DISCOVER-AQ: Tracking Pollution from the Skies (and Space) Above Denver

NASA four-engine turboprop P-38 takes to the sky

NASA four-engine turboprop takes to the sky for clean air science.


EPA scientists have teamed up with colleagues from NASA to advance clean air research. Below is the latest update about that work. 

Denver is the last of four cities in a study by EPA and partners that will give scientists a clearer picture of how to better measure air pollution with instruments positioned on the earth’s surface, flying in the air, and from satellites in space.

The NASA-led study is known as DISCOVER-AQ, and is being conducted July 14 to August 12 in Denver.  The research began in 2011 with air quality measuring conducted in the Baltimore-Washington, DC, area followed by a field campaign in California’s San Joaquin Valley and Houston in 2013.

Right now, monitoring for pollutants such as sulfur dioxides, nitrogen oxides, particulates and ozone is done by ground-based systems strategically located across the U.S. to measure air quality in metropolitan areas and on a regional basis. Researchers want to tap satellite capabilities to look at pollution trends across wide swaths of the country.

“The advantage of using satellites is you can cover a wider area,” said Russell Long, an EPA project scientist.  “But right now, it’s hard for satellites to determine what air pollutants are close to the ground.”

Satellites could be an important tool for monitoring air quality given the large gaps in ground-based pollution sensors across the country and around the world. Improved satellite measurements should lead to better air quality forecasts and more accurate assessments of pollution sources and fluctuations.

However one of the fundamental challenges for space-based instruments that monitor air quality is to distinguish between pollution high in the atmosphere and pollution near the surface where people live.

Ground-based air sensor station

Ground-based air sensor station from the study’s previous Baltimore and Washington area component.

The ground-based sensor readings taken by EPA and other partners in DISCOVER-AQ will be compared to air samples taken by NASA aircraft flown between 1,000 and 15,000 feet in the skies above the Denver metropolitan area. EPA scientists are using the opportunity during the DISCOVER-AQ study to also test various types of low-cost and portable ground-based sensors to determine which ones work the best.

“Our goal is to evaluate the sensors to see how well they perform,” Long said. “By including more sensors it increases our understanding of how they perform in normal monitoring applications and how they compare to the gold standard (for measuring air quality) of reference instrumentation.”

New sensors could augment existing monitoring technology to help air quality managers implement the nation’s air quality standards.

Another big part of EPA’s involvement in DISCOVER-AQ is working with schools and academic institutions to develop a robust citizen science component for pollution monitoring. In Houston, hundreds of student-led research teams all worked to test the air pollution technology by taking regular readings at their schools when NASA aircraft flew overhead.

In Denver, most schools are out for the summer, but EPA researchers will be partnering with the Denver Museum of Nature and Science to share what they are doing in DISCOVER-AQ with the general public.

Long says he is also working with University of Colorado Boulder to look at a unique three-dimensional model of air pollution in the great Denver area. The end result of DISCOVER-AQ will be a   global view of pollution problems, from the ground to space, so that decision makers have better data and communities can better protect public health.

Learn More

DISCOVER-AQ in EPA Science Matters


NASA Discover-AQ Mission