Weather 101: What is a temperature inversion?


ALBANY, N.Y. (NEWS10) — You may have woken up on the morning of November 8 and felt that it was harder to breathe, or you noticed there were air quality alerts in effect for many parts of the Capital Region. This is all thanks to what we call a temperature inversion.

What is a temperature inversion? Are they rare? Not so rare as you might think. Typically, they become more common in the fall and winter months as we see less solar radiation and stronger areas of high pressure. This usually prevents the air from mixing at all layers.

Think of the atmosphere in three dimensions. We usually see air from the surface, typically warmer, rising and cooling.

This is what a “normal” temperature profile in the atmosphere will typically look like.

However, when we see an inversion setup, we see colder air that gets trapped at the surface. Remember, cold air is heavier and denser than warm air, so it is happy to remain near the surface. That is where the problem arises. Because of this, there is now a layer of warmer air just above the cold layer and this does not allow anything to mix up. Think of it as a lid where these two layers meet.

What a temperature profile with an inversion looks like.

Because it is a “lid” none of the particles like pollution, or even smoke can get mixed up in the atmosphere and this can sometimes lead to poor air quality conditions like we experienced this morning for many locations. All of those pollutants get trapped below the lid, and that means closer to the surface of the Earth.

Typically with sunshine in the afternoon the inversion will weaken or break all together, allowing things to mix in all levels of the atmosphere and clearing the lower levels of the pollution. In the case of this morning most of that got “mixed out”, however, we were still left with a little bit of a hazy look to the sky through much of the afternoon.

This is what the upper air sounding from Albany looked like this morning. Notice right in the center of the screen, look at the red line. It starts at 44, that was the temperature in Albany at 7am… However, at an elevation of 1,600 feet the temperature rose to 60 degrees! That is impressive. Looking at this sounding, you would definitely say that this was a rather strong inversion.

Upper air sounding from Sunday morning (11/8/20).

Because high pressure and clear skies will be around for the next few nights I am expecting a repeat of this phenomenon over the next several mornings. Temperatures at the surface will cool quickly, but because we have so much warm air overhead, there will once again be a “lid” that develops and causes concern for air quality.


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