ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

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
    Oxygen minimum zone cryptic sulfur cycling sustained by offshore transport of key sulfur oxidizing bacteria (2018)
    Nature Research
    In:  Nature Communications, 9 (1729).
    Details
    Publication Date: 2021-02-08
    Description: Members of the gammaproteobacterial clade SUP05 couple water column sulfide oxidation to nitrate reduction in sulfidic oxygen minimum zones (OMZs). Their abundance in offshore OMZ waters devoid of detectable sulfide has led to the suggestion that local sulfate reduction fuels SUP05-mediated sulfide oxidation in a so-called “cryptic sulfur cycle”. We examined the distribution and metabolic capacity of SUP05 in Peru Upwelling waters, using a combination of oceanographic, molecular, biogeochemical and single-cell techniques. A single SUP05 species, UThioglobus perditus, was found to be abundant and active in both sulfidic shelf and sulfide-free offshore OMZ waters. Our combined data indicated that mesoscale eddy-driven transport led to the dispersal of UT. perditus and elemental sulfur from the sulfidic shelf waters into the offshore OMZ region. This offshore transport of shelf waters provides an alternative explanation for the abundance and activity of sulfide-oxidizing denitrifying bacteria in sulfide-poor offshore OMZ waters.
    Type: Article , PeerReviewed
    Format: text
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OCEANREP)
  • 2
    facet.materialart.
    Unknown
    Submesoscale CO2 variability across an upwelling front off Peru (2017)
    Copernicus Publications (EGU)
    In:  Ocean Science, 13 (6). pp. 1017-1033.
    Details
    Publication Date: 2020-02-06
    Description: As a major source for atmospheric CO2, the Peruvian upwelling region exhibits strong variability in surface fCO2 on short spatial and temporal scales. Understanding the physical processes driving the strong variability is of fundamental importance for constraining the effect of marine emissions from upwelling regions on the global CO2 budget. In this study, a frontal decay on length scales of 𝒪(10 km) was observed off the Peruvian coast following a pronounced decrease in down-frontal (equatorward) wind speed with a time lag of 9 h. Simultaneously, the sea-to-air flux of CO2 on the inshore (cold) side of the front dropped from up to 80 to 10 mmol m−2 day−1, while the offshore (warm) side of the front was constantly outgassing at a rate of 10–20 mmol m−2 day−1. Based on repeated ship transects the decay of the front was observed to occur in two phases. The first phase was characterized by a development of coherent surface temperature anomalies which gained in amplitude over 6–9 h. The second phase was characterized by a disappearance of the surface temperature front within 6 h. Submesoscale mixed-layer instabilities were present but seem too slow to completely remove the temperature gradient in this short time period. Dynamics such as a pressure-driven gravity current appear to be a likely mechanism behind the evolution of the front.
    Type: Article , PeerReviewed , info:eu-repo/semantics/article
    Format: text
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OCEANREP)
  • 3
    facet.materialart.
    Unknown
    Eastern boundary circulation and hydrography off Peru during the 2017 Coastal El Nino (2018)
    In:  [Talk] In: Ocean Science Meeting 2018, 12.-16.02.2018, Portland, OR, USA .
    Details
    Publication Date: 2019-09-23
    Description: In early 2017 sea surface temperatures in the far eastern tropical Pacific were anomalously high while central Pacific SST anomalies remained neutral or negative. Associated to this anomaly pattern were strong anomalous precipitation events in northern Peru causing severe flooding. During April and May 2017 the near-coastal temperature anomalies declined. In-situ observations from four consecutive research cruises and a glider survey collected between 12°S and 14°S off the coast of Peru are used to describe the eastern boundary circulation and hydrography during declining surface temperature anomalies. The observational data base consists of ship-board hydrography, oxygen and upper-ocean velocity observations, hydrography from glider surveys and velocity time series from mooring deployments. Hydrography at 12°S shows a pronounced warm anomaly near the surface and on the shelf where the full water column warmed by more than 2°C with respect to climatology. Further offshore, a weaker warming was observed below the surface layer as well. The oxycline was displaced downwards and well-oxygenated waters occupied the upper 50m of the water column. Poleward velocities of the Peru-Chile Undercurrent strongly intensified in late-April and May reaching velocities above 50 cm s-1. During this period, near-surface temperature anomalies decreased but subsurface temperatures on the shelf remained high. The forcing of the observed variability of the eastern boundary circulation and of the hydrography during the late phase of the “Coastal El Niño” event is investigated and related to local and remote processes.
    Type: Conference or Workshop Item , NonPeerReviewed
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OCEANREP)
  • 4
    facet.materialart.
    Unknown
    The formation of an anticyclonic mode water eddy within the Peru-Chile Undercurrent (2014)
    In:  [Poster] In: EGU General Assembly 2014, 27.04.-02.05.2014, Vienna, Austria .
