Atmospheric inversions are parallel layers of air that rise in temperature as they get higher. This warm air is light and lies over cool and heavy air, which makes this air have strong upright stability, particularly when there are no strong winds.
Atmospheric inversions have a significant role in the quality of air because they can confine air pollutants below or within them. Atmospheric inversions are common, and they are created in many ways. Surface inversions form during the evening when the radiatively cooling ground turns into a heat sink at the bottom of an air mass, which makes heat flow down through the air. This sets up a temperature slope that coincide with an inversion. Elevated atmospheric inversions form when vertical differences in wind direction allow warm air to set up over cold air.
In near-subtropical latitudes, it is common to get subtropical subsidence inversions. Subtropical subsidence inversions work with mountainous topography to catch horizontal and vertical air.