What defines a temperature inversion?

A temperature inversion is characterized by a condition where temperature increases with height in the atmosphere. Under normal atmospheric conditions, air temperature generally decreases as altitude increases. However, during a temperature inversion, a layer of warm air traps cooler air underneath it at lower altitudes. This phenomenon can lead to various weather effects, such as the trapping of pollutants close to the ground, reduced visibility, and the formation of clouds and fog.

Inversions commonly occur during stable atmospheric conditions, particularly at night or in early morning when the ground cools quickly, causing the air just above it to remain warmer. This condition is important for understanding aviation weather because it can affect aircraft performance and flight safety by influencing turbulence and visibility.

The other choices describe different atmospheric phenomena or relationships. The decrease of temperature with height refers to the normal lapse rate, while the idea of ground temperature rising sharply does not directly define an inversion. Additionally, cold air moving over warm air can contribute to weather events but does not specifically indicate a temperature inversion scenario. The correct answer distinctly captures the essence of how inversions disrupt the typical temperature gradient found in the atmosphere.