Greater Yellowstone
Coordinating Committee

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Importance to the Ecosystem:

Clean air is essential to ecological, social, and economic sustainability. Pollutants deposited from the atmosphere can act as nutrients, acids, or toxins, and alter the health of various terrestrial and aquatic ecosystems. Ground level ozone (O3) concentrations can damage human, animal, and plant cells upon contact. Dust-on-snow events can increase snowmelt rates on both glaciers and perennial snowfields, which can decrease the availability of water downstream in late summer and fall. Clean air is valued positively for physical and mental health and unobscured vistas by communities and visitors.

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Status and Trends in Greater Yellowstone:

• Air pollutants associated with acid rain (nitrogen oxides and sulfur) are decreasing. Exceptions may occur in localized areas with high vehicle congestion.
• Visibility impacted by human-caused pollution sources has been improving on days not impacted by smoke.
• Smoke from wildland fire is increasing in intensity, duration, and the number of days impacted.
• Ammonium deposition and associated fertilizing effects are increasing. The primary source is from agricultural areas including the Snake River Plain.
• Dust events are increasing. Dust contains nitrogen, phosphorus, microplastics, pesticides, and other chemicals.
• Microplastics have been found in water, snowpack, fish, and insects in addition to dust in the GYA.
• High alpine lakes are becoming more eutrophic; the number of lakes with Harmful Algal or Harmful Cyanobacteria
Blooms (HAB/HCBs) is increasing.
• Current levels of nitrogen deposition increase the risk of harm to lichen and alpine plant, aquatic diatom, and algal communities; mycorrhizae associations with conifers; and tree species growth and survival. This air pollution creates poor conditions for ecosystem health.
• Ozone levels have remained relatively unchanged for the past decade, with concentrations being good to fair for both human health and sensitive plant species exposure.
• For mercury, Yellowstone National Park shows a significant improving trend of mercury in precipitation from 2012 to 2021. The 2021 mercury condition for Grand Teton National Park is good. For Yellowstone, it is fair, based on health risks to wildlife from mercury as determined by mercury concentration data in park fish and invertebrates.

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The Greater Yellowstone Fire Action Network has been formed to address challenges communities and the landscape face with wildfire. This effort includes developing Smoke Ready Communities. A smoke ready plan helps local and federal governments know what actions to take and how to disseminate and coordinate information smoothly during a smoke event to protect the public.

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Publications/Products Produced:

Nitrogen deposition sources and patterns in the Greater Yellowstone Ecosystem determined from ion exchange resin collectors, lichens, and isotopes

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Lake and bulk sampling chemistry, NADP, and IMPROVE air quality data analysis on the Bridger-Teton National Forest
(USFS Region 4)

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Long-Term Air Quality Monitoring within the Greater Yellowstone Area

 

Environmental management of air quality issues in the Greater Yellowstone Area

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Spatial variation of atmospheric nitrogen deposition and critical loads for aquatic ecosystems in the Greater Yellowstone Area

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U.S. Forest Service Region 1 Lake Chemistry, NADP, and IMPROVE air quality data analysis

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Yellowstone Winter Use Adaptive Management Plan Air Quality Update 

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Additional Resources:

AirNow.gov

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Air Quality in Parks - Air (U.S. National Park Service) (nps.gov)

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​US Forest Service: Critical Loads Video Series: Lichens (youtube.com)