    Details
    Publication Date: 2015-01-15
    Description: The formation of an anticyclonic mode water eddy in Jan/Feb 2013 within the Peru-Chile Undercurrent is presented based on a multi-platform observational study. Two consecutive research cruises, a glider swarm experiment and moored measurements were conducted as part of the interdisciplinary "SFB 754 Climate-Biogeochemistry Interactions in the Tropical Ocean" project within the Peruvian upwelling regime at 12°S. The dataset allows a detailed investigation of the eddy generation process and its impacts on the near-coastal hydrography and biogeochemistry in space and time. The near-coastal horizontal circulation off Peru at 12°S changes significantly over the two months of observation. In early January, we observe a strong but clear Peru-Chile Undercurrent with maximal pole-ward velocities of ~25 cm/s in 100 - 200 m depth. A week later the vertical shear starts to increases and finally a mode water eddy forms. The eddy has a velocity maximum of ~0.3 m/s in 100 - 200 m depth and a radius of ~45 km. The eddy induced circulation strongly influences the near-coastal hydrography: Across-shore velocities result in an exchange of water masses between the shelf-break and the offshore ocean. At the eddy edge small scale salinity anomalies are found, which seem to be formed by mesoscale stirring. Energetic near-inertial oscillations are observed in the deeper water column during eddy generation that appear to be associated with this feature. After its generation close to the shelf break the eddy propagates westwards.
    Type: Conference or Workshop Item , NonPeerReviewed
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OCEANREP)
  • 5
    facet.materialart.
    Unknown
    Meso and submesoscale variability within the upwelling regime off Peru observed by a fleet of gliders (2014)
    In:  [Poster] In: Ocean Sciences Meeting 2014, 23.-28.02.2014, Honululu, Hawaii, USA .
    Details
    Publication Date: 2019-09-23
    Description: In meso- and submesoscale regimes a strong physical-biogeochemical coupling is thought to exist. A swarm experiment with seven gliders equipped with sensors measuring pressure, temperature, salinity, oxygen and chlorophyll fluorescence was conducted in early 2013 within the upwelling region off Peru. The goal was to study near-coastal pathways for the supply of oxygen from the mixed layer to the oxygen minimum zone. Each glider carried out about one dive per hour measuring two multi-parameter profiles with a lateral resolution of about 500 m. More than 15.000 profiles were recorded during the two-months deployment within a small spatial area to capture both the temporal and spatial variability of the physical and biochemical parameters. The glider-based data show small-scale structures of different tracers such as salinity and oxygen at different depths. There are pronounced density compensated salinity anomalies at about 150 m depth, where lateral eddy-stirring of the lateral background salinity gradient is suggested as the main formation mechanism. Near the surface, non-density compensated salinity and oxygen intrusions are observed, which reached well below the mixed layer. These structures are found in areas of strong lateral density fronts. This suggests that submesoscale frontal processes are responsible for the observed structures. The role of these meso- and submesoscale processes for the near coastal vertical oxygen supply is discussed.
    Type: Conference or Workshop Item , NonPeerReviewed
    Format: image
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OCEANREP)
  • 6
    facet.materialart.
    Unknown
    Near-inertial waves interacting with a coherent anticyclone off Peru (2015)
    In:  [Poster] In: Workshop on Energy transfers in Atmosphere and Ocean, 20.-22.04.2015, Hamburg, Germany .
    Details
    Publication Date: 2019-09-23
    Type: Conference or Workshop Item , NonPeerReviewed
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OCEANREP)
  • 7
    facet.materialart.
    Unknown
    The formation of a subsurface anticyclonic eddy in the Peru-Chile Undercurrent and its impact on the near-coastal salinity, oxygen and nutrient distributions (2016)
    AGU (American Geophysical Union) | Wiley
    In:  Journal of Geophysical Research: Oceans, 121 (1). pp. 476-501.
    Details
    Publication Date: 2019-09-23
    Description: The formation of a subsurface anticyclonic eddy in the Peru-Chile Undercurrent (PCUC) in January and February 2013 is investigated using a multi-platform four-dimensional observational approach. Research vessel, multiple glider and mooring-based measurements were conducted in the Peruvian upwelling regime near 12°30'S. The dataset consists of 〉 10000 glider profiles and repeated vessel-based hydrography and velocity transects. It allows a detailed description of the eddy formation and its impact on the near-coastal salinity, oxygen and nutrient distributions. In early January, a strong PCUC with maximum poleward velocities of ∼ 0.25 m/s at 100 to 200 m depth was observed. Starting on January 20 a subsurface anticyclonic eddy developed in the PCUC downstream of a topographic bend, suggesting flow separation as the eddy formation mechanism. The eddy core waters exhibited oxygen concentrations 〈 1μmol/kg, an elevated nitrogen-deficit of ∼ 17μmol/l and potential vorticity close to zero, which seemed to originate from the bottom boundary layer of the continental slope. The eddy-induced across-shelf velocities resulted in an elevated exchange of water masses between the upper continental slope and the open ocean. Small scale salinity and oxygen structures were formed by along-isopycnal stirring and indications of eddy-driven oxygen ventilation of the upper oxygen minimum zone were observed. It is concluded that mesoscale stirring of solutes and the offshore transport of eddy core properties could provide an important coastal open-ocean exchange mechanism with potentially large implications for nutrient budgets and biogeochemical cycling in the oxygen minimum zone off Peru.
