OBSERVATIONS OF SUSPENDED PARTICULATE MATTER DYNAMICS NEAR THE OCEANIC BOTTOM BOUNARY LAYER

Abstract

 Field surveys of the particulate matter concentration for each particle size were carried out. We found that (1) the particulate matter concentration for each particle size under stratied condition can be significantly decreased above the the BBL compared to within the BBL, and (2) the concentration can be almost uniformely distributed in uniform density fields. The mean turbulence dissipation rates measured by microstructure profiler for case (1) were larger by a factor of 2-3 than the mean turbulence when particulate matter concentraton did not significantly decrease above the the BBL. Our results were consistent with previous numerical study on the effects of turbulent process around the bottom boundary layers (BBLs) on suspended particulate matter dynamics, suggesting that the BBL thickness and the turbulence intensity variation are among the important parameters for determing the distribution of particulate matter concentration.