Bo Call is the air monitoring section manager for the Utah Division of Air Quality. He said an inversion happens when a warmer air layer moves above a colder air layer and traps air underneath it.
Since the air is stagnant, it traps pollution, covering valleys across Utah in smog.
“If you watch the smoke from like smokestacks, or chimneys or whatever, it'll go up, but it won't just keep going up and up and up like you might expect, but it kind of goes up a little bit, and then it starts going sideways," Call said. "There isn't really enough energy in that smoke to get it to go up and out. So it just kind of lingers.”
It takes a storm or some kind of precipitation to break up the air so it’s no longer stuck in the valley. But after a storm clears out one inversion, the cycle begins again.
“During the winter, we don't look at are we going to have an inversion because we have lots of them, that's kind of a normal state, but we look at how long are they going to last,” Call said.
More people means more sources of pollution, he said. That could be one reason residents in the Heber Valley could start to see more smog during inversions in the future.
“It just tends to pile up, there probably isn't one big source that you can point your finger at and say, ‘Ah, that's the reason why our air is bad, because that came and it wasn't here last year,'" Call said. "But as you build over time, and just slowly build up, you tend to increase.”
Jennifer Magoffin has lived in Midway for 10 years. Her parents moved from Salt Lake City to Wasatch County 40 years ago to get away from the smog. Magoffin said she hasn’t noticed a difference in the Midway area’s air quality during the winter.
But if residents start to notice air quality changes in the Heber Valley, she said it could negatively impact Wasatch County.
“I think it would be detrimental," she said. "That is one of the reasons why a lot of people do move to the Wasatch Back is to escape the inversion. It would definitely impact the citizens as well as the tourism and travel.”
John Kennedy also lives in Midway. He’s been there for six years and said the smog in Provo Canyon is becoming more prevalent.
“I have noticed it more recently, over like the last few years when I've been commuting to and from Park City and work and heading back home at the end of the day.”
He hopes the Heber Valley won’t become the second Salt Lake Valley when it comes to pollution.
While the cap on an inversion is different every time, you can usually see where the smog ends and the fresh air begins. And, there is a way to get out of it: go to the mountains above it.
