GLORIA

GEOMAR Library Ocean Research Information Access

feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
  • 1
    Publikationsdatum: 2015-07-01
    Repository-Name: EPIC Alfred Wegener Institut
    Materialart: Article , peerRev
    Format: application/pdf
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 2
    Publikationsdatum: 2019-07-16
    Repository-Name: EPIC Alfred Wegener Institut
    Materialart: Article , isiRev
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 3
    Publikationsdatum: 2019-07-16
    Beschreibung: Today's surface ocean is saturated with respect to calcium carbonate, but increasing atmospheric carbon dioxide concentrations are reducing ocean pHand carbonate ion concentrations, and thus the level of calcium carbonate saturation. Experimental evidence suggests that if these trends continue, key marine organisms such as corals and some plankton will have difficulty maintaining their external calcium carbonate skeletons. Here we use 13 models of the ocean carbon cycle to assess calcium carbonate saturation under the IS92a 'business-as-usual$(B s(Bcenario for future emissions of anthropogenic carbon dioxide. In our projections, Southern Ocean surface waters will begin to become undersaturated with respect to aragonite, a metastable form of calcium carbonate, by the year 2050. By 2100, this undersaturation could extend throughout the entire Southern Ocean and into the subarctic Pacific Ocean. When live pteropods were exposed to our predicted level of undersaturation during a two-day shipboard experiment, their aragonite shells showed notable dissolution. Our findings indicate that conditions detrimental to high-latitude ecosystems could develop within decades, not centuries as suggested previously.
    Repository-Name: EPIC Alfred Wegener Institut
    Materialart: Article , isiRev
    Format: application/pdf
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 4
    Publikationsdatum: 2019-07-16
    Beschreibung: A suite of standard ocean hydrographic and circulation metrics are applied to the equilibrium physical solutions from thirteen global carbon models participating in phase 2 of the Ocean Carbon-cycle Model Intercomparison Project (OCMIP-2). Model-data comparisons are presented for sea surface temperature and salinity, seasonal mixed layer depth, meridional heat and freshwater transport, 3-D hydrographic fields, and meridional overturning. Considerable variation exists among the OCMIP-2 simulations, with some of the solutions falling noticeably outside available observational constraints. For some cases, model-model and model-data differences can be related to variations in surface forcing, sub-grid scale parameterizations, and model architecture. These errors in the physical metrics point to significant problems in the underlying model representations of ocean transport and dynamics, problems that directly propagate into the OCMIP predicted ocean tracer and carbon cycle variables (e.g., air-sea CO2 flux; chlorofluorocarbon and anthropogenic CO2 uptake; export production). The substantial model-model ranges in OCMIP-2 biogeochemical fields (±25-40%), therefore, likely overestimate the uncertainties in ocean carbon cycle dynamics due to large-scale physical circulation.
    Repository-Name: EPIC Alfred Wegener Institut
    Materialart: Article , isiRev
    Format: application/pdf
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 5
    Publikationsdatum: 2019-07-16
    Beschreibung: New radiocarbon and chlorofluorocarbon-11 data from the World Ocean Circulation Experiment are used to assess a suite of 19 ocean carbon cycle models. We use the distributions and inventories of these tracers as quantitative metrics of model skill and find that only about a quarter of the suite is consistent with the new data-based metrics. This should serve as a warning bell to the larger community that not all is well with current generation of ocean carbon cycle models. At the same time, this highlights the danger in simply using the available models to represent the state-of-the-art modeling without considering the credibility of each model.
    Repository-Name: EPIC Alfred Wegener Institut
    Materialart: Article , isiRev
    Format: application/pdf
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 6
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 68 (1990), S. 1606-1609 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Structural properties of ZnTe-ZnSe strained-layer superlattices grown on GaAs(001) substrates by hot wall epitaxy were investigated by transmission electron microscopy. The satellite spots observed in transmission electron diffraction patterns confirmed the superlattice periodicity and agreed very well with the results from x-ray diffraction. Smooth and abrupt interfaces are observed in (110) cross-sectional images. Strain information obtained from the transmission electron diffraction and lattice images indicates that coherent strain has not been achieved in ZnTe-ZnSe superlattices when the layer thickness of each constituent material exceeded 13 A(ring).
