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Filtering by: Has journal Nonlinear Processes in Geophysics Remove constraint Has journal: Nonlinear Processes in Geophysics Advisor Ozkan Haller, H. Tuba Remove constraint Advisor: Ozkan Haller, H. Tuba

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  • Nearshore hydrodynamic model comparisons and predictions of bathymetric evolution

    Creator:
    Lescinski, Jamie M.
    Abstract:
    The surf zone exhibits large energetic signals from wave shoaling and subsequent dissipation due to breaking, forcing circulation. The bathymetry responds to the wave and wave-induced circulation with the growth, transport, and destruction of large scale bathymetric features, such as mega ripples and sand bars. There is an obvious fluctuation...
    Resource Type:
    Masters Thesis
    Full Text:
    : skewness and asymmetry. These nonlinear characteristics have proven to be challenging to predict in a

  • Field validation of a nearshore circulation model for alongshore-nonuniform flows

    Creator:
    Wilson, Gregory W.
    Abstract:
    We investigate, theoretically and experimentally, the problem of modeling depth-integrated (2DH) surf zone circulation on an alongshore-nonuniform natural beach, with waves approaching from an arbitrary angle. An approximate theoretical model is developed, which captures the important effect of advection in the alongshore dynamics, and shows that a nondimensional parameter Re[subscript]s...
    Resource Type:
    Masters Thesis
    Full Text:
    theory is further applied in the context of a fully-nonlinear 2DH hindcast of 455 hours of experimental

  • Offshore controls on nearshore circulation

    Creator:
    Long, Joseph W.
    Abstract:
    The rip current field resulting from the transformation of surface gravity waves over offshore submarine canyons is studied. Employing a wave transformation model and a wave-induced circulation model over observed bathymetry we find that rip current circulation cells exist with alongshore spacing of O(1OOm) even though the nearshore bathymetry displayed...
    Resource Type:
    Masters Thesis
    Full Text:
    strongly influenced by inertial effects. Hence, nonlinear processes are important within the rip current

  • Data assimilation for prediction of shallow water flows with uncertain bathymetry

    Creator:
    Wilson, Gregory W.
    Abstract:
    A new method is introduced for incorporating bathymetric uncertainty into predictions of nearshore and river flows (i.e., unstratified flows primarily forced by pressure and radiation stress gradients). The method involves the use of the ensemble Kalman filter (EnKF) as a parameter estimation scheme, where the parameter to be estimated is...
    Resource Type:
    Dissertation
    Full Text:
    of error: mis-specification of physical processes in the model, and errors in model inputs, namely

  • Depth-dependence of surf zone eddies : a study at Duck, NC

    Creator:
    Aiken, Rebecca A.
    Abstract:
    Surf zone eddies (f < 0.01 Hz) are important in nearshore mixing, shoreline erosion, the distribution of pollutants, and ecological processes, such as offshore transport of larvae. Surf zone eddies have traditionally been treated as two-dimensional features with horizontal length scales larger than the local water depth. Studies by Lippmann...
    Resource Type:
    Masters Thesis
    Full Text:
    processes. In the action balance, the action density, N, is defined as N = E/σ, where E is the wave energy

  • Modeling shallow-water hydrodynamics : rotations, rips, and rivers

    Creator:
    Long, Joseph W.
    Abstract:
    Hydrodynamic models are used as a diagnostic tool to understand the temporal variability of shallow-water processes that are difficult to completely resolve with traditional field measurements. For all simulations, modeled quantities are qualitatively or quantitatively compared with available measurements to gain confidence in conclusions derived from the modeled results. In...
    Resource Type:
    Dissertation
    Full Text:
    transport processes and dispersion of sediments or pollutants in the surf zone, which makes understanding

  • Extreme Wave Runup and Runup Variability on Beaches

    Creator:
    Li, Chuan
    Abstract:
    Wave runup is an important physical process that affects nearshore sediment transport, coastal erosion, and flooding. Large and unexpected runup events can also be dangerous to beach goers. Extreme runup statistics are essential parameters used in engineering design of marine structures and in coastal management. Although the study of runup...
    Resource Type:
    Dissertation
    Full Text:
    and in coastal management. Nevertheless, as with many topics in active research, processes related to

  • Toward wave energy in Oregon : predicting wave conditions and extracted power

    Creator:
    Oskamp, Jeffrey A.
    Abstract:
    Knowledge of wave conditions in nearshore regions supports the development of ocean wave energy technology by providing wave climatology for device design considerations, and power output estimates. By modeling wave transformation over the continental shelf, wave conditions were predicted in nearshore regions where potential wave energy conversion sites are located....
    Resource Type:
    Masters Thesis
    Full Text:
    physical processes contribute to growth of wind waves. Both of them concern pressure differences in the

  • Nearshore wave predictions along the Oregon and southwest Washington coast

    Creator:
    García-Medina, Gabriel
    Abstract:
    This thesis contains a manuscript describing the implementation of a high resolution wave forecasting model for the coasts of Washington and Oregon. The purpose of this project was to advance the wave predictive capabilities of the states of Oregon and the southwest part of Washington by including the effects of...
    Resource Type:
    Masters Thesis
    Full Text:
    understanding of the dominant wave transformation processes in play in the PNW. To satisfy these needs, and

  • Breaking Waves Offshore: Measurements and Modeling of Energy Dissipation

    Creator:
    Ticona Rollano, Fadia M.
    Abstract:
    In the presence of strong winds, ocean surface waves dissipate significant amounts of energy by breaking. Here, breaking rates and wave-following turbulent dissipation rate measurements are compared with numerical WAVEWATCH III estimates of bulk energy dissipation. At high winds, the measurements suggest that turbulent dissipation becomes saturated, however the modeled...
    Resource Type:
    Masters Thesis
    Full Text:
    processes, particularly in extreme conditions. When a wave breaks in the deep water its energy is