• Login
    About WHOAS
    View Item 
    •   WHOAS Home
    • Woods Hole Oceanographic Institution
    • Physical Oceanography (PO)
    • View Item
    •   WHOAS Home
    • Woods Hole Oceanographic Institution
    • Physical Oceanography (PO)
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Browse

    All of WHOASCommunities & CollectionsBy Issue DateAuthorsTitlesKeywordsThis CollectionBy Issue DateAuthorsTitlesKeywords

    My Account

    LoginRegister

    Statistics

    View Usage Statistics

    Characteristics and evolution of an Agulhas ring

    Thumbnail
    View/Open
    Casanova-Masjoan_et_al-2017-Journal_of_Geophysical_Research__Oceans.pdf (3.676Mb)
    Date
    2017-09-01
    Author
    Casanova-Masjoan, Maria  Concept link
    Pelegrí, Josep  Concept link
    Sangrà, Pablo  Concept link
    Martínez-Marrero, Antonio  Concept link
    Grisolía-Santos, Diana  Concept link
    Pérez-Hernández, M. Dolores  Concept link
    Hernández-Guerra, Alonso  Concept link
    Metadata
    Show full item record
    Citable URI
    https://hdl.handle.net/1912/9395
    As published
    https://doi.org/10.1002/2017JC012969
    DOI
    10.1002/2017JC012969
    Keyword
     Agulhas ring; Rotational transport; Altimetry; Drifters; Property anomalies 
    Abstract
    A South Atlantic ring is studied through remote sensing altimetry, hydrographic stations, and drifters' trajectories. The ring's core was characterized by warmer and saltier Indian Ocean waters. At the time of the cruise, the ring's signature extended radially out to 124 km and vertically down to 2000 m, and its core absolute dynamic topography (ADT) exceeded the surrounding Atlantic Ocean waters in 0.4 m. The geostrophic velocities were anticyclonic with maximum speeds about 35 cm s−1 at 100 m and reaching negligible values near 4500 m. The rotational transport inside the ring was 33 Sv in the thermocline and intermediate layers. The drifters' data distinguish a 30-km core revolving as a solid body with periodicity near 5 days and a transitional band that revolves with constant tangential velocity, resembling a Rankine vortex. The ADT data identify the ring's track, showing that it was shed by the Agulhas Current retroflection in November 2009 and propagated northwest rapidly during the first 2 months (mean speed of about 10 cm s−1) but slowed down substantially (3–4 cm s−1) between March and July 2010, when it was last detected. The altimetry data also outlines the evolution of the ring's core ADT, radius, vorticity, and, through a simple calibration with the cruise data, rotational transport. In particular, the ring surface and vertical-mean vorticity decay with time scales of 373 and 230 days, respectively, indicating that most of the property anomalies contained by the ring are diffused out to the subtropical gyre before it reaches the western boundary current system.
    Description
    Author Posting. © American Geophysical Union, 2017. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Oceans 122 (2017): 7049–7065, doi:10.1002/2017JC012969.
    Collections
    • Physical Oceanography (PO)
    Suggested Citation
    Journal of Geophysical Research: Oceans 122 (2017): 7049–7065
     

    Related items

    Showing items related by title, author, creator and subject.

    • Thumbnail

      Agulhas leakage into the Atlantic estimated with subsurface floats and surface drifters 

      Richardson, Philip L. (2006-12-02)
      Surface drifters and subsurface floats drifting at depths near 800 m were used to study the pathways of warm salty Indian Ocean water leaking into the South Atlantic that is a component of the upper limb of the Atlantic ...
    • Thumbnail

      Continental crust beneath the Agulhas Plateau, southwest Indian Ocean 

      Tucholke, Brian E.; Houtz, Robert E.; Barrett, Douglas M. (American Geophysical Union, 1981-05-10)
      The Agulhas Plateau lies 500 km off the Cape of Good Hope in the southwestern Indian Ocean. Acoustic basement beneath the northern one third of this large, aseismic structural high has rugged morphology, but basement in ...
    • Thumbnail

      Satellite image processing for the Agulhas Retroflexion region 

      Luetkemeyer, Kelly (Woods Hole Oceanographic Institution, 1987-07)
      In order to analyze the Advanced Very High Resolution Radiometer satellite data from South Africa, a software package has been written. Methodology and algorithms are described which create geometrically corrected ...
    All Items in WHOAS are protected by original copyright, with all rights reserved, unless otherwise indicated. WHOAS also supports the use of the Creative Commons licenses for original content.
    A service of the MBLWHOI Library | About WHOAS
    Contact Us | Send Feedback | Privacy Policy
    Core Trust Logo