Articles | Volume 16, issue 4
https://doi.org/10.5194/cp-16-1617-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/cp-16-1617-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
27 Aug 2020
Research article |
| 27 Aug 2020
Investigating interdecadal salinity changes in the Baltic Sea in a 1850–2008 hindcast simulation
Hagen Radtke
CORRESPONDING AUTHOR
Department of Physical Oceanography and Instrumentation, Leibniz Institute for Baltic Sea Research Warnemünde, Rostock, Germany
Sandra-Esther Brunnabend
Department of Physical Oceanography and Instrumentation, Leibniz Institute for Baltic Sea Research Warnemünde, Rostock, Germany
present address: Department of Research and Development, Swedish Meteorological and Hydrological Institute, Norrköping, Sweden
Ulf Gräwe
Department of Physical Oceanography and Instrumentation, Leibniz Institute for Baltic Sea Research Warnemünde, Rostock, Germany
H. E. Markus Meier
Department of Physical Oceanography and Instrumentation, Leibniz Institute for Baltic Sea Research Warnemünde, Rostock, Germany
Department of Research and Development, Swedish Meteorological and Hydrological Institute, Norrköping, Sweden
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The understanding of surface water methane production in the world oceans is still poor. By combining field studies and incubation experiments, our investigations suggest that zooplankton contributes to subthermocline methane enrichments in the central Baltic Sea by methane production within the digestive tract of copepods and/or by methane production through release of methane precursor substances into the surrounding water, followed by microbial degradation to methane.
Daniel Neumann, Hagen Radtke, Matthias Karl, and Thomas Neumann
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-365, https://doi.org/10.5194/bg-2018-365, 2018
Publication in BG not foreseen
Short summary
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The contribution of atmospheric nitrogen deposition to the marine dissolved inorganic nitrogen (DIN) pool of the North and Baltic Sea was assessed for the year 2012. Atmospheric deposition accounted for approximately 10 % to 15 % of the DIN but its residence time differed between both water bodies. The nitrogen contributions of atmospheric shipping and agricultural imissions also were assessed. Particularly the latter source had a large impact in coastal regions.
Daniel Neumann, Matthias Karl, Hagen Radtke, and Thomas Neumann
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-364, https://doi.org/10.5194/bg-2018-364, 2018
Manuscript not accepted for further review
Short summary
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Atmospheric nitrogen deposition contributes 20 % to 40 % to bioavailable nitrogen inputs into the North Sea and Baltic Sea. Excessive bioavailable nitrogen may lead to intensified algal blooms in these water bodies resulting in several negative consequences for the marine ecosystem. We traced atmospheric nitrogen in the marine ecosystem via an ecosystem model and estimated the contribution of atmospheric nitrogen to plankton biomass in different regions of the North and Baltic Sea over five years.
Jenny Hieronymus, Kari Eilola, Magnus Hieronymus, H. E. Markus Meier, Sofia Saraiva, and Bengt Karlson
Biogeosciences, 15, 5113–5129, https://doi.org/10.5194/bg-15-5113-2018, https://doi.org/10.5194/bg-15-5113-2018, 2018
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This paper investigates how phytoplankton concentrations in the Baltic Sea co-vary with nutrient concentrations and other key variables on inter-annual timescales in a model integration over the years 1850–2008. The study area is not only affected by climate change; it has also been subjected to greatly increased nutrient loads due to extensive use of agricultural fertilizers. The results indicate the largest inter-annual coherence of phytoplankton with the limiting nutrient.
Daniel Neumann, René Friedland, Matthias Karl, Hagen Radtke, Volker Matthias, and Thomas Neumann
Ocean Sci. Discuss., https://doi.org/10.5194/os-2018-71, https://doi.org/10.5194/os-2018-71, 2018
Revised manuscript not accepted
Short summary
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We found that refining the spatial resolution of nitrogen deposition data had low impact on marine nitrogen compounds compared to the impact by nitrogen deposition data sets of different origin (other model). The shipping sector had a contribution of up to 10 % to the marine dissolved inorganic nitrogen.
Sofia Saraiva, H. E. Markus Meier, Helén Andersson, Anders Höglund, Christian Dieterich, Robinson Hordoir, and Kari Eilola
Earth Syst. Dynam. Discuss., https://doi.org/10.5194/esd-2018-16, https://doi.org/10.5194/esd-2018-16, 2018
Revised manuscript not accepted
Short summary
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Uncertainties are estimated in Baltic Sea climate projections by performing scenarios combining 4 Global Climate Models, 2 future gas emissions (RCP4.5, RCP8.5) and 3 nutrient load scenarios. Results on primary production, nitrogen fixation, and hypoxic areas show that uncertainties caused by the nutrients loads are greater than uncertainties due to GCMs and RCPs. In all scenarios, nutrient load abatement strategy, Baltic Sea Action Plan, will lead to an improvement in the environmental state.
