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2,041 Research products, page 1 of 205

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  • Open Access
    Authors: 
    Frosini, Luca; Pieve, Alessandro;
    Publisher: Zenodo
    Project: EC | AGINFRA PLUS (731001), EC | D4SCIENCE-II (239019), EC | EUBRAZILOPENBIO (288754), EC | IMARINE (283644), EC | D4SCIENCE (212488), EC | ENVRI (283465), EC | EGI-Engage (654142), EC | SoBigData (654024), EC | ENVRI PLUS (654182), EC | PARTHENOS (654119),...

    The gCube System - Accounting Aggregator -------------------------------------------------- Accounting Aggregator Smart Executor Plugin This software is part of the gCube Framework (https://www.gcube-system.org/): an open-source software toolkit used for building and operating Hybrid Data Infrastructures enabling the dynamic deployment of Virtual Research Environments by favouring the realisation of reuse oriented policies. The projects leading to this software have received funding from a series of European Union programmes including: * the Sixth Framework Programme for Research and Technological Development - DILIGENT (grant no. 004260); * the Seventh Framework Programme for research, technological development and demonstration - D4Science (grant no. 212488), D4Science-II (grant no. 239019),ENVRI (grant no. 283465), EUBrazilOpenBio (grant no. 288754), iMarine (grant no. 283644); * the H2020 research and innovation programme - BlueBRIDGE (grant no. 675680), EGIEngage (grant no. 654142), ENVRIplus (grant no. 654182), Parthenos (grant no. 654119), SoBigData (grant no. 654024); Version -------------------------------------------------- 1.2.0-4.8.0-154717 (2017-12-01) Please see the file named "changelog.xml" in this directory for the release notes. Authors -------------------------------------------------- * Alessandro Pieve (alessandro.pieve-AT-isti.cnr.it), Istituto di Scienza e Tecnologie dell'Informazione "A. Faedo" - CNR, Pisa (Italy). * Luca Frosini (luca.frosini-AT-isti.cnr.it), Istituto di Scienza e Tecnologie dell'Informazione "A. Faedo" - CNR, Pisa (Italy). Maintainers ----------- * Luca Frosini (luca.frosini-AT-isti.cnr.it), Istituto di Scienza e Tecnologie dell'Informazione "A. Faedo" - CNR, Pisa (Italy). Download information -------------------------------------------------- Source code is available from SVN: https://svn.research-infrastructures.eu/public/d4science/gcube/trunk/accounting/accounting-aggregator-se-plugin Binaries can be downloaded from the gCube website: https://www.gcube-system.org/ Installation -------------------------------------------------- Installation documentation is available on-line in the gCube Wiki: https://wiki.gcube-system.org/gcube/index.php/SmartExecutor Documentation -------------------------------------------------- Documentation is available on-line in the gCube Wiki: https://wiki.gcube-system.org/gcube/index.php/SmartExecutor Support -------------------------------------------------- Bugs and support requests can be reported in the gCube issue tracking tool: https://support.d4science.org/projects/gcube/ Licensing -------------------------------------------------- This software is licensed under the terms you may find in the file named "LICENSE" in this directory.

  • Open Access
    Authors: 
    Alexandros Antoniadis; Gerasimos Farantatos;
    Publisher: Zenodo
    Project: EC | D4SCIENCE-II (239019), EC | ENVRI (283465), EC | EUBRAZILOPENBIO (288754), EC | IMARINE (283644), EC | D4SCIENCE (212488), EC | BlueBRIDGE (675680), EC | PARTHENOS (654119), EC | EGI-Engage (654142), EC | SoBigData (654024), EC | ENVRI PLUS (654182)

    The gCube System - resourceregistry-configuration-index -------------------------------------------------- ResourceRegistry Configuration Index This software is part of the gCube Framework (https://www.gcube-system.org/): an open-source software toolkit used for building and operating Hybrid Data Infrastructures enabling the dynamic deployment of Virtual Research Environments by favouring the realisation of reuse oriented policies. The projects leading to this software have received funding from a series of European Union programmes including: * the Sixth Framework Programme for Research and Technological Development - DILIGENT (grant no. 004260); * the Seventh Framework Programme for research, technological development and demonstration - D4Science (grant no. 212488), D4Science-II (grant no. 239019),ENVRI (grant no. 283465), EUBrazilOpenBio (grant no. 288754), iMarine (grant no. 283644); * the H2020 research and innovation programme - BlueBRIDGE (grant no. 675680), EGIEngage (grant no. 654142), ENVRIplus (grant no. 654182), Parthenos (grant no. 654119), SoBigData (grant no. 654024); Version -------------------------------------------------- 1.0.3-4.2.0-126435 (2016-12-16) Please see the file named "changelog.xml" in this directory for the release notes. Authors -------------------------------------------------- * Gerasimos Farantatos (g.farantatos-AT-di.uoa.gr), University of Athens, Department of Informatics and Telecommunications. * Alexandros Antoniadis (a.antoniadis-AT-di.uoa.gr), University of Athens, Department of Informatics and Telecommunications. Maintainers ----------- Download information -------------------------------------------------- Source code is available from SVN: http://svn.research-infrastructures.eu/public/d4science/gcube/branches/resource-registry/ResourceRegistry-configuration-index/1.0/ResourceRegistry-configuration-index Binaries can be downloaded from the gCube website: https://www.gcube-system.org/ Installation -------------------------------------------------- Installation documentation is available on-line in the gCube Wiki: https://wiki.gcube-system.org/gcube/index.php Documentation -------------------------------------------------- Documentation is available on-line in the gCube Wiki: https://wiki.gcube-system.org/gcube/index.php Support -------------------------------------------------- Bugs and support requests can be reported in the gCube issue tracking tool: https://support.d4science.org/projects/gcube/ Licensing -------------------------------------------------- This software is licensed under the terms you may find in the file named "LICENSE" in this directory.

  • Open Access English
    Authors: 
    Holcomb, Michael; McCorkle, Daniel C; Cohen, Anne L;
    Publisher: PANGAEA
    Project: EC | EPOCA (211384)

    Zooxanthellate colonies of the scleractinian coral Astrangia poculata were grown under combinations of ambient and elevated nutrients (5 µM NO, 0.3 µM PO4, and 2nM Fe) and CO2 (780 ppmv) treatments for a period of 6 months. Coral calcification rates, estimated from buoyant weights, were not significantly affected by moderately elevated nutrients at ambient CO2 and were negatively affected by elevated CO2 at ambient nutrient levels. However, calcification by corals reared under elevated nutrients combined with elevated CO2 was not significantly different from that of corals reared under ambient conditions, suggesting that CO2 enrichment can lead to nutrient limitation in zooxanthellate corals. A conceptual model is proposed to explain how nutrients and CO2 interact to control zooxanthellate coral calcification. Nutrient limited corals are unable to utilize an increase in dissolved inorganic carbon (DIC) as nutrients are already limiting growth, thus the effect of elevated CO2 on saturation state drives the calcification response. Under nutrient replete conditions, corals may have the ability to utilize more DIC, thus the calcification response to CO2 becomes the product of a negative effect on saturation state and a positive effect on gross carbon fixation, depending upon which dominates, the calcification response can be either positive or negative. This may help explain how the range of coral responses found in different studies of ocean acidification can be obtained.

  • Open Access English
    Authors: 
    Rampen, Sebastiaan W; Willmott, Verónica; Kim, Jung-Hyun; Rodrigo-Gámiz, Marta; Uliana, Eleonora; Mollenhauer, Gesine; Schefuß, Enno; Sinninghe Damsté, Jaap S; Schouten, Stefan;
    Publisher: PANGAEA
    Project: EC | PACEMAKER (226600)

    Long chain alkyl diols form a group of lipids occurring widely in marine environments. Recent studies have suggested several palaeoclimatological applications for proxies based on their distributions, but also revealed uncertainties about their applicability. Here we evaluate the use of long chain 1,14-alkyl diol indices for reconstruction of temperature and upwelling conditions by comparing index values, obtained from a comprehensive set of marine surface sediments, with environmental factors like sea surface temperature (SST), salinity and nutrient concentrations. Previous cultivation efforts indicated a strong effect of temperature on the degree of saturation and the chain length distribution of long chain 1,14-alkyl diols in Proboscia spp., quantified in the diol saturation index (DSI) and diol chain length index (DCI), respectively. However, values of these indices in surface sediments show no relationship with annual mean SST of the overlying water. It remains unknown what determines the DSI, although our data suggests that it may be affected by diagenesis, while the relationship between temperature and DCI may be different for different Proboscia species. In addition, contributions of algae other than Proboscia diatoms may affect both indices, although our data provide no direct evidence for additional long chain 1,14-alkyl diol sources. Two other indices using the abundance of 1,14-diols vs. 1,13-diols and C30 1,15-diols have previously been applied as indicators for upwelling intensity at different locations. The geographical distribution of their values supports the use of 1,14 diols vs. 1,13 diols [C28 + C30 1,14-diols]/[(C28 + C30 1,13-diols) + (C28 + C30 1,14-diols)] as a general indicator for high nutrient or upwelling conditions.

