• 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

    Analysis and interpretation of tidal currents in the coastal boundary layer

    Thumbnail
    View/Open
    May_thesis.pdf (7.290Mb)
    Date
    1979-05
    Author
    May, Paul Wesley  Concept link
    Metadata
    Show full item record
    Citable URI
    https://hdl.handle.net/1912/3083
    Location
    Long Island, NY
    DOI
    10.1575/1912/3083
    Keyword
     Tidal currents; Coasts 
    Abstract
    Concern with the impact of human activities on the coastal region of the world's oceans has elicited interest in the so-called "coastal boundary layer"-that band of water adjacent to the coast where ocean currents adjust to the presence of a boundary. Within this zone, roughly 10 km wide, several physical processes appear to be important. One of these, the tides, is of particular interest because their deterministic nature allows unusually thorough analysis from short time series, and because they tend to obscure the other processes. The Coastal Boundary Layer Transect (COBOLT) experiment was conducted within 12 km of the south shore of Long Island, New York to elucidate the characteristics of the coastal boundary layer in the Middle Atlantic Bight. Analysis of data from this experiment shows that 35% of the kinetic energy of currents averaged over the 30 m depth are due to the semidiurnal and diurnal tides. The tidal ellipses, show considerable vertical structure. Near-surface tidal ellipses rotate in the clockwise direction for semidiurnal and diurnal tides, while near-bottom ellipses rotate in the counterclockwise direction for the semidiurnal tide. The angle between the major axis of the ellipse and the local coastline decreases downward for semidiurnal and increases downward for diurnal tides. The major axis of the tidal ellipse formed from the depth averaged semidiurnal currents is not parallel to the local shoreline but is oriented at an angle of -15 degrees. This orientation "tilt" is a consequence of the onshore flux of energy which is computed to be about 800 watts/m. A constant eddy viscosity model with a slippery bottom boundary condition reproduces the main features observed in the vertical structure of both semidiurnal and diurnal tidal ellipses. Another model employing long, rotational, gravity waves (Sverdrup waves) and an absorbing coastline explains the ellipse orientations and onshore energy flux as a consequence of energy dissipation in shallow water. Finally, an analytical model with realistic topography suggests that tidal dissipation may occur very close (2-3 km) to the shore. Internal tidal oscillations primarily occur at diurnal frequencies in the COBOLT data. Analysis suggests that this energy may be Doppler-shifted to higher frequencies by the mean currents of the coastal region. These motions are trapped to the shore and are almost exclusively first baroclinic mode internal waves.
    Description
    Submitted in partial fulfillment of the requirements for the degree of Doctor of Science at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution May 1979
    Collections
    • Physical Oceanography (PO)
    • WHOI Theses
    Suggested Citation
    Thesis: May, Paul Wesley, "Analysis and interpretation of tidal currents in the coastal boundary layer", 1979-05, DOI:10.1575/1912/3083, https://hdl.handle.net/1912/3083
     

    Related items

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

    • Thumbnail

      Tidal band current variability over the Northern California continental shelf 

      Rosenfeld, Leslie K. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1986-12)
      The focus of this dissertation is on the description and dynamical interpretation of the tidal band current fluctuations over the continental shelf off northern California. The term "tidal band" is used here to denote ...
    • Thumbnail

      The analysis of tidal phenomena in narrow embayments 

      Redfield, Alfred C. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1950-07)
      The tides of coastal embayments derive their energy from the ocean tides rather than from the direct action of lunar and solar gravitational forces. They are considered to be part of co-oscilating systems in which the ...
    • Thumbnail

      Ice shelf-ocean interactions in a general circulation model : melt-rate modulation due to mean flow and tidal currents 

      Dansereau, Veronique (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2012-09)
      Interactions between the ocean circulation in sub-ice shelf cavities and the overlying ice shelf have received considerable attention in the context of observed changes in flow speeds of marine ice sheets around Antarctica. ...
    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