    Type: Article , PeerReviewed
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OCEANREP)
  • 8
    facet.materialart.
    Unknown
    Meso and submesoscale variability within the Peruvian upwelling regime observed by a fleet of seven gliders (2014)
    In:  [Talk] In: Institut Pierre Simon Laplace, 10.10.2014, Paris, France .
    Details
    Publication Date: 2015-01-15
    Description: A swarm experiment with seven gliders equipped with sensors measuring pressure, temperature, salinity, oxygen and chlorophyll fluorescence was conducted in early 2013 within the upwelling region off Peru. The goal was to study the role of meso- and submesoscale proccesses for the near-coastal oxygen ventilation of the Peruvian oxygen minimum zone. Each glider carried out about one dive per hour measuring two multi-parameter profiles with a lateral resolution less than 300 m. About 15.000 profiles were recorded during the two-months deployment within a small spatial area to capture both the temporal and spatial variability of the physical and biochemical parameters. Two main results are presented in the talk: 1) The formation of a low oxygen mode water eddy within the Peru Chile Undercurrent is observed. The near-coastal horizontal circulation off Peru at 12°S changes significantly over the two months of observation. In early January, we observe a pronounced Peru-Chile Undercurrent with maximal poleward velocities of 25 cm/s in 100 - 200 m depth. A week later the circulation start to change and a mode water eddy forms within the glider field. The physical and biogeochemical eddy properties and impacts on the near-coastal salinity and oxygen distribution are described in detail. 2) During an upwelling event the formation and decay of a submesoscale cold water filament is present in the sea surface temperature and glider data. Near the surface, non-density compensated salinity and oxygen intrusions are observed which seem to be associated with this feature. These anomalies reach well below the mixed layer into the thermocline and frontal subduction is suggested as their formation mechanism.
    Type: Conference or Workshop Item , NonPeerReviewed
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OCEANREP)
  • 9
    facet.materialart.
    Unknown
    Water column biogeochemistry of oxygen minimum zones in the eastern tropical North Atlantic and eastern tropical South Pacific Oceans (2016)
    Copernicus Publications (EGU)
    In:  Biogeosciences (BG), 13 . pp. 3585-3606.
    Details
    Publication Date: 2019-09-23
    Description: Recent modeling results suggest that oceanic oxygen levels will decrease significantly over the next decades to centuries in response to climate change and altered ocean circulation. Hence the future ocean may experience major shifts in nutrient cycling triggered by the expansion and intensification of tropical oxygen minimum zones (OMZs). There are numerous feedbacks between oxygen concentrations, nutrient cycling and biological productivity; however, existing knowledge is insufficient to understand physical, chemical and biological interactions in order to adequately assess past and potential future changes. We investigated the pelagic biogeochemistry of OMZs in the eastern tropical North Atlantic and eastern tropical South Pacific during a series of cruise expeditions and mesocosm studies. The following summarizes the current state of research on the influence of low environmental oxygen conditions on marine biota, viruses, organic matter formation and remineralization with a particular focus on the nitrogen cycle in OMZ regions. The impact of sulfidic events on water column biogeochemistry, originating from a specific microbial community capable of highly efficient carbon fixation, nitrogen turnover and N2O production is further discussed. Based on our findings, an important role of sinking particulate organic matter in controlling the nutrient stochiometry of the water column is suggested. These particles can enhance degradation processes in OMZ waters by acting as microniches, with sharp gradients enabling different processes to happen in close vicinity, thus altering the interpretation of oxic and anoxic environments.
    Type: Article , PeerReviewed
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OCEANREP)
  • 10
    facet.materialart.
    Unknown
    Upper ocean mixing processes and their impact on the mixed layer heat balance during the onset of the Atlantic Cold Tongue (2012)
    In:  [Talk] In: Tropical Atlantic Variability Meeting / PIRATA-17 Meeting , 10.-15.09.2012, Kiel, Germany .
    Details
    Publication Date: 2012-10-09
    Type: Conference or Workshop Item , NonPeerReviewed
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OCEANREP)
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...