PIV measurements in the bottom boundary layer of the coastal ocean

Turbulence measurements were recently performed in the bottom boundary layer of the coastal ocean using a submersible PIV system. The system consisted of two 2 Kx2 K digital cameras, operating simultaneously. Optical fibers were used to transmit light from a surface mounted pulsed dye laser to the sample areas. The system was mounted on a seabed platform that allowed the sample areas to be aligned to the current, and measurements to be made up to 10 in above the bed. Sample profiles and time series of mean velocity as well as structure functions are presented. A method to calculate the Reynolds shear stress that is not contaminated by surface wave motion and instrument misalignment is also described.