Ozone measurements made by the European Space Agency Envisat satellite reveal the ozone loss of 40 million tons by 2 October in 2006 and that this exceeds the record ozone loss of about 39 million tons for the whole of 2000. The size of this year’s ozone hole is 28 million square km.
The Ozone layer is a protective layer found about 25 kilometres above us mostly in the stratospheric stratum of the atmosphere that acts as a sunlight filter shielding life on Earth from harmful ultraviolet rays. Over the last few years the effective thickness of the ozone layer declined, increasing the risk of skin cancers, cataracts and harm to marine life. The thinning of the ozone layer is caused by the presence of pollutants in the atmosphere originating from, for instance, chlorofluorocarbons (CFCs), which have still not vanished from the air although banned under the 1987 Montreal Protocol.
“Such significant ozone loss requires very low temperatures in the stratosphere combined with sunlight. This year’s extreme loss of ozone can be explained by the temperatures above Antarctica reaching the lowest recorded in the area since 1979,” European Space Agency Atmospheric Engineer Claus Zehner said.
Ozone (O3) is another allotrope of oxygen. It is bent with a O-O-O angle of about 123° It is formed from electrical discharges or ultraviolet light acting on O2. It is an important component of the atmosphere (in total amounting to the equivalent of a layer about 3 mm thick at ordinary pressures and temperatures) which is vital in preventing harmful ultraviolet rays of the sun from reaching the earth’s surface. Aerosols in the atmosphere have a detrimental effect on the ozone layer. Large holes in the ozone layer are forming over the polar regions and these are increasing in size annually. Paradoxically, ozone is toxic! Undiluted ozone is bluish in colour. Liquid ozone is bluish-black, and solid ozone is violet-black.
IUPAC Name: ozone
Canonical SMILES: [O-][O+]=O
WebElements October 2nd, 2006
Posted In: Chemistry