National Park Service

Chihuahuan Desert Network (CHDN)

CHDN air quality icon symbol

Air Quality Monitoring

air quality, Guadalupe Mountains National Park
Dust can compromise air quality at Guadalupe Mountains National Park.

Monitoring Reports

Protocol Documents

Data & Maps

National Air & Climate Pages

Vital Signs Included in Protocol

  • Ozone
  • Atmospheric deposition (wet and dry)
  • Visibility and particulate matter

Parks Where Protocol Will Be Implemented

Project Contacts

Cheryl McIntyre, Physical Scientist
Chihuahuan Desert Network

Nina Chambers, Science Writer and Editor
Chihuahuan Desert Network

Project Cooperators

Sonoran Desert Network

Southern Plains Network

NPS Air Resources Division


Both the Clean Air Act and the National Park Service Organic Act protect air resources in national parks. Park resources affected by air quality include scenery and vistas, vegetation, water, and wildlife. Understanding changes in air quality can aid in interpreting changes in other monitored vital signs and support evaluation of compliance with legislative and reporting requirements. Three CHDN parks, Big Bend NP, Carlsbad Caverns NP, and Guadalupe Mountains NP, are designated Class I areas under the Clean Air Act, meaning they have the highest level of protection. Over the past three decades, the NPS has developed several internal and cooperative programs for monitoring various measures of air quality. CHDN has identified several components of air quality as high-priority vital signs for monitoring. The networks will acquire and analyze data from existing stations and report on data specific to park units.

Monitoring Objectives

  1. What are the conditions and spatial and temporal trends in ozone, nitrogen deposition, sulfur deposition, and visibility-reducing pollutants in network park units?
  2. How do ozone, nitrogen deposition, sulfur deposition, and visibility-reducing pollutants vary with associated vital signs (e.g., vegetation community composition, exotic plant status, and climate)?


  • Annual concentration (mg/L) and deposition (kg/ha) of sulfate, nitrate, ammonium.
  • Diurnal concentration (ppb) of ozone.
  • Mean daily light extinction (%) and aerosol composition (% by class).

Management Applications

Because emission of harmful air pollutants occurs over broad spatial scales, park managers have little control over the atmospheric conditions of the parks they manage. However, documenting the status and trends of air quality constituents can provide managers with regulatory and policy tools to influence off-site emitters and indirectly stabilize or improve park air resources. Accounting for the potential effects of air quality may also help clarify the consequences of stressors that park managers can directly affect.

Protocol Status

This protocol, developed in cooperation with the Sonoran Desert Network and Southern Plains Network through the Southwest Network Collaboration, has been approved and published. CHDN implemented this protocol in 2012.

Status and Trends

Determination of air quality status and trends is ongoing using current and archived data, largely provided by the NPS Air Resources Division. Status and trends are reported in the documents provided under "Available Information," above.

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Last Updated: October 27, 2014 Contact Webmaster