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| Titel |
Three-dimensional modelling of wave-induced current from the surf zone to the inner shelf |
| VerfasserIn |
H. Michaud, P. Marsaleix, Y. Leredde, C. Estournel, F. Bourrin, F. Lyard, C. Mayet, F. Ardhuin |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1812-0784
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| Digitales Dokument |
URL |
| Erschienen |
In: Ocean Science ; 8, no. 4 ; Nr. 8, no. 4 (2012-08-17), S.657-681 |
| Datensatznummer |
250005756
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| Publikation (Nr.) |
 copernicus.org/os-8-657-2012.pdf |
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| Zusammenfassung |
We develop and implement a new method to take into account the impact of
waves into the 3-D circulation model SYMPHONIE (Marsaleix et al., 2008, 2009a) following the simplified equations of Bennis et al. (2011)
which use glm2z-RANS theory (Ardhuin et al., 2008c). These adiabatic equations
are completed by additional parameterizations of wave breaking, bottom
friction and wave-enhanced vertical mixing, making the forcing valid from the
surf zone through to the open ocean. The wave forcing is performed by wave
generation and propagation models WAVEWATCH III®
(Tolman, 2008, 2009; Ardhuin et al., 2010) and SWAN (Booij et al., 1999).
The model is tested and compared with other models for a plane beach test
case, previously tested by Haas and Warner (2009)and Uchiyama et al. (2010). A
comparison is also made with the laboratory measurements of
Haller et al. (2002) of a barred beach with channels. Results fit with
previous simulations performed by other models and with available
observational data.
Finally, a realistic case is simulated with energetic waves travelling over a
coast of the Gulf of Lion (in the northwest of the Mediterranean Sea) for
which currents are available at different depths as well as an accurate
bathymetric database of the 0–10 m depth range. A grid nesting approach
is used to account for the different forcings acting at different spatial
scales. The simulation coupling the effects of waves and currents is
successful to reproduce the powerful northward littoral drift in the 0–15 m
depth zone. More precisely, two distinct cases are identified: When waves
have a normal angle of incidence with the coast, they are responsible for
complex circulation cells and rip currents in the surf zone, and when they
travel obliquely, they generate a northward littoral drift. These features
are more complicated than in the test cases, due to the complex bathymetry
and the consideration of wind and non-stationary processes. Wave impacts in
the inner shelf are less visible since wind and regional circulation seem to
be the predominant forcings. Besides, a discrepancy between model and
observations is noted at that scale, possibly linked to an underestimation of
the wind stress.
This three-dimensional method allows a good representation of vertical
current profiles and permits the calculation of the shear stress associated with
waves and currents. Future work will focus on the combination with a sediment
transport model. |
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