Several aspects of feedback mechanisms associated with surf zone sandbar response have been characterized using bathymetric surveys, sampled approximately monthly over a 16-year period at the Army Corps of Engineers' Field Research Facility (North Carolina). The measured bathymetry was alongshore averaged and modeled by the superposition of two Gaussian-shaped sandbars...
We review several approaches that have been used to estimate ocean surface gravity wavenumbers from wave-resolving remotely sensed image sequences. Two fundamentally different approaches that utilize these data exist. A power spectral density approach identifies wavenumbers where image intensity variance is maximized. Alternatively, a cross-spectral correlation approach identifies wavenumbers where...
A nonlinear model is developed to study the time‐dependent relationship between the alongshore variability of a sandbar, a(t), and alongshore‐averaged sandbar position, xc(t). Sediment transport equations are derived from energetics‐based formulations. A link between this continuous physical representation and a parametric form describing the migration of sandbars of constant shape...
Time and length scales of beach variability have been quantified using 16 years
of beach surveys sampled at the Army Corps of Engineers' Field Research Facility,
located on the U.S. Atlantic coast. Between 50% and 90% of the bathymetric variability at
this site was explained by alongshore-uniform response over the...
Sandbars are ubiquitous, yet not well understood
beach features that change their position and shape in
response to changing wave conditions. We propose and test
a simple empirical model consisting of two coupled linear
differential equations that represents bar dynamics in terms
of wave forcing and two other state variables:...
The temporal and spatial variability of crescentic sandbars is analyzed with hourly
long-term (months) video observations collected at four barred sites and are qualitatively
compared to the temporal and spatial variability predicted by hypotheses underpinning
existing approaches and models for crescentic bar formation (edge-wave template model,
linear stability analysis, and...