A three-part algorithm is described and tested to provide robust bathymetry maps based solely on long time series observations of surface wave motions. The first phase consists of frequency-dependent characterization of the wave field in which dominant frequencies are estimated by Fourier transform while corresponding wave numbers are derived from...
Western Oregon is home to native Rhododendron species and is the center for cultivated
Rhododendron production in the United States. These Rhododendron spp. are known to
be infected with fungal endophytes. However, the community structure of these
endophytes in native and cultivated Rhododendron is poorly understood. Our study
targeted 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:...
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...
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...
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...
Transformation is a major bottleneck for genetic engineering and gene editing in forest tree species. This includes most genotypes of Populus and Eucalyptus, which are some of the world’s most widely-cultivated genera of plantation forest trees. To provide new tools for transformation, I tested the transcription factor-protein chimera consisting of...