A NASA satellite image of the 2013 Yosemite Rim Fire, one of California's largest fires. The image shows smoke from the fire, located at the cluster of red dots, spreading to Nevada, Idaho and Montana. Credit: NASA
SALT LAKE CITY — The skies over the Salt Lake Valley are grey and filled with wildfire smoke coming from the west coast. But, how much of that are we actually breathing? Researchers at the University of Utah have created a way to predict where wildfire smoke will go, and where it may cause health problems for more people.
University of Utah Chemical Engineering Associate Professor Heather Holmes said the potential health risks from wildfire smoke correlate to how high the smoke has traveled. She says her partner, Dr. S. Marcela Loría-Salazar with the University of Oklahoma, noticed something odd when looking at the pollution data from the Yosemite Rim Fire in 2013.
“She said, ‘there’s smoke going over Fresno, but if you look at the EPA monitor, it doesn’t look like the air pollution is going up as high as you would expect,’” Holmes said.
After taking a closer look they discovered vertical winds had pushed the smoke into the troposphere, away from the earth’s surface. So, the pollution levels stayed relatively low even though the air looked incredibly dirty.
“It wasn’t low enough to be able to mix down into the surface,” said Holmes.
Holmes said people have been able to use weather patterns to predict where the winds will carry the wildfire pollution, but vertical winds have been much harder to predict. However, she and her fellow researchers have developed a system that takes current weather models and combines them with NASA satellite imagery, and they can measure how high the wildfire smoke plumes are.
She said if the smoke stays out of the atmospheric boundary layer it won’t be a major health risk to people below.
“In that layer, the air is mixing all the time. So, if the smoke is above that layer, then it won’t mix down into that boundary layer and it won’t end up at the surface,” she said.
This system also allows researchers to predict where the worst particles from the smoke are going to land.
“If it’s in the boundary layer, it’s going to mix down into the surface where it will impact humans,” Holmes said.
Smoke from wildfires contains thousands of tiny particles which are easily absorbed into the lungs. These include volatile organic compounds, carbon dioxide, carbon monoxide, and hydrocarbons, according to U.S. Air Quality Index.
These compounds can lead to eye irritation and exacerbate existing conditions, such as asthma or cardiovascular disease. Most healthy adults can quickly recover from exposure to wildfire smoke, but people in those more vulnerable populations should avoid breathing it if possible.
Using this new system, Holmes said they hope to create a new smoke forecast, which could warn people of potentially unhealthy levels of pollution a few days before they actually happen. They believe this can help cities know when they should issue health advisories and close schools to keep people safe.
Holmes’ and Loría-Salazar’s study was published in the Journal of Geophysical Research: Atmospheres.