Küstenforschung


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Publications

Bierstedt, S. E., Hünicke, B., Zorita, E., and Ludwig, J. (2017): A wind proxy based on migrating dunes at the Baltic coast: statistical analysis of the link between wind conditions and sand movement. Earth Syst. Dynam., 8, 639-652, doi: 10.5194/esd-8-639-2017

Abstract:

We statistically analyse the relationship between the structure of migrating dunes in the southern Baltic and the driving wind conditions over the past 26 years, with the long-term aim of using migrating dunes as a proxy for past wind conditions at an interannual resolution.

The present analysis is based on the dune record derived from geo-radar measurements by Ludwig et al. (2017). The dune system is located at the Baltic Sea coast of Poland and is migrating from west to east along the coast. The dunes present layers with different thicknesses that can be assigned to absolute dates at interannual timescales and put in relation to seasonal wind conditions. To statistically analyse this record and calibrate it as a wind proxy, we used a gridded regional meteorological reanalysis data set (coastDat2) covering recent decades. The identified link between the dune annual layers and wind conditions was additionally supported by the co-variability between dune layers and observed sea level variations in the southern Baltic Sea.

We include precipitation and temperature into our analysis, in addition to wind, to learn more about the dependency between these three atmospheric factors and their common influence on the dune system. We set up a statistical linear model based on the correlation between the frequency of days with specific wind conditions in a given season and dune migration velocities derived for that season. To some extent, the dune records can be seen as analogous to tree-ring width records, and hence we use a proxy validation method usually applied in dendrochronology, cross-validation with the leave-one-out method, when the observational record is short. The revealed correlations between the wind record from the reanalysis and the wind record derived from the dune structure is in the range between 0.28 and 0.63, yielding similar statistical validation skill as dendroclimatological records.


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Publications

A. Retzmann, T. Zimmermann, D. Pröfrock, T. Prohaska, J. Irrgeher (2017): A fully automated simultaneous single-stage separation of Sr, Pb, and Nd using DGA Resin for the isotopic analysis of marine sediments. Analytical and Bioanalytical Chemistry, pp 1–18, doi: 10.1007/s00216-017-0468-6

Abstract:

A novel, fast and reliable sample preparation procedure for the simultaneous separation of Sr, Pb, and Nd has been developed for subsequent isotope ratio analysis of sediment digests. The method applying a fully automated, low-pressure chromatographic system separates all three analytes in a single-stage extraction step using self-packed columns filled with DGA Resin. The fully automated set-up allows the unattended processing of three isotopic systems from one sediment digest every 2 h, offering high sample throughput of up to 12 samples per day and reducing substantially laboratory manpower as compared to conventional manual methods. The developed separation method was validated using the marine sediment GBW-07313 as matrix-matched certified reference material and combines quantitative recoveries (>90% for Sr, >93% for Pb, and >91% for Nd) with low procedural blank levels following the sample separation (0.07 μg L−1 Sr, 0.03 μg L−1 Pb, and 0.57 μg L−1 Nd). The average δ values for Sr, Pb, and Nd of the separated reference standards were within the certified ranges (δ (87Sr/86Sr)NIST SRM 987 of −0.05(28) ‰, δ(208Pb/206Pb)NIST SRM 981 of −0.21(14) ‰, and δ(143Nd/144Nd)JNdi-1 of 0.00(7) ‰). The DGA Resin proved to be reusable for the separation of >10 sediment digests with no significant carry-over or memory effects, as well as no significant on-column fractionation of Sr, Pb, and Nd isotope ratios. Additional spike experiments of NIST SRM 987 with Pb, NIST SRM 981 with Sr, and JNdi-1 with Ce revealed no significant impact on the measured isotopic ratios, caused by potential small analyte peak overlaps during the separation of Sr and Pb, as well as Ce and Nd.

