FILE: A massive smoke plume, powered by strong winds, rises above the the Woolsey Fire on November 9, 2018 in Malibu, California. (David McNew/Getty Images)
SALT LAKE CITY — A study from the University of Utah found that wildfire plumes are increasing in height across the mountain regions of the western United States. The study compared statistical information associated with wildfire plumes from between the years 2003 to 2020.
The researchers say that the taller wildfire plume heights lift the smoke and aerosols (small particles that made the sunsets red) higher into the atmosphere where they can more greatly impact air quality across a larger region.
The research concludes that the increasing size of wildfire plumes is due to the effects of climate change, specifically, droughts that create bone-dry fuel for wildfires. It also concludes that these plumes will exacerbate poor air quality conditions across the West.
“Should these trends persist into the future,” said Kai Wilmot, a postdoctoral researcher in the Department of Atmospheric Sciences at the University of Utah in a press release, “it would suggest that enhanced Western U.S. wildfire activity will likely correspond to increasingly frequent degradation of air quality at local to continental scales.”
Using information from more than four million smoke plumes in the western U.S. and Canada, between 2003 and 2020, the researchers tracked the heights of wildfire plumes. In the Sierra Nevada region of California, plume heights increased, on average, by 750 feet per year. An average of four western regions showed an increase in plume height of 320 feet per year.
Why the increase? Wilmot said less snow and hotter temperatures are two reasons.
“… We’re seeing larger and more intense wildfires throughout the Western U.S.,” Wilmot said. “And so this is giving us larger burn areas and more intense fires.”
The increasing height of the plumes could be one of the reasons that Utah is so often impacted by smoke from wildfires in neighboring states.
“When smoke is lofted to higher altitudes, it has the potential to be transported over longer distances, degrading air quality over a wider region,” said John Lin, professor of atmospheric sciences at the U.
“So wildfire smoke can go from a more localized issue to a regional to even continental problem.”
The study included regions from the Western United States as well as Canada, including Utah’s Wasatch and Uinta mountain ranges. The researchers report that rising plume heights are seen in Utah. But the trend in Utah is not as strong as those in Colorado or California.
“In terms of the plume trends themselves, it does not appear that Utah is the epicenter of this issue,” Wilmot says. “However, given our position as generally downwind of California, trends in plume top heights and wildfire emissions in California suggest a growing risk to Utah air quality as a result of wildfire activity in the West.”