Application of a Shelf-Scale Model to Wave-Induced Circulation: Rip Currents
Abstract
Wave-induced rip currents on barred planar beaches are using ADCIRC-2DDI, a two-dimensional finite-element hydrodynamic model. Surface wave stress gradients, determined form REF/DIF1, a phase-resolving monochromatic wave model that simulates refraction, diffraction, and wave breaking, are used to force the ADCIRC model. The rip current circulation on an ideal barred beach, approximately 1 sq km in area with a single channel in the center of its alongshore bar, is investigated. Solutions for steady and unsteady circulation are examined by considering the relative influence of lateral mixing and nonlinear bottom stress. Shear-induced vortices are produced by the unsteady rip current, causing it to move in the alongshore and cross-shore directions. ADCIRC-2DDI solutions for the circulation on the ideal beach are found to be qualitatively similar to actual rip currents observed in field and laboratory studies. Good agreement is found between the steady state ADCIRC-2DDI results and the time-averaged laboratory measurements for the water level and the currents. Finally, wave current (w-c) interaction significantly modify the wave field, changing the circulation of the rip current.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 30, 2003
- Accession Number
- ADA415891
Entities
People
- Cheryl A. Blain
- Mark Cobb
Organizations
- United States Naval Research Laboratory