GLORIA

GEOMAR Library Ocean Research Information Access

feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • 2015-2019  (33)
  • 2010-2014  (29)
  • 2000-2004  (3)
Document type
Keywords
Language
Years
Year
  • 1
    Keywords: Hochschulschrift
    Type of Medium: Online Resource
    Pages: Online-Ressource (134 Seiten = 3,5 MB) , Illustration, Graphen
    Language: English
    Note: Zusammenfassung in deutscher und englischer Sprache
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 2
    Keywords: Hochschulschrift
    Type of Medium: Online Resource
    Pages: 1 Online-Ressource (122 Blatt = 60 MB) , Illustrationen, Graphen, Karten
    Language: English
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2024-02-01
    Keywords: Ammonium; Bacteria; Bacteria, biomass as carbon; Carbon, inorganic, dissolved; Carbon, organic, particulate; Carbon/nitrogen analyser (GF/F filtered); Carbon biomass estimation (unspec.); Chlorophyll a; Chlorophyll a, fluorometric determination (Grasshoff et al., 1983, Chemie GmbH); Conductivity; Continuous Flow Automated Analysis (Gordon et al., 1993, WOCE Tech Rpt 93-1); Coulometric titration (Knap et al., 1996, IOC Manuals and Guides 29, UNESCO); Counting by flow cytometer; CTD, Neil Brown, Mark III B, NB-4; CTD/Rosette; CTD-RO; Date/Time of event; DEPTH, water; Elevation of event; Epifluorescence microscopy; Epifluorescence microscopy after acridine orange staining; Eukaryotes; Event label; Fluorescence, chlorophyll; JGOFS; JGOFS-IN-3; Joint Global Ocean Flux Study; Latitude of event; Leucine uptake rate; Longitude of event; Nanoflagellates, heterotrophic; Nitrate; Nitrite; Nitrogen, organic, particulate; Oxidation; then autoanalysis (GF/F filtered); Oxidation (alkaline) with borate buffered potassium persulphate; Oxygen; Oxygen, Winkler (Culberson, 1991, WOCE Report 68/91); Phosphate; Phosphorus, particulate; Pressure, water; Salinity; Seawater analysis after Grasshoff et al., 1983 (Verlag Chemie GmbH Weinheim); Silicate; Silicon, particulate; SO120; SO120_CTD02_002; SO120_CTD03_003; SO120_CTD04_004; SO120_CTD05_005; SO120_CTD06_006; SO120_CTD07_007; SO120_CTD08_008; SO120_CTD09_009; SO120_CTD10_010; SO120_CTD11_011; SO120_CTD12_012; SO120_CTD13_013; SO120_CTD14_014; SO120_CTD15_016; SO120_CTD15_017; SO120_CTD15_019; SO120_CTD16_023; SO120_CTD17_024; SO120_CTD18_027; SO120_CTD18_029; SO120_CTD19_030; SO120_CTD20_033; SO120_CTD20_034; SO120_CTD21_037; SO120_CTD21_038; SO120_CTD22_040; SO120_CTD23_042; SO120_CTD23_043; SO120_CTD24_046; SO120_CTD24_047; SO120_CTD25_050; SO120_CTD25_051; SO120_CTD25_053; SO120_CTD25_054; SO120_CTD28_055; SO120_CTD28_056; SO120_CTD28_057; SO120_CTD31_058; SO120_CTD31_059; SO120_CTD31_060; SO120_CTD34_062; SO120_CTD34_063; SO120_CTD38_066; SO120_CTD39_068; SO120_CTD39_069; SO120_CTD41_071; SO120_CTD41_072; SO120_CTD43_074; SO120_CTD43_075; Sonne; Temperature, water; Thymidine incorporation; Thymidine uptake rate; Tritiated leucine incorporation (Knap et al., 1996, IOC Manuals and Guides 29)
    Type: Dataset
    Format: text/tab-separated-values, 11513 data points
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 2017-01-31
    Repository Name: EPIC Alfred Wegener Institut
    Type: Miscellaneous , notRev
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 5
    Publication Date: 2022-09-13
    Type: Conference or Workshop Item , NonPeerReviewed
    Format: text
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 2020-06-18
    Description: High primary productivity in the equatorial Atlantic and Pacific oceans is one of the key features of tropical ocean biogeochemistry and fuels a substantial flux of particulate matter towards the abyssal ocean. How biological processes and equatorial current dynamics shape the particle size distribution and flux, however, is poorly understood. Here we use high-resolution size-resolved particle imaging and Acoustic Doppler Current Profiler data to assess these influences in equatorial oceans. We find an increase in particle abundance and flux at depths of 300 to 600 m at the Atlantic and Pacific equator, a depth range to which zooplankton and nekton migrate vertically in a daily cycle. We attribute this particle maximum to faecal pellet production by these organisms. At depths of 1,000 to 4,000 m, we find that the particulate organic carbon flux is up to three times greater in the equatorial belt (1° S–1° N) than in off-equatorial regions. At 3,000 m, the flux is dominated by small particles less than 0.53 mm in diameter. The dominance of small particles seems to be caused by enhanced active and passive particle export in this region, as well as by the focusing of particles by deep eastward jets found at 2° N and 2° S. We thus suggest that zooplankton movements and ocean currents modulate the transfer of particulate carbon from the surface to the deep ocean.
    Type: Article , PeerReviewed
    Format: text
    Format: text
    Format: video
    Format: video
    Format: video
    Format: video
    Format: video
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 7
    facet.materialart.
