Wave-current interaction in coastal waters: Effects on the bottom-shear stress
Rosales, P.; Ocampo-Torres, F.J.; Osuna, P.; Monbaliu, J.; Padilla-Hernandez, R. (2008). Wave-current interaction in coastal waters: Effects on the bottom-shear stress. J. Mar. Syst. 71(1-2): 131-148. dx.doi.org/10.1016/j.jmarsys.2007.06.006
In: Journal of Marine Systems. Elsevier: Tokyo; Oxford; New York; Amsterdam. ISSN 0924-7963; e-ISSN 1879-1573, more
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| Keyword |
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| Author keywords |
bottom friction; waves; currents; coupling numerical models |
| Authors | | Top |
- Rosales, P.
- Ocampo-Torres, F.J.
- Osuna, P.
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- Monbaliu, J., more
- Padilla-Hernandez, R.
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| Abstract |
Computer simulations of wave and current fields in the southern North Sea were made with a coupled-models system to study the influence of wave-current interactions on the bottom-shear stress in coastal waters. A third-generation wave-spectral model is coupled with a tide-surge model, which provides current and water level information to take into account wave-current interactions, to calculate the bottom stress. Two different expressions for bottom friction are used; one derived from the JONSWAP experiment, and a second given by Christoffersen and Jonsson that takes into account wave-current interaction at the bottom. The coupled-models system is applied to four nested grids to achieve fine spatial resolution near the Belgium coast. Two events of moderate to high waves are analyzed. Those two events are associated with different wind regimes; SW winds for the first period and NW for the second. The calculations of bottom-shear stress when taking into account wave-current interactions are compared with reference runs where only waves are considered to calculate the energy dissipation at the bottom. Small differences in the bottom-shear stress results are observed mainly related to the water-level variation caused by tides, when coupled and uncoupled runs using the JONSWAP expression were compared. However, when wave-current interactions are taken into account using the expression of Christoffersen and Jonsson, the calculated maximum bottom stress is usually doubled for coupled-model runs compared to the reference runs. The results clearly show that the formulation of the bottom-friction dissipation that accounts for the effect of wave-current interaction has quite a significant effect on the determination of the bottom-shear stress. |
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