Science / Medicine : Ozone Depletion in Arctic

Scientists have detected new evidence that ozone concentrations decline periodically over the Arctic, as in the annual depletion that forms the “ozone hole� over Antarctica. The researchers found a high-altitude ozone deficit that resembles an early step in formation of the Antarctic ozone hole, said study co-author D. J. Hofmann.

Previous research has also suggested ozone depletions over the Arctic.

The Antarctic hole is an area in which up to 50% of atmospheric ozone disappears for a limited time. In the Arctic, perhaps 25% could disappear under highly unusual, worst-case circumstances, Hofmann said.

The new study is reported in the British journal Nature by Hofmann, who is a physics professor at the University of Wyoming, and scientists from France, Japan, New Zealand and the University of Houston.