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PANGAEA - Publishing Network for Geoscientific & Environmental Data (847.310 recursos)

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PANGAEA tech-keyword 'supplement' (10352 data sets)

Mostrando recursos 1 - 20 de 21.907

  1. Ras Umm Sidd bimonthly d18O and Sr/Ca data and annual d18O, Sr/Ca, reconstructed Sr/Ca temperature and reconstructed d18O seawater data of coral core/colony RUS-95

    Felis, Thomas; Ionita, Monica; Rimbu, Norel; Lohmann, Gerrit; Kölling, Martin
    in preparation

  2. Increased fitness of a key appendicularian zooplankton species under warmer, acidified seawater conditions

    Bouquet, Jean-Marie; Troedsson, Christofer; Novac, Aliona; Reeve, Magnus; Lechtenborger, Anna K.; Massart, Wendy; Skaar, Katrine S; Aasjord, Anne; Dupont, Sam; Thompson, Eric M
    Ocean warming and acidification (OA) may alter the fitness of species in marine pelagic ecosystems through community effects or direct physiological impacts. We used the zooplanktonic appendicularian, Oikopleura dioica, to assess temperature and pH effects at mesocosm and microcosm scales. In mesocosms, both OA and warming positively impacted O. dioica abundance over successive generations. In microcosms, the positive impact of OA, was observed to result from increased fecundity. In contrast, increased pH, observed for example during phytoplankton blooms, reduced fecundity. Oocyte fertility and juvenile development were equivalent under all pH conditions, indicating that the positive effect of lower pH on...

  3. Absolute sedimentary concentrations of highly branched isoprenoids, PIP25 indices with derived spring sea ice concentrations, and classification tree predictions of sea ice conditions in three Barents Sea sediment cores

    Köseoğlu, Denizcan; Belt, Simon T; Husum, Katrine; Knies, Jochen
    The development of various combinative methods for Arctic sea ice reconstruction using the sympagic highly-branched isoprenoid IP25 in conjunction with pelagic biomarkers has often facilitated more detailed descriptions of sea ice conditions than using IP25 alone. Here, we investigated the complementary application of the Phytoplankton-IP25 index (PIP25) and a recently proposed Classification Tree (CT) model for describing shifts in sea ice conditions to assess the consistency of both methods. Based on biomarker data from three downcore records from the Barents Sea spanning millennial timescales, we showcase apparent and potential limitations of both approaches, and provide recommendations for their identification or...

  4. Measurements of aerosol and CCN properties in the Mackenzie River delta (Arctic) during RACEPAC

    Herenz, Paul; Wex, Heike; Henning, Silvia; Bjerring Kristensen, Thomas; Rubach, Florian; Roth, Anja; Borrmann, Stephan; Bozem, Heiko; Schulz, Hannes; Stratmann, Frank
    Within the framework of the RACEPAC (Radiation-Aerosol-Cloud Experiment in the Arctic Circle) project, the Arctic aerosol, arriving at a ground-based station in Tuktoyaktuk (Mackenzie River delta area, Canada), was characterized during a period of 3 weeks in May 2014. Basic meteorological parameters and particle number size distributions (PNSDs) were observed and two distinct types of air masses were found. One type were typical Arctic haze air masses, termed accumulation-type air masses, characterized by a monomodal PNSD with a pronounced accumulation mode at sizes above 100 nm. These air masses were observed during a period when back trajectories indicate an air...

  5. Mineralogical, geochemical, sediment provenance and grain-size end members from sediment core AMD0214-02PC and HLY0501-01JPC from the western Arctic Ocean

    Deschamps, Charles-Edouard; Montero-Serrano, Jean-Carlos; St-Onge, Guillaume
    Two sediment piston cores were recovered from the Chukchi-Alaskan (05JPC) and Canadian Beaufort (02PC) margins to investigate grain-size, geochemical and mineralogical compositions. This allowed the reconstruction of changes in detrital sediment provenance and transport related to climate variability since the last deglaciation. The end-member modelling analyses of grain-size indicate that sea ice and nepheloid transport as well as the Mackenzie River sediment plume are major factors influencing sedimentation in the Chukchi-Alaskan and Canadian Beaufort margins, respectively. Unmixing of the sediment composition indicates that detrital sediments in core 02PC are derived mainly from the Mackenzie River, whereas sediments from core 05JPC...