 

Vetere, A., Pröfrock, D. and Schrader, W. (2017): Quantitative and qualitative analysis of three classes of sulfur compounds in crude oil. Angew. Chem. Int. Ed., doi:10.1002/anie.201703205

Abstract:

Due to environmental hazards arising from sulfur containing combustion products, strong legal regulations exist to reduce the sulfur content of transportation fuels down to a few ppm. With the ongoing depletion of low-sulfur crude oil reservoirs, increased technological efforts are needed for crude oil refining to meet these requirements. The desulfurization step is a critical part of the refining process but partly suffers from recalcitrance of certain species against sulfur removal and the inability to quantitatively understand the behaviour of individual classes during the process. Here a new and simple approach for the parallel quantification of three different classes of sulfur species present in crude oils using LC-separation and an online detection and quantification by ICP-MS is shown. This new and simple approach will help to estimate the amount of recalcitrant species and thus to allow a better optimization of desulfurization conditions during fuel production.


Pock­mark­fel­der vor Hel­go­land

Screenshot Website marum.de

Es gibt eine aktuelle Veröffentlichtung zur Studie so genannter Pockmarkfelder vor Helgoland, die unter Federführung des MARUM, Zentrum für Marine Umweltwissenschaften der Universität Bremen, durchgeführt wurde. Daran beteiligt waren Wissenschaftler des Instituts für Küstenforschung aus der Abteilung Aquatische Nährstoffkreisläufe.

Der eng­li­sche Be­griff pock­mark (deutsch: Po­cken­n­ar­be) be­zeich­net cha­rak­te­ris­ti­sche Kra­ter am Ge­wäs­ser­bo­den, die beim Aus­tritt von Flüs­sig­kei­ten oder Ga­sen aus dem Un­ter­grund ent­ste­hen. Vor Helgoland haben die Wissenschaftler beim Kartieren des Meeresbodens tausende Krater entdeckt, die im Zu­sam­men­hang mit er­höh­ten Me­than­kon­zen­tra­tio­nen im Se­di­ment als so ge­nann­te Pock­marks iden­ti­fi­ziert wurden.

Weitere Informationen zur Studie und den Ergebnissen gibt es auf der MARUM Webseite.

Knut Krä­mer, Pe­ter Hol­ler, Ga­bri­el Herbst, Alex­an­der Bra­tek, Soe­ren Ah­mer­kamp, An­dre­as Neu­mann, Alex­an­der Bar­tho­lo­mä, Jus­tus E.E. van Beu­se­kom, Mo­ritz Hol­tap­pels und Chris­ti­an Win­ter (2017): Ab­rupt emer­gence of a lar­ge pock­mark field in the Ger­man Bight, sou­theas­tern North Sea. Sci­en­ti­fic Re­ports 7, 2017; DOI: 10.1038/s41598-017-05536-1

Abstract:

A series of multibeam bathymetry surveys revealed the emergence of a large pockmark field in the southeastern North Sea. Covering an area of around 915 km2, up to 1,200 pockmarks per square kilometer have been identified. The time of emergence can be confined to 3 months in autumn 2015, suggesting a very dynamic genesis. The gas source and the trigger for the simultaneous outbreak remain speculative. Subseafloor structures and high methane concentrations of up to 30 μmol/l in sediment pore water samples suggest a source of shallow biogenic methane from the decomposition of postglacial deposits in a paleo river valley. Storm waves are suggested as the final trigger for the eruption of the gas. Due to the shallow water depths and energetic conditions at the presumed time of eruption, a large fraction of the released gas must have been emitted to the atmosphere. Conservative estimates amount to 5 kt of methane, equivalent to 67% of the annual release from the entire North Sea. These observations most probably describe a reoccurring phenomenon in shallow shelf seas, which may have been overlooked before because of the transient nature of shallow water bedforms and technology limitations of high resolution bathymetric mapping.


