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  • Publisher's note: "Waves on unsteady currents" [Phys. Fluids 19, 126601 (2007)]

    Creator:
    Haller, Merrick C. and Özkan-Haller, H. Tuba
    Abstract:
    This article was originally published online and in print with an incorrect version of Fig. 1. AIP apologizes for this error. All online versions of the article have been corrected.
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    Article
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    . Fluids 19, 126601 „2007…‡ Merrick C. Haller1 and H. Tuba Özkan-Haller2 1School of Civil and Construction

  • Waves on unsteady currents

    Creator:
    Haller, Merrick C. and Özkan-Haller, H. Tuba
    Abstract:
    Models for surface gravity wave propagation in the presence of currents often assume the current field to be quasi-stationary, which implies that the absolute wave frequency is time invariant. However, in the presence of unsteady currents or time-varying water depth, linear wave theory predicts a time variation of the absolute...
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    Civil and Construction Engineering, Oregon State University, Corvallis, Oregon 97330, USA H. Tuba Özkan

  • Bathymetry correction using an adjoint component of a coupled nearshore wave-circulation model: Tests with synthetic velocity data

    Creator:
    Kurapov, Alexander L. and Özkan-Haller, H. Tuba
    Abstract:
    The impact of assimilation of wave-averaged flow velocities on the bathymetric correction is studied in tests with synthetic (model-generated) data using tangent-linear and adjoint components of a one-way coupled nearshore wave-circulation model. Weakly and strongly nonlinear regimes are considered, featuring energetic unsteady along-beach flows responding to time-independent wave-averaged forcing due...
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    Alexander L. Kurapov1 and H. Tuba €Ozkan-Haller1 Received 19 December 2012; revised 1 July 2013; accepted 6

  • Forcing and variability of nonstationary rip currents

    Creator:
    Long, J. W. and Özkan-Haller, H. Tuba
    Abstract:
    urface wave transformation and the resulting nearshore circulation along a section of coast with strong alongshore bathymetric gradients outside the surf zone are modeled for a consecutive 4 week time period. The modeled hydrodynamics are compared to in situ measurements of waves and currents collected during the Nearshore Canyon Experiment...
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    : Long, J. W., and H. T. €Ozkan-Haller (2016), Forcing and variability of nonstationary rip currents, J

  • Effects of wave-current interaction on shear instabilities of longshore currents

    Creator:
    Özkan-Haller, H. Tuba and Li, Ye
    Abstract:
    We examine the effects of wave-current interaction on the dynamics of instabilities of the surf zone longshore current. We utilize coupled models for the simulation of the incident waves and the wave-induced nearshore circulation. The coupling between the models occurs through radiation stress gradient terms (accounting for the generation of...
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    instabilities of longshore currents H. Tuba Özkan-Haller College of Oceanic and Atmospheric Sciences, Oregon

  • Low-frequency characteristics of wave group-forced vortices

    Creator:
    Long, Joseph W. and Özkan-Haller, H. Tuba
    Abstract:
    The dynamics of vorticity motions forced by wave groups incident on an alongshore-uniform barred beach are analyzed. For both normally and obliquely incident wave groups, the potential vorticity and enstrophy equations reveal that the temporal variability of wave group–forced vortices is directly linked to the variability in the incoming wave...
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    vortices Joseph W. Long1 and H. Tuba Özkan-Haller1 Received 1 May 2008; revised 25 March 2009; accepted

  • Offshore controls on nearshore rip currents

    Creator:
    Long, Joseph W. and Özkan-Haller, H. Tuba
    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 wave height variations associated with undulations in the canyon contours cause rip current circulation cells with...
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    Joseph W. Long and H. Tuba Özkan-Haller College of Oceanic and Atmospheric Sciences, Oregon State

  • Ensemble-Based Data Assimilation for Estimation of River Depths

    Creator:
    Wilson, Greg and Özkan-Haller, H. Tuba
    Abstract:
    A method is presented for estimating bathymetry in a river, based on observations of depth-averaged velocity during steady flow. The estimator minimizes a cost function that combines known information in the form of a prior estimate and measured data (including measurement noise). State augmentation is used to relate the measured...
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    Estimation of River Depths GREG WILSON AND H. TUBA ÖZKAN-HALLER College of Earth, Ocean, and Atmospheric

  • Formulation of the undertow using linear wave theory

    Creator:
    Guannel, G. and Özkan-Haller, H. Tuba
    Abstract:
    The undertow is one of the most important mechanisms for sediment transport in nearshore regions. As such, its formulation has been an active subject of research for at least the past 40 years. Still, much debate persists on the exact nature of the forcing and theoretical expression of this current....
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    Formulation of the undertow using linear wave theory Guannel, G., & Özkan-Haller, H. T. (2014). Formulation

  • Power Calculations for a Passively Tuned Point Absorber Wave Energy Converter on the Oregon Coast

    Creator:
    Oskamp, Jeffrey A. and Özkan-Haller, H. Tuba
    Abstract:
    A wave-structure interaction model is implemented, and power output estimates are made for a simplified wave energy converter operating in measured spectral wave conditions. In order to estimate power output from a wave energy converter, device response to hydrodynamic forces is computed using a boundary element method potential flow model....
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    Geophysical Research, 104(C4):7649–7666, 1999. [5] T. K. A. Brekken, H. T. Özkan-Haller, and A. Simmons. A