English_Master June 7, 2016 No Comments
OZONE DEPLETION: DANGER FOR ATMOSPHERE  The Sun emits radiation over a broad range of wavelengths to which human eye respond in the region from approximately 400nm to 70 nm. The ranges can be divided into three categories: UVA (Ultra violet): 320-400nm). DVB (280-320 nm) partially absorbed by Ozone. UVC (200-280 nm) completely absorbed by Ozone. The maximum concentration (about 0.5 ppm) occurs between the altitude of 20 to 35 km. and the layer at this level is called ozone layer. The presence of ozone is an essential necessity for life on Earth. Stratospheric ozone layer absorbs dangerous UVB rays of the sun and this protects the earth surface from these high-energy radiations. Over the past few decades 03 layer is thinning out because of manmade pollutants, which catalyze the dissociation of 03 at a very fast rate. Major pollutants responsible for depletion of Ozone are chloroflourocarbons (CPCs) nitrogen oxides, hydrocarbons and oxides of chlorine and bromine. Increased ultraviolet radiation would retard photosynthesis in plants. Moreover it would increase earths mean temperature which would have disastrous consequence of flooding submerging many low lying islands. Recently it has been found that the ultraviolet radiation degrades polymers used in paints and building materials. Most ozone are created and destroyed in the stratosphere....
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