||Illinois State Water Survey Div., Champaign.; Illinois Univ. at Urbana-Champaign.; Department of Agriculture, Washington, DC.; Department of the Interior, Washington, DC.; Environmental Protection Agency, Washington, DC.
In 2005, scientists, students, educators, and others logged more than 310,000 sessions on the National Atmospheric Deposition Program (NADP) web site. This site had nearly 90,000 unique visitors, 19 percent more than in 2004. Users retrieved 18,564 data files, an increase of 35 percent, and they retrieved more than three times as many Mercury Deposition Network (MDN) data files as in 2004, reflecting the growing interest in these data. Records show that 61 percent of users study atmospheric deposition or its effects on aquatic and terrestrial ecosystems and cultural resources, and 39 percent use NADP data for educational purposes. Educators included NADP maps and other information in textbooks, and the NADP web site was used in public education and outreach materials. Government agencies continued to use NADP data to assess the nation's air quality and evaluate policy decisions. In the 2005 National Acid Precipitation Assessment Program Report to Congress - An Integrated Assessment, NTN concentration and deposition maps were presented to describe the current state of acid precipitation in the United States. Sulfate and nitrate trends from NTN data were especially effective in demonstrating the impact of sulfur and nitrogen oxide emissions reductions since 1990. The report emphasized the growing importance of nitrogen deposition in eastern U.S. estuaries and high-elevation Rocky Mountain ecosystems.