A layer in which temperature increases with altitude. The principal characteristic of an inversion layer is its marked static stability, so that very little turbulent exchange can occur within it. Strong wind shears often occur across inversion layers, and abrupt changes in concentrations of atmospheric particulates and atmospheric water vapor may be encountered on ascending through the inversion. When an inversion is mentioned in meteorological literature and discussion, a temperature inversion is usually meant. See frontal inversion, subsidence inversion, trade-wind inversion.