Ye Liu, H. E. Markus Meier, and Kari Eilola
Biogeosciences, 14, 2113–2131, https://doi.org/10.5194/bg-14-2113-2017, https://doi.org/10.5194/bg-14-2113-2017, 2017
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From the reanalysis, nutrient transports between sub-basins, between the coastal zone and the open sea, and across latitudinal and longitudinal cross sections, are calculated. Further, the spatial distributions of regions with nutrient import or export are examined. Our results emphasize the important role of the Baltic proper for the entire Baltic Sea. For the calculation of sub-basin budgets, the location of the lateral borders of the sub-basins is crucial.
S.-E. Brunnabend, H. A. Dijkstra, M. A. Kliphuis, H. E. Bal, F. Seinstra, B. van Werkhoven, J. Maassen, and M. van Meersbergen
Ocean Sci., 13, 47–60, https://doi.org/10.5194/os-13-47-2017, https://doi.org/10.5194/os-13-47-2017, 2017
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An important contribution to future changes in regional sea level extremes is due to the changes in intrinsic ocean variability, in particular ocean eddies. Here, we study a scenario of future dynamic sea level (DSL) extremes using a strongly eddying version of the Parallel Ocean Program. Changes in 10-year return time DSL extremes are very inhomogeneous over the globe and are related to changes in ocean currents and corresponding regional shifts in ocean eddy pathways.
Elin Almroth-Rosell, Moa Edman, Kari Eilola, H. E. Markus Meier, and Jörgen Sahlberg
Biogeosciences, 13, 5753–5769, https://doi.org/10.5194/bg-13-5753-2016, https://doi.org/10.5194/bg-13-5753-2016, 2016
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Nutrients from land have been discussed to increase eutrophication in the open sea. This model study shows that the coastal zone works as an efficient filter. Water depth and residence time regulate the retention that occurs mostly in the sediment due to processes such as burial and denitrification. On shorter timescales the retention capacity might seem less effective when the land load of nutrients decreases, but with time the coastal zone can import nutrients from the open sea.
Joeran Maerz, Richard Hofmeister, Eefke M. van der Lee, Ulf Gräwe, Rolf Riethmüller, and Kai W. Wirtz
Biogeosciences, 13, 4863–4876, https://doi.org/10.5194/bg-13-4863-2016, https://doi.org/10.5194/bg-13-4863-2016, 2016
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We investigated sinking velocity (ws) of suspended particulate matter (SPM) in the German Bight. By inferring ws indirectly from an extensive turbidity data set and hydrodynamic model results, we found enhanced ws in a coastal transition zone. Combined with known residual circulation patterns, this led to a new conceptual understanding of the retention of fine minerals and nutrients in shallow coastal areas. The retention is likely modulated by algal excretions enhancing flocculation of SPM.
Rahel Vortmeyer-Kley, Ulf Gräwe, and Ulrike Feudel
Nonlin. Processes Geophys., 23, 159–173, https://doi.org/10.5194/npg-23-159-2016, https://doi.org/10.5194/npg-23-159-2016, 2016
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Since eddies play a major role in the dynamics of oceanic flows, it is of great interest to gain information about their tracks, lifetimes and shapes. We develop an eddy tracking tool based on structures in the flow with collecting (attracting) or separating (repelling) properties. In test cases mimicking oceanic flows it yields eddy lifetimes close to the analytical ones. It even provides a detailed view of the dynamics that can be useful to gain more insight into eddy dynamics in oceanic flows.
S.-E. Brunnabend, H. A. Dijkstra, M. A. Kliphuis, B. van Werkhoven, H. E. Bal, F. Seinstra, J. Maassen, and M. van Meersbergen
Ocean Sci., 10, 881–891, https://doi.org/10.5194/os-10-881-2014, https://doi.org/10.5194/os-10-881-2014, 2014
Short summary
Short summary
Regional sea surface height (SSH) changes due to an abrupt weakening of the Atlantic meridional overturning circulation (AMOC) are simulated with a high- and low-resolution model. A rapid decrease of the AMOC in the high-resolution version induces shorter return times of several specific regional and coastal extremes in North Atlantic SSH than in the low-resolution version. This effect is caused by a change in main eddy pathways associated with a change in separation latitude of the Gulf Stream.
