Articles | Volume 18, issue 6
https://doi.org/10.5194/os-18-1725-2022
© 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-18-1725-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
12 Dec 2022
Research article |
| 12 Dec 2022
| 12 Dec 2022
Modelling the impact of anthropogenic measures on saltwater intrusion in the Weser estuary
Pia Kolb
CORRESPONDING AUTHOR
Federal Waterways Engineering and Research Institute, Wedeler
Landstraße 157, 22559 Hamburg, Germany
Anna Zorndt
Federal Waterways Engineering and Research Institute, Wedeler
Landstraße 157, 22559 Hamburg, Germany
Hans Burchard
Leibniz Institute for Baltic Sea Research Warnemünde,
Seestraße 15, 18119 Rostock, Germany
Ulf Gräwe
Leibniz Institute for Baltic Sea Research Warnemünde,
Seestraße 15, 18119 Rostock, Germany
Frank Kösters
Federal Waterways Engineering and Research Institute, Wedeler
Landstraße 157, 22559 Hamburg, Germany
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EGUsphere, https://doi.org/10.5194/egusphere-2024-283, https://doi.org/10.5194/egusphere-2024-283, 2024
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Coastal environments are often sheltered by intertidal flats and salt-marshes. These environments are at severe risk from drowning under sea level rise. Recent analyses in the Wadden Sea demonstrated tidal flats grew faster than the local mean sea level contrary to expectation. We found that tidal high and low water increased proportionally with SLR while coastal bathymetry evolution caused spatially-varying tidal adaptation with sharp increase-decrease edges at the coast.
Marvin Lorenz and Ulf Gräwe
Ocean Sci., 19, 1753–1771, https://doi.org/10.5194/os-19-1753-2023, https://doi.org/10.5194/os-19-1753-2023, 2023
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We study the variability of extreme sea levels in a 13 member hindcast ensemble for the Baltic Sea. The ensemble mean shows good agreement with observations regarding return levels and trends. However, we find great variability and uncertainty within the ensemble. We argue that the variability of storms in the atmospheric data directly translates into the variability of the return levels. These results highlight the need for large regional ensembles to minimise uncertainties.
Joshua Kiesel, Marvin Lorenz, Marcel König, Ulf Gräwe, and Athanasios T. Vafeidis
Nat. Hazards Earth Syst. Sci., 23, 2961–2985, https://doi.org/10.5194/nhess-23-2961-2023, https://doi.org/10.5194/nhess-23-2961-2023, 2023
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Among the Baltic Sea littoral states, Germany is anticipated to experience considerable damage as a result of increased coastal flooding due to sea-level rise (SLR). Here we apply a new modelling framework to simulate how flooding along the German Baltic Sea coast may change until 2100 if dikes are not upgraded. We find that the study region is highly exposed to flooding, and we emphasise the importance of current plans to update coastal protection in the future.
Bronwyn E. Cahill, Piotr Kowalczuk, Lena Kritten, Ulf Gräwe, John Wilkin, and Jürgen Fischer
Biogeosciences, 20, 2743–2768, https://doi.org/10.5194/bg-20-2743-2023, https://doi.org/10.5194/bg-20-2743-2023, 2023
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We quantify the impact of optically significant water constituents on surface heating rates and thermal energy fluxes in the western Baltic Sea. During productive months in 2018 (April to September) we found that the combined effect of coloured
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Matthias Gröger, Manja Placke, H. E. Markus Meier, Florian Börgel, Sandra-Esther Brunnabend, Cyril Dutheil, Ulf Gräwe, Magnus Hieronymus, Thomas Neumann, Hagen Radtke, Semjon Schimanke, Jian Su, and Germo Väli
Geosci. Model Dev., 15, 8613–8638, https://doi.org/10.5194/gmd-15-8613-2022, https://doi.org/10.5194/gmd-15-8613-2022, 2022
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Comparisons of oceanographic climate data from different models often suffer from different model setups, forcing fields, and output of variables. This paper provides a protocol to harmonize these elements to set up multidecadal simulations for the Baltic Sea, a marginal sea in Europe. First results are shown from six different model simulations from four different model platforms. Topical studies for upwelling, marine heat waves, and stratification are also assessed.
Vera Fofonova, Tuomas Kärnä, Knut Klingbeil, Alexey Androsov, Ivan Kuznetsov, Dmitry Sidorenko, Sergey Danilov, Hans Burchard, and Karen Helen Wiltshire
Geosci. Model Dev., 14, 6945–6975, https://doi.org/10.5194/gmd-14-6945-2021, https://doi.org/10.5194/gmd-14-6945-2021, 2021
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We present a test case of river plume spreading to evaluate coastal ocean models. Our test case reveals the level of numerical mixing (due to parameterizations used and numerical treatment of processes in the model) and the ability of models to reproduce complex dynamics. The major result of our comparative study is that accuracy in reproducing the analytical solution depends less on the type of applied model architecture or numerical grid than it does on the type of advection scheme.
