Integrated assessment of ecosystem effects of atmospheric deposition

Several inter, multi, and trans-disciplinary research and assessment programs that have helped inform managers to guide air quality management programs in Europe and North America are presented. These approaches include long-term measurements, experimental manipulations, synoptic surveys, and both conceptual and mathematical modeling. Synoptic-scale surveys have enabled researchers and managers to quantify the spatial extent of the impacts of atmospheric deposition. A series of atmospheric transport models such as ADOM, RADM, CMAQ AURAMS, EMEP were developed to improve scientific understanding of processes affecting the transport, transformations, and deposition of air contaminants, and watershed acidification. The US Clean Air Act (CAA) of 1970 established National Ambient Air Quality Standards that were focused on limiting concentrations of individual air pollutants in urban areas rather than deposition to more distant rural and remote areas.