Data acquisition instrumentation for the study of tidal flat and estuarine physics

Tides, wind-driven currents, and wind waves all contribute to the complex morphologies of estuaries and embayments, and exert in particular a controlling influence on the morphology of tidal flats. A new research tool (STAR: sediment transport autonomous recorder) has been designed primarily to study the dynamics of tidal flats and estuarine circulation/sediment transport. The new, low-profile instrument can simultaneously measure wave height and direction, mean water velocity and direction, and turbidity. The low-power, battery-operated data acquisition system can provide the synoptic view necessary to explore the interaction between currents and waves in shallow water, and how this interaction influences the erosion and deposition of sediment. An historically reliable sensor suite has been chosen and integrated with a generic subsea data logger with few modifications. The high quality sensor suite includes: the Marsh-McBirney electromagnetic flow sensor, Paroscientific Digiquartz pressure sensor. And the D&A Instruments OBS turbidity sensor. Though developed in part for tidal flat sedimentation studies, the instrument suite can be adapted quite simply for boundary layer measurements from shallow estuaries out to the continental shelf edge. Standardization of sensors and integration of sophisticated data acquisition techniques with standardized and extensive software permits scientists and engineers who are not specialists in boundary layer physics, turbulence, or sediment transport to make the measurements required in support of their related research.