Modeling the influence of wave-enhanced turbulence in a shallow tide- and wind-driven water column

[1] The ability of one-dimensional hydrodynamic models to reproduce dissipation ofturbulent kinetic energy and velocity profiles for conditions of whitecapping waves in ashallow water, tide- and wind-forced environment was assessed. The models were forcedwith the conditions experienced during a month-long field experiment in a shallowestuarine embayment, and the results were compared with the observed dissipation andmean velocity profiles. Three turbulence models were assessed: the k-w model and twok-l models, with different prescribed bilinear relationships for the turbulent lengthscale, l. The k-w turbulence model was found to best replicate the measured decay ofdissipation with depth with a surface roughness length, z0s = 1.3Hs, and wave energyparameter, a = 60. The k-l model achieved equally as good reproduction of theobservations as the k-w model when the proportionality constant in the prescribed linearlength scale relationship for the upper half of the water column was modified from thetraditionally employed von Karman’s constant, k = 0.4, to 0.25. The model results showthat the whitecapping waves often supplied the dominant source of turbulent kinetic energy