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Detailed Reference Information |
Raubenheimer, B., Elgar, S. and Guza, R.T. (2004). Observations of swash zone velocities: A note on friction coefficients. Journal of Geophysical Research 109: doi: 10.1029/2003JC001877. issn: 0148-0227. |
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Vertical flow structure and turbulent dissipation in the swash zone are estimated using cross-shore fluid velocities observed on a low-sloped, fine-grained sandy beach <Raubenheimer, 2002> with two stacks of three current meters located about 2, 5, and 8 cm above the bed. The observations are consistent with an approximately logarithmic vertical decay of wave orbital velocities within 5 cm of the bed. The associated friction coefficients are similar in both the uprush and downrush, as in previous laboratory results. Turbulent dissipation rates estimated from velocity spectra increase with decreasing water depth from O(400 cm2/s3) in the inner surf zone to O(1000 cm2/s3) in the swash zone. Friction coefficients in the swash interior estimated with the logarithmic model and independently estimated by assuming that turbulent dissipation is balanced by production from vertical shear of the local mean flow and from wave breaking are between 0.02 and 0.06. These values are similar to the range of friction coefficients (0.02--0.05) recently estimated on impermeable, rough, nonerodible laboratory beaches and to the range of friction coefficients (0.01--0.03) previously estimated from field observations of the motion of the shoreward edge of the swash (run-up). |
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Abstract |
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Keywords
Oceanography, Physical, Nearshore processes, Oceanography, Physical, Surface waves and tides, Oceanography, Physical, Turbulence, diffusion, and mixing processes, beach, swash, waves |
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Publisher
American Geophysical Union 2000 Florida Avenue N.W. Washington, D.C. 20009-1277 USA 1-202-462-6900 1-202-328-0566 service@agu.org |
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