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  • 2013-2022
  • European Marine Science

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  • Open Access
    Authors: 
    Gazert, Volker; Luedecke, Cornelia;
    Publisher: Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung
    Country: Germany
  • Authors: 
    Stefan van Leeuwen; Ron Hoogenboom; Antoine Nijrolder; Wim Traag; Jaap Immerzeel; Hanneke Brust; Caroline Dirks; Wouter A. Gebbink; Liz Leenders;
    Publisher: 4TU.ResearchData

    On behalf of the Ministry of Agriculture, Nature and Food Quality (LNV), Wageningen Food Safety Research analyses samples of agricultural products of animal origin for dioxins, PCBs, brominated flame retardants (BFRs) and poly- and perfluorinated alkyl substances (PFASs). This includes meat, milk, eggs and fish.The samples are taken at the primary production or processing stage (e.g. in slaughterhouses or raw milk collection services). For dioxin-like compounds, 350 samples are first screened with the DR CALUX® method. Samples giving a signal indicating a level above the lowest action level are regarded as suspected. These samples are further examined using GC/HRMS as confirmatory method. Concerning fish, shellfish and crustaceans, approx. 25 samples are collected at sea by research vessels, at the fish auction, or from whole-sale traders (farmed fish).

  • Open Access
    Authors: 
    Wesche, Christine; Regnery, Julia;
    Publisher: Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung
    Country: Germany
  • Open Access English
    Authors: 
    Waelbroeck, Claire; Tjiputra, Jerry; Guo, Chuncheng; Nisancioglu, Kerim H.; Jansen, Eystein; Vazquez Riveiros, Natalia; Toucanne, Samuel; Eynaud, Frédérique; Rossignol, Linda; Dewilde, Fabien; +3 more
    Project: EC | ICE2ICE (610055), EC | ACCLIMATE (339108)

    We combine consistently dated benthic carbon isotopic records distributed over the entire Atlantic Ocean with numerical simulations performed by a glacial configuration of the Norwegian Earth System Model with active ocean biogeochemistry, in order to interpret the observed Cibicides δ13C changes at the stadial-interstadial transition corresponding to the end of Heinrich Stadial 4 (HS4) in terms of ocean circulation and remineralization changes. We show that the marked increase in Cibicides δ13C observed at the end of HS4 between ~2000 and 4200 m in the Atlantic can be explained by changes in nutrient concentrations as simulated by the model in response to the halting of freshwater input in the high latitude glacial North Atlantic. Our model results show that this Cibicides δ13C signal is associated with changes in the ratio of southern-sourced (SSW) versus northern-sourced (NSW) water masses at the core sites, whereby SSW is replaced by NSW as a consequence of the resumption of deep water formation in the northern North Atlantic and Nordic Seas after the freshwater input is halted. Our results further suggest that the contribution of ocean circulation changes to this signal increases from ~40 % at 2000 m to ~80 % at 4000 m. Below ~4200 m, the model shows little ocean circulation change but an increase in remineralization across the transition marking the end of HS4. The simulated lower remineralization during stadials than interstadials is particularly pronounced in deep subantarctic sites, in agreement with the decrease in the export production of carbon to the deep Southern Ocean during stadials found in previous studies.

  • Open Access
    Authors: 
    Lenz, Josefine; Fuchs, Matthias; Nitze, Ingmar; Strauß, Jens; Grosse, Guido;
    Publisher: Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung
    Country: Germany
  • Open Access English
    Authors: 
    Dagmara Rusiecka;
    Publisher: Zenodo

    Triple threat processes and/or other forcings can lead to changes in the ocean happening fast and abruptly. These changes, referred to as “tipping points”, are critical thresholds in a marine system that, when exceeded, can lead to a significant change in the state of the system, which often can be irreversible. This leaflet has been prepared mainly (but not only) for high school pupils with the financial support of Norges forskningsråd (Research Council of Norway) (309382).

  • Open Access English
    Authors: 
    Romero-Alvarez, Johana; Lupaşcu, Aurelia; Lowe, Douglas; Badia, Alba; Acher-Nicholls, Scott; Dorling, Steve R.; Reeves, Claire E.; Butler, Tim;
    Project: EC | ASIBIA (616938)

