O,O2 and O3 are present in the stratosphere in a dynamic equilibrium of chemical reactions caused by absorbance of UV
Stratospheric ozone is located above earth's surface 12-24km
Ozone prevents most High energy UVsolar radiation reaching earth's surface
UV is short wavelength electromagnetic energy
If UV is not absorbed in the atmosphere it reaches earth and living cells may absorb it, this can break up biolomogical molecules causing skin damage, dna damage, cancer and affected photosynthesis rates
Climate change affects the ozone layer: an increase in temperature changes in wind, changes in atmospheric composition all influence chemical and physical processes in the ozone layer
Chloroflourocarbons are used in air conditioning units, refrigerators, aerosol cans and is also a greenhouse gas
Ozone layer depletion causes increased UV radiation to reach the surface, causing living organisms harm
Ozone depletion is caused by release of man-made chemicals containing chlorine, bromine such as chloroflourocarbons
Substances such as chloroflourocarbons are stable and do not dissolve in rain hence remain in the atmosphere for years
When these stable chemicals are carried into the ozone, solar UV radiations breaks it down releasing chlorine and bromine atoms which can destroy ozone molecules
Some gases that cause ozone depletion are also greenhouse gases contributing to global warming
Measuring ozone using the dobson unit, this estimates the thickness of all ozone in the atmosphere
An ozone hole refers to levels below 220 du this has only been measured after increased pollution
Ground based data collection at antarctica is evidence of ozone depletion, detection of higher levels of UV at ground level was evidence of ozone loss in the stratosphere
Satellite surveys are evidence of ozone depletion
Air samples can be taken in the stratosphere as eveidence for ozone depletion, they showed high UV levels
Air samples collected by helium balloons confirmed chemicals were causing ozone depletion
Ozone depletion over antarctica, atmospheric conditions over antarctica are unique, and hence ozone depletion is more severe here
Restoration of ozone layer involved Vienna convention for protection of ozone, this was an agreement between every country in UN to protect ozone layer but it was not legally binding
Montreal protocol (1987) is a method of ozone restoration: manufacture and use of cfcs were phased out and banned, there is a fund to help countries implement Montreal protocol
Montreal protocol has been implemented by use of alternative process of materials, such as stick on or roll on deoderants, hydrochlorofluorocarbons replaced chloroflourocarbons, chloroflourocarbon solvents replaced by alcohol