The Atmospheric Turbulence and Diffusion Laboratory at Oak Ridge , Tennessee has been conducting routine probing of the lower troposphere and comparing the results with those obtained with turbidity photometers and a distant suspended particulate station . The change in scale height , K ( sub z ) divided by v ( sub s ) , with time permits the vertical turbulence coefficient K ( sub z ) to be estimated if v ( sub s ) is known or assumed . Extremely high monthly correlations of turbidity versus the log of backscatter at 100 meters have been obtained . In addition , high correlations of suspended particulate matter at Chattanooga and Oak Ridge suggest that the bulk of particulate matter is of natural , rather than industrial , origin .