Scientists to probe ozone mysteries near Alert

Why does the atmosphere above the High Arctic change so radically in the spring?


MONTREAL ó An international team of scientists has returned from the Canadian forces station at Alert after a three-month study of ozone depletion in the High Arctic. Their project, called “Alert 2000,” looked at the amazing and baffling atmospheric changes that occur in the High Arctic when the sun returns in mid-March.

Researchers noted how the atmosphere radically changes at the polar sunrise. Then, ozone gas, which protects humans and animals from harmful ultra-violet radiation from the sun, completely disappears at ground level within 24 hours.

“What surprised us this year is that the ozone levels were never normal the whole time we were there. They were low,” said Jan Bottenheim, a Canadian scientist who is the project’s organizer. “Suddenly, we have a whole new ball game.”

When there are low levels of ozone near the ground, mercury also seems to drop out of the air and accumulate in the snow. This is a “very strange curiosity,” Bottenheim says.

“But it’s still too early to say what it means for people,” he said.

A severe loss of ozone in the higher atmosphere was also noted by scientists in Northern Sweden this winter, who found ozone depletion of more than 60 per cent in the layer that lies 18 km. above the earth.

The Alert 2000 project, officially sponsored by the Atmospheric Environmental Services branch of Environment Canada, involved 29 scientists from Canada, the States, Germany, Japan, Italy and France.

Their data may shed light on what processes are at work in the High Arctic when the sun hits the frozen snow, and their analysis of snow near Alert may also provide the “missing link” of evidence needed to better understand what ice samples from glaciers say about past climates.

Project organizers had hoped to set up an ice camp four kilometers from Alert to conduct experiments on the sea ice.

During the so-called “dark phase” of the project, they wanted to look at the frozen ocean surface, examining its physical and chemical make-up.

But this camp was buried during a bli ard and had to be abandoned, so the scientists had to work outside in frigid temperatures instead.

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