GLORIA

GEOMAR Library Ocean Research Information Access

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    facet.materialart.
    Unknown
    Feedback of mesoscale ocean currents on atmospheric winds in high-resolution coupled models and implications for the forcing of ocean-only models (2017)
    Copernicus Publications (EGU)
    In:  Ocean Science Discussions .
    Details
    Publication Date: 2021-03-04
    Description: The repercussions of surface ocean currents for the near-surface wind and the air-sea momentum flux are investigated in two versions of a global climate model with eddying ocean. The focus is on the effect of mesoscale ocean current features at scales of less than 150 km, by considering high-pass filtered, monthly-mean model output fields. We find a clear signature of a mesoscale oceanic imprint in the wind fields over the energetic areas of the oceans, particularly along the extensions of the western boundary currents and the Antarctic Circumpolar Current. These areas are characterized by a positive correlation between mesoscale perturbations in the curl of the surface currents and the wind curl. The coupling coefficients are spatially non-uniform and show a pronounced seasonal cycle. The positive feedback of mesoscale current features on the near-surface wind acts in opposition to their damping effect on the wind stress. A tentative incorporation of this feedback in the surface stress formulation of an eddy-permitting global ocean-only model leads to a gain in the kinetic energy of up to 10 %, suggesting a fundamental shortcoming of present ocean model configurations.
    Type: Article , NonPeerReviewed , info:eu-repo/semantics/article
    Format: text
    DOI: 10.5194/os-2017-24
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    OceanRep: Article in a Scientific Journal - without review
  • 2
    facet.materialart.
    Unknown
    Evaluating surface eddy properties in coupled climate simulations with ‘eddy-present’ and ‘eddy-rich’ ocean resolution (2020)
    Elsevier
    Details
    Publication Date: 2023-02-08
    Description: As climate models move towards higher resolution, their ocean components are now able to explicitly resolve mesoscale eddies. High resolution for ocean models is roughly classified into eddy-present (EP, 1/4°) and eddy-rich (ER, 1/12°) resolution. The cost–benefit of ER resolution over EP resolution remains debated. To inform this discussion, we quantify and compare the surface properties of coherent mesoscale eddies in high-resolution versions of the HadGEM3-GC3.1 coupled climate model, using an eddy tracking algorithm. The modelled properties are compared to altimeter observations. Relative to EP, ER resolution simulates more (+60%) and longer-lasting (+23%) eddies, in better agreement with observations. The representation of eddies in Western Boundary Currents (WBCs) and the Southern Ocean compares well with observations at both resolutions. However a common deficiency in the models is the low eddy population in subtropical gyre interiors, which reflects model biases at the Eastern Boundary Upwelling Systems and at the Indonesian outflow, where most of these eddies are generated in observations. Despite a grid spacing larger than the Rossby radius of deformation at high-latitudes, EP resolution does allow for eddy growth in these regions, although at a lower rate than seen in observations and ER resolution. A key finding of our analysis is the large differences in eddy size across the two resolutions and observations: the median speed-based radius increases from 14 km at ER resolution to 32 km at EP resolution, compared with 48 km in observations. It is likely that observed radii are biased high by the effective resolution of the gridded altimeter dataset due to post-processing. Our results highlight the limitations of the altimeter products and the required caution when employed for understanding eddy dynamics and developing eddy parameterizations.
    Type: Article , PeerReviewed
    Format: text
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    OceanRep: Article in a Scientific Journal - peer-reviewed
  • 3
    facet.materialart.
    Unknown
    The Atlantic Meridional Overturning Circulation in High‐Resolution Models (2020)
    AGU (American Geophysical Union)
    Details
    Publication Date: 2023-02-08
    Description: The Atlantic meridional overturning circulation (AMOC) represents the zonally integrated stream function of meridional volume transport in the Atlantic Basin. The AMOC plays an important role in transporting heat meridionally in the climate system. Observations suggest a heat transport by the AMOC of 1.3 PW at 26°N—a latitude which is close to where the Atlantic northward heat transport is thought to reach its maximum. This shapes the climate of the North Atlantic region as we know it today. In recent years there has been significant progress both in our ability to observe the AMOC in nature and to simulate it in numerical models. Most previous modeling investigations of the AMOC and its impact on climate have relied on models with horizontal resolution that does not resolve ocean mesoscale eddies and the dynamics of the Gulf Stream/North Atlantic Current system. As a result of recent increases in computing power, models are now being run that are able to represent mesoscale ocean dynamics and the circulation features that rely on them. The aim of this review is to describe new insights into the AMOC provided by high-resolution models. Furthermore, we will describe how high-resolution model simulations can help resolve outstanding challenges in our understanding of the AMOC.
