Measuring the effect of wildfires on air quality

Wildfires erupting in areas such as forests, grasslands, or prairies have recently grown in frequency and intensity – most likely due to climate change – increasingly impacting a variety of ecosystems, as well as human lives. Although wildfires are often considered ecologically beneficial, they also have many negative effects, such as degradation of air quality from the smoke and pollutants released.

In a new study, experts from the NASA Langley Research Center, in collaboration with scientists from the National Oceanic and Atmospheric Administration (NOAA), have monitored the levels of carbon monoxide (CO) and ozone (O₃) in wildfire plumes in order to better understand the effects of wildfires on air quality. 

While CO is directly generated during wildfires, O₃ is produced from precursors emitted during wildfires and depends on various factors for its production, while their presence within wildfire plumes determines the plume age. Thus, reliably assessing its concentrations is crucial for better understanding how wildfires affect the air quality, weather, and climate.

The scientists measured the atmospheric CO and O₃ levels across the continental U.S. by using a remote sensor called “National Airborne Sounder Testbed-Interferometer” (NAST-I) that provided both high spatial and spectral resolution. 

“The NAST-I, onboard NASA ER-2 aircraft, covers a space large enough to monitor the wildfire plume from its origination, evolution, and transport, and provides 3D distributions of the O₃ and CO concentrations at a higher spatial resolution compared to that of satellite infrared-ultraspectral sensors,” said study lead author Daniel K. Zhou, a physical scientist at NASA.

Based on their measurements, the researchers estimated the plume age by observing the differential concentrations ratios of O₃ and CO. “Our results showed enhanced levels of CO in the evolving plume as it was transported away from the site of the fire. The plume age was associated with the plume distance in both vertical and horizontal directions,” Zhou explained.

These findings – published in the Journal of Applied Remote Sensing – provide important insights into the effects of wildfires on the atmosphere and the steps needed to mitigate their negative impact on air quality and thus public health. 

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By Andrei Ionescu, Earth.com Staff Writer