  6. Sulfur Isotopic Measurements of Canadian and South African Rivers

    Torres, Mark A; Paris, Guillaume; Adkins, Jess; Fischer, Woodward W
    During a time of negligible atmospheric pO2, Earth's early sulfur cycle generated a spectacular geological signal seen as the anomalous fractionation of multiple sulfur isotopic ratios. The disappearance of this signal from the geologic record has been hypothesized to constrain the timing of atmospheric oxygenation, though interpretive challenges exist. Asymmetry in existing S isotopic data, for example, suggest that the Archean crust was not mass balanced, with the implication that the loss of S isotope anomalies from the geologic record might lag the rise of atmospheric O2. Here, we present new S isotopic analyses of modern surface and groundwaters that...

  7. Effect of wind speed on the size distribution of gel particles in the sea surface microlayer: Insights from a wind wave channel experiment

    Sun, Cui-Cui; Sperling, Martin; Engel, Anja

  8. Ice thickness and bedrock elevation data of Nioghalvfjerdsfjorden Glacier from seismic investigations in 1997/1998

    Mayer, Christoph; Reeh, Niels; Jung-Rothenhäusler, Frederik; Huybrechts, Philippe; Oerter, Hans
    During an extensive field program, glaciologcal data have been collected at Nioghalvfjerdsfjiorden Glacier (79 North Glacier) in NE-Greenland in 1997 and 1998. A central part of the field work was dedicated to seismic investigations of the floating part of the glacier, determining the ice thickness, the underlying water column depth and the bedrock elevation. The seismic reflexion measurements were carried out with a 24-channel seismograph (Strataview). 600g explosives were used as energy source at a distance of 100 m from the first geophone. Details about the measurements and the project can be found in Mayer et al. (2000).

  9. Seawater carbonate chemistry and trophic flows and the living biomass of detritivores, herbivores, and carnivores

    Ullah, Hadayet; Nagelkerken, Ivan; Goldenberg, Silvan U; Fordham, Damien A; Loreau, Jean-Paul
    Global warming and ocean acidification are forecast to exert significant impacts on marine ecosystems worldwide. However, most of these projections are based on ecological proxies or experiments on single species or simplified food webs. How energy fluxes are likely to change in marine food webs in response to future climates remains unclear, hampering forecasts of ecosystem functioning. Using a sophisticated mesocosm experiment, we model energy flows through a species-rich multilevel food web, with live habitats, natural abiotic variability, and the potential for intra- and intergenerational adaptation. We show experimentally that the combined stress of acidification and warming reduced energy flows...

  10. Surface pollen assemblages from Rebun Island, common fossil pollen taxa recorded in the RK12 sediment core (Lake Kushu) and dimensional measurements of charred barley grains from the Hamanaka 2 archaeological site (Rebun Island)

    Leipe, Christian; Müller, Stefanie; Hille, Konrad; Kato, Hirofumi; Kobe, Franziska; Schmidt, Mareike; Seyffert, Konrad; Spengler III, Robert; Wagner, Mayke; Weber, Andrzej W; Tarasov, Pavel E

  11. Atlantic Pa/Th composite, new tropical Atlantic sedimentary Pa/Th data and age models

    Ng, Hong Chin; Robinson, Laura F; McManus, Jerry F
    Abrupt climate changes in the past have been attributed to variations in Atlantic Meridional Overturning Circulation (AMOC) strength. However, the exact timing and magnitude of past AMOC shifts remain elusive, which continues to limit our understanding of the driving mechanisms of such climate variability. Here we show a remarkably consistent signal of the 231Pa/230Th proxy that reveals a spatially coherent picture of western Atlantic circulation changes over the last deglaciation, during abrupt millennial-scale climate transitions. At the onset of deglaciation, we observe an early slowdown of circulation in the western Atlantic from around 19 to 16.5 thousand years ago (ka),...