Publications

Andreas Neumann, Justus E.E. van Beusekom, Moritz Holtappels, Kay-Christian Emeis (2017): Nitrate consumption in sediments of the German Bight (North Sea). Journal of Sea Research, available online 29 June 2017, doi: 10.1016/j.seares.2017.06.012

Abstract:

Denitrification on continental margins and in coastal sediments is a major sink of reactive N in the present nitrogen cycle and a major ecosystem service of eutrophied coastal waters. We analyzed the nitrate removal in surface sediments of the Elbe estuary, Wadden Sea, and adjacent German Bight (SE North Sea) during two seasons (spring and summer) along a eutrophication gradient ranging from a high riverine nitrate concentrations at the Elbe Estuary to offshore areas with low nitrate concentrations. The gradient encompassed the full range of sediment types and organic carbon concentrations of the southern North Sea. Based on nitrate penetration depth and concentration gradient in the porewater we estimated benthic nitrate consumption rates assuming either diffusive transport in cohesive sediments or advective transport in permeable sediments. For the latter we derived a mechanistic model of porewater flow. During the peak nitrate discharge of the river Elbe in March, the highest rates of diffusive nitrate uptake were observed in muddy sediments (up to 2.8 mmol m− 2 d− 1). The highest advective uptake rate in that period was observed in permeable sediment and was tenfold higher (up to 32 mmol m− 2 d− 1). The intensity of both diffusive and advective nitrate consumption dropped with the nitrate availability and thus decreased from the Elbe estuary towards offshore stations, and were further decreased during late summer (minimum nitrate discharge) compared to late winter (maximum nitrate discharge). In summary, our rate measurements indicate that the permeable sediment accounts for up to 90% of the total benthic reactive nitrogen consumption in the study area due to the high efficiency of advective nitrate transport into permeable sediment. Extrapolating the averaged nitrate consumption of different sediment classes to the areas of Elbe Estuary, Wadden Sea and eastern German Bight amounts to an N-loss of 3.1 ∗ 106 mol N d− 1 from impermeable, diffusion-controlled sediment, and 5.2 ∗ 107 mol N d− 1 from permeable sediment with porewater advection.


Publications

Onur Kerimoglu, Stéphan Jacquet, Brigitte Vinçon-Leite, Bruno J. Lemaire, Frédéric Rimet, Frédéric Soulignac, Dominique Trévisan, Orlane Anneville (2017): Modelling the plankton groups of the deep, peri-alpine Lake Bourget. Ecological Modelling, Volume 359, 10 September 2017, Pages 415–433, doi: 10.1016/j.ecolmodel.2017.06.005

Abstract:

Predicting phytoplankton succession and variability in natural systems remains to be a grand challenge in aquatic ecosystems research. In this study, we identified six major plankton groups in Lake Bourget (France), based on cell size, taxonomic properties, food-web interactions and occurrence patterns: cyanobacterium Planktothrix rubescens, small and large phytoplankton, mixotrophs, herbivorous and carnivorous zooplankton. We then developed a deterministic dynamic model that describes the dynamics of these groups in terms of carbon and phosphorus fluxes, as well as of particulate organic phosphorus and dissolved inorganic phosphorus. The modular and generic model scheme, implemented as a set of modules under Framework for Aquatic Biogeochemical Models (FABM) enables run-time coupling of the plankton module an arbitrary number of times, each time with a prescribed position across the autotrophy/heterotrophy continuum. Parameters of the plankton groups were mainly determined conjointly by the taxonomic and allometric relationships, based on the species composition and average cellular volume of each group. The biogeochemical model was coupled to the one-dimensional General Ocean Turbulence Model (GOTM) and forced with local meteorological conditions. The coupled model system shows very high skill in predicting the spatiotemporal distributions of water temperature and dissolved inorganic phosphorus for five simulated years within the period 2004 to 2010, and intermediate skill in predicting the plankton succession. We performed a scenario analysis to gain insight into the factors driving the sudden disappearance of P. rubescens in 2010. Our results provide evidence for the hypothesis that the abundance of this species before the onset of stratification is critical for its success later in the growing season, pointing thereby to a priority effect.


