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  • 1
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    Vertical flux reconstruction for sediment cores off Chile
    PANGAEA
    In:  Supplement to: Dezileau, Laurent; Ulloa, Osvaldo; Hebbeln, Dierk; Lamy, Frank; Reyss, Jean-Louis (2004): Iron control of past productivity in the coastal upwelling system off the Atacama Desert, Chile. Paleoceanography, 19(3), PA3012, https://doi.org/10.1029/2004PA001006
    Details
    Publication Date: 2023-05-12
    Description: Biogenic opal and organic carbon vertical rain rates in sediment cores reveal a strong cyclicity in the productivity of the upwelling system off presently arid northern Chile during the last 100,000 years. Changes in productivity are found to be in phase with the precessional cycle (~20,000 years) and with inputs of iron from the continent. During austral summer insolation maxima, increased precipitation and river runoff in the region appear to have brought high inputs of iron, mainly from the Andes, to the coastal ocean enhancing primary productivity there. We interpret our results as providing evidence for iron control of past productivity in this upwelling system and for a tight link between productivity and orbital forcing at midlatitudes.
    Type: Dataset
    Format: application/zip, 2 datasets
    Location Call Number Limitation Availability
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    DATA PANGAEA
  • 2
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    Global distributions of picophytoplankton abundance and biomass - Gridded data product (NetCDF) - Contribution to the MAREDAT World Ocean Atlas of Plankton Functional Types (2012)
    PANGAEA
    Details
    Publication Date: 2023-03-27
    Description: The smallest marine phytoplankton, collectively termed picophytoplankton, have been routinely enumerated by flow cytometry since the late 1980s, during cruises throughout most of the world ocean. We compiled a database of 40,946 data points, with separate abundance entries for Prochlorococcus, Synechococcus and picoeukaryotes. We use average conversion factors for each of the three groups to convert the abundance data to carbon biomass. After gridding with 1° spacing, the database covers 2.4% of the ocean surface area, with the best data coverage in the North Atlantic, the South Pacific and North Indian basins. The average picophytoplankton biomass is 12 ± 22 µg C L-1 or 1.9 g C m-2. We estimate a total global picophytoplankton biomass, excluding N2-fixers, of 0.53 - 0.74 Pg C (17 - 39 % Prochlorococcus, 12 - 15 % Synechococcus and 49 - 69 % picoeukaryotes). Future efforts in this area of research should focus on reporting calibrated cell size, and collecting data in undersampled regions.
    Keywords: MAREMIP; MARine Ecosystem Model Intercomparison Project
    Type: Dataset
    Format: application/zip, 6.6 MBytes
    Location Call Number Limitation Availability
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    DATA PANGAEA
  • 3
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    (Table 2) Age determination of sediment core GeoB7139-2
    PANGAEA
    In:  Supplement to: De Pol-Holz, Ricardo; Ulloa, Osvaldo; Lamy, Frank; Dezileau, Laurent; Sabatier, Pierre; Hebbeln, Dierk (2007): Late Quaternary variability of sedimentary nitrogen isotopes in the eastern South Pacific Ocean. Paleoceanography, 22(2), PA2207, https://doi.org/10.1029/2006PA001308
    Details
    Publication Date: 2023-06-27
    Description: We present high-resolution bulk sedimentary d15N data from the southern edge of the present-day oxygen minimum zone of the eastern South Pacific. The record is interpreted as representing changes in water column nitrogen removal during the last 70,000 years. We found significant fluctuations in the isotopic signal that suggest major reorganizations of the oxygen minimum zone at millennial timescales. These fluctuations were not related to other millennial-scale changes like the Northern Hemisphere's Dansgaard-Oeschger climate swings or local changes in primary productivity, so appear to be dictated by the Southern Hemisphere's climate rhythm. This is preliminarily corroborated by an overall agreement between our d15N data and the sedimentary proxy of ice sheet dynamics in Patagonia, which is in turn correlated with surface water properties at the midlatitude subduction region of the eastern South Pacific intermediate waters. Finally, potential implications on late Quaternary changes in atmospheric CO2 concentrations are discussed.
