I have found out that blue and purple meant that the area has the least ozone whereas red, yellow, green meant that the area has the most amount of ozone. 
Unit 2: Protecting the Ozone Layer
I learnt about how ozone is being formed and depleted at the same rate, giving rise to its steady state. The ozone layer helps to protect us from the harmful ultraviolet rays from the sun, which might bring about health problems such as skin cancer. I also found out about the 3 different types of UV radiation, UV-A, UV-B and UV-C.
Ozone
Majority of the ozone in the atmosphere exists in the stratosphere.
The function of the ozone is to absorb the ultraviolet radiation, preventing a large percentage of ultraviolet radiation from reaching the Earth’s surface.
Ozone layer
Ozone in the stratosphere absorbs ultraviolet radiation.
Ozone in the troposphere is harmful to man.
Red has the greatest wavelength, which corresponds to lowest energy.
UV-C is the most harmful among UV-A, UV-B and UV-C.
Ozone Layer
90% of the ozone layer is found in the stratosphere. Ozone actually protects us humans from the harmful UV radiation. However, in recent years, the ozone layer is depleting and the main cause is probably due to CFCs. Chlorine atoms destroy the ozone layer. If this prolongs, we will be more exposed to the harmful UV radiation which may cause skin cancer. In 1989, countries have step up and banned the production of CFCs to prevent the ozone layer from further depletion.