Publications

Johannes Pätsch, Hans Burchard, Christian Dieterich, Ulf Gräwe, Matthias Gröger, Moritz Mathis, Hartmut Kapitza, Manfred Bersch, Andreas Moll, Thomas Pohlmann, Jian Su, Ha T.M. Ho-Hagemann, Achim Schulz, Alberto Elizalde, Carsten Eden (2017): An evaluation of the North Sea circulation in global and regional models relevant for ecosystem simulations. Ocean Modelling (2017), doi:10.1016/j.ocemod.2017.06.005

Abstract:

Simulations of the North Sea circulation by the global ocean model MPI-OM and the regional ocean models GETM, HAMSOM, NEMO, TRIM are compared against each other and with observational data for the period 1998-2009. The aim of the study is to evaluate the quality of the simulations in particular with respect to their suitability to drive biogeochemical shelf sea models. Our results demonstrate the benefit of the global model to avoid the specification of lateral open boundary conditions. Due to its stretched grid configuration, which provides a higher grid resolution at the Northwest European Shelf, the global model is able to reproduce the large-scale features, such as the water mass distribution and the thermal stratification in the central and northern North Sea, qualitatively similar to the regional models. The simulation of temperature and salinity near the coast however, shows large biases in almost all models because of the coarse meteorological forcing and too coarse vertical resolutions. The simulation of the Baltic Sea exchange and the spread of freshwater along the Norwegian coast proved difficult for all models except GETM, which reproduces impacts of the Baltic Sea outflow reasonably well.

 

Florian Dutschke, Johanna Irrgeher and Daniel Pröfrock (2017): Optimisation of an extraction/leaching procedure for the characterisation and quantification of titanium dioxide (TiO2) nanoparticles in aquatic environments using SdFFF-ICP-MS and SEM-EDX analyses. Analytical Methods, doi:10.1039/C7AY00635G

Abstract:

The quantitative recovery of nanoparticles from environmental samples represents a critical step during the implementation of routine analytical monitoring methods for the reliable quantitative determination of nanomaterials released into aquatic environments at the expected low concentration levels. In this work, several approaches based on different extraction agents have been evaluated with respect to their suitability for the recovery of TiO2 nanomaterials from fresh sediment samples. Centrifugal-field-flow-fractionation (SdFFF) hyphenated to inductively coupled plasma tandem mass spectrometry (ICP-MS/MS) has been applied to separate the extracted nanoparticles as well as to overcome the known interference problem related to their Ti-specific detection when using ICP-based techniques. SdFFF-ICP-MS/MS method validation included in particular parameters such as particle recovery or stability of the particle size-distribution. Spike recoveries from the optimized colloidal extraction procedure of up to 95 ± 11% have been achieved. In a case study conducted from 2015 to 2016, the developed method was applied to monitor the release of nano-sized TiO2 materials into a lake environment that is frequently used for recreational activities such as swimming and surfing. The investigated sediment samples show a significant increase of the Ti concentration from 26.2 ± 2.7 mg kg−1 in June 2015 to 40.2 ± 4.6 mg kg−1 in December 2016 originating from TiO2 particles.


Publications

Bieser, J., Slemr, F., Ambrose, J., Brenninkmeijer, C., Brooks, S., Dastoor, A., DeSimone, F., Ebinghaus, R., Gencarelli, C. N., Geyer, B., Gratz, L. E., Hedgecock, I. M., Jaffe, D., Kelley, P., Lin, C.-J., Jaegle, L., Matthias, V., Ryjkov, A., Selin, N. E., Song, S., Travnikov, O., Weigelt, A., Luke, W., Ren, X., Zahn, A., Yang, X., Zhu, Y., and Pirrone, N. (2017): Multi-model study of mercury dispersion in the atmosphere: vertical and interhemispheric distribution of mercury species. Atmos. Chem. Phys., 17, 6925-6955, doi:10.5194/acp-17-6925-2017

Abstract:

Atmospheric chemistry and transport of mercury play a key role in the global mercury cycle. However, there are still considerable knowledge gaps concerning the fate of mercury in the atmosphere. This is the second part of a model intercomparison study investigating the impact of atmospheric chemistry and emissions on mercury in the atmosphere. While the first study focused on ground-based observations of mercury concentration and deposition, here we investigate the vertical and interhemispheric distribution and speciation of mercury from the planetary boundary layer to the lower stratosphere. So far, there have been few model studies investigating the vertical distribution of mercury, mostly focusing on single aircraft campaigns. Here, we present a first comprehensive analysis based on various aircraft observations in Europe, North America, and on intercontinental flights.

