What does inversion mean

In science

An inversion means that the air is warmer above. Usually, the temperature sinks with an average of 0.65 C per 100 meters of altitude. This is because warm rising air cools down by the adiabatic effect of a lesser pressure aloft.

But sometimes, it can be the opposite, at least for a part of the troposphere. For example, during a high pressure with a clear sky and little or no wind, during the night the heat stored during the day in the surface of the earth, radiates back into space. Early in the morning, it is much colder near the ground than above. This is when inversion occurs and sometimes it can even cause fog patches.

Sometimes an inversion can also occur at a higher level. For example, when mild air climbs over colder one along a warm front. The inversion then causes stratus clouds of flat layers.

Sometimes, at night, the cold air from the surrounding hills come down in the valleys, causing a wind called a katabatic wind. In the morning, it is then much colder in the valley than on the top of the hills. That is also an inversion.

in·ver·sion Noun
1. The action of inverting
something or the state of being
inverted.
2. Reversal of the normal order
of words, typically for rhetorical
effect but also found in the
regular formation of questions
in English.