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 7
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 68 (1990), S. 112-115 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: X-ray diffraction from the (110) thin edges is proposed to analyze the ZnTe-ZnSe strained-layer superlattices grown on GaAs(001) substrates. Strained lattice spacings parallel to the interfaces and the critical layer thickness of coherent growth can be determined directly by this technique. In spite of the large (7%) lattice mismatch between ZnTe and ZnSe layers, the experimental results show that the ZnTe-ZnSe superlattices have been prepared coherently by hot wall epitaxy and the critical thickness is about 10 A(ring). The strained lattice spacings determined by x-ray [440] diffraction, together with those of Raman scattering measurement, agree very well with the theoretical results. The residual strain in ZnTe/GaAs(001) was also estimated to be about 5×10−4 (biaxial tensile) by x-ray diffraction, where the main cause is found to be the difference of thermal expansion between ZnTe films and GaAs substrates.
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 8
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 3 (1996), S. 4278-4280 
    ISSN: 1089-7674
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Local eigenmodes of field-reversed configurations (FRCs) were previously computed using ideal magnetohydrodynamics, including compressibility and double adiabaticity. Here the eigenmodes are compared with earlier analytic models. In equilibria, as initially generated in θ pinches, the rigid displacements of the analytic models are similar to actual eigenmodes in structure and growth rate; moreover, the growth rates are similar to those of global modes. In equilibria that naturally arise later in the quiescent FRC, the analytic models fail to predict features of the eigenmode behavior: ballooning-like structure, and much faster growth rate than global modes. This suggests explanations for the difficulty of forming large FRCs in θ pinches, and for the appearance of characteristic profiles in quiescent FRCs. © 1996 American Institute of Physics.
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 9
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 1 (1994), S. 1523-1528 
    ISSN: 1089-7674
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: New results show that a toroidal plasma can be ideally stable to gross modes without a toroidal magnetic field. Previous ideal-magnetohydrodynamic (MHD) studies for such systems [commonly called field-reversed configurations (FRC)] have consistently predicted instability to the tilting mode (lowest-order kink mode). However, a new range of equilibria not previously considered are found, which are stable to tilting in ideal-MHD theory. The equilibrium properties that promote stability are hollow current profile, and racetrack separatrix shape. Stable equilibria may not be possible in a θ-pinch system, but could be achieved with a properly designed vertical field coil set. The stability of FRC's in past θ-pinch experiments arises partly from nonideal effects, but benefits considerably from hollow current profile and racetrack separatrix shape.
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 10
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 1 (1994), S. 4022-4031 
    ISSN: 1089-7674
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The local stability of field-reversed configurations (FRC) is analyzed using hydrodynamic stability theory. The equation of state includes both compressibility and double-adiabatic effects. For the first time, eigenmodes of the linearized equations of motion have been computed. The most unstable modes have fast growth rates, comparable to the Alfvén transit time across the FRC radius; i.e., somewhat faster than the frequency (or growth rate) of global modes. In realistic equilibria, the most unstable local modes concentrate, ballooning-mode style, in the high curvature region of magnetic flux lines. The familiar interchange stability criterion is irrelevant for FRCs, since the actual eigenmodes differ markedly from interchange, both in structure and stability. The appearance of fast local modes raises the possibility that they may regulate FRC equilibria. However, surprisingly, equilibria with realistic internal structure (i.e. resembling experiments) are more unstable to ideal local modes than less realistic equilibria, as have often been studied theoretically. Thus, a nonideal theory will be needed to explain the equilibria observed in experiments. © 1994 American Institute of Physics.
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...