The investigated models proved to be able to reproduce the distribution of total and elemental mercury concentrations in the troposphere including interhemispheric trends. One key aspect of the study is the investigation of mercury oxidation in the troposphere. We found that different chemistry schemes were better at reproducing observed oxidized mercury patterns depending on altitude. High concentrations of oxidized mercury in the upper troposphere could be reproduced with oxidation by bromine while elevated concentrations in the lower troposphere were better reproduced by OH and ozone chemistry. However, the results were not always conclusive as the physical and chemical parameterizations in the chemistry transport models also proved to have a substantial impact on model results.


Publications

Monika J. Barcikowska, Sarah B. Kapnick, Frauke Feser (2017): Impact of large-scale circulation changes in the North Atlantic sector on the current and future Mediterranean winter hydroclimate. Climate Dynamics, 2017, doi: 10.1007/s00382-017-3735-5

Abstract:

The Mediterranean region, located in the transition zone between the dry subtropical and wet European mid-latitude climate, is very sensitive to changes in the global mean climate state. Projecting future changes of the Mediterranean hydroclimate under global warming therefore requires dynamic climate models to reproduce the main mechanisms controlling regional hydroclimate with sufficiently high resolution to realistically simulate climate extremes. To assess future winter precipitation changes in the Mediterranean region we use the Geophysical Fluid Dynamics Laboratory high-resolution general circulation model for control simulations with pre-industrial greenhouse gas and aerosol concentrations which are compared to future scenario simulations. Here we show that the coupled model is able to reliably simulate the large-scale winter circulation, including the North Atlantic Oscillation and Eastern Atlantic patterns of variability, and its associated impacts on the mean Mediterranean hydroclimate. The model also realistically reproduces the regional features of daily heavy rainfall, which are absent in lower-resolution simulations. A five-member future projection ensemble, which assumes comparatively high greenhouse gas emissions (RCP8.5) until 2100, indicates a strong winter decline in Mediterranean precipitation for the coming decades. Consistent with dynamical and thermodynamical consequences of a warming atmosphere, derived changes feature a distinct bipolar behavior, i.e. wetting in  the north—and drying in the south. Changes are most pronounced over the northwest African coast, where the projected winter precipitation decline reaches 40% of present values. Despite a decrease in mean precipitation, heavy rainfall indices show drastic increases across most of the Mediterranean, except the North African coast, which is under the strong influence of the cold Canary Current.

 

Juan José Gómez-Navarro, Eduardo Zorita, Christoph C. Raible, Raphael Neukom (2017): Pseudo-proxy tests of the analogue method to reconstruct spatially resolved global temperature during the Common Era. Clim. Past, 13, 629-648, 2017, doi: 10.5194/cp-13-629-2017

Abstract:

This study addresses the possibility of carrying out spatially resolved global reconstructions of annual mean temperature using a worldwide network of proxy records and a method based on the search of analogues. Several variants of the method are evaluated, and their performance is analysed. As a test bed for the reconstruction, the PAGES 2k proxy database (version 1.9.0) is employed as a predictor, the HadCRUT4 dataset is the set of observations used as the predictand and target, and a set of simulations from the PMIP3 simulations are used as a pool to draw analogues and carry out pseudo-proxy experiments (PPEs). The performance of the variants of the analogue method (AM) is evaluated through a series of PPEs in growing complexity, from a perfect-proxy scenario to a realistic one where the pseudo-proxy records are contaminated with noise (white and red) and missing values, mimicking the limitations of actual proxies. Additionally, the method is tested by reconstructing the real observed HadCRUT4 temperature based on the calibration of real proxies. The reconstructed fields reproduce the observed decadal temperature variability. From all the tests, we can conclude that the analogue pool provided by the PMIP3 ensemble is large enough to reconstruct global annual temperatures during the Common Era. Furthermore, the search of analogues based on a metric that minimises the RMSE in real space outperforms other evaluated metrics, including the search of analogues in the range-reduced space expanded by the leading empirical orthogonal functions (EOFs). These results show how the AM is able to spatially extrapolate the information of a network of local proxy records to produce a homogeneous gap-free climate field reconstruction with valuable information in areas barely covered by proxies and make the AM a suitable tool to produce valuable climate field reconstructions for the Common Era.

 

Wang, J., Yang, B., Ljungqvist, F.C., Luterbacher, J., Osborn, T.J., Briffa, K.R., Zorita, E. (2017): Internal and external forcing of multidecadal Atlantic climate variability over the past 1,200 years. Nature Geoscience, 2017, doi: 10.1038/ngeo2962

Abstract:

The North Atlantic experiences climate variability on multidecadal scales, which is sometimes referred to as Atlantic multidecadal variability. However, the relative contributions of external forcing such as changes in solar irradiance or volcanic activity and internal dynamics to these variations are unclear. Here we provide evidence for persistent summer Atlantic multidecadal variability from AD 800 to 2010 using a network of annually resolved terrestrial proxy records from the circum-North Atlantic region. We find that large volcanic eruptions and solar irradiance minima induce cool phases of Atlantic multidecadal variability and collectively explain about 30% of the variance in the reconstruction on timescales greater than 30 years. We are then able to isolate the internally generated component of Atlantic multidecadal variability, which we define as the Atlantic multidecadal oscillation. We find that the Atlantic multidecadal oscillation is the largest contributor to Atlantic multidecadal variability over the past 1,200 years. We also identify coherence between the Atlantic multidecadal oscillation and Northern Hemisphere temperature variations, leading us to conclude that the apparent link between Atlantic multidecadal variability and regional to hemispheric climate does not arise solely from a common response to external drivers, and may instead reflect dynamic processes.


Publications

Meinke, I. (2017): On the comparability of knowledge transfer activities – a case study at the German Baltic Sea Coast focusing regional climate services. Adv. Sci. Res., 14, 145-151, doi:10.5194/asr-14-145-2017

 

Abstract:

In this article the comparability of knowledge transfer activities is discussed by accounting for external impacts. It is shown that factors which are neither part of the knowledge transfer activity nor part of the participating institution may have significant impact on the potential usefulness of knowledge transfer activities.

Differences in the potential usefulness are leading to different initial conditions of the knowledge transfer activities. This needs to be taken into account when comparing different knowledge transfer activities, e.g., in program evaluations. This study is focusing on regional climate services at the German Baltic Sea coast. It is based on two surveys and experiences with two identical web tools applied on two regions with different spatial coverage.

The results show that comparability among science based knowledge transfer activities is strongly limited through several external impacts. The potential usefulness and thus the initial condition of a particular knowledge transfer activity strongly depends on (1) the perceived priority of the focused topic, (2) the used information channels, (3) the conformity between the research agenda of service providing institutions and information demands in the public, as well as (4) on the spatial coverage of a service.

It is suggested to account for the described external impacts for evaluations of knowledge transfer activities. The results show that the comparability of knowledge transfer activities is limited and challenge the adequacy of quantitative measures in this context. Moreover, as shown in this case study, in particular regional climate services should be individually evaluated on a long term perspective, by potential user groups and/or by its real users. It is further suggested that evaluation criteria should be co-developed with these stakeholder groups.


Publications

Springer book Coastline Changes of the Baltic Sea from South to East edited by Harff, J., Furmanczyk, K., and Von Storch, H., in which HZG colleagues have contributed to.