  • Authors: 
    Beaufort Luc; Probert Ian; de Garidel-Thoron Thibault; Bendif E M; Ruiz-Pino Diana; Metzi N; Goyet Catherine; Buchet Noëlle; Coupel P; Grelaud Michaël; +3 more
    Project: EC | EPOCA (211384)
  • Open Access English
    Authors: 
    Badger, Marcus P S; Chalk, Thomas B; Foster, Gavin L; Bown, Paul R; Gibbs, Samantha J; Sexton, Philip F; Schmidt, Daniela N; Pälike, Heiko; Mackensen, Andreas; Pancost, Richard D;
    Publisher: PANGAEA
    Project: UKRI | Timing, Causes and Conseq... (NE/H006273/1), EC | TGRES (340923)

    Atmospheric _p_CO~2~ is a critical component of the global carbon system and is considered to be the major control of Earth's past, present and future climate. Accurate and precise reconstructions of its concentration through geological time are, therefore, crucial to our understanding of the Earth system. Ice core records document _p_CO~2~ for the past 800 kyrs, but at no point during this interval were CO~2~ levels higher than today. Interpretation of older _p_CO~2~ has been hampered by discrepancies during some time intervals between two of the main ocean-based proxy methods used to reconstruct _p_CO~2~: the carbon isotope fractionation that occurs during photosynthesis as recorded by haptophyte biomarkers (alkenones) and the boron isotope composition (δ^11^B) of foraminifer shells. Here we present alkenone and δ^11^B-based _p_CO~2~ reconstructions generated from the same samples from the Plio-Pleistocene at ODP Site 999 across a glacial-interglacial cycle. We find a muted response to _p_CO~2~ in the alkenone record compared to contemporaneous ice core and δ^11^B records, suggesting caution in the interpretation of alkenone-based records at low _p_CO~2~ levels. This is possibly caused by the physiology of CO~2~ uptake in the haptophytes. Our new understanding resolves some of the inconsistencies between the proxies and highlights that caution may be required when interpreting alkenone-based reconstructions of _p_CO~2~.

  • Authors: 
    Russell Bayden D; Thompson Jo-Anne I; Falkenberg Laura J; Connell Sean D;
    Project: EC | EPOCA (211384)
  • Open Access English
    Authors: 
    De Deckker, Patrick; Moros, Matthias; Blanz, Thomas; Schneider, Ralph R; Barrows, Timothy T; Perner, Kerstin;
    Publisher: PANGAEA
    Project: EC | ICE2ICE (610055)

    The data relate to a paper submitted to Quaternary Science Reviews. All the data support a study of the last 94 ka recorded in core MD03-2611 and an adjacent multicore MD03-MUC 3 taken on the fringe of one of the Murray Canyons offshore Kangaroo Island. Additional data pertain to core SS0206-GC15 taken offshore Victoria south of Warrnambool, but its record only spans the last 25ka. The records are at high resolution and cover a multitude of parameters. Radiocarbon dates for these cores are presented in the supplementary section of this paper.

  • Open Access
    Authors: 
    Schneider, Robert; Schmitt, Jochen; Koehler, Peter; Joos, Fortunat; Fischer, Hubertus;
    Project: EC | PAST4FUTURE (243908), SNSF | Climate and Environmental... (147174)

    The reconstruction of the stable carbon isotope evolution in atmospheric CO2 (d13Catm ), as archived in Antarctic ice cores, bears the potential to disentangle the contributions of the different carbon cycle fluxes causing past CO2 variations. Here we present a new record of d13Catm before, during and after the Marine Isotope Stage 5.5 (155 000 to 105 000 years BP). The record was derived with a well established sublimation method using ice from the EPICA Dome C (EDC) and the Talos Dome ice cores in East Antarctica. We find a 0.4 permil shift to heavier values between the mean d13Catm level in the Penultimate (~ 140 000 years BP) and Last Glacial Maximum (~ 22 000 years BP), which can be explained by either (i) changes in the isotopic composition or (ii) intensity of the carbon input fluxes to the combined ocean/atmosphere carbon reservoir or (iii) by long-term peat buildup. Our isotopic data suggest that the carbon cycle evolution along Termination II and the subsequent interglacial was controlled by essentially the same processes as during the last 24 000 years, but with different phasing and magnitudes. Furthermore, a 5000 years lag in the CO2 decline relative to EDC temperatures is confirmed during the glacial inception at the end of MIS 5.5 (120 000 years BP). Based on our isotopic data this lag can be explained by terrestrial carbon release and carbonate compensation.

