The coupling of real-time measurements and numerical models will be important
in overcoming the challenges in environmental and oceanographic assessments in
surface waters. Continuous monitoring will take advantage of current state-of-the-art in
sensor development, remote sensing technology. The numerical modeling tools available
exist in many different forms and varying levels of complexity from depth integrated
one-dimensional (1-D) models to full three-dimensional (3-D) models. Common to all
are the constraints and forcing required in driving the models. These include
hydrodynamic and barometric information, which are relatively difficult to obtain given
the time scale of the bio-chemical and physical processes governing the fate and
transport of the constituents of interest.
This study is focused on the development of a framework that couples real-time
measurements and numerical simulation for tracking constituents in surface waters.
The parameterization of the mixing and turbulent diffusion impacts the formulation of
the constituent-transport governing equations to the extent that the numerical model is being driven by near real-time observations of hydrodynamic data and the consequent
evaluation of model coefficients. The effects of shear-augmented diffusion processes in
shallow embayment and near-shore waters are investigated in order to develop
algorithms for obtaining a shear diffusion coefficient, Ke from shear-current
measurements and turbulent diffusion-coefficient, Kz measured by the auto-correlation
function, Rτ of the velocity time-series.
Typically, the diffusion coefficients are measured through tracer experiments as
determined by the time rate of change of the variance of a growing patch (K = ½ dσ2 /dt),
which introduces the concept of diffusion length-scale (or time-scale). In this study, the
dye-tracer experiment was used, not so much in the context of evaluation of a diffusion
coefficient, but within a modeling framework to validate a numerical scheme driven by
real-time hydrodynamic observations. Overall, the effect of shear-currents in shallow
wind-driven estuaries is studied using a prototype bay typical of the Texas Gulf-coast. A
numerical model was developed and used in testing these hypotheses through a series of
dye-tracer experiments under varying meteorological conditions.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/3875 |
| Date | 16 August 2006 |
| Creators | Ojo, Temitope O. |
| Contributors | Bonner, James S. |
| Publisher | Texas A&M University |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Dissertation, text |
| Format | 3872565 bytes, electronic, application/pdf, born digital |
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