    Unknown
    Copernicus Publications (EGU)
    In:  Geoscientific Model Development, 10 . pp. 127-154.
    Publication Date: 2020-02-06
    Description: Global biogeochemical ocean models contain a variety of different biogeochemical components and often much simplified representations of complex dynamical interactions, which are described by many (≈10–≈100) parameters. The values of many of these parameters are empirically difficult to constrain, due to the fact that in the models they represent processes for a range of different groups of organisms at the same time, while even for single species parameter values are often difficult to determine in situ. Therefore, these models are subject to a high level of parametric uncertainty. This may be of consequence for their skill with respect to accurately describing the relevant features of the present ocean, as well as their sensitivity to possible environmental changes. We here present a framework for the calibration of global biogeochemical ocean models on short and long time scales. The framework combines an offline approach for transport of biogeochemical tracers with an Estimation of Distribution Algorithm (Covariance Matrix Adaption Evolution Strategy, CMAES). We explore the performance and capability of this framework by five different optimizations of six biogeochemical parameters of a global biogeochemical model. First, a twin experiment explores the feasibility of this approach. Four optimizations against a climatology of observations of annual mean dissolved nutrients and oxygen determine the extent, to which different setups of the optimization influence model's fit and parameter estimates. Because the misfit function applied focuses on the large-scale distribution of inorganic biogeochemical tracers, parameters that act on large spatial and temporal scales are determined earliest, and with the least spread. Parameters more closely tied to surface biology, which act on shorter time scales, are more difficult to determine. In particular the search for optimum zooplankton parameters can benefit from a sound knowledge of maximum and minimum parameter values, leading to a more efficient optimization. It is encouraging that, although the misfit function does not contain any direct information about biogeochemical turnover, the optimized models nevertheless provide a better fit to observed global biogeochemical fluxes.
    Type: Article , PeerReviewed
    Format: text
    Format: archive
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 8
    Publication Date: 2019-09-23
    Description: The Apparent Oxygen Utilisation (AOU) is a classical measure of the amount of oxygen respired in the ocean's interior. We show that AOU systematically overestimates True Oxygen Utilisation (TOU) in 6 coupled circulation-biogeochemical ocean models. This is due to atmosphere–ocean oxygen disequilibria in the subduction regions, consistent with previous work. We develop a simple, new, observationally-based approach which we call Evaluated Oxygen Utilisation (EOU). In this approach, we take into account the impact of the upper ocean oxygen disequilibria into the interior, considering that transport takes place predominantly along isopycnal surfaces. The EOU approximates the TOU with less than half of the bias of AOU in all 6 models despite large differences in the physical and biological components of the models. Applying the EOU approach to a global observational dataset yields an oxygen consumption rate 25% lower than that derived from AOU-based estimates, for a given ventilation rate.
    Type: Article , PeerReviewed
    Format: text
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 9
    Publication Date: 2019-09-23
    Description: Highlights: • We examine the role of marine particle for regulating trace element distribution. • We review the state of the art for modelling the oceanic distribution of specific tracers: Thorium, Protactinium, Iron, and Aluminium. • We review the state of the art for modelling particle distribution in large scale ocean biogeochemical model. The distribution of trace elements in the ocean is governed by the combined effects of various processes, and by exchanges with external sources. Modelling these represents an opportunity to better understand and quantify the mechanisms that regulate the oceanic tracer cycles. Observations collected during the GEOTRACES program provide an opportunity to improve our knowledge regarding processes that should be considered in biogeochemical models to adequately represent the distributions of trace elements in the ocean. Here we present a synthesis about the state of the art for simulating selected trace elements in biogeochemical models: Protactinium, Thorium, Iron and Aluminium. In this contribution we pay particular attention on the role of particles in the cycling of these tracers and how they may provide additional constraints on the transfer of matter in the ocean.
    Type: Article , PeerReviewed
    Format: text
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 10
    Publication Date: 2019-09-23
    Description: Although of substantial importance for marine tracer distributions and eventually global carbon, oxygen, and nitrogen fluxes, the interaction between sinking and remineralization of organic matter, benthic fluxes and burial is not always represented consistently in global biogeochemical models. We here aim to investigate the relationships between these processes with a suite of global biogeochemical models, each simulated over millennia, and compared against observed distributions of pelagic tracers and benthic and pelagic fluxes. We concentrate on the representation of sediment–water interactions in common numerical models, and investigate their potential impact on simulated global sediment–water fluxes and nutrient and oxygen distributions. We find that model configurations with benthic burial simulate global oxygen well over a wide range of possible sinking flux parameterizations, making the model more robust with regard to uncertainties about the remineralization length scale. On a global scale, burial mostly affects oxygen in the meso- to bathypelagic zone. While all model types show an almost identical fit to observed pelagic particle flux, and the same sensitivity to particle sinking speed, comparison to observational estimates of benthic fluxes reveals a more complex pattern, but definite interpretation is not straightforward because of heterogeneous data distribution and methodology. Still, evaluating model results against observed pelagic and benthic fluxes of organic matter can complement model assessments based on more traditional tracers such as nutrients or oxygen. Based on a combined metric of dissolved tracers and biogeochemical fluxes, we here identify two model descriptions of burial as suitable candidates for further experiments and eventual model refinements.
    Type: Article , PeerReviewed , info:eu-repo/semantics/article
    Format: text
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...