The surface acoustic shear sensor (SASS) as used during the Shelf Mixed Layer Experiment (SMILE) November 1988-March 1989

Abstract

The SMILE (Shelf Mixed Layer Experiment) field program took place during the winter of 1988-1989. The SMILE program itself was large and involved many investigators and instruments. This report documents the use of the Surface Acoustic Shear Sensor (SASS) as part of the suite of measurements taken during SMILE. The SMILE mooring array was deployed from early November 1988 until June, 1989. SASS, being a newly developed instrument, was deployed for two shorter periods; a test deployment between November 26 and December 8, 1988, and a longer second deployment, February 23 through March 14, 1989. SASS is based on BASS (Benthic Acoustic Stress Sensor) components (Williams et al., 1987), mounted on a structure that allowed continuous sampling of velocity, temperature and conductivity in the top five meters of the ocean. BASS was modified for this surface application to acquire data from a gyro, and conductivity sensors. The attitude data from the gyro allows the velocities of the current meter to be referenced to an inertial frame of reference. The other data obtained from SASS will be used to calculate shear current gradients, and other descriptors of turbulence and mixing.