• 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

    Circulation around a thin zonal island

    Thumbnail
    View/Open
    Wells Circulation.pdf (883.2Kb)
    Date
    2001-06-22
    Author
    Wells, Judith R.  Concept link
    Helfrich, Karl R.  Concept link
    Metadata
    Show full item record
    Citable URI
    https://hdl.handle.net/1912/153
    As published
    https://doi.org/10.1017/S0022112001004402
    DOI
    10.1017/S0022112001004402
    Keyword
     Zonal boundary layer dynamics; Island Rule 
    Abstract
    Laboratory and numerical experiments are used to study flow of a uniform-density fluid on the [beta]-plane around a thin zonally elongated island (or ridge segment in the abyss). This orientation is chosen specifically to highlight the roles of the zonal boundary layer dynamics in controlling the circulation around the island. There are examples of deep ocean topography that fall into this category which make the work directly applicable to oceanic flows. Linear theory for the transport around the island and the flow structure is based on a modification of the Island Rule (Pedlosky et al. 1997; Pratt & Pedlosky 1999). The linear solution gives a north–south symmetric flow around the island with novel features, including stagnation points which divide the zonal boundary layers into eastward and westward flowing zones, and a western boundary layer of vanishing length, and zonal jets. Laboratory experiments agree with the linear theory for small degrees of nonlinearity, as measured by the ratio of the inertial to Munk boundary layer scales. With increasing nonlinearity the north–south symmetry is broken. The southern stagnation point (for anticyclonic forcing) moves to the eastern tip of the island. The flow rounding the eastern tip from the northern side of the island now separates from the island. Time-dependence emerges and recirculation cells develop on the northern side of the island. Mean transport around the island is relatively unaffected by nonlinearity and given to within 20% by the modified Island Rule. Numerical solutions of the shallow water equations are in close agreement with the laboratory results. The transition from zonal to meridional island orientation occurs for island inclinations from zonal greater than about 20°.
    Description
    Author Posting. © Cambridge University Press, 2001. This article is posted here by permission of Cambridge University Press for personal use, not for redistribution. The definitive version was published in Journal of Fluid Mechanics 437 (2001): 301-323, doi:10.1017/S0022112001004402.
    Collections
    • Physical Oceanography (PO)
    Suggested Citation
    Journal of Fluid Mechanics 437 (2001): 301-323
     

    Related items

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

    • Thumbnail

      Role of eddy forcing in the dynamics of multiple zonal jets in a model of the North Atlantic 

      Kamenkovich, Igor V.; Berloff, Pavel S.; Pedlosky, Joseph (American Meteorological Society, 2009-06)
      Multiple zonal jets are observed in satellite data–based estimates of oceanic velocities, float measurements, and high-resolution numerical simulations of the ocean circulation. This study makes a step toward understanding ...
    • Thumbnail

      A model of multiple zonal jets in the oceans : dynamical and kinematical analysis 

      Berloff, Pavel S.; Kamenkovich, Igor V.; Pedlosky, Joseph (American Meteorological Society, 2009-11)
      Multiple alternating zonal jets observed in the ocean are studied with an idealized quasigeostrophic zonal-channel model, with the supercritical, zonal background flow imposed. Both eastward and westward background flows ...
    • Thumbnail

      Hydraulics and instabilities of quasi-geostrophic zonal flows 

      Ralph, Elise A. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1994-09)
      The thesis addresses the applicability of traditional hydraulic theory to an unstable, mid-latitude jet where the only wave present is the Rossby wave modified by shear. While others (Armi 1989, Pratt 1989, Haynes et ...
    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