What’s temperature inversion and how does it work?

Weather Headlines

(WTAJ) — A temperature inversion is when the air temperature increase with height instead of what it normally does, cool with height. This happens quite a bit in Central PA and I bet you have seen this many times. Let me explain why.

Central PA is mountainous, it has its peaks and valleys. A temperature inversion or also know as a capping inversion favors valleys because they are sheltered from the wind. Also, many of us use wood-burning stoves and chimneys for heat. These produce smoke and because of the inversion, the smoke and other pollutants become trapped to the surface and can not escape into the atmosphere.

What causes a temperature inversion? Air near the ground cools faster than the air aloft. This occurs on a clear and calm night. The clear sky and calm winds allow the ground to quickly cool. The air aloft does not cool as quickly so it becomes warmer. Air parcels rising into the warmer layer of air become cooler and more stable, thus not allowing it to rise. The warm layer of air is known as a cap. The cap acts like a lid and traps the smoke and other pollutants from escaping. This can lead to air quality issues.

The temperature inversion beings to form around sunset and linger into the next day at sunrise. The wind has to pick up or the temperature at the surface has to become warmer than the “warm layer” for the inversion to disappear. So when you notice smoke and haze near the ground, you know that there is a temperature inversion above you.


Copyright 2021 Nexstar Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.

Trending Stories

Don't Miss