Stratosphere Stratosphere The stratosphere () is the second major layer of Earth's atmosphere, just above the troposphere, and below the mesosphere. The stratosphere is stratified in temperature, with warmer layers higher and cooler layers closer to the Earth; this increase of temperature with altitude is a result of the absorption of the Sun's ultraviolet radiation by the ozone layer. This is in contrast to the troposphere, near the Earth's surface, where temperature decreases with altitude. The border between the troposphere and stratosphere, the tropopause, marks where this temperature inversion begins. Near the equator, the stratosphere starts at as high as ,
UV filter differ in biological behavior and effects. Swimming pool water is usually disinfected by chlorination, bromination, ozonation or UV radiation. Upon the presence of some UV filters such as Avobenzone in swimming pools, toxic products are produced as a result of the interaction between Avobenzone and the active chlorine and UV radiation. Benzophenones (BPs) are widely used in UV filters, fragrance enhancers,and plastic additives. The major sources of BP-3 are reported to be human recreational activities and wastewater treatment plant (WWTP) effluents.The anionic forms of both BP-3 and 4-OH-BP3 can undergo direct photodegradation. The photolytic rates of both compounds in natural