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...
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...
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...
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....
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....
An operational inner-shelf wave forecasting system was implemented for the Oregon and southwest Washington coast in the U.S. Pacific Northwest (PNW). High-resolution wave forecasts are useful for navigational planning, identifying wave energy resources, providing information for site-specific coastal flood models, and having an informed recreational beach user group, among other...
Interest in validating the eddy covariance (EC) technique under wave-induced flows led to a series of experiments in a 104-m-long large wave flume (LWF) using an acoustic Doppler velocimeter (ADV) and two oxygen microelectrodes (tips ~2 mm apart) mounted on a sturdy tripod. Four additional ADVs positioned within the flume...
We investigate the momentum balance in the surf zone, in a setting which is weakly varying in the alongshore direction. Our focus is on the role of nonlinear advective terms. Using numerical experiments, we find that advection tends to counteract alongshore variations in momentum flux, resulting in more uniform kinematics....
A methodology is described for assimilating observations in a steady state twodimensional
horizontal (2‐DH) model of nearshore hydrodynamics (waves and currents),
using an ensemble‐based statistical estimator. In this application, we treat bathymetry as a
model parameter, which is subject to a specified prior uncertainty. The statistical estimator
uses state augmentation...
Velocity measurements from drifter GPS records are used in an ensemble-based data assimilation technique to extract the river bathymetry. The method is tested on a deep meandering reach and a shallow braided reach of the Kootenai River in Idaho. The Regional Ocean Modeling System (ROMS) is used to model numerous...