Which condition results in a stable atmosphere?

A stable atmosphere occurs when the temperature of the air decreases with altitude at a slower rate than usual, or when warmer air rests over cooler air. In this case, the condition that leads to a stable atmosphere is cooled ground air. When the ground cools at night, the air directly above it may also cool, creating a situation where colder air is trapped beneath a layer of warmer air. This results in stability, as the colder air does not rise easily.

In contrast to this, warm surface air tends to rise, leading to instability. Strong winds can also contribute to atmospheric turbulence, which disrupts stability. Low humidity generally promotes a more stable atmosphere, but it is the cooled ground air specifically that is responsible for creating that layer of cooler air under warmer air, thus causing the overall stability in the environment.