Air Quality Monitoring & Access to Data
The National Park Service Air Resources Division administers an extensive Air Monitoring Program that measures air pollution levels in national parks. The purpose of the Program is to establish current air quality conditions and to assess long-term trends of air pollutants that affect park resources. The data are also used to determine compliance with the National Ambient Air Quality Standards and to assess national and regional air pollution control policies. Measuring air pollution levels in parks is an essential part of the NPS air resource management program and provides vital information to Congress, air pollution control agencies, academia, and the public.
The NPS Air Monitoring Program consists of an extensive network of air monitoring stations in almost 70 national parks across the country. Several of these sites have been in operation for over 20 years. The Program has three primary components: visibility, gaseous pollutants (mainly ozone), and atmospheric deposition (wet and dry). Meteorological monitoring is also conducted at many locations to aid in the interpretation of measured air pollution levels. For more information, please see the table below.
Air Monitoring Programs | Visibility
|
Ozone & Meteorology
|
Wet & Dry Deposition
|
---|---|---|---|
Network Names | IMPROVE (Interagency Monitoring of Protected Visual Environments) | GPMN (Gaseous Pollutant Monitoring Network) CASTNET (Clean Air Status and Trends Network) |
NADP (National Atmospheric Deposition Program) CASTNet (Clean Air Status and Trends Network) |
Parameters Measured | fine and coarse particle (PM2.5 & PM10) mass, elements, sulfate, nitrate, organic and elemental carbon scenic views, scattering, and absorption |
ozone, wind speed, wind direction, ambient temperature, relative humidity, solar radiation, wetness | Wet: sulfate, nitrate, ammonium, cations, and mercury in precipitation Dry: sulfur dioxide, sulfate, nitric acid, nitrate, and ammonium; wind speed, wind direction, ambient temperature, relative humidity, solar radiation, wetness |
Frequency of Measurements | 24-hrs every 3 days | continuous, hourly averages | weekly |
Access to Data | Visibility Data | Ozone & Met Data | Wet Deposition Data Dry Deposition Data |
In addition to long-term monitoring, the NPS is involved in many special studies that tend to be short-term and more intensive in nature. These studies are often initiated to answer specific local and regional research questions, such as identifying sources of air pollution or assessing the potential risk of natural resources in parks.
Locations
The Air Resources Division monitors air quality in cooperation with several national networks. This monitoring complements the efforts of other federal, state, and local agencies. The following map shows where different monitors are located within the national park system. Links below the map provide site location information for each monitoring network.
Trends
Assessing how air quality is changing is a prime function of the NPS Air Monitoring Program. In fact, the National Park Service measures the success of its air resource management program based on results achieved, even though the NPS has no authority to regulate sources of air pollution located outside park boundaries. Monitoring data on visibility, ozone, and atmospheric deposition show that air pollution is affecting some park resources nationwide. Consistent with the Government Performance and Results Act, the NPS has established the air quality goal of stable or improved air quality in 70% of reporting park areas by September 30, 2008. An area meets the goal if it does not show statistically significant deterioration in any of the performance indicators. The NPS has greatly expanded its annual reporting of air quality trends in national parks, from 52 to 141 parks. Previously, only parks with on-site monitoring were evaluated. The current report also includes parks with nearby air quality monitoring stations operated by state and local agencies. For the period 1996-2005, 86% of the parks have stable or improving air quality, exceeding the NPS goal. In addition, for the first time, the annual report includes air quality conditions for parks. For more information, view the 2006 GPRA Report.