    Keywords: Age, 14C AMS; Age, 14C calibrated; Age, comment; Age, dated; Age, dated standard deviation; Calendar age; DEPTH, sediment/rock; GeoB7139-2; Gravity corer (Kiel type); PUCK; SL; SO156/2; Sonne; South-East Pacific
    Type: Dataset
    Format: text/tab-separated-values, 38 data points
    Location Call Number Limitation Availability
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    DATA PANGAEA
  • 4
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    (Table 2) Vertical fluxes of TOC, opal and iron of sediment core GeoB7101-1
    PANGAEA
    Details
    Publication Date: 2023-06-27
    Keywords: 230Th-normalised; Accumulation rate, uranium, authigenic; AGE; Carbon, organic, flux; Flux, standard deviation; GeoB7101-1; Gravity corer (Kiel type); Iron, flux; Iron, flux, standard deviation; off Chile; Opal, flux; PUCK; Ratio; SL; SO156/1; Sonne; Standard deviation; Thorium-230 excess, decay-corrected; Thorium-230 excess, decay-corrected, standard deviation; Vertical rain rate; Vertical rain rate, standard deviation
    Type: Dataset
    Format: text/tab-separated-values, 416 data points
    Location Call Number Limitation Availability
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    DATA PANGAEA
  • 5
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    (Table 1) Th, TOC and opal content in sediment cores GeoB3375-1 and GeoB7101-1
    PANGAEA
    Details
    Publication Date: 2023-06-27
    Keywords: AGE; Alpha spectrometry; Carbon, organic, total; Carbon, organic, total, standard deviation; CHIPAL; Density, dry bulk; DEPTH, sediment/rock; Element analyser CHN-O Rapid, Heraeus; Event label; GeoB3375-1; GeoB7101-1; Gravity corer (Kiel type); off Chile; Opal, auto analysis (Müller & Schneider, 1993); Opal, biogenic silica; Opal, biogenic silica, standard deviation; PUCK; SL; SO102/2; SO156/1; Sonne; South-East Pacific; Terrigenous; Thorium-230; Thorium-230, standard deviation; Thorium-230 excess; Thorium-230 excess, decay-corrected; Thorium-230 excess, decay-corrected, standard deviation; Thorium-230 excess, standard deviation; Thorium-232; Thorium-232, standard deviation; Uranium-238; Uranium-238, authigenic; Uranium-238, authigenic, standard deviation; Uranium-238, standard deviation; Weight loss during freeze-drying
    Type: Dataset
    Format: text/tab-separated-values, 576 data points
    Location Call Number Limitation Availability
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    DATA PANGAEA
  • 6
    Electronic Resource
    Electronic Resource
    Estimation of new production in the ocean by compound remote sensing (1991)
    [s.l.] : Nature Publishing Group
    Nature 353 (1991), S. 129-133 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Oceanic new production can be estimated from remotely sensed data on ocean colour and temperature. This approach, which depends on parameterizations developed from ship observations, as well as on satellite data, yields more representative estimates of the large-scale average new production than ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/353129a0
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    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Nutrient control of phytoplankton photosynthesis in the Western North Atlantic (1992)
    [s.l.] : Nature Publishing Group
    Nature 356 (1992), S. 229-231 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] The dependence of phytoplankton photosynthesis on light can be determined routinely during oceanographic cruises. Each light-saturation curve is described by two parameters: the initial slope aB, an index of the efficiency of photosynthesis in weak light, and the assimilation number P*, a measure ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/356229a0
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    Paper (German National Licenses)
    Fulltext
  • 8
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    Ammonium and nitrite oxidation at nanomolar oxygen concentrations in oxygen minimum zone waters (2016)
    National Academy of Sciences
    In:  PNAS Proceedings of the National Academy of Sciences of the United States of America, 113 (38). pp. 10601-10606.
