He considered other possibilities, with a temperature inversion as the most likely cause.

This usually occurs during a temperature inversion, and lasts for a few days.

As goes the ozone layer, so go our temperature inversions.

Due to the mountains to the south of the city, temperature inversions are common, occurring on about 200 days per year.

During temperature inversions, they reportedly exceed such levels by up to 10 times.

The sky is all overcast, so maybe it's a temperature inversion.

It was held down by a temperature inversion and was moving slowly.

And it's quite true that there's no vertical movement of the air in a temperature inversion.

The surface cooling results in a large temperature inversion at the top of the marine layer.

When temperature inversions arise in winter, heavy ice fog often results.