Urban landscapes and their environments typically exhibit higher concentrations and depositional fluxes of atmospheric particles and chemicals than rural environments.  Most atmospheric pollutants originate from the combustion of fossil fuels, industrial emissions, and wear products from vehicles, all of which are associated with cities. These include nitrogen oxides, sulfur oxides, heavy metals, and numerous organic chemicals.  In addition, urban landscapes have unique source-sink relationships of pollutants at various scales, which make it difficult to predict their spatial-temporal depositional and accumulation patterns and thus the potential for human exposure and ecosystem impacts.  A newly formed ad-hoc Subcommittee on Urban Atmospheric Monitoring (SCUAM) was formed to address the monitoring and assessment of urban atmospheric environments.  We are in the early stages of designing an urban network by initiating a pilot in three cities: Bronx or Brooklyn, NY; Boston, MA; and a suburban site in Maryland.

The urban network will consist of existing NADP networks, in particular the National Trends Network (NTN), Mercury Deposition Network (MDN), and the Ammonia Monitoring Network (AMON).  We hope to expand the mercury analysis to include heavy metals. To expand on the number of observations and to quantify the spatial and temporal heterogeneity of urban atmospheric environments, we will utilize passive and through-fall samplers.  Preliminary data collected from the Bronx and Boston sites will be presented to address questions related to the effect of tree canopies on fine particulates and gaseous pollutants; the amount of mostly wet deposition that occurs; and finally the spatial and temporal patterns of “hot moments and spots” that happen in urban landscapes