Ozone Layer
Our Earth’s atmosphere is divided into several layers. The lowest region, the troposphere, extends from the Earth’s surface up to 10 kilometer in altitude. All human activity occurs in the troposphere. The next layer, the stratosphere, continues from the end of the troposphere to about 50 km. Most air traffic occurs in the stratosphere. Ozone is a tri-atomic allotrope of oxygen that accounts for the distinctive odour after a thunderstorm or around electrical equipment. The odour of ozone around electrical machines was reported as early as 1785, and ozone’s chemical make-up was determined in 1872. Ozone is an irritating, pale blue gas that is explosive and toxic, even at low concentrations. Ozone is 1.5 times as dense as oxygen. At -12°C, it condenses into a dark blue liquid, which freezes at -412°C. Ozone is an extremely powerful oxidizing agent. It is used commercially as a bleaching agent and as a strong germicide used to sterilize drinking water as well as to remove objectionable doors and flavours. Most atmospheric ozone is concentrated in the stratosphere, about 15-30 km above the Earth’s surface, Ozone is a molecule containing three oxygen atoms.
