International days Events
Ozone | International Day for the Preservation of the Ozone Layer
Ozone
Ozone is an inorganic molecule. Its chemical formula is O3. It is a pale blue gas with pungent smell. It is formed by the combination of dioxygen and atmospheric electrical discharges by the action of ultraviolet light. Its molecular mass is 48g/mol and density is 2.14 kg/m³. Boiling and melting points of O3 gas is -122 °C and -192.2 °C. The O3 gas is beneficial for plants and animals because it prevents damaging ultraviolet light from reaching the Earth’s surface.
Ozone Layer
The ozone layer is a region of Earth’s stratosphere. It absorbs most ultraviolet (UV) radiation of sun from reaching the Earth directly. Stratosphere contains high concentrations of O3 as compared to other parts of the atmosphere. Small ratio of other gases also present in the stratosphere. It is mainly found in the lower portion of the stratosphere, from approximately 20 to 30 kilometres above Earth. The thickness of this layer varies seasonally and geographically. This layer absorbs 97 to 99 percent ultraviolet light (from about 200 nm to 315 nm wavelength) coming from sun. Otherwise exposed life forms near the surface would potentially damage.
O3 gas Depletion
There is a steady decline of about four percent in the total amount of O3 gas in Earth’s stratosphere and decrease in stratospheric ozone around Earth’s polar regions referred to ozone depletion. Chloro-flouro carbons (CFCs) and other contributory substances are referred to as O3 depleting substances. Photodissociation of man-made halocarbon refrigerants, solvents, propellants, and foam-blowing agents is the main source of these atoms in the stratosphere. Increased UV exposure causes sunburn, skin cancer, cataracts, damage to plants and reduction of plankton populations in the oceans.
16th September: International Day for the Preservation of the Ozone Layer
The United Nations has designated September 16 as the International day for the preservation of the ozone layer. On 16th september this day is celebrated worldwide. This day promotes activities related preservation of this beneficial layer. Celebration of this day helps in promoting awareness about the causes and prevention of O3 gas layer throughout the world.
