BOISE -- The inversion has been sticking around for a couple weeks. We know we do not like it but, what exactly is it?
It is a thick cloud of pollution hanging between the foothills and the Owyhees, and the people of the Treasure Valley are stuck in the middle unless, they climb above it.
We found Peter Dietrich skiing at Bogus Basin on Wednesday. "We just came up to get out of the gloom and doom."
Like many people, he was enjoying the slopes, and the clean air. "It's just nice to get out of town."
'Nice,' because back home in the Valley, it is dreary. Up in the mountains above the Treasure Valley, the days are beautiful. So why is it so cold and grey in the Valley, and so relatively bright and warm up in the mountains?
It's the inversion.
"You go up to Bogus Basin, you look out and you see almost this one white cloud across the whole Valley, and that's the inversion layer you're looking at," said Michael Toole, Regional Airshed Coordinator for the Idaho DEQ.
Toole explains exactly what an inversion is, and how we can see temperatures 20-30 degrees warmer than the Valley, up in the mountains. "What happens is you get a cooler air mass, a denser air mass at the ground level, here on the valley floor, and you get a warmer air mass above it. And what does, is acts like a cap. There's really nowhere else for the pollution to go."
To illustrate what Mike was talking about, we came up with a bit of a demonstration, which you can see in the video. We took a clear glass vase (representing the Valley), and put ice at the very bottom (representing the ice and snow in the Valley). Next, we lit a piece of paper on fire so we could track the smoke (representing the air), and capped the vase (representing the inversion). All the smoke from the paper tried to get up out of the proverbial Valley, but then hit the inversion, went right back down, and collected right around the bottom.
All this is caused by stagnant weather. Our Meteorologists say there is a front moving through Wednesday night, but it won't be strong enough to knock the inversion out of the Valley. That's expected to happen this weekend.
In addition, a quick reminder, a burn ban is in effect for cities and counties in the Treasure Valley, because of the poor air quality.
To watch the video of Justin's experiment, click on the play icon above. To watch on the mobile app, go to the video tab.