Nearshore circulation over transverse bar and rip morphology with oblique wave forcing

Auteur(s) et Affiliation(s)



Description :
A combination of in-situ current meters and surf zone drifters are used to characterize the nearshore circulation over a transverse bar and rip morphology at Pensacola Beach, Florida in the presence of relatively low energy oblique waves. Current speeds vary in response to the relative wave height ratio (Hs/h), which defines the degree and extent of breaking over the shoal. In the absence of wave breaking the nearshore circulation was dominated by an alongshore current driven by the oblique waves. As waves begin to break across the shoal, the nearshore circulation is characterized by a meandering alongshore current. As conditions became more dissipative, the meandering current is replaced by an unsteady rip circulation that moves offshore between the shoals before turning alongshore in the direction of wave advance outside the surf zone. While the currents had a low velocity and would not pose a significant hazard to the average swimmer, the results of this study suggest that the transverse bar and rip morphology is sufficient to create an alongshore variation in wave dissipation that forces alongshore meandering and low-energy rip circulation systems under oblique wave forcing.


Type de document :
Article de périodique

Source :
Earth surface processes and landforms, issn : 0197-9337, 2013, vol. 38, n°. 11, p. 1269-1279, nombre de pages : 11, Références bibliographiques : 2 p.

Date :
2013

Editeur :
Pays édition : Royaume-Uni, Chichester, Wiley