Introduction:

The importance of sea-level and coastline changes increases for the population living along the edge of the world’s oceans and seas. This holds in particular where eustatic sea-level rise is superimposed on isostatic subsidence and storm induced coastal erosion. This is the case on the southern and eastern Baltic Sea coast. In the South, glacio-isostatic subsidence enhances the effect of climate induced sea-level rise and strong storm effects cause a continuous retreat of the coast. On the eastern coast the glacio-isostatic uplift compensates eustatic sea-level rise, but storm induced waves cause permanent morphodynamic changes of the coastline. Concepts for protection, defense but also for the economic use of the coastal zone adjusted to their different environments are required increasingly. The elaboration of these management concepts can be facilitated through models generating future projection of coastal developments in front of the modern climate change. The anthology comprises results of a research project “Coastline Changes of the southern Baltic Sea – Past and future projection (CoPaF)” which was run by a team of Estonian, German, and Polish geoscientists and coastal engineers from 2010 to 2013. In the first part, the chapters are devoted to the explanation of conceptual and dynamical models to describe morphodynamic changes along the Baltic Sea southern coasts consisting of Pleistocene and Holocene sediments. In the second part, regional studies are published ranging from the Mecklenburgian Bay to the Gulf of Finland. Here, not only local and regional effects of coastal dynamics are considered, but also methodological aspects, such as the use of historical maps for the parameterization of morphodynamic models. As the southern and eastern Baltic serves as a natural laboratory for the investigation of coastal processes – the achievements of the project will contribute not only to the solution of regional problems in Baltic coastal research and engineering, but, will also contribute to general problems in the description, modelling and parameterization of coastal processes and morphodynamics.

Harff, J., J. Deng, J. Durzinska-Nowak, P. Fröhle, A. Groh, B. Hünicke, T. Soomere, and W. Zhang (2017): Chapter 2: What determines the change of coastlines in the Baltic Sea? In: Harff J., Furmanczyk K., von Storch H. (eds) Coastline changes of the Baltic Sea from south to east – past and future projection. Coastal research library, vol 19. Springer, Cham, Switzerland. DOI:10.1007/978-3-319-49894-2

Abstract:

The change of coastline positions of the Baltic Sea is mainly determined by both the eustatic sea-level change and the glacio-isostatic adjustment (GIA). For changes on the Holocene time scale, the relative sea-level change can be reconstructed from paleo-coastline positions and correspondingly dated sediments and organic remains. On the decadal scale, tide gauge data are available. Both data sets display the relative value of sea-level change resulting from the superposition of climatically and meteorologically induced factors, vertical crustal displacement, and related gravitational forces. The isolation of the GIA signal from the compound relative sea-level change data plays a critical role for future projections of coastline changes within the frame of coastal zone management. To separate different components of sea-level data sets, statistical methods for the exploration of empirical water level, meteorological, and GPS data are combined with analytical methods to solve the sea-level equation. In the result, the pattern of vertical crustal movement can be displayed as maps covering the uplifting Fennoscandian Shield and its subsiding belt. Whereas along the uplifting coasts morphodynamic processes play a subordinated role, in the subsiding Southeast and South, Quaternary sediments are permanently exposed to coastal erosion, sediment transport, and re-deposition. This mainly wave-driven sediment dynamics together with aeolian processes depend on meteorological forcing of the in general west-east directed air-flow from the northern Atlantic Ocean to Eurasia. Regional coastal morphogenesis can generally be described by alongshore sediment transport pattern deduced from the integration of subregional to local models of transport capacities. For future projection, coastlines and the morphology of the adjacent zones have to be regarded a function of its position related to the vertical displacement of the Earth’s crust, the regional climatic and meteorological conditions, and the geological setting. Results of climate modelling, the Earth’s visco-elastic response to the deglaciation, geological data and regional sediment transport capacities have to be interpreted comprehensively.

Hünicke, B., E. Zorita, and H. von Storch (2017): Chapter 3: The Challenge of Baltic Sea Level Change.

