About NADP
The National Atmospheric Deposition Program (NADP) monitors precipitation chemistry.
The program is a cooperative effort between many different group, including
federal, state, tribal and local governmental agencies, educational institutions, private companies, and non-governmental agencies.
History
In 1977, U.S. State Agricultural Experiment Stations (SAES) organized a project,
later titled the National Atmospheric Deposition Program (NADP), to measure atmospheric deposition and study its effects on the environment.
Sites in the NADP precipitation chemistry network began operations in 1978 with the goal of
providing data on the amounts, trends, and geographic distributions of acids, nutrients,
and base cations in precipitation. The network grew rapidly in the early 1980s. Much of this
expansion was funded by the National Acid Precipitation Assessment Program (NAPAP), established
in 1981 to improve understanding of the causes and effects of acidic precipitation. Reflecting
the federal NAPAP role in the NADP, the network name was changed to NADP National Trends Newtwork (NTN). Today, the NADP
is SAES National Research Support Project - 3. The NTN network currently has 250 sites.
A second network, the Atmospheric Integrated Research Monitoring Network (AIRMoN) joined the NADP in 1992, and currently has seven sites.
Although measuring the same chemicals as NTN, AIRMoN sampling is daily rather than weekly.
These higher resolution samples enhance researchers’ ability to evaluate how emissions
affect precipitation chemistry using computer simulations of atmospheric transport and
pollutant removal. This network also evaluates alternative sample collection and
preservation methods.
A third network, the Mercury Deposition NEtwork (MDN) joined the NADP in 1996, and currently has over 100 sites in the United States and Canada. All MDN samples are analyzed
for total mercury, and some for the more toxic methyl mercury. Fish consumption advisories for mercury exist in almost every state in the country
warning people to limit consumption of fish, and a few states also have wildlife consumption advisories for mercury. Researchers use MDN data to evaluate
the role of precipitation as a source of mercury in these water bodies.