Environment
Originally published on Thu December 8, 2011 4:08 pm
A cold air inversion concentrated east of the Cascades is keeping the air clogged with tiny particles. And public health officials in Washington, Oregon, and Idaho warn that people trying to warm up in front of wood fires could make the pollution worse.
Here's what's going on in the atmosphere: Usually, air temperature decreases as you get higher. But in an air inversion, the opposite happens. And the warmer air acts like a lid, keeping particles concentrated near the surface.
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