Nearshore Wave Processes
Abstract
Waves breaking on a beach drive a vertically sheared cross-shore flow, directed onshore near the surface and offshore near the bed. Models, based on conservation of both mass and momentum flux, exist for monochromatic waves and have been tested in laboratories. They provide predictions for the vertical profile of the mean cross-shore currents below the wave trough level which agree qualitatively well with the measurements. This study extends these models to random waves and tests them with field data. A second class of model, based on incomplete physics but valid over the whole water column, is developed and also compared with the measurements. Data from two field experiments are used in this study to make a statistically meaningful test of the models. Three current meters over the vertical were deployed on a sled during the SuperDuck Experiment held near Duck, North Carolina during October 1986. Five current meters over the vertical were deployed at each of three stacks at Scripps Institution of Oceanography. La Jolla, California during March and April 1987. Model comparisons with the data from both field experiments show that, while the models give values that are within the expected range, they do not yet adequately predict the vertical structure of the velocity profile over the water column. The statistical measures of fit reported in this study give additional quantitative insights into the behavior of the models.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 30, 1992
- Accession Number
- ADA271863
Entities
People
- Gary Griggs
Organizations
- University of California, Santa Cruz