Nearshore Wave-Topography Interactions [report]

Rob Holman
2001 unpublished
LONG-TERM GOAL My long term goal is to develop a predictive understanding of the fluid dynamics of a random wave field shoaling over the complicated bathymetry of a natural beach, and the response of the beach to those overlying wave and current motions. Success requires improvements in understanding and modeling as well the development of innovative methods for collecting measurements needed to seed those models. OBJECTIVES Over the last decade, our scientific focus has been on the development
more » ... and implementation of an extensive, robust sampling capability for nearshore processes (the Argus Program) and documentation of the plethora of new phenomenology that were observed. Our current work sees a re-focussing on understanding the physics of electro-optical imaging. We wish to develop a physics-based model for the Modulation Transfer Function (MTF) relating optical radiance to underlying geophysical variables. Thus, observations will shift from a basis in contrast (for waves) and morphology (patterns of sand) to actual time series of sea surface elevation and bathymetry. This work includes both optical processes outside the surf zone where radiance is based on Fresnel reflection from a sloping and wavey sea surface as well as radiance for breaking-induced foam. Results are then applied to a range of nearshore phenomena. APPROACH Our approach has been to develop a sampling strategy based around optical remote sensing through the Argus Program. This involves two phases. First is the development and ground-truth testing of techniques for the estimation of a variety of important geophysical variables. Ground truth data is primarily from the SandyDuck data set, collected in 1997. The second phase is application of these collection techniques to the 10 Argus stations around the world and examination of the sampled dynamics.
doi:10.21236/ada626212 fatcat:vj3ml7jscnc6dint6lxdxdpgq4