Answer:
1 A temperature inversion is a deviation from the normal decrease of atmospheric temperature with altitude in the lower portion ( troposphere) of a planetary atmosphere ( atmosphere, Structure). Temperature inversions inhibit vertical motion, because the warmer air is at a higher altitude and tends to remain there.
question 2
An inversion exists when temperature increases with altitude. The figure below shows the four layers: the Troposphere, the Stratosphere, the Mesosphere, and the Thermosphere. Between each layer exists a "pause" in which the temperature remains constant with height.