  • Open Access English
    Authors: 
    Morris, K. J.; Herrera, S.; Gubili, C.; Tyler, P. A.; Rogers, A.; Hauton, C.;
    Project: EC | HERMIONE (226354)

    Despite being an abundant group of significant ecological importance the phylogenetic relationships of the Octocorallia remain poorly understood and very much understudied. We used 1132 bp of two mitochondrial protein-coding genes, nad2 and mtMutS (previously referred to as msh1), to construct a phylogeny for 161 octocoral specimens from the Atlantic, including both Isididae and non-Isididae species. We found that four clades were supported using a concatenated alignment. Two of these (A and B) were in general agreement with the of Holaxonia–Alcyoniina and Anthomastus–Corallium clades identified by previous work. The third and fourth clades represent a split of the Calcaxonia–Pennatulacea clade resulting in a clade containing the Pennatulacea and a small number of Isididae specimens and a second clade containing the remaining Calcaxonia. When individual genes were considered nad2 largely agreed with previous work with MtMutS also producing a fourth clade corresponding to a split of Isididae species from the Calcaxonia–Pennatulacea clade. It is expected these difference are a consequence of the inclusion of Isisdae species that have undergone a gene inversion in the mtMutS gene causing their separation in the MtMutS only tree. The fourth clade in the concatenated tree is also suspected to be a result of this gene inversion, as there were very few Isidiae species included in previous work tree and thus this separation would not be clearly resolved. A~larger phylogeny including both Isididae and non Isididae species is required to further resolve these clades.

Advanced search in Research products
Research products
arrow_drop_down
Searching FieldsTerms
Any field
arrow_drop_down
includes
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Include:
The following results are related to European Marine Science. Are you interested to view more results? Visit OpenAIRE - Explore.
2,041 Research products, page 1 of 205
  • Open Access
    Authors: 
    Frosini, Luca; Pieve, Alessandro;
    Publisher: Zenodo
    Project: EC | AGINFRA PLUS (731001), EC | D4SCIENCE-II (239019), EC | EUBRAZILOPENBIO (288754), EC | IMARINE (283644), EC | D4SCIENCE (212488), EC | ENVRI (283465), EC | EGI-Engage (654142), EC | SoBigData (654024), EC | ENVRI PLUS (654182), EC | PARTHENOS (654119),...

    The gCube System - Accounting Aggregator -------------------------------------------------- Accounting Aggregator Smart Executor Plugin This software is part of the gCube Framework (https://www.gcube-system.org/): an open-source software toolkit used for building and operating Hybrid Data Infrastructures enabling the dynamic deployment of Virtual Research Environments by favouring the realisation of reuse oriented policies. The projects leading to this software have received funding from a series of European Union programmes including: * the Sixth Framework Programme for Research and Technological Development - DILIGENT (grant no. 004260); * the Seventh Framework Programme for research, technological development and demonstration - D4Science (grant no. 212488), D4Science-II (grant no. 239019),ENVRI (grant no. 283465), EUBrazilOpenBio (grant no. 288754), iMarine (grant no. 283644); * the H2020 research and innovation programme - BlueBRIDGE (grant no. 675680), EGIEngage (grant no. 654142), ENVRIplus (grant no. 654182), Parthenos (grant no. 654119), SoBigData (grant no. 654024); Version -------------------------------------------------- 1.2.0-4.8.0-154717 (2017-12-01) Please see the file named "changelog.xml" in this directory for the release notes. Authors -------------------------------------------------- * Alessandro Pieve (alessandro.pieve-AT-isti.cnr.it), Istituto di Scienza e Tecnologie dell'Informazione "A. Faedo" - CNR, Pisa (Italy). * Luca Frosini (luca.frosini-AT-isti.cnr.it), Istituto di Scienza e Tecnologie dell'Informazione "A. Faedo" - CNR, Pisa (Italy). Maintainers ----------- * Luca Frosini (luca.frosini-AT-isti.cnr.it), Istituto di Scienza e Tecnologie dell'Informazione "A. Faedo" - CNR, Pisa (Italy). Download information -------------------------------------------------- Source code is available from SVN: https://svn.research-infrastructures.eu/public/d4science/gcube/trunk/accounting/accounting-aggregator-se-plugin Binaries can be downloaded from the gCube website: https://www.gcube-system.org/ Installation -------------------------------------------------- Installation documentation is available on-line in the gCube Wiki: https://wiki.gcube-system.org/gcube/index.php/SmartExecutor Documentation -------------------------------------------------- Documentation is available on-line in the gCube Wiki: https://wiki.gcube-system.org/gcube/index.php/SmartExecutor Support -------------------------------------------------- Bugs and support requests can be reported in the gCube issue tracking tool: https://support.d4science.org/projects/gcube/ Licensing -------------------------------------------------- This software is licensed under the terms you may find in the file named "LICENSE" in this directory.

