Suspended particulate concentrations: Spatial correlations in the Detroit-Windsor area

During a 14-month period in 1967–68, 24-hr suspended particulate concentrations were measured every third day at 56 stations in the Windsor–Detroit, Sarnia–Port Huron region. In this paper, spatial correlation coefficients have been computed, and isopleths have been plotted. Using the entire data set, these correlations are rather low. By dividing the data into subsets each with similar wind direction patterns, however, the correlation coefficients are increased, and some interesting patterns emerge. It is concluded that on individual days, the particulate levels measured at a single site are not useful indicators of urban particulate loadings unless the meteorological situation is specified. Some implications for optimizing the density of air pollution networks are discussed.