M. Duran-Matute, T. Gerkema, G. J. de Boer, J. J. Nauw, and U. Gräwe
Ocean Sci., 10, 611–632, https://doi.org/10.5194/os-10-611-2014, https://doi.org/10.5194/os-10-611-2014, 2014
B. van Werkhoven, J. Maassen, M. Kliphuis, H. A. Dijkstra, S. E. Brunnabend, M. van Meersbergen, F. J. Seinstra, and H. E. Bal
Geosci. Model Dev., 7, 267–281, https://doi.org/10.5194/gmd-7-267-2014, https://doi.org/10.5194/gmd-7-267-2014, 2014
Related subject area
Subject: Ocean Dynamics | Archive: Modelling only | Timescale: Centennial-Decadal
Volcanic impact on the Atlantic Ocean over the last millennium
The global ocean circulation on a retrograde rotating earth
J. Mignot, M. Khodri, C. Frankignoul, and J. Servonnat
Clim. Past, 7, 1439–1455, https://doi.org/10.5194/cp-7-1439-2011, https://doi.org/10.5194/cp-7-1439-2011, 2011
V. Kamphuis, S. E. Huisman, and H. A. Dijkstra
Clim. Past, 7, 487–499, https://doi.org/10.5194/cp-7-487-2011, https://doi.org/10.5194/cp-7-487-2011, 2011
Cited articles
Aguiar-Conraria, L. and Soares, M. J.: The continuous wavelet transform: A
primer, Tech. Rep. 16, Núcleo de Investigação em Políticas Económicas,
Universidade do Minho, Minho, Portugal, available at:
https://repositorium.sdum.uminho.pt/bitstream/1822/12398/4/NIPE_WP_16_2011.pdf (last access: 18 August 2020),
2011. a
Axell, L. B.: Wind-driven internal waves and Langmuir circulations in a
numerical ocean model of the southern Baltic Sea, J. Geophys.
Res.-Oceans, 107, 3204, https://doi.org/10.1029/2001JC000922, 2002. a
Bergström, S. and Carlsson, B.: River runoff to the Baltic Sea –
1950–1990, Ambio, 23, 280–287, 1994. a
Burchard, H., Bolding, K., Feistel, R., Gräwe, U., Klingbeil, K., MacCready,
P., Mohrholz, V., Umlauf, L., and van der Lee, E. M.: The Knudsen theorem
and the Total Exchange Flow analysis framework applied to the Baltic
Sea, Prog. Oceanogr., 165, 268–286,
https://doi.org/10.1016/j.pocean.2018.04.004, 2018. a
Canuto, V. M., Howard, A., Cheng, Y., and Dubovikov, M. S.: Ocean turbulence.
Part I: One-point closure model – Momentum and heat vertical
diffusivities, J. Phys. Oceanogr., 31, 1413–1426,
https://doi.org/10.1175/1520-0485(2001)031<1413:OTPIOP>2.0.CO;2, 2001. a
Cyberski, J., Wróblewski, A., and Stewart, J.: Riverine water inflows and the Baltic Sea water volume 1901–1990, Hydrol. Earth Syst. Sci., 4, 1–11, https://doi.org/10.5194/hess-4-1-2000, 2000. a
Elsberry, R. L. and Garwood Jr., R. W.: Sea-surface temperature anomaly
generation in relation to atmospheric storms, B. Am.
