Wednesday, November 13, 2013

Invisible Smoke Ceiling

It's typical to have  fields burning across Region 8 in November. On many afternoons, you can look on the horizon and see smoke. Today, I got a tweet that spawned this blog:
If you look at the pic above (click to enlarge), it appears that the smoke hits an invisible ceiling and starts fanning out. In fact, that is exactly what it does! As the smoke rises, it comes to a point where something happens. But, what is it?

If you look below, we have a skew T for the time period of the pic. This diagram is showing you what the temperature (red line) and dewpoint (green line) is as you go vertically into the atmosphere. At about 2300', the temperature stops dropping, as it typically would, and starts rising! This is a temperature inversion and because of the inversion, the smoke stops rising. Remember, warm air rises. The smoke encountered air that was warmer than it was and it stopped rising.

Have a great day!

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