    Tropospheric ozone (O3) concentrations depend on a combination of hemispheric, regional, and local-scale processes. Estimates of how much O3 is produced locally vs. transported from further afield are essential in air quality management and regulatory policies. Here, a tagged-ozone mechanism within the Weather Research and Forecasting model coupled with chemistry (WRF-Chem) is used to quantify the contributions to surface O3 in the UK from anthropogenic nitrogen oxide (NOx) emissions from inside and outside the UK during May–August 2015. The contribution of the different source regions to three regulatory O3 metrics is also examined. It is shown that model simulations predict the concentration and spatial distribution of surface O3 with a domain-wide mean bias of −3.7 ppbv. Anthropogenic NOx emissions from the UK and Europe account for 13 % and 16 %, respectively, of the monthly mean surface O3 in the UK, as the majority (71 %) of O3 originates from the hemispheric background. Hemispheric O3 contributes the most to concentrations in the north and the west of the UK with peaks in May, whereas European and UK contributions are most significant in the east, south-east, and London, i.e. the UK's most populated areas, intensifying towards June and July. Moreover, O3 from European sources is generally transported to the UK rather than produced in situ. It is demonstrated that more stringent emission controls over continental Europe, particularly in western Europe, would be necessary to improve the health-related metric MDA8 O3 above 50 and 60 ppbv. Emission controls over larger areas, such as the Northern Hemisphere, are instead required to lessen the impacts on ecosystems as quantified by the AOT40 metric.

  • Other research product . Other ORP type . 2022
    Open Access
    Authors: 
    Mark, Felix; Cremer, Charlotte; Havermans, Charlotte; Murray, Ayla Rosina Cherrington; Verhaegen, Gerlien; Wollenburg, Jutta; Wukovits, Julia;
    Country: Germany

    The primary aim of this expedition was to investigate the spatial and temporal distribution, the ecology and physiology, as well as competition of co-occurring gadoid species (Atlantic cod, Polar cod, haddock) in the communities of Arctic and Atlantic influence around Svalbard. We sampled the benthic and pelagic communities (including plankton) on the shallow shelf regions of Svalbard to estimate the effects of climate change on Arctic ecosystems to obtain a picture of the entire system structure and function for a long-term monitoring program of the ‘Atlantification’ of the Svalbard region. We assessed the potential impact of changes in trophic interaction (predator-prey relations) of Atlantic cod (Gadus morhua), Polar cod (Boreogadus saida), haddock (Melanogrammus aeglefinus) and decapod crabs on the productivity and stability of benthic and pelagic communities in Arctic ecosystems, into which their distribution ranges now extend due to ocean warming. In addition to a stock assessment and distribution analysis of gadoid fish and decapod crabs, we aimed to obtain specimens of these species in the Atlantic and polar waters around Svalbard, which were transported alive back to Germany. Laboratory experiments under scenarios of climate change at the Alfred Wegener Institute then provided (and still provide) further insight into capacities for adaptation, performance and interaction of selected species of the Arctic ecosystem around Svalbard. The results will on the one hand be used in an international Norwegian-German project and the pan-Arctic data management system (Piepenburg et al. 2011), on the other hand they will flow into fisheries modelling at the University of Hamburg, the Thuenen Institute and socio-economic modelling approaches that build on the German ocean acidification project BIOACID (www.bioacid.de).

  • Other research product . 2022
    Open Access
    Authors: 
    Kasten, Sabine;
    Publisher: Alfred Wegener Institute for Polar and Marine Research
    Country: Germany
  • Open Access English
    Authors: 
    Kjær, Helle Astrid; Zens, Patrick; Black, Samuel; Lund, Kasper Holst; Svensson, Anders; Vallelonga, Paul;
    Project: EC | ICE2ICE (610055)

    Greenland ice cores provide information about past climate. Few impurity records covering the past 2 decades exist from Greenland. Here we present results from six firn cores obtained during a 426 km long northern Greenland traverse made in 2015 between the NEEM and the EGRIP deep-drilling stations situated on the western side and eastern side of the Greenland ice sheet, respectively. The cores (9 to 14 m long) are analyzed for chemical impurities and cover time spans of 18 to 53 years (±3 years) depending on local snow accumulation that decreases from west to east. The high temporal resolution allows for annual layers and seasons to be resolved. Insoluble dust, ammonium, and calcium concentrations in the six firn cores overlap, and the seasonal cycles are also similar in timing and magnitude across sites, while peroxide (H2O2) and conductivity both have spatial variations, H2O2 driven by the accumulation pattern, and conductivity likely influenced by sea salt. Overall, we determine a rather constant dust flux over the period, but in the data from recent years (1998–2015) we identify an increase in large dust particles that we ascribe to an activation of local Greenland sources. We observe an expected increase in acidity and conductivity in the mid-1970s as a result of anthropogenic emissions, followed by a decrease due to mitigation. Several volcanic horizons identified in the conductivity and acidity records can be associated with eruptions in Iceland and in the Barents Sea region. From a composite ammonium record we obtain a robust forest fire proxy associated primarily with Canadian forest fires (R=0.49).

