The NPS Air Resources Division (ARD) operates a network of air quality monitoring stations (sometimes referred to as the Gaseous Pollutant Monitoring Network) that measures meteorological parameters and ozone. The gaseous pollutant monitoring program determines levels of two gaseous air pollutants, ozone and sulfur dioxide, which are potentially toxic to native vegetative species found in NPS units when their levels exceed the National Ambient Air Quality Standards (NAAQS). Ozone monitoring in national parks has been ongoing since the early 1980s using EPA reference or equivalent methods. This allows for the direct comparison of NPS data with data collected by state and local air pollution control agencies and the EPA.
Visibility & Particulate Matter
National parks and wilderness areas offer stunning mountain vistas and scenery full of unique landscapes and geologic features. The enjoyment and appreciation of these are linked to one's ability to see clearly through the atmosphere. Unfortunately, air pollution affects our ability to fully appreciate these scenic vistas. Small particles suspended in the atmosphere, mostly as a result of human-caused air pollution, often create haze -- a gray or white veil over the scene that scrubs it of its colors, forms, and textures.
The National Park Service and the U.S. Environmental Protection Agency (EPA) first began long-term visibility monitoring at selected national parks in 1979. In 1985, a national visibility monitoring program was established called Interagency Monitoring of Protected Visual Environments (IMPROVE). IMPROVE is a cooperative effort between the EPA, U.S. Forest Service, National Park Service, Fish and Wildlife Service, Bureau of Land Management, National Oceanic and Atmospheric Administration, and several interstate air quality management organizations.
Wet & Dry Deposition
The NPS monitors wet deposition through the National Atmospheric Deposition Program (NADP). NADP started in 1978 with 22 original monitoring sites and has grown to over 240 sites nationwide, providing the only long-term record of precipitation chemistry in the U.S. The Program is a cooperative effort between federal and state governments, universities and private organizations.
Monitor trends in the dry deposition of sulfur and inorganic nitrogen in and near network parks.