• Login
    About WHOAS
    View Item 
    •   WHOAS Home
    • Woods Hole Oceanographic Institution
    • Academic Programs
    • WHOI Theses
    • View Item
    •   WHOAS Home
    • Woods Hole Oceanographic Institution
    • Academic Programs
    • WHOI Theses
    • 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

    On the role of topography and of boundary forcing in the ocean circulation

    Thumbnail
    View/Open
    Cessi_thesis.pdf (4.662Mb)
    Date
    1987-08
    Author
    Cessi, Paola  Concept link
    Metadata
    Show full item record
    Citable URI
    https://hdl.handle.net/1912/3947
    DOI
    10.1575/1912/3947
    Keyword
     Ocean circulation; Oceanic mixing 
    Abstract
    This thesis consists of two loosely related problems, both of which analyze some consequences of the failure of Sverdrup relation. In the first part, Chapters 2 and 3, the Sverdrup relation is invalidated because substantial flow is obtained at the bottom where topography exists. The eddies play an essential role in transfering momentum vertically from the surface, where the forcing is applied, to the bottom, which is otherwise unforced. If the topography has a structure in the longitudinal direction, then the inviscid theory predicts the occurence of strong jets in the interior of the model ocean. According to the structure of the topography these internal jets can occur in both vertically homeogenous and baroclinic oceans. If the topographic slope changes sign, then one kind of jets is observed both in stratified and in homogeneous oceans. This phenomenon is robust to moderate amounts of dissipation and is not disturbed by the occurrence of recirculating gyres within the basin. If the topographic slope is constant, then another kind of internal jets is observed, and it occurs in stratified models only. I was unable to observe this kind of jets in the presence of weak dissipation. The reason for this failure is twofold: on one hand friction, especially interfacial friction, tends to make the flow more barotropic (and we believe that indeed this is one of the processes that the eddies accomplish in a stratified fluid) and therefore the phenomena that rely strongly on baroclinicity are discouraged. On the other hand, reduction of the dissipation leads to the onset of a strong recirculating, inertial gyre which, although confined in space, affects the global properties of the flow. In the second part of the thesis (Chapters 4 and 5) I developed a simple model of the recirculating, inertial gyre. Again the dynamics of this feature are far from being in Sverdrup balance. In this case inertia is responsible for the failure of Sverdrup relation, together with the eddy field which provides a mean for transfering momentum vertically and laterally into regions away from where the forcing is applied. In this model there is no direct forcing in the recirculation region, and the input of momentum is confined to the boundary currents surrounding the gyre, for example the separated Gulf Stream. One of the results of the recirculation model is the prediction of its transport. It is shown that most of the transport is depth independent, i.e. it can be calculated without detailed knowledge of the density structure of the ocean. It is also shown that the "barotropic" part of the transport increases as the cube of the meridional extent of the gyre.
    Description
    Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution August 1987
    Collections
    • Physical Oceanography (PO)
    • WHOI Theses
    Suggested Citation
    Thesis: Cessi, Paola, "On the role of topography and of boundary forcing in the ocean circulation", 1987-08, DOI:10.1575/1912/3947, https://hdl.handle.net/1912/3947
     

    Related items

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

    • Thumbnail

      Oceanic fluxes of mass, heat, and freshwater : a global estimate and perspective 

      Macdonald, Alison M. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1995-08)
      Data from fifteen globally distributed, modern, high resolution, hydrographic oceanic transects are combined in an inverse calculation using large scale box models. The models provide estimates of the global meridional ...
    • Thumbnail

      Adaptive error estimation in linearized ocean general circulation models 

      Chechelnitsky, Michael Y. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1999-06)
      Data assimilation methods, such as the Kalman filter, are routinely used in oceanography. The statistics of the model and measurement errors need to be specified a priori. In this study we address the problem of estimating ...
    • Thumbnail

      On the world ocean circulation. Volume I, some global features/North Atlantic circulation 

      Schmitz, William J. (Woods Hole Oceanographic Institution, 1996-06)
      This is the first volume of a "final report" that summarizes, often in a speculative vein, what I have learned over the past 35 years or so about large-scale, low-frequency ocean currents, primarily with support from the ...
    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