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
| 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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Based on profiling pCO2 measurements from a field campaign, we quantify the biomass production of a cyanobacteria bloom in the Baltic Sea, the export of which would foster deep water deoxygenation. We further demonstrate how this biomass production can be accurately reconstructed from long-term surface measurements made on cargo vessels in combination with modelled temperature profiles. This approach enables a better understanding of a severe concern for the Baltic’s good environmental status.
Tobias Peter Bauer, Peter Holtermann, Bernd Heinold, Hagen Radtke, Oswald Knoth, and Knut Klingbeil
Geosci. Model Dev., 14, 4843–4863, https://doi.org/10.5194/gmd-14-4843-2021, https://doi.org/10.5194/gmd-14-4843-2021, 2021
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We present the coupled atmosphere–ocean model system ICONGETM. The added value and potential of using the latest coupling technologies are discussed in detail. An exchange grid handles the different coastlines from the unstructured atmosphere and the structured ocean grids. Due to a high level of automated processing, ICONGETM requires only minimal user input. The application to a coastal upwelling scenario demonstrates significantly improved model results compared to uncoupled simulations.
Erik Jacobs, Henry C. Bittig, Ulf Gräwe, Carolyn A. Graves, Michael Glockzin, Jens D. Müller, Bernd Schneider, and Gregor Rehder
Biogeosciences, 18, 2679–2709, https://doi.org/10.5194/bg-18-2679-2021, https://doi.org/10.5194/bg-18-2679-2021, 2021
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We use a unique data set of 8 years of continuous carbon dioxide (CO2) and methane (CH4) surface water measurements from a commercial ferry to study upwelling in the Baltic Sea. Its seasonality and regional and interannual variability are examined. Strong upwelling events drastically increase local surface CO2 and CH4 levels and are mostly detected in late summer after long periods of impaired mixing. We introduce an extrapolation method to estimate regional upwelling-induced trace gas fluxes.
Robert Daniel Osinski, Kristina Enders, Ulf Gräwe, Knut Klingbeil, and Hagen Radtke
Ocean Sci., 16, 1491–1507, https://doi.org/10.5194/os-16-1491-2020, https://doi.org/10.5194/os-16-1491-2020, 2020
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This study investigates the impact of the uncertainty in atmospheric data of a storm event on the transport of microplastics and sediments. The model chain includes the WRF atmospheric model, the WAVEWATCH III® wave model, and the GETM regional ocean model as well as a sediment transport model based on the FABM framework. An ensemble approach based on stochastic perturbations of the WRF model is used. We found a strong impact of atmospheric uncertainty on the amount of transported material.
Robert Daniel Osinski and Hagen Radtke
Ocean Sci., 16, 355–371, https://doi.org/10.5194/os-16-355-2020, https://doi.org/10.5194/os-16-355-2020, 2020
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The idea of this study is to quantify the uncertainty in hindcasts of severe storm events by applying a state-of-the-art ensemble generation technique. Other ensemble generation techniques are tested. The atmospheric WRF model is driven by the ERA5 reanalysis. A setup of the Wavewatch III® wave model for the Baltic Sea is used with the wind fields produced with the WRF ensemble. The effect of different spatio-temporal resolutions of the wind fields on the significant wave height is investigated.
Daniel Neumann, Matthias Karl, Hagen Radtke, Volker Matthias, René Friedland, and Thomas Neumann
Ocean Sci., 16, 115–134, https://doi.org/10.5194/os-16-115-2020, https://doi.org/10.5194/os-16-115-2020, 2020
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The study evaluates how much bioavailable nitrogen is contributed to the nitrogen budget of the western Baltic Sea by deposition of shipping-emitted nitrogen oxides. Bioavailable nitrogen compounds are nutrients for phytoplankton (algae). Excessive input of nutrients into water bodies may lead to eutrophication: more algal blooms with subsequently more oxygen limitation at the seafloor. Hence, reducing shipping emissions might reduce the anthropogenic pressure on the marine ecosystem.
Hagen Radtke, Marko Lipka, Dennis Bunke, Claudia Morys, Jana Woelfel, Bronwyn Cahill, Michael E. Böttcher, Stefan Forster, Thomas Leipe, Gregor Rehder, and Thomas Neumann
Geosci. Model Dev., 12, 275–320, https://doi.org/10.5194/gmd-12-275-2019, https://doi.org/10.5194/gmd-12-275-2019, 2019
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This paper describes a coupled benthic–pelagic biogeochemical model, ERGOM-SED. We demonstrate its use in a one-dimensional physical model, which is horizontally integrated and vertically resolved. We describe the application of the model to seven stations in the south-western Baltic Sea. The model was calibrated using pore water profiles from these stations. We compare the model results to these and to measured sediment compositions, benthopelagic fluxes and bioturbation intensities.
Beate Stawiarski, Stefan Otto, Volker Thiel, Ulf Gräwe, Natalie Loick-Wilde, Anna K. Wittenborn, Stefan Schloemer, Janine Wäge, Gregor Rehder, Matthias Labrenz, Norbert Wasmund, and Oliver Schmale
Biogeosciences, 16, 1–16, https://doi.org/10.5194/bg-16-1-2019, https://doi.org/10.5194/bg-16-1-2019, 2019
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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
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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
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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
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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
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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
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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
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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...
