A Study of the Velocity Structure in a Marine Boundary Layer - Instrumentation and Observations.
Abstract
The design and operation of a unique flow measuring instrument for bottom boundary layer studies in the marine environment is documented. The effectiveness of the instrument in acquiring data with which models of near bottom flows in the ocean can be tested is demonstrated by the results of a field experiment in Vineyard Sound. The instrument uses four sensors which measure the mean and fluctuating parts parts of the three components of the velocity vector at four heights above the sea bed. The sensors employ the acoustic travel time difference technique, and are designed to minimize sensor-induced flow disturbances. BASS, an acronym for Benthic Acoustic Stress Sensor, has a resolution of .033 cm/sec per least bit, a range of + or - cm/sec, noise of .07 cm/sec in 10 sec, and an estimated accuracy of + or - .5 cm/sec, referred to an in situ zero point. A complete set of velocity measurements is made every .750 seconds, each measurement being the vector component averaged over 15 cm. The data is internally recorded on digital cassette tape. Eight hours of continuous data can be recorded. BASS was deployed in a tidal flow in Vineyard Sound at a depth of 10 m where a time series of u, v, and w velocities at 26 cm, 46 cm, 96 cm, and 210 cm above the bottom was recorded.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1978
- Accession Number
- ADA062842
Entities
People
- John Steven Tochko
Organizations
- Woods Hole Oceanographic Institution