Leon TEISSENREC BORT of highlights in 1902 the role of the ozone layer that absorbs solar radiation (UV actually).
In 1974 two American scientists: Mario Molina and F. SHERWOOD ROWLAND made for the first time the theory of depletion of the ozone layer under the impact of Chlorofluorocarbons (CFCs), appeared in 1938. And J. FARMAN British Antarctica Survey (BAS) announced in 1985 that a "hole" temporary but important (up 50% loss) appears each spring in the ozone layer over Antarctica since 1979 and resolves to early fall.
Evolution of the hole in the ozone layer
What is ozone?
The ozone (O3) is a specific chemical form of oxygen, very unstable and reactive.
Ozone is generated by including the bombing of the oxygen molecule stable O2 by utraviolets (UV). Condition critical: the presence of oxygen that was produced in large quantities with the proliferation of photosynthetic micro-organisms in the Precambrian.
{mosgoogle center}The ozone layer is schematically part of the atmosphere where its concentration is highest. Thus, ozone is more present at a distance of ground between 15 and 40 km (more heavily toward 35 km) with a concentration around 8 ppmv, a layer called the stratosphere. Hence the appellation stratospheric ozone not to be confused with ground-level ozone induced largely by vehicular traffic and particularly irritates the eyes and respiratory tract.
At this altitude, the ozone content result of a balance between training and destruction under the dependence of solar activity, temperature, the presence of other chemicals.
By then absorbing UV, ozone contributes to warm the stratosphere. ozone formation is more important over the tropics and then won the pole through the movement of air masses. However, it shows a low concentration of a few parts per million at most.
They talk about "hole in the ozone layer when the value of the integrated column ozone is less than 220 Dobson units (normal value is about 300 Dobson units). Dobson units express all the ozone in a column that part of the ground and through the whole atmosphere.Starting from now, ladies and gentlemen I ask you all a bit of attention, I ask you to make a small gesture to help the earth, some gesture on your part will doubtless the resistance of the "Earth".
If all the world will make a small gesture of the Earth will change a line, but unfortunately people can participate.
On Earth we are billions of people who could be put into action.
I thank you in advance that you will espirant few articles on your blogs talking about pollution of the Earth, climate change, melting ice, and the greenhouse effect of the ozone layer.