  • Open Access
    Authors: 
    Alexandros Antoniadis; Gerasimos Farantatos;
    Publisher: Zenodo
    Project: EC | D4SCIENCE-II (239019), EC | ENVRI (283465), EC | EUBRAZILOPENBIO (288754), EC | IMARINE (283644), EC | D4SCIENCE (212488), EC | BlueBRIDGE (675680), EC | PARTHENOS (654119), EC | EGI-Engage (654142), EC | SoBigData (654024), EC | ENVRI PLUS (654182)

    The gCube System - resourceregistry-configuration-index -------------------------------------------------- ResourceRegistry Configuration Index This software is part of the gCube Framework (https://www.gcube-system.org/): an open-source software toolkit used for building and operating Hybrid Data Infrastructures enabling the dynamic deployment of Virtual Research Environments by favouring the realisation of reuse oriented policies. The projects leading to this software have received funding from a series of European Union programmes including: * the Sixth Framework Programme for Research and Technological Development - DILIGENT (grant no. 004260); * the Seventh Framework Programme for research, technological development and demonstration - D4Science (grant no. 212488), D4Science-II (grant no. 239019),ENVRI (grant no. 283465), EUBrazilOpenBio (grant no. 288754), iMarine (grant no. 283644); * the H2020 research and innovation programme - BlueBRIDGE (grant no. 675680), EGIEngage (grant no. 654142), ENVRIplus (grant no. 654182), Parthenos (grant no. 654119), SoBigData (grant no. 654024); Version -------------------------------------------------- 1.0.3-4.2.0-126435 (2016-12-16) Please see the file named "changelog.xml" in this directory for the release notes. Authors -------------------------------------------------- * Gerasimos Farantatos (g.farantatos-AT-di.uoa.gr), University of Athens, Department of Informatics and Telecommunications. * Alexandros Antoniadis (a.antoniadis-AT-di.uoa.gr), University of Athens, Department of Informatics and Telecommunications. Maintainers ----------- Download information -------------------------------------------------- Source code is available from SVN: http://svn.research-infrastructures.eu/public/d4science/gcube/branches/resource-registry/ResourceRegistry-configuration-index/1.0/ResourceRegistry-configuration-index Binaries can be downloaded from the gCube website: https://www.gcube-system.org/ Installation -------------------------------------------------- Installation documentation is available on-line in the gCube Wiki: https://wiki.gcube-system.org/gcube/index.php Documentation -------------------------------------------------- Documentation is available on-line in the gCube Wiki: https://wiki.gcube-system.org/gcube/index.php Support -------------------------------------------------- Bugs and support requests can be reported in the gCube issue tracking tool: https://support.d4science.org/projects/gcube/ Licensing -------------------------------------------------- This software is licensed under the terms you may find in the file named "LICENSE" in this directory.

