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British Antarctic Survey (BAS)
www.antarctica.ac.uk
PDF
http://www.antarctica.ac.uk/met/jds/ozone
Ozone is a gas consisting of three oxygen atoms that is formed by the action of
sunlight on normal oxygen. When it is found near the surface of the earth (such as
in smogs formed from car exhausts) it is a noxious substance. When it occurs much
higher in the atmosphere, the ozone layer protects us from the harmful effects of
ultra-violet radiation.
BAS scientists discovered the Antarctic ozone hole twenty years ago and continue
to study its annual formation and disappearance. The Antarctic ozone hole in 2002
was unusual and small but 2003 saw a near record hole. What will 2005 bring? Ozone
depletion is now seen over the Arctic during the spring, but so far no major ozone
hole has formed there. The physics behind the instrument that measures ozone will
be explained and you will discover why it is normally only the Antarctic ozone
layer that develops a large hole each spring.
Although the amount of ozone-depleting gases in the atmosphere is beginning to
decrease, we think that it will be another decade before we can say for sure that
the ozone layer is beginning to recover.
Some topics to think about before coming to the exhibition:
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Differences between the Antarctic and Arctic.
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Many environmental changes will take place over tens of years, but the
measuring instruments may only operate over a few years. How can we tell
if or when there has been a significant change in what we are measuring?
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BAS scientist Karen Storey makes an ozone measurement at Halley station
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Emperor penguins live on the sea-ice not far from Halley station
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The aurora australis (southern lights) above Halley station
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