    Type: Article , PeerReviewed
    Format: text
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    OceanRep: Article in a Scientific Journal - peer-reviewed
  • 4
    facet.materialart.
    Unknown
    Resolving and Parameterising the Ocean Mesoscale in Earth System Models (2020)
    Springer
    Details
    Publication Date: 2023-02-08
    Description: Purpose of Review: Assessment of the impact of ocean resolution in Earth System models on the mean state, variability, and future projections and discussion of prospects for improved parameterisations to represent the ocean mesoscale. Recent Findings: The majority of centres participating in CMIP6 employ ocean components with resolutions of about 1 degree in their full Earth System models (eddy-parameterising models). In contrast, there are also models submitted to CMIP6 (both DECK and HighResMIP) that employ ocean components of approximately 1/4 degree and 1/10 degree (eddy-present and eddy-rich models). Evidence to date suggests that whether the ocean mesoscale is explicitly represented or parameterised affects not only the mean state of the ocean but also the climate variability and the future climate response, particularly in terms of the Atlantic meridional overturning circulation (AMOC) and the Southern Ocean. Recent developments in scale-aware parameterisations of the mesoscale are being developed and will be included in future Earth System models. Summary: Although the choice of ocean resolution in Earth System models will always be limited by computational considerations, for the foreseeable future, this choice is likely to affect projections of climate variability and change as well as other aspects of the Earth System. Future Earth System models will be able to choose increased ocean resolution and/or improved parameterisation of processes to capture physical processes with greater fidelity.
    Type: Article , PeerReviewed , info:eu-repo/semantics/article
    Format: text
    Format: text
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    OceanRep: Article in a Scientific Journal - peer-reviewed
  • 5
    facet.materialart.
    Unknown
    Tropical Cyclone Integrated Kinetic Energy in an Ensemble of HighResMIP Simulations (2021)
    AGU (American Geophysical Union) | Wiley
    Details
    Publication Date: 2024-02-07
    Description: This study investigates tropical cyclone integrated kinetic energy, a measure which takes into account the intensity and the size of the storms and which is closely associated with their damage potential, in three different global climate models integrated following the HighResMIP protocol. In particular, the impact of horizontal resolution and of the ocean coupling are assessed. We find that, while the increase in resolution results in smaller and more intense storms, the integrated kinetic energy of individual cyclones remains relatively similar between the two configurations. On the other hand, atmosphere-ocean coupling tends to reduce the size and the intensity of the storms, resulting in lower integrated kinetic energy in that configuration. Comparing cyclone integrated kinetic energy between a present and a future scenario did not reveal significant differences between the two periods.
    Type: Article , PeerReviewed
    Format: text
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    OceanRep: Article in a Scientific Journal - peer-reviewed
  • 6
    facet.materialart.
    Unknown
    Ocean Mesoscale and Frontal-Scale Ocean–Atmosphere Interactions and Influence on Large-Scale Climate: A Review (2023)
    AMS (American Meteorological Society)
    Details
    Publication Date: 2024-02-07
    Description: Two decades of high-resolution satellite observations and climate modeling studies have indicated strong ocean–atmosphere coupled feedback mediated by ocean mesoscale processes, including semipermanent and meandrous SST fronts, mesoscale eddies, and filaments. The air–sea exchanges in latent heat, sensible heat, momentum, and carbon dioxide associated with this so-called mesoscale air–sea interaction are robust near the major western boundary currents, Southern Ocean fronts, and equatorial and coastal upwelling zones, but they are also ubiquitous over the global oceans wherever ocean mesoscale processes are active. Current theories, informed by rapidly advancing observational and modeling capabilities, have established the importance of mesoscale and frontal-scale air–sea interaction processes for understanding large-scale ocean circulation, biogeochemistry, and weather and climate variability. However, numerous challenges remain to accurately diagnose, observe, and simulate mesoscale air–sea interaction to quantify its impacts on large-scale processes. This article provides a comprehensive review of key aspects pertinent to mesoscale air–sea interaction, synthesizes current understanding with remaining gaps and uncertainties, and provides recommendations on theoretical, observational, and modeling strategies for future air–sea interaction research.
