BLIPS: A System for Studying Benthic Boundary Layer Dynamics

Abstract

A Boundary Layer Interaction Profiting System (BLIPS) has been developed to measure kinematic quantities necessary for verification of theoretical, two-phase boundary layer flow models. BLIPS sensors include electromagnetic current meters, temperature probes, transmissometers, pressure cell and acoustic altimeter. Microprocessors control data acquisition and recording functions. The support frame is modular, the components coupled with an acoustic release. This arrangement permits measurements near the bottom while eliminating direct contact between the instrument package and the seabed. Burst sampling interval is switch selectable from 5 min to 12 h; maximum sampling frequency is 8 Hz. Collection of calibration data at the beginning and end of a burst allows continuous monitoring of system performance. Flume tests indicate that velocity data collected when currents are within a 120° arc in front of the frame are of sufficient accuracy for computing dynamical quantities that are influenced by sediment in suspension. Some preliminary results from a study in the Gulf of Mexico are also presented.