    Details
    Publication Date: 2019-02-01
    Description: A major percentage of fixed nitrogen (N) loss in the oceans occurs within nitrite-rich oxygen minimum zones (OMZs) via denitrification and anammox. It remains unclear to what extent ammonium and nitrite oxidation co-occur, either supplying or competing for substrates involved in nitrogen loss in the OMZ core. Assessment of the oxygen (O2) sensitivity of these processes down to the O2 concentrations present in the OMZ core (〈10 nmol⋅L−1) is therefore essential for understanding and modeling nitrogen loss in OMZs. We determined rates of ammonium and nitrite oxidation in the seasonal OMZ off Concepcion, Chile at manipulated O2 levels between 5 nmol⋅L−1 and 20 μmol⋅L−1. Rates of both processes were detectable in the low nanomolar range (5–33 nmol⋅L−1 O2), but demonstrated a strong dependence on O2 concentrations with apparent half-saturation constants (Kms) of 333 ± 130 nmol⋅L−1 O2 for ammonium oxidation and 778 ± 168 nmol⋅L−1 O2 for nitrite oxidation assuming one-component Michaelis–Menten kinetics. Nitrite oxidation rates, however, were better described with a two-component Michaelis–Menten model, indicating a high-affinity component with a Km of just a few nanomolar. As the communities of ammonium and nitrite oxidizers were similar to other OMZs, these kinetics should apply across OMZ systems. The high O2 affinities imply that ammonium and nitrite oxidation can occur within the OMZ core whenever O2 is supplied, for example, by episodic intrusions. These processes therefore compete with anammox and denitrification for ammonium and nitrite, thereby exerting an important control over nitrogen loss.
    Type: Article , PeerReviewed
    Format: text
    DOI: 10.1073/pnas.1600359113
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    OceanRep: Article in a Scientific Journal - peer-reviewed
  • 9
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    Peru–Chile Current System (2019)
    Elsevier
    In:  In: Encyclopedia of Ocean Sciences. Elsevier, ., pp. 437-444. ISBN 978-0-12-813082-7
    Details
    Publication Date: 2020-02-17
    Description: The Peru-Chile Current System (PCCS) is the combined name for the equatorward and poleward currents along the Chilean and Peruvian coasts. The PCCS is a “typical” eastern boundary current system with predominately coast parallel equatorward winds, intensive upwelling, and high biological productivity. An important peculiarity of the PCCS is its tight connection to the equatorial Pacific communicating the globally strongest mode of interannual variability, the “El Niño/Southern Oscillation”, into the region. In addition, at intermediate depths, the PCCS region hosts one of the most intense oxygen-minimum zones that reaches from the coastal areas into the open ocean and influences the ecology and biogeochemical cycling in the region.
    Type: Book chapter , NonPeerReviewed
    DOI: 10.1016/B978-0-12-409548-9.11335-1
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    OceanRep: Book chapter
  • 10
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    Nitrogen assimilation in picocyanobacteria inhabiting the oxygen‐deficient waters of the eastern tropical North and South Pacific (2020)
    ASLO (Association for the Sciences of Limnology and Oceanography) | Wiley
    Details
    Publication Date: 2023-02-08
    Description: Prochlorococcus and Synechococcus are the most abundant free-living photosynthetic microorganisms in the ocean. Uncultivated lineages of these picocyanobacteria also thrive in the dimly illuminated upper part of oxygen-deficient zones (ODZs), where an important portion of ocean nitrogen (N) loss takes place via denitrification and anaerobic ammonium oxidation. Recent metagenomic studies revealed that ODZ Prochlorococcus have the genetic potential for using different N forms, including nitrate and nitrite, uncommon N sources for Prochlorococcus, but common for Synechococcus. To determine which N sources ODZ picocyanobacteria are actually using in nature, the cellular N-15 natural abundance (delta N-15) and assimilation rates of different N compounds were determined using cell sorting by flow cytometry and mass spectrometry. The natural delta N-15 of the ODZ Prochlorococcus varied from -4.0 parts per thousand to 13.0 parts per thousand (n = 9), with 50% of the values in the range of -2.1-2.6 parts per thousand. While the highest values suggest nitrate use, most observations indicate the use of nitrite, ammonium, or a mixture of N sources. Meanwhile, incubation experiments revealed potential assimilation rates of ammonium and urea in the same order of magnitude as that expected for total N in several environments including ODZs, whereas rates of nitrite and nitrate assimilation were very low. Our results thus indicate that reduced forms of N and nitrite are the dominant sources for ODZ picocyanobacteria, although nitrate might be important on some occasions. ODZ picocyanobacteria might thus represent potential competitors with anammox bacteria for ammonium and nitrite, with ammonia-oxidizing archaea for ammonium, and with nitrite-oxidizing bacteria for nitrite.
    Type: Article , PeerReviewed
    Format: text
    Format: text
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    OceanRep: Article in a Scientific Journal - peer-reviewed
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