Meteorol. Soc., 59, 786–789, 1978. a
Gailiušis, B., Kriaučiūnienė, J., Jakimavičius, D., and Šarauskienė, D.:
The variability of long-term runoff series in the Baltic Sea drainage
basin, Baltica, 24, 45–54, 2011. a
Good, R. and Fletcher, H. J.: Reporting explained variance, J. Res. Sci. Teach., 18, 1–7, https://doi.org/10.1002/tea.3660180102, 1981. a
Graham, P.: Modeling runoff to the Baltic Sea, Ambio, 28, 328–334, 1999. a
Grinsted, A., Moore, J. C., and Jevrejeva, S.: Application of the cross wavelet transform and wavelet coherence to geophysical time series, Nonlin. Processes Geophys., 11, 561–566, https://doi.org/10.5194/npg-11-561-2004, 2004. a
Gräwe, U., Klingbeil, K., Kelln, J., and Dangendorf, S.: Decomposing mean sea
level rise in a semi-enclosed basin, the Baltic Sea, J. Climate, 32, 3089–3108,
https://doi.org/10.1175/JCLI-D-18-0174.1, 2019. a
Gustafsson, B. G. and Andersson, H. C.: Modeling the exchange of the Baltic
Sea from the meridional atmospheric pressure difference across the North
Sea, J. Geophys. Res.-Ocean., 106, 19731–19744,
https://doi.org/10.1029/2000JC000593, 2001. a
Gustafsson, B. G., Schenk, F., Blenckner, T., Eilola, K., Meier, H. M.,
Müller-Karulis, B., Neumann, T., Ruoho-Airola, T., Savchuk, O. P., and
Zorita, E.: Reconstructing the development of Baltic Sea eutrophication
1850–2006, Ambio, 41, 534–548, https://doi.org/10.1007/s13280-012-0318-x, 2012. a
Hansson, D., Eriksson, C., Omstedt, A., and Chen, D.: Reconstruction of river
runoff to the Baltic Sea, AD 1500–1995, Int. J.
Climatol., 31, 696–703, https://doi.org/10.1002/joc.2097, 2011. a, b, c
Holtermann, P. L., Umlauf, L., Tanhua, T., Schmale, O., Rehder, G., and Waniek,
J. J.: The Baltic Sea tracer release experiment: 1. Mixing rates,
J. Geophys. Res.-Ocean., 117, C01021, https://doi.org/10.1029/2011JC007439,
2012. a
Håkansson, B. G., Broman, B., and Dahlin, H.: The flow of water and salt in
the Sound during the Baltic Major Inflow event in January 1993,
Tech. Rep. 1993/C:57, ICES, Copenhagen, available at:
http://www.ices.dk/sites/pub/CM Doccuments/1993/C/1993_C57.pdf (last access: 18 August 2020),
1993. a
Höflich, K., Lehmann, A., and Myrberg, K.: Towards an improved mechanistic
understanding of major saltwater inflows into the Baltic Sea,
oral presentation at the 11th Baltic Sea
Science Congress, Rostock, June 2017, Zenodo, https://doi.org/10.5281/zenodo.3567086, 2017. a
Höflich, K., Lehmann, A., and Myrberg, K.: Decadal variations in barotropic
inflow characteristics and their relation with Baltic Sea salinity
variability, oral presentation at the 2nd
Baltic Earth Conference in Helsingør, Denmark, June 2018, Zenodo, https://doi.org/10.5281/zenodo.3567070, 2018. a
Höglund, A., Meier, H. E. M., Broman, B., and Kriezi, E.: Validation and
correction of regionalised ERA-40 wind fields over the Baltic Sea using
the Rossby Centre Atmosphere model RCA3.0, Tech. Rep. 97, SMHI,
Norrköping,
available at: http://smhi.diva-portal.org/smash/get/diva2:947574/FULLTEXT01.pdf (last access: 18 August 2020),
2009. a
ICES: ICES Oceanography, available at:
https://ocean.ices.dk/HydChem/HydChem.aspx?plot=yes (last access:
14 February 2020), 2019. a
Jones, P. D., Jonsson, T., and Wheeler, D.: Extension to the North Atlantic
oscillation using early instrumental pressure observations from Gibraltar
and south-west Iceland, Int. J. Climatol., 17,
1433–1450,
https://doi.org/10.1002/(SICI)1097-0088(19971115)17:13<1433::AID-JOC203>3.0.CO;2-P,
1998. a, b
Kennedy, J. J., Rayner, N. A., Smith, R. O., Parker, D. E., and Saunby, M.:
Reassessing biases and other uncertainties in sea surface temperature
observations measured in situ since 1850: 1. Measurement and sampling
uncertainties, J. Geophys. Res., 116, D14103,
https://doi.org/10.1029/2010JD015218, 2011a. a
Kennedy, J. J., Rayner, N. A., Smith, R. O., Parker, D. E., and Saunby, M.:
