Turbulence and optics characterization from an autonomous underwater vehicle

A combination of turbulence, optics, and hydrographic data acquisition from AUVs enables a new class of sampling strategies not available with older technologies, for near-synoptic horizontal mapping of a variety of coastal process studies. Horizontal profiles of turbulence are obtained using two piezo-ceramic shear probes sampling shear orthogonal to the vehicle´s direction of motion, a single ultrafast thermistor, and three orthogonal accelerometers, all mounted on a sting. Horizontal profiles of optical absorption and attenuation are obtained with a WET Labs AC-9 instrument mounted in a wet well, with the proper flow rate provided by a pump. Field trials in the Narragansett Bay tidal estuary in January 1996 resulted in obtaining turbulence and optical data in the mid-water pycnocline, as well as in the ocean surface layer during wind row occurrences