Measurements of enhanced turbulence in short wind-induced water waves

Particle Tracking Velocimetry was used to study turbulence beneath short
wind-induced water-waves at the circular wind-wave facility of the Institute
for Environmental Physics. Recording image sequences at up to 200 Hz allow
an extensive study of the flow field. An automatic tracking algorithm
was developed for the evaluation of the trajectories. Monte Carlo simulations
show that Lagrangian flow field measurements offer an ideal approach
to the study of drift profiles (mass transport) in the turbulent wave region.
Also bulk velocity and surface velocities can be calculated. A measure for
the turbulence was gained by the calculation of the friction velocity profile
by correlating horizontal and vertical velocity components (eddy correlation
technique).