Investigation of estuarine turbulent flow and suspended sediment structures using high resolution coherent Doppler current profilers and a Sontek ADV ocean probe

High resolution coherent Doppler current profilers, developed at the Proudman Oceanographic Laboratory, have been used to measure the near bed vertical and horizontal flow profiles, and the suspended sediment structures in an estuarine environment. Profiles are available at intervals of one sixteenth of a second, giving the ability to measure turbulent flow and rapid variability in sediment concentration. The range used by the Doppler systems was 1.5 metres, with a resolution of 46 mm. The profile data enables measurements to be made of the temporal and spatial scales of the velocity and flow structures. The data collected using these systems have also been compared with the point measurements obtained using a Sontek ADV Ocean Probe, mounted at a small distance from the Doppler transducers. The data from the two different types of instrument were compared, and showed good correlation between the measurements of both mean and turbulent flow. The temporal variability in the two data sets gave further detail of the velocity field structures.