Urban dispersion models typically make use of either data obtained from a single nearby set of instrumentation or estimates of prevailing conditions derived from models. It has recently been shown that the aggregation of data from surface network locations surrounding locations of special interest might have useful applicability if the urban area in question is sufficiently homogeneous and if the instrumentation is reporting correctly. The present analysis focuses on the need to develop methods to utilize relevant information from a local network of surface sites, in a manner that is widely applicable.

Data obtained in studies of the surface boundary layer in Washington, DC, and New York City, NY, are used to show how such data might be used directly, or used to modify the values of conventional drivers of dispersion calculations, specifically the appropriate wind speed (u), its direction (θ), and the corresponding standard deviations (σ(u) and σ(θ)). It is concluded that aggregated data provide input guidance that suffers little from the problems normally encountered with the data used to drive dispersion models – (a) the inappropriateness of data from nearby airports, and (b) the lack of representativeness of data from any single local site.