Wave-driven setup and alongshore flows observed onshore of a submarine canyon
Guza, R. T.
MetadataShow full item record
The effect of alongshore variations in the incident wavefield on wave-driven setup and on alongshore flows in the surfzone is investigated using observations collected onshore of a submarine canyon. Wave heights and radiation stresses at the outer edge of the surfzone (water depth ≈2.5 m) varied by up to a factor of 4 and 16, respectively, over a 450 m alongshore distance, resulting in setup variations as large as 0.1 m along the shoreline (water depth ≈0.3 m). Even with this strong alongshore variability, wave-driven setup was dominated by the cross-shore gradient of the wave radiation stress, and setup observed in the surfzone is predicted well by a one-dimensional cross-shore momentum balance. Both cross-shore radiation stress gradients and alongshore setup gradients contributed to the alongshore flows observed in the inner surfzone when alongshore gradients in offshore wave heights were large, and a simplified alongshore momentum balance suggests that the large [O(1 kg/(s2 m)] observed setup-induced pressure gradients can drive strong [O(1 m/s)] alongshore currents.
Author Posting. © American Geophysical Union, 2008. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 113 (2008): C07025, doi:10.1029/2007JC004514.
Showing items related by title, author, creator and subject.
Kumar, Nirnimesh; Voulgaris, George; List, Jeffrey H.; Warner, John C. (John Wiley & Sons, 2013-10-15)Nearshore measurements of waves and currents off Cape Hatteras, North Carolina, U.S.A, are used to investigate depth-averaged subtidal circulation and alongshore momentum balances in the surf and inner shelf region around ...
Feddersen, Falk; Trowbridge, John H. (American Meteorological Society, 2005-11)The effect of breaking-wave-generated turbulence on the mean circulation, turbulence, and bottom stress in the surf zone is poorly understood. A one-dimensional vertical coupled turbulence (k–ε) and mean-flow model is ...
Connolly, Thomas P.; Hickey, Barbara M.; Shulman, Igor; Thomson, Richard E. (American Meteorological Society, 2014-01)The California Undercurrent (CUC), a poleward-flowing feature over the continental slope, is a key transport pathway along the west coast of North America and an important component of regional upwelling dynamics. This ...