"The ' lies above the , extending to about 48 or 1 , and is capped by the '. It is a vertically stable, stratified region—hence its name—in which increases with altitude. The ' ("middle sphere") stretches from the stratopause to about 80 km, with temperatures again decreasing with height. The region of transition to interplanetary space, about 80 km, is the '. ... The only region where the incoming is strongly absorbed is in the stratosphere, where absorbs wavelengths. The stratopause marks the level of maximum absorption of solar radiation by ozone, but it is not the location of the greatest ozone concentration. Ozone concentrations generally peak near about 25 km elevation, but much of the ultraviolet radiation has been removed from the incoming solar beam at that level by the ozone above."