ S to 40∘ S, J. Geophys. Res.-Oceans, 125, e2020JC016500, https://doi.org/10.1029/2020JC016500, 2020.
Book, J., Perkins, H., Signell, R., and Wimbush, M.: The Adriatic Circulation Experiment winter 2002/2003 mooring data report: a case study in ADCP data processing, 2007.
Burchard, H. and Bolding, K.: GETM – a general estuarine transport model. Scientific Documentation, Technical report EUR 20253 en., Tech. Rep. European Commission, Ispra, Italy, https://op.europa.eu/en/publication-detail/-/publication/5506bf19-e076-4d4b-8648-dedd06efbb38 (last access: 3 December 2019), 2002.
Carstensen, J., Andersen, J. H., Gustafsson, B. G., and Conley, D. J.: Deoxygenation of the baltic sea during the last century, P. Natl. Acad. Sci. USA, 111, 5628–5633, https://doi.org/10.1073/pnas.1323156111, 2014.
Csanady, G. T.: Circulation in the Coastal Ocean, Adv. Geophys., 23, 101–183, https://doi.org/10.1016/S0065-2687(08)60331-3, 1981.
Dargahi, B.: Dynamics of vortical structures in the Baltic Sea, Dynam. Atmos. Oceans, 88, 101117, https://doi.org/10.1016/j.dynatmoce.2019.101117, 2019.
Davis, R. E.: On the coastal-upwelling overturning cell, J. Mar. Res., 68, 369–385, https://doi.org/10.1357/002224010794657173, 2010.
Döös, K., Meier, H. E. M., and Döscher, R.: The Baltic Haline Conveyor Belt or The Overturning Circulation and Mixing in the Baltic, AMBIO A J. Hum. Environ., 33, 261–266, https://doi.org/10.1579/0044-7447-33.4.261, 2004.
Ekman, V. W.: On the influence of the earth's rotation on ocean currents, Ark. Mat., Astron. Fys., 11, 1–52, 1905.
Elken, J., Raudsepp, U., and Lips, U.: On the estuarine transport reversal in deep layers of the Gulf of Finland, J. Sea Res., 49, 267–274, https://doi.org/10.1016/S1385-1101(03)00018-2, 2003.
Geyer, W. R. and MacCready, P.: The Estuarine Circulation, Annu. Rev. Fluid Mech., 46, 175–197, https://doi.org/10.1146/annurev-fluid-010313-141302, 2014.
Giddings, S. N. and MacCready, P.: Reverse Estuarine Circulation Due to Local and Remote Wind Forcing, Enhanced by the Presence of Along-Coast Estuaries, J. Geophys. Res.-Oceans, 122, 10184–10205, https://doi.org/10.1002/2016JC012479, 2017.
Gilcoto, M., Largier, J. L., Barton, E. D., Piedracoba, S., Torres, R., Graña, R., Alonso-Pérez, F., Villacieros-Robineau, N., and de la Granda, F.: Rapid response to coastal upwelling in a semienclosed bay, Geophys. Res. Lett., 44, 2388–2397, https://doi.org/10.1002/2016GL072416, 2017.
Golenko, M., Krayushkin, E., and Lavrova, O.:
Investigation of coastal surface currents in the South-East
Baltic based on concurrent drifter and satellite observations and
numerical modeling,
Curr. Probl. Remote Sens. Earth from Space, 280–296,
https://doi.org/10.21046/2070-7401-2017-14-7-280-296, 2017 (in Russian).
Gräwe, U. and Wolff, J.-O.: Suspended particulate matter dynamics in a particle framework, Environ. Fluid Mech., 10, 21–39, https://doi.org/10.1007/s10652-009-9141-8, 2010.
Hagen, E. and Feistel, R.: Observations of low-frequency current fluctuations in deep water of the Eastern Gotland Basin/Baltic Sea, J. Geophys. Res.-Oceans, 109, C03044, https://doi.org/10.1029/2003JC002017, 2004.
Hagen, E. and Feistel, R.: Synoptic changes in the deep rim current during stagnant hydrographic conditions in the Eastern Gotland Basin, Baltic Sea, Oceanologia, 49, 185–208, 2007.
