In some cases the process is called inversion if the temperature of the atmosphere rises instead of falling.
This is due to the effect of factors such as long winter nights, stable air, clear skies, windless nights, icy regions, etc.
And the layers that rise in the atmosphere during that period are relatively warm.
Hence the situation is called inversion temperature.
Such an inversion of temperature is felt in the northern and south polar glacial regions, high mountain regions as well as valley regions.