The stratospheric ozone layer exists at altitudes between about 10 and 40km depending on latitude, just above the tropopause. Its existence is crucial for life on earth as we know it, because the ozone layer controls the absorption of a portion of the deadly ultraviolet (UV) rays from the sun. UV-A rays, including wavelengths between 320 and 400nm, are not affected by ozone. UV-C rays between 200 and 280nm, are absorbed by the other atmospheric constituents besides ozone. It is the UV-B rays, between 280 and 320nm, absorbed only by ozone, that ....