Fluid Mechanical Measurements within the Bottom Boundary Layer During Coastal Mixing and Optics
Abstract
To quantify and understand the role of vertical mixing processes in determining mid-shelf vertical structure of hydrographic and optical properties and particulate matter, the Office of Naval Research (ONR) funded a program called Coastal Mixing and Optics (CMO), which was conducted at a mid-shelf location in the Mid-Atlantic Bight, south of Martha's Vineyard, Massachusetts. As part of the CMO program, a tall tripod, called SuperBASS,' was equipped to collect a year-tong, near-bottom time-series of velocity, temperature, salinity and pressure. The BASS sensors were modified to measure absolute as well as differential acoustic travel time, to provide sound speed (a surrogate for temperature) and velocity in a single sample volume. Seven BASS velocity and travel time sensors were placed between 0.4 and 7 meters above bottom (mab). Three acoustic Doppler velocity (ADV) meters were mounted near the bottom-most BASS sensor at 0.3 meters above bottom. The sensors were used to obtain high-quality time-series measurements of velocity and temperature throughout a large fraction of the bottom boundary layer on the New England shelf. The measurements provide vertical structure of the Reynolds-averaged velocity and temperature fields, direct covariance estimates of turbulent Reynolds stress and turbulent heat flux, and indirect inertial range estimates of dissipation rate for turbulent kinetic energy and temperature variance. The purpose of this report is to describe the SuperBASS instrumentation and deployments, to provide summaries of the data collected, and to document the processing, preliminary analysis and archival of the data collected for this component of the program.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 2001
- Accession Number
- ADA400411
Entities
People
- A. J. Williams Iii
- George Voulgaris
- J. J. Fredericks
- John H. Trowbridge
- W. M. Shaw
Organizations
- Woods Hole Oceanographic Institution