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 oxidizing specie is responsible of damaging lipids, proteins and DNA and generating high stress levels in marine organisms. Inorganic UV-filters (i.e. TiO2) can also generate ROS, which is toxic for the marine phytoplankton .The toxicity of nano-TiO is due to its photochemical properties under solar radiation that depend on the radiation intensity, the crystalline structure and the concentration of the nanoparticles. In addition, the inert coating layer of the nanoparticles which protects against photoreactivity is dissolved in aquatic environments after being released from sunscreens. Photolysis is the main abiotic route for transformation of UV filters. Photolysis dissociates the organic filters