  • Open Access English
    Authors: 
    Holcomb, Michael; McCorkle, Daniel C; Cohen, Anne L;
    Publisher: PANGAEA
    Project: EC | EPOCA (211384)

    Zooxanthellate colonies of the scleractinian coral Astrangia poculata were grown under combinations of ambient and elevated nutrients (5 µM NO, 0.3 µM PO4, and 2nM Fe) and CO2 (780 ppmv) treatments for a period of 6 months. Coral calcification rates, estimated from buoyant weights, were not significantly affected by moderately elevated nutrients at ambient CO2 and were negatively affected by elevated CO2 at ambient nutrient levels. However, calcification by corals reared under elevated nutrients combined with elevated CO2 was not significantly different from that of corals reared under ambient conditions, suggesting that CO2 enrichment can lead to nutrient limitation in zooxanthellate corals. A conceptual model is proposed to explain how nutrients and CO2 interact to control zooxanthellate coral calcification. Nutrient limited corals are unable to utilize an increase in dissolved inorganic carbon (DIC) as nutrients are already limiting growth, thus the effect of elevated CO2 on saturation state drives the calcification response. Under nutrient replete conditions, corals may have the ability to utilize more DIC, thus the calcification response to CO2 becomes the product of a negative effect on saturation state and a positive effect on gross carbon fixation, depending upon which dominates, the calcification response can be either positive or negative. This may help explain how the range of coral responses found in different studies of ocean acidification can be obtained.

  • Open Access English
    Authors: 
    Rampen, Sebastiaan W; Willmott, Verónica; Kim, Jung-Hyun; Rodrigo-Gámiz, Marta; Uliana, Eleonora; Mollenhauer, Gesine; Schefuß, Enno; Sinninghe Damsté, Jaap S; Schouten, Stefan;
    Publisher: PANGAEA
    Project: EC | PACEMAKER (226600)

    Long chain alkyl diols form a group of lipids occurring widely in marine environments. Recent studies have suggested several palaeoclimatological applications for proxies based on their distributions, but also revealed uncertainties about their applicability. Here we evaluate the use of long chain 1,14-alkyl diol indices for reconstruction of temperature and upwelling conditions by comparing index values, obtained from a comprehensive set of marine surface sediments, with environmental factors like sea surface temperature (SST), salinity and nutrient concentrations. Previous cultivation efforts indicated a strong effect of temperature on the degree of saturation and the chain length distribution of long chain 1,14-alkyl diols in Proboscia spp., quantified in the diol saturation index (DSI) and diol chain length index (DCI), respectively. However, values of these indices in surface sediments show no relationship with annual mean SST of the overlying water. It remains unknown what determines the DSI, although our data suggests that it may be affected by diagenesis, while the relationship between temperature and DCI may be different for different Proboscia species. In addition, contributions of algae other than Proboscia diatoms may affect both indices, although our data provide no direct evidence for additional long chain 1,14-alkyl diol sources. Two other indices using the abundance of 1,14-diols vs. 1,13-diols and C30 1,15-diols have previously been applied as indicators for upwelling intensity at different locations. The geographical distribution of their values supports the use of 1,14 diols vs. 1,13 diols [C28 + C30 1,14-diols]/[(C28 + C30 1,13-diols) + (C28 + C30 1,14-diols)] as a general indicator for high nutrient or upwelling conditions.

  • Authors: 
    Beaufort Luc; Probert Ian; de Garidel-Thoron Thibault; Bendif E M; Ruiz-Pino Diana; Metzi N; Goyet Catherine; Buchet Noëlle; Coupel P; Grelaud Michaël; +3 more
    Project: EC | EPOCA (211384)
  • Open Access English
    Authors: 
    Badger, Marcus P S; Chalk, Thomas B; Foster, Gavin L; Bown, Paul R; Gibbs, Samantha J; Sexton, Philip F; Schmidt, Daniela N; Pälike, Heiko; Mackensen, Andreas; Pancost, Richard D;
    Publisher: PANGAEA
    Project: UKRI | Timing, Causes and Conseq... (NE/H006273/1), EC | TGRES (340923)

    Atmospheric _p_CO~2~ is a critical component of the global carbon system and is considered to be the major control of Earth's past, present and future climate. Accurate and precise reconstructions of its concentration through geological time are, therefore, crucial to our understanding of the Earth system. Ice core records document _p_CO~2~ for the past 800 kyrs, but at no point during this interval were CO~2~ levels higher than today. Interpretation of older _p_CO~2~ has been hampered by discrepancies during some time intervals between two of the main ocean-based proxy methods used to reconstruct _p_CO~2~: the carbon isotope fractionation that occurs during photosynthesis as recorded by haptophyte biomarkers (alkenones) and the boron isotope composition (δ^11^B) of foraminifer shells. Here we present alkenone and δ^11^B-based _p_CO~2~ reconstructions generated from the same samples from the Plio-Pleistocene at ODP Site 999 across a glacial-interglacial cycle. We find a muted response to _p_CO~2~ in the alkenone record compared to contemporaneous ice core and δ^11^B records, suggesting caution in the interpretation of alkenone-based records at low _p_CO~2~ levels. This is possibly caused by the physiology of CO~2~ uptake in the haptophytes. Our new understanding resolves some of the inconsistencies between the proxies and highlights that caution may be required when interpreting alkenone-based reconstructions of _p_CO~2~.