Advanced search in
Research products
arrow_drop_down
Searching FieldsTerms
Any field
arrow_drop_down
includes
arrow_drop_down
Include:
5,535 Research products, page 1 of 554
  • Open Access
    Authors: 
    Gazert, Volker; Luedecke, Cornelia;
    Publisher: Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung
    Country: Germany
  • Authors: 
    Stefan van Leeuwen; Ron Hoogenboom; Antoine Nijrolder; Wim Traag; Jaap Immerzeel; Hanneke Brust; Caroline Dirks; Wouter A. Gebbink; Liz Leenders;
    Publisher: 4TU.ResearchData

    On behalf of the Ministry of Agriculture, Nature and Food Quality (LNV), Wageningen Food Safety Research analyses samples of agricultural products of animal origin for dioxins, PCBs, brominated flame retardants (BFRs) and poly- and perfluorinated alkyl substances (PFASs). This includes meat, milk, eggs and fish.The samples are taken at the primary production or processing stage (e.g. in slaughterhouses or raw milk collection services). For dioxin-like compounds, 350 samples are first screened with the DR CALUX® method. Samples giving a signal indicating a level above the lowest action level are regarded as suspected. These samples are further examined using GC/HRMS as confirmatory method. Concerning fish, shellfish and crustaceans, approx. 25 samples are collected at sea by research vessels, at the fish auction, or from whole-sale traders (farmed fish).

  • Open Access
    Authors: 
    Wesche, Christine; Regnery, Julia;
    Publisher: Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung
    Country: Germany
  • Open Access English
    Authors: 
    Waelbroeck, Claire; Tjiputra, Jerry; Guo, Chuncheng; Nisancioglu, Kerim H.; Jansen, Eystein; Vazquez Riveiros, Natalia; Toucanne, Samuel; Eynaud, Frédérique; Rossignol, Linda; Dewilde, Fabien; +3 more
    Project: EC | ICE2ICE (610055), EC | ACCLIMATE (339108)

    We combine consistently dated benthic carbon isotopic records distributed over the entire Atlantic Ocean with numerical simulations performed by a glacial configuration of the Norwegian Earth System Model with active ocean biogeochemistry, in order to interpret the observed Cibicides δ13C changes at the stadial-interstadial transition corresponding to the end of Heinrich Stadial 4 (HS4) in terms of ocean circulation and remineralization changes. We show that the marked increase in Cibicides δ13C observed at the end of HS4 between ~2000 and 4200 m in the Atlantic can be explained by changes in nutrient concentrations as simulated by the model in response to the halting of freshwater input in the high latitude glacial North Atlantic. Our model results show that this Cibicides δ13C signal is associated with changes in the ratio of southern-sourced (SSW) versus northern-sourced (NSW) water masses at the core sites, whereby SSW is replaced by NSW as a consequence of the resumption of deep water formation in the northern North Atlantic and Nordic Seas after the freshwater input is halted. Our results further suggest that the contribution of ocean circulation changes to this signal increases from ~40 % at 2000 m to ~80 % at 4000 m. Below ~4200 m, the model shows little ocean circulation change but an increase in remineralization across the transition marking the end of HS4. The simulated lower remineralization during stadials than interstadials is particularly pronounced in deep subantarctic sites, in agreement with the decrease in the export production of carbon to the deep Southern Ocean during stadials found in previous studies.

  • Open Access
    Authors: 
    Lenz, Josefine; Fuchs, Matthias; Nitze, Ingmar; Strauß, Jens; Grosse, Guido;
    Publisher: Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung
    Country: Germany
  • Open Access English
    Authors: 
    Dagmara Rusiecka;
    Publisher: Zenodo

    Triple threat processes and/or other forcings can lead to changes in the ocean happening fast and abruptly. These changes, referred to as “tipping points”, are critical thresholds in a marine system that, when exceeded, can lead to a significant change in the state of the system, which often can be irreversible. This leaflet has been prepared mainly (but not only) for high school pupils with the financial support of Norges forskningsråd (Research Council of Norway) (309382).

  • Open Access English
    Authors: 
    Romero-Alvarez, Johana; Lupaşcu, Aurelia; Lowe, Douglas; Badia, Alba; Acher-Nicholls, Scott; Dorling, Steve R.; Reeves, Claire E.; Butler, Tim;
    Project: EC | ASIBIA (616938)