Hersbach, H., Bell, B., Berrisford, P., Hirahara, S., Horányi, A., Muñoz-Sabater, J., Nicolas, J., Peubey, C., Radu, R., Schepers, D., Simmons, A., Soci, C., Abdalla, S., Abellan, X., Balsamo, G., Bechtold, P., Biavati, G., Bidlot, J., Bonavita, M., De Chiara, G., Dahlgren, P., Dee, D., Diamantakis, M., Dragani, R., Flemming, J., Forbes, R., Fuentes, M., Geer, A., Haimberger, L., Healy, S., Hogan, R. J., Hólm, E., Janisková, M., Keeley, S., Laloyaux, P., Lopez, P., Lupu, C., Radnoti, G., de Rosnay, P., Rozum, I., Vamborg, F., Villaume, S., and Thépaut, J.-N.: The ERA5 global reanalysis, Q. J. Roy. Meteor. Soc., 146, 1999–2049, https://doi.org/10.1002/QJ.3803, 2020.
Hinrichsen, H. H., von Dewitz, B., and Dierking, J.: Variability of advective connectivity in the Baltic Sea, J. Marine Syst., 186, 115–122, https://doi.org/10.1016/j.jmarsys.2018.06.010, 2018.
Hofmeister, R., Burchard, H., and Beckers, J.-M.: Non-uniform adaptive vertical grids for 3D numerical ocean models, Ocean Model., 33, 70–86, https://doi.org/10.1016/j.ocemod.2009.12.003, 2010.
Holtermann, P. L., Prien, R., Naumann, M., Mohrholz, V., and Umlauf, L.: Deepwater dynamics and mixing processes during a major inflow event in the central Baltic Sea, J. Geophys. Res.-Oceans, 122, 6648–6667, https://doi.org/10.1002/2017JC013050, 2017.
Jakobsen, F., Hansen, I. S., Ottesen Hansen, N. E., and Østrup-Rasmussen, F.: Flow resistance in the Great Belt, the biggest strait between the North Sea and the Baltic Sea, Estuar. Coast. Shelf S., 87, 325–332, https://doi.org/10.1016/j.ecss.2010.01.014, 2010.
Janssen, F., Schrum, C., and Backhaus, J. O.: A climatological data set of temperature and salinity for the Baltic Sea and the North Sea, Dtsch. Hydrogr. Zeitschrift, 51, 5–245, https://doi.org/10.1007/BF02933676, 1999.
Jędrasik, J. and Kowalewski, M.: Mean annual and seasonal circulation patterns and long-term variability of currents in the Baltic Sea, J. Marine Syst., 193, 1–26, https://doi.org/10.1016/j.jmarsys.2018.12.011, 2019.
Jedrasik, J., Cieślikiewicz, W., Kowalewski, M., Bradtke, K., and Jankowski, A.: 44 Years Hindcast of the sea level and circulation in the Baltic Sea, Coast. Eng., 55, 849–860, https://doi.org/10.1016/j.coastaleng.2008.02.026, 2008.
Johansson, J.: Total and regional runoff to the Baltic Sea, HELCOM Balt, Sea Environ. Fact Sheets., https://helcom.fi/media/documents/BSEFS_Total-and-regional-runoff-to-the-Baltic-Sea-in-2015.pdf (last access: 3 January 2020), 2016.
Jönsson, B., Döös, K., Nycander, J., and Lundberg, P.: Standing waves in the Gulf of Finland and their relationship to the basin-wide Baltic seiches, J. Geophys. Res., 113, C03004, https://doi.org/10.1029/2006JC003862, 2008.
Krayushkin, E., Lavrova, O., and Strochkov, A.: Application of GPS/GSM Lagrangian mini-drifters for coastal ocean dynamics analysis, Russ. J. Earth Sci., 19, ES1001, https://doi.org/10.2205/2018ES000642, 2019.
Leppäranta, M. and Myrberg, K.: Circulation, in: Physical Oceanography of the Baltic Sea, Springer, Berlin, Heidelberg, 131–187, ISBN 978-3-540-79703-6, 2009.
Liblik, T., Laanemets, J., Raudsepp, U., Elken, J., and Suhhova, I.: Estuarine circulation reversals and related rapid changes in winter near-bottom oxygen conditions in the Gulf of Finland, Baltic Sea, Ocean Sci., 9, 917–930, https://doi.org/10.5194/os-9-917-2013, 2013.
Liblik, T., Naumann, M., Alenius, P., Hansson, M., Lips, U., Nausch, G., Tuomi, L., Wesslander, K., Laanemets, J., and Viktorsson, L.: Propagation of Impact of the Recent Major Baltic Inflows From the Eastern Gotland Basin to the Gulf of Finland, Front. Mar. Sci., 5, 222, https://doi.org/10.3389/fmars.2018.00222, 2018.
