Record Details
The effects of tides on swash statistics on an intermediate beach
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | The effects of tides on swash statistics on an intermediate beach |
| Names |
Guedes, R. M. C.
(creator) Bryan, K. R. (creator) Coco, G. (creator) Holman, R. A. (creator) |
| Date Issued | 2011 (iso8601) |
| Abstract | Swash hydrodynamics were investigated on an intermediate beach using runup data obtained from video images. Under mild, near-constant, offshore wave conditions, the presence of a sandbar and the tidally controlled water depth over its crest determined whether most of the incoming waves broke before reaching the shoreline. This forced a change in the pattern of wave energy dissipation across the surf zone between low and high tide, which was reflected by changes to swash on time scales of a few hours. Significant runup height (Rs, defined as 4 times the standard deviation of the waterline time series), was found to vary by a factor of 2 between low tide, when most of the waves were breaking over the sandbar (Rs/Hs ≈ 1.5, where Hs is the offshore significant wave height) and high tide, when the waves were barely breaking (Rs/Hs ≈ 2.7). The increase in wave energy dissipation during low tide was also associated with changes in swash maxima distribution, a decrease in mean swash period, and increasing energy at infragravity frequencies. Bispectral analysis suggested that this infragravity modulation might have been connected with the presence of secondary waves. |
| Genre | Article |
| Topic | swash hydrodynamics |
| Identifier | Guedes, R. M. C., K. R. Bryan, G. Coco, and R. A. Holman (2011), The effects of tides on swash statistics on an intermediate beach, Journal of Geophysical Research, 116, C04008, doi:10.1029/2010JC006660. |