  12. Holocene and MIS2 atmospheric mineral dust concentration and composition from the Talos Dome ice core and from potential source areas

    Baccolo, Giovanni; Delmonte, Barbara; Albani, Samuel; Baroni, Carlo; Cibin, Giannantonio; Frezzotti, Massimo; Hampai, Dariush; Marcelli, Augusto; Revel, Marie; Salvatore, Maria Cristina; Stenni, Barbara; Maggi, Valter
    The present data concerns: -Atmospheric dust concentration from the Antarctic ice core Talos Dome during the time interval between 700 and 25,000 years before present (AICC2012 chronology). -Dust Potential Source Areas Composition: the major element composition of potential dust source areas from Antarctica (Victoria Land), Australia and South America. -The major element composition of the atmospheric mineral dust extracted from the Talos Dome ice core sections. The age of the samples ranges between 1.9 Kyr BP and 32.9 Kyr BP (AICC2012 chronology).

  13. Seawater carbonate chemistry and gene abundance and community composition in two contrasting coastal marine sediments

    Currie, Ashleigh R; Tait, Karen; Parry, Helen E; de Francisco-Mora, Beatriz; Hicks, Natalie; Osborn, A M; Widdicombe, Steve; Stahl, Henrik
    Marine ecosystems are exposed to a range of human-induced climate stressors, in particular changing carbonate chemistry and elevated sea surface temperatures as a consequence of climate change. More research effort is needed to reduce uncertainties about the effects of global-scale warming and acidification for benthic microbial communities, which drive sedimentary biogeochemical cycles. In this research, mesocosm experiments were set up using muddy and sandy coastal sediments to investigate the independent and interactive effects of elevated carbon dioxide concentrations (750 ppm CO2) and elevated temperature (ambient + 4 °C) on the abundance of taxonomic and functional microbial genes. Specific q-PCR primers...

  14. Sea-surface temperature reconstructions over 30-40 ka, supplement data to Jensen et al. 2018

    Jensen, Mari F; Nummelin, Aleksi; Nielsen, Søren B; Sadatzki, Henrik; Sessford, Evangeline; Risebrobakken, Bjørg; Andersson, Carin; Voelker, Antje H L; Roberts, William H G; Pedro, Joel B; Born, Andreas
    Here we establish a spatio-temporal evolution of the sea-surface temperatures in the North Atlantic over Dansgaard-Oeschger (DO) events 5-8 (c.30-40ka) using the proxy surrogate reconstruction method. Proxy data suggest a large variability in North Atlantic sea-surface temperatures during the DO-events of the last glacial period. However, proxy data availability is limited and cannot provide a full spatial picture of the oceanic changes. Therefore, we combine fully coupled, general circulation model simulations with planktic foraminifera based sea-surface temperature reconstructions to obtain a broader spatial picture of the ocean state during DO-events 5-8. The resulting spatial sea-surface temperature patterns agree over a...

  15. Measurements of sediment core MD00-2361, ODP Hole 122-762B as well as land-based samples

    Stuut, Jan-Berend W; DeDekker, Patrick; Saavedra-Pellitero, Mariem; Bassinot, Franck C; Drury, Anna Joy; Walczak, Maureen H; Nagashima, Kana; Murayama, Masafumi
    These data were generated at the Kochi Core Center (KCC) in Kochi, Japan and were used (together with additional data from a nearby piston core MD00-2361 as well as land-based samples to produce the manuscript: "A 5.3-million-year history of monsoonal precipitation in northwestern Australia", which has been submitted to Science.

