Antarctic ozone hole the biggest ever: Officials

[CHIMO]

WASHINGTON — This year's Antarctic ozone hole is the biggest ever, U.S. government scientists said Thursday.

The so-called hole is a region where there is severe depletion of the layer of ozone — a form of oxygen — in the upper atmosphere that protects life on Earth by blocking ultraviolet rays from the sun.

Scientists say human-produced gases such as bromine and chlorine damage the layer causing the hole. That is the reason many compounds such as spray-can propellants have been banned in recent years.

"From September 21 to 30, the average area of the ozone hole was the largest ever observed, at 10.6 million square miles (27.4 million square kilometres)," said Paul Newman, atmospheric scientist at NASA's Goddard Space Flight Center. That is larger than the area of North America.

http://www.thestar.com/NASApp/cs/ContentServer?pagename=thestar/Layout/Article_Type1&c=Article&pubid=968163964505&cid=1161294617402&col=968705899037&call_page=TS_News&call_pageid=968332188492&call_pagepath=News/News

[hatrack]

1. Oops.

How much of the delay in ozone restoration is caused by warming?

Stratospheric ozone destruction is regulated (in part) by stratospheric temperatures, and as heat remains below the tropopause, the stratosphere, along with the mesosphere, continues to cool. The cooler the stratospheric temperatures, the greater ozone destruction, and so on.