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
    Electronic Resource
    Electronic Resource
    Evidence for Improved Cerebral Function After Minimally lnvasive Bypass Surgery (1998)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of cardiac surgery 13 (1998), S. 0 
    Details
    ISSN: 1540-8191
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract Background: Neurological impairment is a major cause of morbidity after cardiac surgery and may be associated with occurrence of cerebral microemboli generated during cardiopulmonary bypass (CPB). This study evaluates cerebral dysfunction following coronary artery surgery on-pump and off-pump. Methods: Neurological outcome was evaluated in 322 patients with a coronary artery bypass graft (CABG). Conventional CPB was used (on-pump) in 305 patients and in 17 patients no CPB was used (off-pump). Intraoperatively, a pulsed-wave transcranial Doppler with a 2-MHZ probe measured high-intensity transient signals (HITS) by ultrasonic insonnation of the middle cerebral artery indicating the presence of emboli within the vessel lumen. Transcranial near-infrared spectroscopy measured cerebral venous oxygen saturation for adequate perfusion. Postoperatively, all patients were subjected to the antisaccadic eye movement (ASEM) test, a sensitive indicator of neurocognitive deficits secondary to frontal lobe dysfunction. Results: While there was no significant difference in O2 saturation, the number of microemboli HITS generated was significantly higher in the on-pump group than the off-pump group. In the off-pump group, 16 (94%) of 17 patients had perfect scores on the ASEM test, while only 108 (35.4%) of 305 patients achieved a perfect score in the on-pump group (p 〈 0.01). Furthermore, while all patients in the off-pump group achieved at least 90%, 28% (86/305) in the on-pump group scored “zero” on the ASEM test. Conclusion: Cerebral dysfunction as evidenced by ASEM errors is common following coronary bypass on-pump, but rare with off-pump bypass surgery. Cerebral microemboli generated during CPB may account for this difference. (J Card Surg 1998;13:27–31
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1540-8191.1998.tb01050.x
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    facet.materialart.
    Unknown
    The Atlantic meridional overturning circulation in high resolution models (2020)
    In:  EPIC3Journal of Geophysical Research: Oceans, ISSN: 2169-9275
    Details
    Publication Date: 2020-02-10
    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.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 3
    facet.materialart.
    Unknown
    The effect on simulated ocean climate of a parameterization of unbroken wave-induced mixing incorporated into the k-epsilon mixing scheme (2018)
    Details
    Publication Date: 2018-05-02
    Description: A new parameterization of mixing processes in the upper ocean is tested in a1=48resolutionglobal ocean climate model. The parameterization represents the effect of turbulent mixing by unbrokenwaves as an additional turbulent shear production term in the k-epsilon mixing scheme. The results showthat the inclusion of this parameterization has a noticeable effect on ocean climate, particularly in regionsof high wave activity such as the Southern Ocean. Inclusion of this process also leads to some reduction inthe biases of the simulated climate, including mixed layer depth, compared with available observations.
    Description: Published
    Description: 735–758
    Description: 4A. Oceanografia e clima
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 4
    facet.materialart.
    Unknown
    An assessment of the Arctic Ocean in a suite of interannual CORE-II simulations. Part III: Hydrography and fluxes (2016)
    In:  EPIC3Ocean Modelling, 100, pp. 141-161, ISSN: 14635003
    Details
    Publication Date: 2016-04-15
    Description: In this paper we compare the simulated Arctic Ocean in 15 global ocean–sea ice models in the framework of the Coordinated Ocean-ice Reference Experiments, phase II (CORE-II). Most of these models are the ocean and sea-ice components of the coupled climate models used in the Coupled Model Intercomparison Project Phase 5 (CMIP5) experiments. We mainly focus on the hydrography of the Arctic interior, the state of Atlantic Water layer and heat and volume transports at the gateways of the Davis Strait, the Bering Strait, the Fram Strait and the Barents Sea Opening. We found that there is a large spread in temperature in the Arctic Ocean between the models, and generally large differences compared to the observed temperature at intermediate depths. Warm bias models have a strong temperature anomaly of inflow of the Atlantic Water entering the Arctic Ocean through the Fram Strait. Another process that is not represented accurately in the CORE-II models is the formation of cold and dense water, originating on the eastern shelves. In the cold bias models, excessive cold water forms in the Barents Sea and spreads into the Arctic Ocean through the St. Anna Through. There is a large spread in the simulated mean heat and volume transports through the Fram Strait and the Barents Sea Opening. The models agree more on the decadal variability, to a large degree dictated by the common atmospheric forcing. We conclude that the CORE-II model study helps us to understand the crucial biases in the Arctic Ocean. The current coarse resolution state-of-the-art ocean models need to be improved in accurate representation of the Atlantic Water inflow into the Arctic and density currents coming from the shelves.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 5
    facet.materialart.
