Küstenforschung


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BRIESE PREIS für Meeresforschung / BRIESE Award for Marine Science

Screenshot briese-research.de

Die Reederei Briese Schiffahrts GmbH & Co. KG (Leer) vergibt seit 2010, zusammen mit dem Leibniz-Institut für Ostseeforschung Warnemünde (IOW), den „BRIESE-Preis für Meeresforschung“. Mit dem Preis, der jährlich vergeben wird, sollen herausragende Promotionen der Meeresforschung prämiert werden, deren Ergebnisse in besonders engem Zusammenhang mit dem Einsatz von Forschungsschiffen und der Verwendung und Entwicklung von Technik und/oder der Datenerhebung auf See stehen. Ein vorrangiges Kriterium bei der Vergabe ist die Tragweite der im Rahmen der Arbeit gewonnen wissenschaftlichen Erkenntnis. Die Auszeichnung ist mit einem Preisgeld von 5.000 € verbunden. (Quelle: Website briese-research.de)

==> zur vollständigen Ausschreibung (Deutsch)

Since 2010 the shipping company Briese Schiffahrts GmbH & Co. KG (Leer, Germany), together with the Leibniz Institute for Baltic Sea Research Warnemünde (IOW), grants the „BRIESE-award for Marine Science”. This annual award honors exceptional doctoral theses in marine science. The dissertations should closely relate to the use of research vessels and to the development of technologies and/or techniques of data acquisition at sea. Primary criterions for the award are the outstanding results of the dissertation and their importance for the marine science. The award is endowed with price money of 5000 €. (source: website briese-research.de)

==> detailed infos for application procedure (English)


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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.


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.


Job offer / Stellenangebot

Scientist (m/f)

The Institute of coastal research at the Helmholtz-Zentrum Geesthacht hosts a number of highly motivated and experienced researchers in the broad field of coastal research. A research focus lies on numerical modelling of coastal processes with specific expertise in modelling of atmosphere, ocean, marine biogeochemistry, atmosphere and ocean chemistry and sediment transport and morphodynamics on regional and coastal scales. We plan to enlarge our modeling team by an expert in discharge modelling and invite applications for a permanent position. We are looking for a highly motivated and experienced scientist (m/f) and acknowledged expert (m/f) in hydrological modeling on climate timescales. The duration of the position is 24 months.

Your tasks:

  • model development to resolve and understand the feedbacks in the coupled regional atmosphere-land-ocean systems with particular focus on coastal systems
  • further development of hydrological discharge models/river routing schemes such as HD model, TRIP
  • independently building up this research field at Helmholtz-Zentrum Geesthacht
  • conduct research about the land-ocean coupling and climate and anthropogenic system drivers on various time scales in collaboration with atmospheric and oceanic modelers
  • establishing collaboration with other Helmholtz Centers to develop research at the land-ocean-atmosphere interface
  • networking with national and international modeling communities
  • supervising of master and PhD students, collaboration with postdoctoral researchers
  • project applications and participation in national and international projects
  • publication in relevant scientific journals
  • presenting the research at international conferences and committees

Profile and qualification:

  • the successful applicant (m/f) has a university degree in Physics, Mathematics, Hydrology, Environmental Science, or related disciplines and holds a relevant PhD
  • she/he has outstanding expertise in hydrological discharge modelling on climate time scales
  • long standing experience in model development and evaluation including competence in using observational data for both purposes
  • documented expertise in working with models simulating river runoff on climate model scales and global and regional climate models
  • expertise in dealing with climate model biases and bias correction methods would be advantageous.
  • Relevant scientific expertise is documented in a range of publications in peer reviewed scientific literature.
  • the successful applicant (m/f) has excellent programming skills, familiar with FORTRAN and shell scripts within a unix/linux and High Performance Computing environment
  • excellent command of English and the ability and experience to work in an inter- and transdisciplinary environment
  • Networking with national and international modeling communities
  • the successful applicant (m/f) has participated in national and international projects and ideally also successfully applied for funding
  • contributed or independently supervised master and PhD students and guided and collaborated with postdoctoral researchers
  • and is ideally experienced in building up and leading an own research group

Closing date for applications is July, 14th, 2017.

==> detailed information for this job offer


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.


Job offer / Stellenangebot

PhD Position (m/f) in numerical modelling of coastal and shelf morphodynamics

The Institute of Coastal Research at the Helmholtz-Zentrum Geesthacht investigates coastal and shelf processes including interaction between land, sea and human being. As a means to identify the potential for change, sustainability and adaptation, scientists at the institute provide the tools, assessments and scenarios for managing the vulnerable coastal and shelf landscape. Coastal and shelf mud deposits represent the proximal sink for continent-derived material during modern sea level conditions. They serve as habitat for benthic life and store large quantities of carbon, nutrients, and contaminants. Most of them initiated to develop during mid- to late Holocene. Despite of their important role in the global source-to-sink transport and ecosystem functioning, their growth dynamics and the particular natural as well as anthropogenic drivers that shape their morphology remain largely unknown.

The objective of the position is to investigate the basic driving mechanisms for morphogenesis and morphological development of large-scale (10-100 km in length) shelf mud depocenters, with particular emphasis on the impact of extreme/energetic events (e.g. storms, floods, energetic internal waves and submesoscale eddies) as well as intensive human activity (bottom trawling).

The duration of the position is 36 months.

Your tasks include:

  • analysis of existing datasets from hydrographic monitoring and sediment cores
  • applying and modifying existing numerical models to simulate sediment transport and morphodynamics of shelf mud depocenters
  • work as an integrative part of a motivated multidisciplinary team within the institute and external academic partners
  • scientific publication and presentation

Job requirements:

  • a strong background in physical oceanography, fluid mechanics, geosciences, or related disciplines
  • good scientific programming skills with FORTRAN
  • good knowledge of English (written and oral)
  • high degree of creativity and flexibility; ability to work under pressure
  • ability and willingness to participate in sea-going research
  • good communication skills and ability to work in an interdisciplinary team with sedimentologists, climatologists and physical oceanographers

The following qualifications would be desirable:

  • experience in using Unix/Linux
  • research experience on sediment transport
  • an academic publication record

Closing date for applications is July, 14th, 2017.


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.