I would like to touch a problem of ozone holes over our planet, as it is one of the biggest issues nowadays concerning the space.
To make a picture clear, ozone holes are in reality not holes, because that would be crucial fot living beings on the Earth. Scientists call them like this meaning some areas where ozone concentration is under 220 Dobson Units, so it is very-very thin. For sure, it is dangerous for the climate and planet upon the whole, that is why after having put the Earth into this situation, nowadays the humanity is trying to find effective solutions.
For this, scientists at first have studied the ozon layer, observing it for a long time and with different methods. One of the newest ways to explore this factor was Ozone Monitoring Instrument (OMI) that is on board of Aura satellite. OMI was developed by the Royal Netherlands Meteorological Institute and tranfers all needed data here.
Have a look at the picture below to understand what it is all about. Green, yellow, orange and red colors mean that the ozone thickness corresponds to a normal level, but blue and purple signify the ozone hole.
It is scary a bit to imagine its size, looking at the globe, and more scary to realize that it was caused by humans. The main reason of the ozone hole forming are chlorofluorocarbons (CFCs) — longstanding chemicals that were used for well-known refrigerators and aerosols. In the beginning since 1930, CFCs massed up in the atmosphere. Having become a large amount, they went penetrated the stratosphere where UV light made them break apart. Moreover, they started to release chlorine which activates ozone demolition.
People started to undestand if they did not stop using dangerous chemicals, the consequences would be terrible very soon. Irreversible processes could commence in the space. That is why in 1989 there was signed Montreal Protocol according to which production of ozone-destroying chemicals was forbidden.
As a natural result, in comparison with 2005, ozone layer thickness is recorded to be 20% less depleted over Antarctic. This is a very positive and inspiring news! The data is based not only on statistics, but on chemical analyses as well, thanks to modern technologies. Can you imagine that every day from 2005 till 2016 specialists gathered, recorded and compared information on atmospheric gases? Because the main thing was to know if CFCs was responsible for that decrease, as chlorine is seen in different forms of molecules. Scientists discovered that each year there was a 0,8% decrease of chlorine levels.
Diminishing of ozone depletion was expected relying on the data above. Though there is still one unclear issue: degression of ozone attenuation during mid-September happens due to diminishing chlorine levels from CFCs, but after mid-September it falls under complete control of temperature that varies each year and this is difficult to explore.
It goes without saying, that to cure the Antarctic ozone hole will take many years, as CFCs continue their existence for 50-100 years. Scientists predict that it might vanish just up to 2080.
I would like our planet to prosper, be clean and exist for many generations more.
Let us always remember to take care of it!
The pictures are under License CC0 unless indicated otherwise.