Reassessing biases and other uncertainties in sea surface temperature
observations measured in situ since 1850: 2. Biases and homogenization,
J. Geophys. Res., 116, D14104, https://doi.org/10.1029/2010JD015220,
2011b. a
Khlebovich, V. V.: Aspects of animal evolution related to critical salinity and
internal state, Mar. Biol., 2, 338–345, https://doi.org/10.1007/BF00355713, 1969. a
Kniebusch, M., Meier, H. E. M., Neumann, T., and Börgel, F.: Temperature
Variability of the Baltic Sea Since 1850 and Attribution to
Atmospheric Forcing Variables, J. Geophys. Res.-Oceans,
124, 4168–4187, https://doi.org/10.1029/2018JC013948, 2019. a
Langmuir, I.: Surface motion of water induced by wind, Science, 87, 119–123,
1938. a
Lass, H. U. and Matthäus, W.: On temporal wind variations forcing salt water
inflows into the Baltic Sea, Tellus A, 48, 663–671,
https://doi.org/10.1034/j.1600-0870.1996.t01-4-00005.x, 1996. a
Leibniz Institute for Baltic Sea Research Warnemünde: GETM – A 3D hydrodynamic model for coastal oceans, https://getm.eu/, last access: 18 August 2020. a
Mårtensson, S., Meier, H. E. M., Pemberton, P., and Haapala, J.: Ridged sea
ice characteristics in the Arctic from a coupled multicategory sea ice
model, J. Geophys. Res.-Oceans, 117, C00D15,
https://doi.org/10.1029/2010JC006936, 2012. a
MacCready, P.: Calculating Estuarine Exchange Flow Using Isohaline
Coordinates, J. Phys. Oceanogr., 41, 1116–1124,
https://doi.org/10.1175/2011JPO4517.1, 2011. a
MacKenzie, B. R., Gislason, H., Möllmann, C., and Köster, F. W.: Impact of
21st century climate change on the Baltic Sea fish community and
fisheries, Glob. Change Biol., 13, 1348–1367,
https://doi.org/10.1111/j.1365-2486.2007.01369.x, 2007. a
Malmberg, S.-A. and Svansson, A.: Variations in the physical marine environment
in relation to climate, Tech. Rep. 1982/Gen:4, International Council for the
Exploration of the Sea, Copenhagen, available at:
http://www.ices.dk/sites/pub/CM Doccuments/1982/Gen/1982_Gen4.pdf (last access: 18 August 2020),
not to be cited without prior reference to the authors!, 1982. a, b
Maraun, D. and Kurths, J.: Cross wavelet analysis: significance testing and pitfalls, Nonlin. Processes Geophys., 11, 505–514, https://doi.org/10.5194/npg-11-505-2004, 2004. a
Meier, H. E. M.: Modeling the pathways and ages of inflowing salt- and
freshwater in the Baltic Sea, Estuar. Coast. Shelf Sci., 74,
610–627, https://doi.org/10.1016/j.ecss.2007.05.019, 2007. a
Meier, H. E. M. and Kauker, F.: Sensitivity of the Baltic Sea salinity to
the freshwater supply, Clim. Res., 24, 231–242,
https://doi.org/10.3354/cr024231,
2003a. a, b
Meier, H. E. M., Eilola, K., Almroth-Rosell, E., Schimanke, S., Kniebusch, M.,
Höglund, A., Pemberton, P., Liu, Y., Väli, G., and Saraiva, S.:
Disentangling the impact of nutrient load and climate changes on Baltic
Sea hypoxia and eutrophication since 1850, Clim. Dynam., 53,
1145–1166, https://doi.org/10.1007/s00382-018-4483-x, 2018a. a, b, c, d
Meier, H. M., Andersson, H. C., Arheimer, B., Blenckner, T., Chubarenko, B.,
Donnelly, C., Eilola, K., Gustafsson, B. G., Hansson, A., and Havenhand, J.:
Comparing reconstructed past variations and future projections of the
Baltic Sea ecosystem – first results from multi-model ensemble
simulations, Environ. Res. Lett., 7, 034005,
https://doi.org/10.1088/1748-9326/7/3/034005, 2012. a
Meier, H. M., Väli, G., Naumann, M., Eilola, K., and Frauen, C.: Recently
accelerated oxygen consumption rates amplify deoxygenation in the Baltic
Sea, J. Geophys. Res.-Oceans, 123, 3227–3240,
https://doi.org/10.1029/2017JC013686, 2018b. a
Mellor, G. L. and Yamada, T.: Development of a turbulence closure model for
geophysical fluid problems, Rev. Geophys., 20, 851–875,
https://doi.org/10.1029/RG020i004p00851, 1982. a
Mikulski, Z.: Inflow from drainage basin, in: Water Balance of the Baltic
Sea, vol. 16 of Baltic Sea Environment Proceedings, pp.