    Unknown
    An assessment of the Arctic Ocean in a suite of interannual CORE-II simulations. Part III: Hydrography and fluxes (2016)
    Elsevier
    In:  Ocean Modelling, 100 . pp. 141-161.
    Details
    Publication Date: 2019-06-28
    Description: Highlights: • We compare the simulated Arctic Ocean in 15 global ocean–sea ice models. • There is a large spread in temperature bias in the Arctic Ocean between the models. • Warm bias models have a strong temperature anomaly of inflow of Atlantic Water. • Dense outflows formed on Arctic shelves are not captured accurately in the models. In this paper we compare the simulated Arctic Ocean in 15 global ocean-sea ice models in the framework of the Coordinated Ocean-ice Reference Experiments, phase II (CORE-II). Most of these models are the ocean and sea-ice components of the coupled climate models used in the Coupled Model Intercomparison Project Phase 5 (CMIP5) experiments. We mainly focus on the hydrography of the Arctic interior, the state of Atlantic Water layer and heat and volume transports at the gateways of the Davis Strait, the Bering Strait, the Fram Strait and the Barents Sea Opening. We found that there is a large spread in temperature in the Arctic Ocean between the models, and generally large differences compared to the observed temperature at intermediate depths. Warm bias models have a strong temperature anomaly of inflow of the Atlantic Water entering the Arctic Ocean through the Fram Strait. Another process that is not represented accurately in the CORE-II models is the formation of cold and dense water, originating on the eastern shelves. In the cold bias models, excessive cold water forms in the Barents Sea and spreads into the Arctic Ocean through the St. Anna Through. There is a large spread in the simulated mean heat and volume transports through the Fram Strait and the Barents Sea Opening. The models agree more on the decadal variability, to a large degree dictated by the common atmospheric forcing. We conclude that the CORE-II model study helps us to understand the crucial biases in the Arctic Ocean. The current coarse resolution state-of-the-art ocean models need to be improved in accurate representation of the Atlantic Water inflow into the Arctic and density currents coming from the shelves.
    Type: Article , PeerReviewed , info:eu-repo/semantics/article
    Format: text
    DOI: 10.1016/j.ocemod.2016.02.004
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    OceanRep: Article in a Scientific Journal - peer-reviewed
  • 6
    facet.materialart.
    Unknown
    ENSO-driven interhemispheric Pacific mass transports (2014)
    AGU (American Geophysical Union) | Wiley
    In:  Journal of Geophysical Research: Oceans, 119 (9). pp. 6221-6237.
    Details
    Publication Date: 2019-09-23
    Description: Previous studies have shown that ENSO's anomalous equatorial winds, including the observed southward shift of zonal winds that occurs around the event peak, can be reconstructed with the first two Empirical Orthogonal Functions (EOFs) of equatorial region wind stresses. Using a high-resolution ocean general circulation model, we investigate the effect of these two EOFs on changes in warm water volume (WWV), interhemispheric mass transports, and Indonesian Throughflow (ITF). Wind stress anomalies associated with the first EOF produce changes in WWV that are dynamically consistent with the conceptual recharge oscillator paradigm. The ITF is found to heavily damp these WWV changes, reducing their variance by half. Wind stress anomalies associated with the second EOF, which depicts the southward wind shift, are responsible for WWV changes that are of comparable magnitude to those driven by the first mode. The southward wind shift is also responsible for the majority of the observed interhemispheric upper ocean mass exchanges. These winds transfer mass between the Northern and the Southern Hemisphere during El Niño events. Whilst water is transferred in the opposite direction during La Niña events, the magnitude of this exchange is roughly half of that seen during El Niño events. Thus, the discharging of WWV during El Niño events is meridionally asymmetric, while the WWV recharging during a La Niña event is largely symmetric. The inclusion of the southward wind shift is also shown to allow ENSO to exchange mass with much higher latitudes than that allowed by the first EOF alone.