    Type: Article , PeerReviewed
    Format: text
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    OceanRep: Article in a Scientific Journal - peer-reviewed
  • 7
    Electronic Resource
    Electronic Resource
    The libration–vibration bands of the ammonium ion in ammonium tetraphenylborate: Evidence for nearly free rotation (1987)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 87 (1987), S. 6393-6405 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The N–H stretching and H–N–H bending regions of the infrared spectrum of the title compound (ATPB) have been examined with care. The stretching bands show rotation-like structure that we attribute to rotational motion of NH+4 in a very low barrier. The barrier has the symmetry of a tetrahedral molecule in a tetrahedral site and is characterized by the dimensionless parameter β=1. The J=0 and J=1 levels are below the barrier and the J=2 levels are above it. Slow interconversion of nuclear spin species is seen in keeping with the low barrier model. The spectra of the ATPB with some NH3D+, with a high concentration of K+ and with deuterated phenyl groups have been examined, and show spectra in keeping with the model.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.453470
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Quantum rotations of the ammonium ions in ammonium tetraphenyl–borate. III. Inelastic neutron scattering results (1990)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 93 (1990), S. 8963-8967 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Incoherent inelastic neutron scattering experiments have been performed on polycrystalline samples of NH4B(C6H5)4 and NH4B(C6D5)4 in the 1.5–120 K temperature range. A high-resolution inelastic neutron scattering spectrum at the lowest temperatures reveals a rotational tunneling spectrum containing two peaks at 26.5 and 53.0 μeV and is characteristic of ammonium ions in a cubic environment. From the intensities of these peaks it seems that about half of the ammonium ions are involved in this tunneling. Two further peaks are found at higher energy, 4.3 and 8.2 meV, either of which may be correlated as the libration associated with the observed tunnel splitting depending on the form of the potential. An alternative assignment of the peaks at 4.3 and 8.2 meV as transitions of a free rotor from the ground state to the J=2 and J=3 levels is also discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.459235
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    The vibration and orientation bands of the NH+4 ion in ammonium tetraphenylborate. IV. Raman studies (1990)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 93 (1990), S. 7632-7638 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The N–H stretching and low frequency regions of the Raman spectrum of the title compound [ammonium tetraphenylborate (ATPB) and ATPB-d20 ] are examined at low temperatures. In the low frequency Raman region, we observe the predicted orientational transitions directly. The Raman N–H spectrum shows features similar to those in the infrared spectrum of this region, interpreted as showing nearly free rotation of the NH+4 ions. Many of the features of both the low frequency and N–H stretching regions arise from the effect of D2d site symmetry on the otherwise tetrahedral NH+4 ion. The picture of some of the NH+4 ions in this crystal as perturbed, but very nearly free to rotate is confirmed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.459394
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    The crystalline site symmetry and its effect on the vibrational spectra of a weakly hindered molecule. V. Crystallization effects in NH4B(C6H5)4 (1990)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 93 (1990), S. 8524-8534 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Changes in the vibrational spectra for molecules that nearly freely rotate or perform rotational tunneling at low temperatures are explained through the systematic study of the combined symmetry of the molecule, the site, and the molecule's nuclear spins. The changes observed for different crystallizations in the low temperature vibrational spectra of the NH+4 ion dilute in KTPB and in NH4B(C6D5)4, the NH3D+ ion in ATPB and NH4ClO4, and of solid CH4 II are examined and explained as arising from slight perturbations of the crystalline site symmetry.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.459290
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...