What is a temperature inversion?

A temperature inversion is a meteorological phenomenon where the normal temperature gradient of the atmosphere is reversed. Under typical conditions, air temperature decreases with altitude; however, during a temperature inversion, warm air sits above cooler air near the earth's surface. This situation causes the cooler air to become trapped, preventing the vertical mixing of air layers.

The characteristic of having cooler air near the soil surface, while warmer air overlays it, is significant because it can lead to various environmental consequences, particularly relating to air quality. Pollutants and pesticides can become concentrated in the cooler air layer if the inversion persists, as they are unable to disperse upwards. This is crucial for pesticide applicators to understand, as applications may become more effective under certain conditions or may pose greater risks to human health and the environment if inversions trap these materials close to ground level.