Liblik, T., Väli, G., Lips, I., Lilover, M.-J., Kikas, V., and Laanemets, J.: The winter stratification phenomenon and its consequences in the Gulf of Finland, Baltic Sea, Ocean Sci., 16, 1475–1490, https://doi.org/10.5194/os-16-1475-2020, 2020.
Liblik, T., Väli, G., Salm, K., Lips, U., Laanemets, J., and Lilove, M.-J.:
ADCP and GETM simulation data in the Baltic Proper, Zenodo [data set], https://doi.org/10.5281/zenodo.6616795, 2022.
Lilover, M.-J., Pavelson, J., and Kõuts, T.: Wind forced currents over the shallow naissaar Bank in the Gulf of Finland, 2011.
Lilover, M.-J., Elken, J., Suhhova, I., and Liblik, T.: Observed flow variability along the thalweg, and on the coastal slopesof the Gulf of Finland, Baltic Sea, Estuar. Coast. Shelf S., 195, 23–33, 2017.
Longdill, P. C., Healy, T. R., and Black, K. P.: Transient wind-driven coastal upwelling on a shelf with varying width and orientation, New Zeal. J. Mar. Fresh., 42, 181–196, https://doi.org/10.1080/00288330809509947, 2008.
Macdonald, A. M.: The global ocean circulation: a hydrographic estimate and regional analysis, Prog. Oceanogr., 41, 281–382, https://doi.org/10.1016/S0079-6611(98)00020-2, 1998.
Männik, A. and Merilain, M.: Verification of different precipitation forecasts during extended winter-season in Estonia, HIRLAM Newsl., 65-−70, Swedish Meteorol. Hydrol. Institute, 2007.
Matthäus, W. and Franck, H.: Characteristics of major Baltic inflows—a statistical analysis, Cont. Shelf Res., 12, 1375–1400, https://doi.org/10.1016/0278-4343(92)90060-W, 1992.
McDougall, T. J. and Barker, P. M.: Getting started with TEOS-10 and the Gibbs Seawater (GSW) Oceanographic Toolbox, SCOR/IAPSO WG127, 28 pp., ISBN 978-0-646-55621-5, 2011.
Meier, H. E.: Modeling the pathways and ages of inflowing salt- and freshwater in the Baltic Sea, Estuar. Coast. Shelf S., 74, 610–627, https://doi.org/10.1016/J.ECSS.2007.05.019, 2007.
Mensah, V., Le Menn, M., and Morel, Y.: Thermal mass correction for the evaluation of salinity, J. Atmos. Ocean. Technol., 26, 665–672, https://doi.org/10.1175/2008JTECHO612.1, 2009.
Mohrholz, V.: Major Baltic Inflow Statistics – Revised, Front. Mar. Sci., 5, 384, https://doi.org/10.3389/fmars.2018.00384, 2018.
Ollitrault, M. and Rannou, J.-P.: ANDRO: An Argo-based deep displacement dataset, Argo [data set], https://doi.org/10.17882/47077, 2013.
Placke, M., Meier, H. E. M., Gräwe, U., Neumann, T., Frauen, C., and Liu, Y.: Long-Term Mean Circulation of the Baltic Sea as Represented by Various Ocean Circulation Models, Front. Mar. Sci., 5, 287, https://doi.org/10.3389/fmars.2018.00287, 2018.
Rasmus, K., Kiirikki, M., and Lindfors, A.: Long-term
field measurements of turbidity and current speed in the Gulf of
Finland leading to an estimate of natural resuspension of bottom
sediment, Boreal Environ. Res., 20, 735–747, 2015.
Reissmann, J. H., Burchard, H., Feistel, R., Hagen, E., Lass, H. U., Mohrholz, V., Nausch, G., Umlauf, L., and Wieczorek, G.: Vertical mixing in the Baltic Sea and consequences for eutrophication – A review, Prog. Oceanogr., 82, 47–80, https://doi.org/10.1016/j.pocean.2007.10.004, 2009.
Rubio, A., Gomis, D., Jordà, G., and Espino, M.: Estimating geostrophic
and total velocities from CTD and ADCP data: Intercomparison of
different methods, J. Marine Syst., 77, 61–76, https://doi.org/10.1016/J.JMARSYS.2008.11.009, 2009.
Scully, M. E.: Mixing of dissolved oxygen in Chesapeake Bay driven by the interaction between wind-driven circulation and estuarine bathymetry, J. Geophys. Res.-Oceans, 121, 5639–5654, https://doi.org/10.1002/2016JC011924, 2016.
