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 stratified conditions can be significantly lower above the bottom boundary layer(BBL)than within the BBL, and (2) the particles can be widely distributed under uniform density. The observed results were consistent with a previous numerical study that investigated the effects of turbulent processes on suspended particulate matter dynamics around the BBL. The vertical one-dimensional numerical experiment demonstrated that the vertical distribution of particle concentration is strongly controlled by the balance between vertical mixing and settling of particles. These results suggest that the BBL thickness and turbulent processes are important factors for determining the distribution of the particulate matter concentration.