Ozone Layer and Population Location
Country: United States
Date: October 2006
Why is the ozone layer thinning over Antarctica,
where the population and pollution is less than other places?
The opportunity for creating ozone is related to the intensity of
the solar radiation. The layer of the atmosphere in which the ozone
forms receives a direct strike form the sun's radiation near the
equator. It is only a glancing blow near the poles.
The meteorology over Antarctica is unique. During the
Southern Hemisphere Spring (September-November) a very
stationary and stable weather pattern forms over Antarctica,
much like a large high pressure system might form and persist
in the central part of the United States in Summer (but for
months instead of days).
This weather pattern prevents air from escaping from
Antarctica, and also prevents dilution by air from
areas outside of Antarctica. CFCs (chlorofluorocarbons)
that have built up in the Stratosphere over the past century
have an extended period of time to react with and destroy many
ozone molecules (possibly as many as 10,000 ozone molecules
can be destroyed by one CFC molecule). Furthermore, ice particles
that also persist during this unusual weather pattern apparently
enhance this ozone destroying process.
David R. Cook
Climate Research Section
Environmental Science Division
Argonne National Laboratory
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