Jens Daniel Müller, Bernd Schneider, Ulf Gräwe, Peer Fietzek, Marcus Bo Wallin, Anna Rutgersson, Norbert Wasmund, Siegfried Krüger, and Gregor Rehder
Biogeosciences, 18, 4889–4917, https://doi.org/10.5194/bg-18-4889-2021, https://doi.org/10.5194/bg-18-4889-2021, 2021
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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.
Qing Li, Jorn Bruggeman, Hans Burchard, Knut Klingbeil, Lars Umlauf, and Karsten Bolding
Geosci. Model Dev., 14, 4261–4282, https://doi.org/10.5194/gmd-14-4261-2021, https://doi.org/10.5194/gmd-14-4261-2021, 2021
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Different ocean vertical mixing schemes are usually developed in different modeling framework, making the comparison across such schemes difficult. Here, we develop a consistent framework for testing, comparing, and applying different ocean mixing schemes by integrating CVMix into GOTM, which also extends the capability of GOTM towards including the effects of ocean surface waves. A suite of test cases and toolsets for developing and evaluating ocean mixing schemes is also described.
Robert Hagen, Andreas Plüß, Romina Ihde, Janina Freund, Norman Dreier, Edgar Nehlsen, Nico Schrage, Peter Fröhle, and Frank Kösters
Earth Syst. Sci. Data, 13, 2573–2594, https://doi.org/10.5194/essd-13-2573-2021, https://doi.org/10.5194/essd-13-2573-2021, 2021
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We established an open-access, integrated marine data collection for 1996 to 2015 in the German Bight as a database of scientific, economic, and governmental interest. This paper presents data for tidal elevation, depth-averaged current velocity, bottom shear stress, depth-averaged salinity, and wave parameters and spectra at a high temporal and spatial resolution. Data are additionally processed into meaningful parameters (i.e., tidal characteristic values, e.g., tidal range) for accessibility.
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.
Hagen Radtke, Sandra-Esther Brunnabend, Ulf Gräwe, and H. E. Markus Meier
Clim. Past, 16, 1617–1642, https://doi.org/10.5194/cp-16-1617-2020, https://doi.org/10.5194/cp-16-1617-2020, 2020
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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.
Marvin Lorenz, Knut Klingbeil, Parker MacCready, and Hans Burchard
Ocean Sci., 15, 601–614, https://doi.org/10.5194/os-15-601-2019, https://doi.org/10.5194/os-15-601-2019, 2019
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Estuaries are areas where riverine and oceanic waters meet and mix. The exchange flow of an estuary describes the water properties of the inflowing and outflowing water. These can be described by simple bulk values for volume fluxes and salinities. This work focuses on the numerics of one computational method for these values, the Total Exchange Flow. We show that only the so-called dividing salinity method is able to reliably calculate the correct values, even for complex situations.
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.
Carsten Lemmen, Richard Hofmeister, Knut Klingbeil, M. Hassan Nasermoaddeli, Onur Kerimoglu, Hans Burchard, Frank Kösters, and Kai W. Wirtz
Geosci. Model Dev., 11, 915–935, https://doi.org/10.5194/gmd-11-915-2018, https://doi.org/10.5194/gmd-11-915-2018, 2018
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To describe coasts in a computer model, many processes have to be represented, from the air to the water to the ocean floor, from different scientific disciplines. No existing computer model adequately addresses this complexity. We present the Modular System for Shelves and Coasts (MOSSCO), which embraces this diversity and flexibly connects several tens of individual process models. MOSSCO also makes it easier to bring local knowledge to the Earth system level.
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.
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
A. Plüß and F. Kösters
Adv. Geosci., 39, 61–68, https://doi.org/10.5194/adgeo-39-61-2014, https://doi.org/10.5194/adgeo-39-61-2014, 2014
Related subject area
Approach: Numerical Models | Properties and processes: Tides | Depth range: Estuaries | Geographical range: Shelf Seas | Challenges: Other
A tidally driven fjord-like strait close to an amphidromic region
Sissal Vágsheyg Erenbjerg, Jon Albretsen, Knud Simonsen, Erna Lava Olsen, Eigil Kaas, and Bogi Hansen
Ocean Sci., 17, 1639–1655, https://doi.org/10.5194/os-17-1639-2021, https://doi.org/10.5194/os-17-1639-2021, 2021
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Here, we describe a strait that has narrow and shallow sills in both ends and is close to an amphidromic region. This generates tidally driven flows into and out of the strait, but with very different exchange rates across the entrances in both ends so that it behaves like a mixture between a strait and a fjord. Using a numerical model, we find a fortnightly signal in the net transport through the strait, generated by long-period tides. Our findings are verified by observations.
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Short summary
River engineering measures greatly changed tidal dynamics in the Weser estuary. We studied the effect on saltwater intrusion with numerical models. Our analysis shows that a deepening of the navigation channel causes saltwater to intrude further into the Weser estuary. This effect is mostly masked by the natural variability of river discharge. In our study, it proved essential to recalibrate individual hindcast models due to differences in sediments, bed forms, and underlying bathymetric data.
River engineering measures greatly changed tidal dynamics in the Weser estuary. We studied the...
