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
  • 1
    Publication Date: 2021-05-19
    Description: The Cape Verde Front (CVF) separates the North Atlantic subtropical gyre (NASG) from the north-eastern North Atlantic tropical gyre (NATG). Within the NASG, the Canary Current (CC) and the Canary Upwelling Current (CUC) comprise a relatively shallow (down to about 200-300 m) flow of North Atlantic Central Waters (NACW): the CC is found far offshore as a wide and poorly defined current while the CUC is a near-slope intense baroclinic jet linked to the coastal upwelling front. Within the top 300 m of the NATG, the along-slope Mauritania Current and the Cape Verde Current (CVC, a north-eastern extension of the North Equatorial Counter Current that broadly rotates around the Guinea Dome) carry South Atlantic Central Waters northwards. As a result, the frontal system is the site of intense along-slope flow convergence and offshore transport in the top 300 m of the water column. Further deep, down to some 500 m, the interior flow is very weak in both gyres, likely dominated by mesoscale features, except along the continental slope, where the northward Poleward Undercurrent (PUC) feeds through localized inputs from the interior ocean; in particular, within the NATG the CVC appears as responsible for southward transfer of NACW, across the CVF, which eventually reaches the PUC.
    Description: Published
    Keywords: Eastern boundary currents ; Cape Verde Front ; Canary Upwelling Current ; Poleward Undercurrent ; Guinea Dome ; CCLME
    Repository Name: AquaDocs
    Type: Report Section , Refereed
    Format: pp. 81-92
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2021-05-19
    Description: Inorganic nutrients increase with depth as a result of the enhanced remineralization of organic matter with aging waters (the time since they were last near the sea surface), and the opposite happens with dissolved oxygen (except within the saturated surface mixed layer). In the Canary Current Large Marine Ecosystem there is also a marked latitudinal gradient, with the Cape Verde Front separating relatively nutrient-poor and oxygen-rich subtropical waters from the nutrient-rich and oxygen-poor tropical waters. Along a latitudinal band off North-West Africa, coastal upwelling brings the subsurface waters towards the sea surface, locally raising the inorganic nutrient levels. This becomes an important lateral source to both gyres, especially to the nutrient-poor subtropical one, taking place through lateral mixing (mainly as a result of the instability of the coastal-upwelling baroclinic jet) and localized coastal filaments (in those regions, typically capes, where the coastal flow converges and offshore advection takes place). In the southernmost portion of our domain, within tropical waters, there is also high (wind-induced) offshore primary production. This, together with the slow ventilation of the subsurface waters, leads to much enhanced remineralization, producing a region with very low oxygen and high inorganic nutrient levels, the oxygen minimum zone of the North Atlantic Ocean.
    Description: Published
    Keywords: Cape Verde Front ; Inorganic nutrient supply ; Biogeochemical processes ; Spatial distributions ; Oxygen minimum zone ; CCLME
    Repository Name: AquaDocs
    Type: Report Section , Refereed
    Format: pp. 133-142
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 3
    facet.materialart.
    Unknown
    IOC-UNESCO | Paris, France
    Publication Date: 2021-05-19
    Description: North of Cape Blanc, the north-easterly winds cause offshore flow of surface waters that are replaced by subsurface inflow of relatively cold and nutrient-rich waters, driving the vertical cell of coastal upwelling. This vertical circulation, together with surface heating and horizontal mixing, causes the coastal upwelling front (typically about 200 m deep) that separates cold onshore from warm offshore waters. A southward baroclinic coastal jet is associated to this front, which causes vertical shear and mixing that contribute to the intensity of the vertical cell. Very importantly, this jet feeds from upstream waters, resulting in an along-slope coherent flow, or the horizontal cell of coastal upwelling – this is the Canary Upwelling Current (CUC) that connects all surface coastal African waters north of Cape Blanc. Further south, because of the northward offshore flow and the seasonality of the winds, the connection remains only during winter and spring, very close to shelf break and in the top 100 m. North of Cape Blanc, a Poleward Undercurrent (PUC) flows in the relatively homogenous upwelled waters that found over the continental slope. South of Cape Blanc the PUC appears as a nearshore expression of the Mauritania Current. Both the southward CUC and the northward PUC constitute the true skeleton of the Canary Current Large Marine Ecosystem.
    Description: Published
    Keywords: Coastal upwelling ; Recirculation cells ; Canary Upwelling Current ; Poleward Undercurrent ; CCLME ; ASFA15::E::Ekman transport
    Repository Name: AquaDocs
    Type: Report Section , Refereed
    Format: pp. 93-103
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 2022-05-26
    Description: © The Author(s), 2016. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Ocean Science 12 (2016): 137-151, doi:10.5194/os-12-137-2016.
    Description: We investigate the rapidly changing equilibrium between the momentum sources and sinks during the passage of a single two-peak storm over the Catalan inner shelf (NW Mediterranean Sea). Velocity measurements at 24 m water depth are taken as representative of the inner shelf, and the cross-shelf variability is explored with measurements at 50 m water depth. During both wind pulses, the flow accelerated at 24 m until shortly after the wind maxima, when the bottom stress was able to compensate for the wind stress. Concurrently, the sea level also responded, with the pressure-gradient force opposing the wind stress. Before, during and after the second wind pulse, there were velocity fluctuations with both super- and sub-inertial periods likely associated with transient coastal waves. Throughout the storm, the Coriolis force and wave radiation stresses were relatively unimportant in the along-shelf momentum balance. The frictional adjustment timescale was around 10 h, consistent with the e-folding time obtained from bottom drag parameterizations. The momentum evolution at 50 m showed a larger influence of the Coriolis force at the expense of a decreased frictional relevance, typical in the transition from the inner to the mid-shelf.
    Description: This work was supported by DARDO (ENE2012-38772-C02-02), Rises-AM (GA603396), Plan-Wave (CTM2013-45141-R) and ICoast project (Echo/SUB/2013/661009).
    Repository Name: Woods Hole Open Access Server
    Type: Article
    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...