臭氧层(ozone layer)，亦作ozonosphere。
距地表约10～50公里的高空大气。其中臭氧浓度相当高，温度分布大多取决於臭氧的辐射性质。地球大气中总有微量臭氧存在，而以臭氧层的浓度最大，它主要是由太阳紫外辐射的作用形成的。臭氧强烈吸收太阳紫外辐射，使层顶上的大气温度上升至0℃（30℉），并有效地阻止了几乎全部的太阳辐射到达地球表面，否则这种紫外辐射会损害多数生物。氯氟烃和其他空气污染物质，常向臭氧层扩散，加速臭氧的破坏。1980年代中期科学家发现南极洲上空周期性出现臭氧洞，臭氧层也比正常浓度稀薄了40～50%。区域性臭氧减少被解释为一种自然现象，但另一个原因可能是氯氟烃的作用使臭氧层进一步遭到破坏。紫外辐射可能会引起皮肤癌。1978年国际上强迫限制生产和使用氯氟烃和其他臭氧破坏污染物质。
English version：
ozone layer
Region in the upper atmosphere, about 6-30 mi (10-50 km) high, with significant concentrations of ozone, formed by the effect of solar ultraviolet (UV) radiation on oxygen and also present in trace quantities elsewhere in earth's atmosphere. Ozone strongly absorbs solar UV radiation, causing atmospheric temperature to climb to about 30°F (0°C) at the top of the layer, and preventing much of this radiation from reaching earth's surface, where it would injure many living things. Chlorofluorocarbons, or CFCs, and some other air pollutants that diffuse into the ozone layer destroy ozone. In the mid-1980s, scientists discovered that a “hole”—an area where the ozone is up to 50% thinner than normal—develops periodically in the ozone layer above Antarctica. This severe regional depletion, explained as a natural seasonal depletion, appears to have been exacerbated by the effects of CFCs, and may have led to an increase in skin cancer caused by UV exposure. Restrictions on the manufacture and use of CFCs and other ozone-destroying pollutants were imposed in 1978.