    Type: Article , PeerReviewed
    Format: text
    DOI: 10.1002/2014JC010286
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    OceanRep: Article in a Scientific Journal - peer-reviewed
  • 7
    facet.materialart.
    Unknown
    An assessment of Southern Ocean water masses and sea ice during 1988–2007 in a suite of interannual CORE-II simulations (2015)
    Elsevier
    In:  Ocean Modelling, 94 . pp. 67-94.
    Details
    Publication Date: 2019-09-23
    Description: We characterise the representation of the Southern Ocean water mass structure and sea ice within a suite of 15 global ocean-ice models run with the Coordinated Ocean-ice Reference Experiment Phase II (CORE-II) protocol. The main focus is the representation of the present (1988-2007) mode and intermediate waters, thus framing an analysis of winter and summer mixed layer depths; temperature, salinity, and potential vorticity structure; and temporal variability of sea ice distributions. We also consider the interannual variability over the same 20 year period. Comparisons are made between models as well as to observation-based analyses where available. The CORE-II models exhibit several biases relative to Southern Ocean observations, including an underestimation of the model mean mixed layer depths of mode and intermediate water masses in March (associated with greater ocean surface heat gain), and an overestimation in September (associated with greater high latitude ocean heat loss and a more northward winter sea-ice extent). In addition, the models have cold and fresh/warm and salty water column biases centred near 50 degrees S. Over the 1933-2007 period, the CORE-II models consistently simulate spatially variable trends in sea-ice concentration, surface freshwater fluxes, mixed layer depths, and 200-700 in ocean heat content. In particular, sea-ice coverage around most of the Antarctic continental shelf is reduced, leading to a cooling and freshening of the near surface waters. The shoaling of the mixed layer is associated with increased surface buoyancy gain, except in the Pacific where sea ice is also influential. The models are in disagreement, despite the common CORE-II atmospheric state, in their spatial pattern of the 20-year trends in the mixed layer depth and sea-ice
    Type: Article , PeerReviewed
    Format: text
    DOI: 10.1016/j.ocemod.2015.07.022
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    OceanRep: Article in a Scientific Journal - peer-reviewed
  • 8
    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
  • 9
    facet.materialart.
    Unknown
    Subtropical-tropical pathways of spiciness anomalies and their impact on equatorial Pacific temperature (2021)
    Springer
    Details
    Publication Date: 2024-02-07
    Description: Understanding mechanisms of tropical Pacific decadal variability (TPDV) is of high importance for differentiating between natural climate variability and human induced climate change as this region sustains strong global teleconnections. Here, we use an ocean general circulation model along with a Lagrangian tracer simulator to investigate the advection of density compensated temperature anomalies (“spiciness mechanism”) as a potential contributor to TPDV during the 1980–2016 period. Consistent with observations, we find the primary regions of spiciness generation in the eastern subtropics of each hemisphere. Our results indicate that 75% of the equatorial subsurface water originates in the subtropics, of which two thirds come from the Southern hemisphere. We further show two prominent cases where remotely generated spiciness anomalies are advected to the equatorial Pacific, impacting subsurface temperature. The relative contribution of Northern versus Southern Hemisphere prominence and/or interior versus western boundary pathways depends on the specific event. The anomalously warm case largely results from advection via the Southern hemisphere interior (65%), while the anomalously cold case largely results from advection via the Northern hemisphere western boundary (48%). The relatively slow travel times from the subtropics to the equator (〉 4 years) suggests that these spiciness anomalies underpin a potentially predictable contribution to TPDV. However, not all decadal peaks in equatorial spiciness can be explained by remotely generated spiciness anomalies. In those cases, we propose that spiciness anomalies are generated in the equatorial zone through changes in the proportion of Northern/Southern hemisphere source waters due to their different mean spiciness distribution.
    Type: Article , PeerReviewed
    Format: text
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    OceanRep: Article in a Scientific Journal - peer-reviewed
  • 10
    facet.materialart.
    Unknown
    Public understanding in Great Britain of ocean acidification (2016)
    Springer Nature
    Details
    Publication Date: 2016-07-28
    Description: Public understanding of climate change is well researched, but little is known about public perceptions of ocean acidification. New survey data shows that public awareness of ocean acidification in Great Britain is low compared to that of climate change. Nature Climate Change 6 763 doi: 10.1038/nclimate3005
    Print ISSN: 1758-678X
    Electronic ISSN: 1758-6798
    Topics: Geosciences
    Published by Springer Nature
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...