Abstract:

Baltic Sea level variability is caused by different climatic and geological factors that render their understanding more difficult than for other areas of the Earth. Yet this understanding is crucial to predict with reliability the sea-level rise in the Baltic Sea that will be brought about by anthropogenic climate change. We illustrate this complexity by a few, in our opinion, important questions that ultimately are related to the estimation of long-term trends in the presence of land crust movements, to the heterogeneity of the Baltic sea-level response to atmospheric forcing, and the difficulty of identifying a sea-level rise acceleration in the observed records.

 

Deng, J., J. Harff, W. Zhang, R. Schneider, J. Durzinska-Nowak, A. Giza, P. Terefenko, and K. Furmanczyk (2017): Chapter 5: The Dynamic Equilibrium Shore Model for the Reconstruction and Future Projection of Coastal Morphodynamics.

Abstract:

Sea level and coastline change are becoming increasingly important topics to the population living along the edge of the world’s oceans and seas. This is the case at the southern Baltic Sea coast where climate change and glacio-isostatic response cause a relative sea-level rise of up to 2 mm/y and where storms events lead to continuous coastal retreat. There is an increasing need of numerical models applicable for reconstruction and future projection of coastal morphogenesis within the frame of coastal zone management and planning. By adopting a concept of dynamic equilibrium changes of coastal profiles and three dimensional generalization of the generalized Bruun concept, a quantitative model Dynamic Equilibrium Shore Model (DESM) is elaborated to study coastal morphogenesis including the reconstruction of the geological past and projection to future on the decadal to centennial time scale. The DESM model requires data of historical coastline configuration derived from maps, a high-resolution modern Digital Elevation Model (DEM), relative sea-level change data, and modelling data of long-shore sediment transport capacity. This model is applied in the study to three research areas of the southern Baltic Sea (Swina Gate, Łeba coast and Hel Peninsula). Their developments represent distinct examples of morphodynamics at wave dominated coast: formation of barrier islands, development of open coasts and processes at sandy spits. This study concentrates on areas in particular vulnerable to erosion and destruction due to their geological build-up, the glacio-isostatic subsidence and an exposure to the westerly and northern wind and storm tracks.

 

Zhang W., R. Schneider, J. Harff, B. Hünicke, and P. Fröhle (2017): Chapter 6: Modelling of Medium-Term (Decadal) Coastal Foredune Morphodynamics-Historical Hindcast and Future Scenarios of the Świna Gate Barrier Coast (Southern Baltic Sea).

Abstract:

Coastal foredunes are developed as a result of interplay among multi-scale land-sea processes. Natural foredune ridges along the Świna Gate barrier coast (southern Baltic Sea) developed since 6000 cal. year BP provide an excellent laboratory to study the land-sea interaction under a medium- to long-term climatic control. In this paper we investigate several basic driving mechanisms of coastal foredune morphodynamics as well as natural environmental factors involved in shaping the foredune geometry by a numerical model. The model couples a process-based module for subaqueous sediment transport and a probabilistic-type module for subaerial aeolian sand transport and vegetation growth. After an evaluation of the model performance for a 61-year (1951–2012 AD) historical hindcast of the foredune development along a 1 km-long section of the Świna Gate barrier coast, the model is applied for a future projection of the same area to 2050 AD based on three different climate change scenarios. The climate change scenarios represent three different impact levels with regard to their capacity to shape the coastal morphology. Simulation results demonstrate a remarkable variability in foredune development even along a small (1 km) coast section, implying that the medium-term land-sea interaction and foredune morphodynamics is quite sensitive to boundary conditions and various processes acting on multi-temporal and spatial scales. Foredune morphodynamics such as migration, bifurcation, destruction and separation are determined by different combinations of storm frequency, onshore sediment supply rate and relative sea-level change. In contrast to a low rate of relative sea-level rise during the last few decades, an accelerated sea level-rise over the twenty-first century predicted by existing literature, would result in a dramatic and non-linear response from the foredune development according to our simulations.