Observations of waves' impact on currents in a mixed-energy tidal inlet : Arcachon on the southern French Atlantic coast
Fiche du document
2013
- handle: 10670/1.hes8jw
- hal: hal-01080906
- doi: 10.2112/SI65-347.1
Ce document est lié à :
info:eu-repo/semantics/altIdentifier/doi/10.2112/SI65-347.1
info:eu-repo/semantics/OpenAccess
Mots-clés
Storm Wave breaking Undertow Wave Longshore driftSujets proches
Shore drift Drift, Littoral Longshore driftCiter ce document
Nadia Sénéchal et al., « Observations of waves' impact on currents in a mixed-energy tidal inlet : Arcachon on the southern French Atlantic coast », HAL-SHS : géographie, ID : 10.2112/SI65-347.1
Métriques
Partage / Export
Résumé
Coastal morphodynamic processes around tidal inlets in mixed-energy environments are particularly complex due tosevere tide and wave conditions. Collecting data in this area is generally very challenging .Here we present the first hydrodynamic data collected in the outer inlet of the Arcachon lagoon, a mixed-energy inlet situated on the southern part of the French Atlantic coast. Data consist in vertical current profiles and sea surface elevations collected on the offshore edge of the ebb delta under various tidal and wave conditions. In particular datawere collected during the severe Joachim storm associated to wave heights up to 8 m. Preliminary results indicate that current profiles, intensities and direction are very sensitive to wave conditions. Under energetic conditions, the vertical profile of currents becomeuniform and the longshore drift is enhanced (up to 1.5 m/s). Nevertheless data show that under severe wave conditions(Hm0> 6.0m) and despite high incidence of waves, the longshore drift is weaker (l< 1 m/s) than under ‘usual’ stormconditions associated to Hm 0= 4–5m. More surprisingly, directions of the longshore drift are not always consistent with wave incidenceunder those severe storm conditions and the cross-shore components are very weak while under less energetic conditions weobserve intense offshore currents(upto 0.8 m/s).