  16. Carbon, nitrogen and radiocarbon data from permafrost cores of two small Arctic river deltas in northern Alaska

    Fuchs, Matthias; Grosse, Guido; Jones, Benjamin M; Strauss, Jens; Baughman, Carson A; Walker, Donald A
    This data set describes the soil core and sample characteristics from the Ikpikpuk and Fish Creek river delta on the Arctic Coastal Plain in northern Alaska. The collection of the permafrost soil cores and the analysis of the samples are described in Fuchs et al. (in review). Sedimentary and geochemical characteristics of two small permafrost-dominated Arctic river deltas in northern Alaska. This data compilation consists of two data set. The first data set describes the properties of the collected permafrost soil cores from the Ikpikpuk river (IKP) and Fish Creek river (FCR) delta. This includes the coordinates of the nine coring...

  17. Seawater carbonate chemistry and fatty acid content of plankton

    Wang, Tifeng; Tong, Shanying; Liu, Nana; Li, Futian; Wells, Mark L; Gao, Kunshan
    Ocean Acidification (OA) effects on marine plankton are most often considered in terms of inorganic carbon chemistry, but decreasing pH may influence other aspects of cellular metabolism. Here we present the effects of OA on the fatty acid (FA) content and composition of an artificial phytoplankton community (Phaeodactylum tricornutum, Thalassiosira weissflogii, and Emiliania huxleyi) in a fully replicated, 4 m**3 mesocosm study in subtropical coastal waters (Wuyuan Bay, China, 24.52°N, 117.18°E) at present day (400 μatm) and elevated (1000 μatm) pCO2 concentrations. Phytoplankton growth occurred in three phases during the 33-day experiment: an initial exponential growth leading to senescence and...

  18. Great tits (Parus major) nestling cloacal microbiota at eight and fifteen days old, effect of the nesting environment

    Teyssier, Aimeric; Lens, Luc; Matthysen, Erik; White, Joël
    Despite the increasing knowledge on the processes involved in the acquisition and development of the gut microbiota in model organisms, the factors influencing early microbiota successions in natural populations remain poorly understood. In particular, little is known on the role of the rearing environment in the establishment of the gut microbiota in wild birds. Here we examined the influence of the nesting environment on the gut microbiota of Great tits (Parus major) by performing a partial cross-fostering experiment during the intermediate stage of nestling development. We found that the cloacal microbiota of great tit nestlings underwent substantial changes between 8...

  19. Biomarker contents, freshwater algae counts and compound specific radiocarbon in sediment cores from Sea of Okhotsk

    Winterfeld, Maria; Mollenhauer, Gesine
    The datasets contain measured contents of terrigenous biomarkers, specifically of branched glycerol dialkyl glycerol tetraethers (brGDGTs) and of long-chain n-alkanes, compound-specific radiocarbon concentrations of long-chain n-alkanoic acids with 26 or 28 carbon atoms expressed as F14C with a 1 sigma uncertainty, and counts of Pediastrum spp. freshwater algae valves expressed in number per gram sediment. These data have been obtained on two cores: SO178-13-6 for the biomarker contents, LV28-4-4 for the freshwater algae; compound-specific radiocarbon concentrations are available for both cores.

  20. Water chemistry and aggregates analysis from the Galapagos Archipelago sampled on Queen Mabel during Galapagos cruise in 2014

    Guevara, Nataly; Hassenrück, Christiane; Buttigieg, Pier Luigi; Gärdes, Astrid
    Bacteria play a crucial role in the marine carbon cycle. To better understand the impacts of ocean warming and acidification on marine carbon cycling, natural analogues for future ocean conditions have gained increasing popularity. Here, we investigated three contrasting oceanographic settings in the Galapagos Archipelago regarding their suitability to represent future ocean conditions in research on organic carbon pools and bacterioplankton communities. Compared to a reference site representative of ambient pH and temperature (Cowley Islet; CoI), we studied a submarine CO2 vent at Roca Redonda (RoR), and an upwelling site at Bolivar Channel (BoC) subjected to a weak El-Nino event...

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