Spectre of an Arctic ozone hole looms

[jpak]

http://blogs.nature.com/news/thegreatbeyond/2011/03/spectre_of_an_arctic_ozone_hol.html

Atmospheric ozone measurements taken since early January at 30 stations across the High North suggest that the Arctic is heading towards unprecedented ozone depletion this spring.

Ozone loss resulting from chemical reactions involving chlorofluorocarbons (CFCs) is normally less severe in the Arctic stratosphere than over colder Antarctica, where full-fledged ozone holes have occurred each year in the last couple of decades. The reactions that eat away ozone molecules take place at the surface of polar stratospheric clouds which can only form when temperature drops below -78 degrees Celsius.

During the unusually cold Arctic winter in 2005 more than half of the ozone molecules in the atmosphere were destroyed.

But this winter has been even colder, raising fears that the depletion of the already thin Arctic ozone layer will continue for another two or three weeks.

<not much more>