24–34, Baltic Marine Environment Protection Commission, Helsinki, 1986. a
Rodhe, J. and Winsor, P.: On the influence of the freshwater supply on the
Baltic Sea mean salinity, Tellus A, 54, 175–186,
https://doi.org/10.1034/j.1600-0870.2002.01307.x, 2002. a, b
Rodhe, J. and Winsor, P.: On the influence of the freshwater supply on the
Baltic Sea mean salinity, Tellus A, 55, 455–456,
https://doi.org/10.1034/j.1600-0870.2003.00037.x, 2003. a
Schenk, F. and Zorita, E.: Reconstruction of high resolution atmospheric fields for Northern Europe using analog-upscaling, Clim. Past, 8, 1681–1703, https://doi.org/10.5194/cp-8-1681-2012, 2012. a, b, c
Schimanke, S. and Meier, H. E. M.: Decadal-to-Centennial Variability of
Salinity in the Baltic Sea, J. Climate, 29, 7173–7188,
https://doi.org/10.1175/JCLI-D-15-0443.1
2016. a
Schott, F.: Der Oberflächensalzgehalt in der Nordsee, Deutsche
Hydrografische Zeitschrift, p. 58, 1966. a
Seifert, T., Tauber, F., and Kayser, B.: A high resolution spherical grid
topography of the Baltic Sea – 2nd edition, available at:
https://www.io-warnemuende.de/topography-of-the-baltic-sea.html
(last access: 14 February 2020), 2001. a
Simpson, G.: Modelling seasonal data with GAMs, available at:
https://www.fromthebottomoftheheap.net/2014/05/09/modelling-seasonal-data-with-gam/ (last access: 18 August 2020),
2014. a
Smagorinsky, J.: General circulation experiments with the primitive equations:
I. The basic experiment, Mon. Weather Rev., 91, 99–164,
https://doi.org/10.1175/1520-0493(1963)091<0099:GCEWTP>2.3.CO;2, 1963. a
SMHI: Ladda ner meteorologiska observationer, available at:
https://www.smhi.se/data/meteorologi/ladda-ner-meteorologiska-observationer/#param=airtemperatureInstant,stations=all
(last access: 14 February 2020), 2019. a
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. a
van Oldenborgh, G. J., te Raa, L. A., Dijkstra, H. A., and Philip, S. Y.: Frequency- or amplitude-dependent effects of the Atlantic meridional overturning on the tropical Pacific Ocean, Ocean Sci., 5, 293–301, https://doi.org/10.5194/os-5-293-2009, 2009.
a, b
Vuorinen, I., Hänninen, J., Rajasilta, M., Laine, P., Eklund, J.,
Montesino-Pouzols, F., Corona, F., Junker, K., Meier, H. M., and Dippner,
J. W.: Scenario simulations of future salinity and ecological consequences in
the Baltic Sea and adjacent North Sea areas–implications for
environmental monitoring, Ecol. Ind., 50, 196–205,
https://doi.org/10.1016/j.ecolind.2014.10.019, 2015. a
Walin, G.: A theoretical framework for the description of estuaries, Tellus,
29, 128–136, https://doi.org/10.3402/tellusa.v29i2.11337, 1977. a
Walin, G.: On the relation between sea-surface heat flow and thermal
circulation in the ocean, Tellus, 34, 187–195,
https://doi.org/10.1111/j.2153-3490.1982.tb01806.x, 1982. a
Winsor, P., Rodhe, J., and Omstedt, A.: Baltic Sea ocean climate: an analysis
of 100 yr of hydrographic data with focus on the freshwater budget, Clim.
Res., 18, 5–15, https://doi.org/10.3354/cr018005, 2001. a
Winton, M.: A reformulated three-layer sea ice model, J. Atmos.
Ocean. Tech., 17, 525–531,
https://doi.org/10.1175/1520-0426(2000)017<0525:ARTLSI>2.0.CO;2, 2000. a
Zorita, E. and Laine, A.: Dependence of salinity and oxygen concentrations in
the Baltic Sea on large-scale atmospheric circulation, Clim. Res.,
14, 25–41, https://doi.org/10.3354/cr014025, 2000. a
Short summary
During the last century, salinity in the Baltic Sea showed a multidecadal oscillation with a period of 30 years. Using a numerical circulation model and wavelet coherence analysis, we demonstrate that this variation has at least two possible causes. One driver is river runoff which shows a 30-year variation. The second one is a variation in the frequency of strong inflows of saline water across Darss Sill which also contains a pronounced 30-year period.
During the last century, salinity in the Baltic Sea showed a multidecadal oscillation with a...
