The term "inversion" is used to describe the conditions where:

Inversion refers to a meteorological phenomenon where temperature increases with height in the atmosphere, which is counter to the typical atmospheric behavior where temperature usually decreases with altitude. This situation can lead to various weather phenomena, such as trapping pollutants and creating fog or clouds below the inversion layer.

In a normal lapse rate, as altitude increases, air temperature decreases, allowing for the development of vertical mixing and convection. However, during an inversion, the warmer air sits above the cooler air at the surface, leading to very stable atmospheric conditions that inhibit air movement. This can affect flight operations, as well as visibility and air quality.

Understanding the concept of inversion is crucial for pilots, as it can influence flight planning and safety by creating conditions that may not be conducive to flying or could require specific considerations for navigation and visibility.