    Tropospheric ozone (O3) concentrations depend on a combination of hemispheric, regional, and local-scale processes. Estimates of how much O3 is produced locally vs. transported from further afield are essential in air quality management and regulatory policies. Here, a tagged-ozone mechanism within the Weather Research and Forecasting model coupled with chemistry (WRF-Chem) is used to quantify the contributions to surface O3 in the UK from anthropogenic nitrogen oxide (NOx) emissions from inside and outside the UK during May–August 2015. The contribution of the different source regions to three regulatory O3 metrics is also examined. It is shown that model simulations predict the concentration and spatial distribution of surface O3 with a domain-wide mean bias of −3.7 ppbv. Anthropogenic NOx emissions from the UK and Europe account for 13 % and 16 %, respectively, of the monthly mean surface O3 in the UK, as the majority (71 %) of O3 originates from the hemispheric background. Hemispheric O3 contributes the most to concentrations in the north and the west of the UK with peaks in May, whereas European and UK contributions are most significant in the east, south-east, and London, i.e. the UK's most populated areas, intensifying towards June and July. Moreover, O3 from European sources is generally transported to the UK rather than produced in situ. It is demonstrated that more stringent emission controls over continental Europe, particularly in western Europe, would be necessary to improve the health-related metric MDA8 O3 above 50 and 60 ppbv. Emission controls over larger areas, such as the Northern Hemisphere, are instead required to lessen the impacts on ecosystems as quantified by the AOT40 metric.

  • Other research product . Other ORP type . 2022
    Open Access
    Authors: 
    Mark, Felix; Cremer, Charlotte; Havermans, Charlotte; Murray, Ayla Rosina Cherrington; Verhaegen, Gerlien; Wollenburg, Jutta; Wukovits, Julia;
    Country: Germany

    The primary aim of this expedition was to investigate the spatial and temporal distribution, the ecology and physiology, as well as competition of co-occurring gadoid species (Atlantic cod, Polar cod, haddock) in the communities of Arctic and Atlantic influence around Svalbard. We sampled the benthic and pelagic communities (including plankton) on the shallow shelf regions of Svalbard to estimate the effects of climate change on Arctic ecosystems to obtain a picture of the entire system structure and function for a long-term monitoring program of the ‘Atlantification’ of the Svalbard region. We assessed the potential impact of changes in trophic interaction (predator-prey relations) of Atlantic cod (Gadus morhua), Polar cod (Boreogadus saida), haddock (Melanogrammus aeglefinus) and decapod crabs on the productivity and stability of benthic and pelagic communities in Arctic ecosystems, into which their distribution ranges now extend due to ocean warming. In addition to a stock assessment and distribution analysis of gadoid fish and decapod crabs, we aimed to obtain specimens of these species in the Atlantic and polar waters around Svalbard, which were transported alive back to Germany. Laboratory experiments under scenarios of climate change at the Alfred Wegener Institute then provided (and still provide) further insight into capacities for adaptation, performance and interaction of selected species of the Arctic ecosystem around Svalbard. The results will on the one hand be used in an international Norwegian-German project and the pan-Arctic data management system (Piepenburg et al. 2011), on the other hand they will flow into fisheries modelling at the University of Hamburg, the Thuenen Institute and socio-economic modelling approaches that build on the German ocean acidification project BIOACID (www.bioacid.de).

  • Other research product . 2022
    Open Access
    Authors: 
    Kasten, Sabine;
    Publisher: Alfred Wegener Institute for Polar and Marine Research
    Country: Germany
  • Open Access English
    Authors: 
    Kjær, Helle Astrid; Zens, Patrick; Black, Samuel; Lund, Kasper Holst; Svensson, Anders; Vallelonga, Paul;
    Project: EC | ICE2ICE (610055)

    Greenland ice cores provide information about past climate. Few impurity records covering the past 2 decades exist from Greenland. Here we present results from six firn cores obtained during a 426 km long northern Greenland traverse made in 2015 between the NEEM and the EGRIP deep-drilling stations situated on the western side and eastern side of the Greenland ice sheet, respectively. The cores (9 to 14 m long) are analyzed for chemical impurities and cover time spans of 18 to 53 years (±3 years) depending on local snow accumulation that decreases from west to east. The high temporal resolution allows for annual layers and seasons to be resolved. Insoluble dust, ammonium, and calcium concentrations in the six firn cores overlap, and the seasonal cycles are also similar in timing and magnitude across sites, while peroxide (H2O2) and conductivity both have spatial variations, H2O2 driven by the accumulation pattern, and conductivity likely influenced by sea salt. Overall, we determine a rather constant dust flux over the period, but in the data from recent years (1998–2015) we identify an increase in large dust particles that we ascribe to an activation of local Greenland sources. We observe an expected increase in acidity and conductivity in the mid-1970s as a result of anthropogenic emissions, followed by a decrease due to mitigation. Several volcanic horizons identified in the conductivity and acidity records can be associated with eruptions in Iceland and in the Barents Sea region. From a composite ammonium record we obtain a robust forest fire proxy associated primarily with Canadian forest fires (R=0.49).

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