Abstract: Alongshore currents and nearshore dynamics generated on plane and barred beaches are successfully simulated using a shallow water model, ADCIRC, whose traditional applications have been focused on shelf-scale processes. ADCIRC-2DDI is a two-dimensional, finite-element-based coastal circulation model. Wave fields obtained from REF/DIFI, a monochromatic wave model that simulates refraction, diffraction, and wave breaking, are used to compute surface wave radiation stress gradients that force the hydrodynamic model. Processes such as advection, lateral diffusion/dispersion, and nonlinear bottom stress are examined at high resolution (^5 m) in order to determine their relative influence on the computed nearshore circulation. Unsteady circulation patterns are observed in our plane beach simulations for decreased values of the nonlinear bottom friction and/or lateral mixing coefficients. The structure and dynamics of these unsteady circulation patterns are very similar to shear waves described by Bowen and Holman (1989). Model-data comparisons made using data from Leadbetter, California (1980) and the 1990 DELILAH experiment at Duck, North Carolina, indicate that alongshore currents forced by wave radiation stress gradients are well simulated by the ADCIRC-2DDI model.
| Limitations: |
 APPROVED FOR PUBLIC RELEASE |
| Description: |
Rept. for 29-31 Oct 2002 |
| Pages: |
23 |
| Report Date: |
11 MAR 2003 |
| Report Number: |
A302214 |
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