Open AccessModeling the alongshore current on barred beaches
Author(s) -
Ruessink B. G.,
Miles J. R.,
Feddersen F.,
Guza R. T.,
Elgar Steve
Publication year - 2001
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2000jc000766
Subject(s) - bathymetry , forcing (mathematics) , trough (economics) , geology , maxima , current (fluid) , wind stress , oceanography , climatology , atmospheric sciences , art , performance art , economics , macroeconomics , art history
Mean alongshore currents observed on two barred beaches are compared with predictions based on the one‐dimensional, time‐ and depth‐averaged alongshore momentum balance between forcing (by breaking waves, wind, and 10–100 km scale alongshore surface slopes), bottom stress, and lateral mixing. The observations span 500 hours at Egmond, Netherlands, and 1000 hours at Duck, North Carolina, and include a wide range of conditions with maximum mean currents of 1.4 m/s. Including rollers in the wave forcing results in improved predictions of the observed alongshore‐current structure by shifting the predicted velocity maxima shoreward and increasing the velocity in the bar trough compared with model predictions without rollers. For these data, wave forcing balances the bottom stress within the surfzone, with the other terms of secondary importance. The good agreement between observations and predictions implies that the one‐dimensional assumption holds for the range of conditions examined, despite the presence of small alongshore bathymetric nonuniformities. With stronger bathymetric variations the model skill deteriorates, particularly in the bar trough, consistent with earlier modeling and laboratory studies.