A
computer-enhanced (增强)
map, taken from satellite
observations (观察资料)
of ozone (臭氧)
levels in the
atmosphere over the South Pole, shows the region
(区域)
of
ozone depletion (损耗)
that has begun to appear each
spring over
Antarctica.
Ozone, a form of oxygen, occurs (发生)
naturally in the
Earth's upper atmosphere where it forms a
layer that
prevents some ultraviolet (紫外的)
solar radiation
from
striking the Earth. If this atmospheric ozone were to
become less dense (浓厚), more
ultraviolet rays would
reach the
Earth, possibly damaging crops and perhaps
leading to
increased incidence (发生率)
of human skin
cancer.
Ozone hole over Antarctic largest ever
CCG - 1998-10-05: The hole in the world's protective ozone layer
(层)
grew to a record size -- two and half times the area of Europe -- over Antarctica in September, a senior United Nations expert reported.
http://www.e5.org/pages/ccga1098.htm#20
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