Stratosphere the stratosphere temperatures increase with altitude "(see temperature inversion)"; the top of the stratosphere has a temperature of about 270 K (−3°C or 26.6°F). This vertical stratification, with warmer layers above and cooler layers below, makes the stratosphere dynamically stable: there is no regular convection and associated turbulence in this part of the atmosphere. However, exceptionally energetic convection processes, such as volcanic eruption columns and overshooting tops in severe supercell thunderstorms, may carry convection into the stratosphere on a very local and temporary basis. Overall the attenuation of solar UV at wavelengths that damage DNA by the ozone layer allows
UV filter to sun irradiation, while swimming-pool water is required to be disinfected by chlorination, bromination, ozonation, or UV-irradiation. UV filters can undergo degradation and transformation to more toxic products. For example, Avobenzone undergoes transformation in the presence of chlorinated disinfection products and UV radiation to substituted chlorinated phenols and acetophenones, which are known for their toxicity. Some organic UV filters under UV radiation can generate reactive Oxygen Species (ROS) (OH, HO) (e.g. BP-3, octocrylene (OCR), OMC, phenylbenzimidazole sulphonic acid (PBS), PABA, etc.).The levels of HO in waters of Mediterranean beach reached 270 nM/day as a result of Sunscreens. HO as an