Ozone hole '20% smaller'

2004-10-01 07:48

Wellington - The ozone hole that develops above Antarctica in the late southern hemisphere winter is 20% smaller this year, a New Zealand scientist said on Friday.

Atmospheric scientist Stephen Wood said measurements at New Zealand's Antarctic base confirmed Nasa satellite data that the hole had shrunk from its record size last year.

But Wood said ozone levels were still lower than before the hole began forming in the early 1980s.

Scientists say the hole is caused by ozone destroying fluorocarbons combining with the atmospheric ice particles that form above Antarctica in the low temperatures of late winter and early spring.

The effect disappears as rising temperatures melt the ice.

Ozone blocks cancer-inducing ultra violet rays from the sun and the hole is blamed for the comparatively high incidence of skin cancers in Australia and New Zealand.

Wood said the hole would indirectly affect New Zealand later this year, when ozone-depleted air broke up in November or early December and moved over the country.

"If New Zealand experiences a combination of lower ozone with high sun and few clouds, then skin-damaging UV levels can be extreme," he said. - Sapa-dpa

- SAPA