Ozone Hole Is Smaller

The Antarctic ozone "hole" is smaller than last year, NASA scientists reported Wednesday.

The hole, actually an area of depleted ozone concentration high in the atmosphere, remains very large, however, said researcher Richard McPeters.

Satellite data show the depleted area stretched 9.8 million square miles on Sept. 15. The record area of Antarctic ozone depletion of 10.5 million square miles was set on Sept. 19, 1998.

Ozone in the upper atmosphere forms a protective layer, helping block dangerous ultraviolet radiation from the sun. Environmentalists fear the depletion could spread to other areas, leading to more skin cancer and other problems.

NASA officials said the decreased size of the ozone hole from last year is not an indication of the recovery of Antarctic ozone levels, saying year-to-year variations of size and depth of the ozone hole depend primarily on the variations in weather.

In addition to the main ozone depleted area, the scientists found a thinning area of ozone had formed between New Zealand and Antarctica on Sept. 17 and drifted west for several days. Referred to as a "mini-hole," this resulted from the redistribution of ozone by a large weather system.

The ozone is damaged by chlorine and bromine compounds released by industrial products. International treaties regulate the production of these gases, and the amount of chlorine in some regions of the stratosphere is beginning to decline.