The
very low winter temperatures
in the Antarctic stratosphere cause polar stratospheric clouds (PSCs) to form. Special reactions that occur on PSCs, combined with the relative isolation of polar stratospheric air, allow chlorine and bromine reactions to pro- duce the ozone hole in Antarctic springtime.
Why is the Antarctic ozone hole important?
World of Change: Antarctic Ozone Hole. The stratospheric ozone layer
protects life on Earth by absorbing ultraviolet light
, which damages DNA in plants and animals (including humans) and leads to sunburns and skin cancer.
What is the significance of the ozone layer?
Why is Ozone Layer important?
Ozone protects the Earth from harmful ultraviolet (UV) rays from the Sun
. Without the Ozone layer in the atmosphere, life on Earth would be very difficult. Plants cannot live and grow in heavy ultraviolet radiation, nor can the planktons that serve as food for most of the ocean life.
What is the ozone layer in Antarctica?
The formation of ozone hole in the Antarctic has been an annual occurrence and has been recorded for the last 40 years. Human-made chemicals migrate into the stratosphere and accumulate inside the polar vortex. It begins to shrink in size as warmer temperatures dominate.
What causes the ozone hole?
The ozone hole has developed because
people have polluted the atmosphere with chemicals containing chlorine and bromine
. The primary chemicals involved are chlorofluorocarbons (CFCs for short), halons, and carbon tetrachloride. … Once released from CFCs, chlorine (Cl) then reacts with ozone (O3) to form ClO and O2.
What time of year is the ozone hole the largest?
From August to October, during the Southern Hemisphere’s late winter as the returning sun’s rays start ozone-depleting reactions, the ozone hole increases in size, reaching a maximum
between mid-September and mid-October
.
Do we still have a hole in the ozone layer?
The 2020 Antarctic ozone hole grew rapidly from mid-August and peaked at around 24.8 million square kilometres on 20 September 2020, spreading over most of the Antarctic continent. …
There is still enough ozone depleting substances in the atmosphere
to cause ozone depletion on an annual basis,” said Dr Tarasova.
How does the ozone layer protect us?
The ozone layer is a natural layer of gas in the upper atmosphere that protects humans
and other living things from harmful ultraviolet (UV) radiation from the sun
. … The ozone layer filters out most of the sun’s harmful UV radiation and is therefore crucial to life on Earth.
Where is ozone hole found on Earth?
The ozone hole occurs during
the Antarctic spring
, from September to early December, as strong westerly winds start to circulate around the continent and create an atmospheric container. Within this polar vortex, over 50 percent of the lower stratospheric ozone is destroyed during the Antarctic spring.
Why is the ozone hole over Australia?
Firstly, the ozone layer in the mid-latitude (e.g. over Australia)
is thinned
, leading to more UV radiation reaching the earth. … Secondly, the ozone layer over the Antarctic, and to a lesser extent the Arctic, is dramatically thinned in spring, leading to an ‘ozone hole’.
How was the ozone hole discovered?
Researchers at the British Antarctic Survey discovered the ozone hole in
1985
, and NASA’s satellite estimates of total column ozone from the Total Ozone Mapping Spectrometer confirmed the 1985 event, revealing the ozone hole’s continental scale.
Which gas is destroying the ozone layer?
The main ozone-depleting gases are
chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs)
.
Why is damage to ozone layer a cause?
The main cause of ozone depletion and the ozone hole is
manufactured chemicals
, especially manufactured halocarbon refrigerants, solvents, propellants, and foam- blowing agents (chlorofluorocarbons (CFCs), HCFCs, halons).
What are 3 causes of depletion to the ozone layer?
Chlorofluorocarbons or CFCs
are the main cause of ozone layer depletion. These are released by solvents, spray aerosols, refrigerators, air-conditioners, etc. The molecules of chlorofluorocarbons in the stratosphere are broken down by the ultraviolet radiations and release chlorine atoms.
How did we fix the ozone hole?
To halt the depletion of the ozone layer,
countries around the world agreed to stop using ozone-depleting substances
. This agreement was formalised in the Vienna Convention for the Protection of the Ozone Layer in 1985 and the Montreal Protocol on Substances that Deplete the Ozone Layer in 1987.