  • Authors: 
    Russell Bayden D; Thompson Jo-Anne I; Falkenberg Laura J; Connell Sean D;
    Project: EC | EPOCA (211384)
  • Open Access English
    Authors: 
    De Deckker, Patrick; Moros, Matthias; Blanz, Thomas; Schneider, Ralph R; Barrows, Timothy T; Perner, Kerstin;
    Publisher: PANGAEA
    Project: EC | ICE2ICE (610055)

    The data relate to a paper submitted to Quaternary Science Reviews. All the data support a study of the last 94 ka recorded in core MD03-2611 and an adjacent multicore MD03-MUC 3 taken on the fringe of one of the Murray Canyons offshore Kangaroo Island. Additional data pertain to core SS0206-GC15 taken offshore Victoria south of Warrnambool, but its record only spans the last 25ka. The records are at high resolution and cover a multitude of parameters. Radiocarbon dates for these cores are presented in the supplementary section of this paper.

  • Open Access
    Authors: 
    Schneider, Robert; Schmitt, Jochen; Koehler, Peter; Joos, Fortunat; Fischer, Hubertus;
    Project: EC | PAST4FUTURE (243908), SNSF | Climate and Environmental... (147174)

    The reconstruction of the stable carbon isotope evolution in atmospheric CO2 (d13Catm ), as archived in Antarctic ice cores, bears the potential to disentangle the contributions of the different carbon cycle fluxes causing past CO2 variations. Here we present a new record of d13Catm before, during and after the Marine Isotope Stage 5.5 (155 000 to 105 000 years BP). The record was derived with a well established sublimation method using ice from the EPICA Dome C (EDC) and the Talos Dome ice cores in East Antarctica. We find a 0.4 permil shift to heavier values between the mean d13Catm level in the Penultimate (~ 140 000 years BP) and Last Glacial Maximum (~ 22 000 years BP), which can be explained by either (i) changes in the isotopic composition or (ii) intensity of the carbon input fluxes to the combined ocean/atmosphere carbon reservoir or (iii) by long-term peat buildup. Our isotopic data suggest that the carbon cycle evolution along Termination II and the subsequent interglacial was controlled by essentially the same processes as during the last 24 000 years, but with different phasing and magnitudes. Furthermore, a 5000 years lag in the CO2 decline relative to EDC temperatures is confirmed during the glacial inception at the end of MIS 5.5 (120 000 years BP). Based on our isotopic data this lag can be explained by terrestrial carbon release and carbonate compensation.

  • Open Access English
    Authors: 
    Morris, K. J.; Herrera, S.; Gubili, C.; Tyler, P. A.; Rogers, A.; Hauton, C.;
    Project: EC | HERMIONE (226354)

    Despite being an abundant group of significant ecological importance the phylogenetic relationships of the Octocorallia remain poorly understood and very much understudied. We used 1132 bp of two mitochondrial protein-coding genes, nad2 and mtMutS (previously referred to as msh1), to construct a phylogeny for 161 octocoral specimens from the Atlantic, including both Isididae and non-Isididae species. We found that four clades were supported using a concatenated alignment. Two of these (A and B) were in general agreement with the of Holaxonia–Alcyoniina and Anthomastus–Corallium clades identified by previous work. The third and fourth clades represent a split of the Calcaxonia–Pennatulacea clade resulting in a clade containing the Pennatulacea and a small number of Isididae specimens and a second clade containing the remaining Calcaxonia. When individual genes were considered nad2 largely agreed with previous work with MtMutS also producing a fourth clade corresponding to a split of Isididae species from the Calcaxonia–Pennatulacea clade. It is expected these difference are a consequence of the inclusion of Isisdae species that have undergone a gene inversion in the mtMutS gene causing their separation in the MtMutS only tree. The fourth clade in the concatenated tree is also suspected to be a result of this gene inversion, as there were very few Isidiae species included in previous work tree and thus this separation would not be clearly resolved. A~larger phylogeny including both Isididae and non Isididae species is required to further resolve these clades.