An atmospheric condition in which the typical lapse rate is reversed and temperature increases vertically through a given layer. In the troposphere an inversion layer marks conditions of great stability, i.e. a region in which vertical motion is strongly damped, with an absence of turbulence. An inversion acts as a ceiling, preventing further upward convection, and is generally the limit for cloud development. Marked and persistent inversions occur at lower levels, with subsiding air in major anticyclonic cells, such as the Azores high-pressure zone and cold anticyclones over continents. See also atmospheric structure; environmental lapse rate.