Siiriä, S., Roiha, P., Tuomi, L., Purokoski, T., Haavisto, N., and Alenius, P.: Applying area-locked, shallow water Argo floats in Baltic Sea monitoring, J. Oper. Oceanogr., 12, 58–72, https://doi.org/10.1080/1755876X.2018.1544783, 2019.
Sokolov, A. and Chubarenko, B.: Wind Influence on the Formation of Nearshore Currents in the Southern Baltic: Numerical Modelling Results, Arch. Hydroengineering Environ. Mech., 59, 37–48, https://doi.org/10.2478/v10203-012-0003-3, 2012.
Soomere, T. and Keevallik, S.: Anisotropy of moderate and strong winds in the Baltic Proper, http://kirj.ee/public/va_te/t50-1-3.pdf (last access: 7 February 2019), 2001.
Suhhova, I., Pavelson, J., and Lagemaa, P.: Variability of currents over the southern slope of the Gulf of Finland, Oceanologia, 57, 132–143, https://doi.org/10.1016/j.oceano.2015.01.001, 2015.
Suhhova, I., Liblik, T., Lilover, M.-J., and Lips, U.: A descriptive analysis of the linkage between the vertical stratification and current oscillations in the Gulf of Finland, Boreal Environ. Res., 23, 83–103, 2018.
Umlauf, L. and Burchard, H.: Second-order turbulence closure models for geophysical boundary layers. A review of recent work, Cont. Shelf Res., 25, 795–827, https://doi.org/10.1016/j.csr.2004.08.004, 2005.
Umlauf, L., Arneborg, L., Umlauf, L., and Arneborg, L.: Dynamics of Rotating Shallow Gravity Currents Passing through a Channel. Part I: Observation of Transverse Structure, J. Phys. Oceanogr., 39, 2385–2401, https://doi.org/10.1175/2009JPO4159.1, 2009.
Väli, G., Meier, H. E. M., and Elken, J.: Simulated halocline variability in the Baltic Sea and its impact on hypoxia during 1961–2007, J. Geophys. Res.-Oceans, 118, 6982–7000, https://doi.org/10.1002/2013JC009192, 2013.
Villacieros-Robineau, N., Herrera, J. L., Castro, C. G., Piedracoba, S., and Roson, G.: Hydrodynamic characterization of the bottom boundary layer in a coastal upwelling system (Ría de Vigo, NW Spain), Cont. Shelf Res., 68, 67–79, https://doi.org/10.1016/j.csr.2013.08.017, 2013.
Wu, H., Deng, B., Yuan, R., Hu, J., Gu, J., Shen, F., Zhu, J., and Zhang, J.: Detiding Measurement on Transport of the Changjiang-Derived Buoyant Coastal Current, J. Phys. Oceanogr., 43, 2388–2399, https://doi.org/10.1175/JPO-D-12-0158.1, 2013.
Wu, J.: Wind-Stress coefficients over Sea surface near Neutral Conditions – A Revisit, J. Phys. Oceanogr., 10, 727–740, https://doi.org/10.1175/1520-0485(1980)010<0727:WSCOSS>2.0.CO;2, 1980.
Zhurbas, V., Elken, J., Paka, V., Piechura, J., Väli, G., Chubarenko, I., Golenko, N., and Shchuka, S.: Structure of unsteady overflow in the supsk furrow of the baltic sea, J. Geophys. Res.-Oceans, 117, 4027, https://doi.org/10.1029/2011JC007284, 2012.
Zhurbas, V., Väli, G., Golenko, M., and Paka, V.: Variability of bottom friction velocity along the inflow water pathway in the Baltic Sea, J. Marine Syst., 184, 50–58, https://doi.org/10.1016/J.JMARSYS.2018.04.008, 2018.
Zhurbas, V., Väli, G., and Kuzmina, N.: Striped texture of submesoscale fields in the northeastern Baltic Proper: Results of very high-resolution modelling for summer season, Oceanologia, 64, 1–21, https://doi.org/10.1016/J.OCEANO.2021.08.003, 2021.
Short summary
An extensive measurement campaign and numerical simulations were conducted in the central Baltic Sea. The persistent circulation patterns were detected in steady weather conditions. The patterns included various circulation features. A coastal boundary current was observed along the eastern coast. The deep layer current towards the north was detected as well. This current is an important deeper limb of the overturning circulation of the Baltic Sea. The circulation regime has an annual cycle.
An extensive measurement campaign and numerical simulations were conducted in the central Baltic...
