What is a temperature inversion?

A temperature inversion is indeed characterized by a situation where temperature increases with altitude, which is the opposite of the typical lapse rate. In a standard atmospheric condition, one would expect temperature to decrease with an increase in altitude, due to the thinning of the atmosphere and radiative cooling; however, during a temperature inversion, a layer of warmer air sits above cooler air near the Earth's surface.

This phenomenon has various implications for weather and air quality. It can lead to the trapping of pollutants near the surface, as the warmer air above creates a cap that prevents the cool air below from rising. Consequently, temperature inversions often occur under specific weather conditions, typically during clear nights when the ground cools rapidly.

While the other options reference different atmospheric phenomena or conditions, only the description of a lapse rate where temperature increases with altitude accurately captures what characterizes a temperature inversion.