29 August 2007

Antarctic Ozone Hole

It's ozone-hole season again, and this year is off with a bang...

A hole in the ozone layer over Antarctica has appeared earlier than usual in 2007, the UN weather agency says.


"It is still too early to give a definitive statement about the development of this year's ozone hole and the degree of ozone loss that will occur. This will, to a large extent, depend on the meteorological conditions," the Geneva-based agency says.

But it says that observations so far could "indicate that the 2007 ozone hole will be relatively small".

The WMO report is here. Their reasoning behind the forecast is that 1.) the polar vortex, while the largest ever, is relatively unstable, and 2.) Hydrochloric acid (HCl) , the chemical species that converts into the ozone-destroying catalyst chlorine oxide (ClO), is nearly depleted near the vortex.

The report suggests that the early start was brought about by the non-circular shape of the vortex

No comments: