PIV measurements in the bottom boundary layer of the coastal ocean

Abstract.

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 K×2 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 m 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.