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Ozone Hole Local
Name: Paul G.
Status: Educator
Age: 20s
Location: N/A
Country: N/A
Date: January 2000
Question:
Why is the ozone layer hole located over the South Pole
rather than else where on the globe?
Replies:
There is a pretty good tutorial at
http://www.nas.nasa.gov/About/Education/Ozone/antarctic.html.
There are
three main reasons that the Antarctic gets an ozone hole:
1. In the Antarctic winter, the region receives no sunlight. Sunlight is
needed for the formation of ozone. Thus, any ozone destroyed will not be
replaced.
2. Also in the Antarctic winter, wind patterns are such that the air over
Antarctica does not mix with air in the rest of the atmosphere. Thus, ozone
lost cannot be replaced until the wind patterns change in the spring.
3. Finally, in the extreme cold, special clouds form in the stratosphere in
the polar winter. These clouds are made of ice crystals, which provide a
surface for chlorine-mediated reactions that destroy ozone.
These three conditions are not found anywhere else in the atmosphere.
Conditions are somewhat similar over the Arctic, but the isolation of the
arctic atmosphere is not as complete as over the Antarctic. As you might
expect, then, there is a smaller depletion of stratospheric ozone over the
Arctic during its winter.
Richard E. Barrans Jr., Ph.D.
Assistant Director
PG Research Foundation, Darien, Illinois
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Update: June 2012
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