Arctic Science Journeys
Radio Script
1997

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Ozone Holes Discovered over the Arctic
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STORY: Scientists spotted the first one in March--a hole about twice the size of Texas in the ozone layer over Russia. Since then other, smaller holes have opened in the protective layer high in the earth's atmosphere. Climatologist Elizabeth Weatherhead from the University of Colorado says the ozone holes over the Arctic are very different from ones now common over the Antarctic.

WEATHERHEAD: "We actually have two types of ozone holes that we've observed in the Arctic. A sort of long-term type that lasts maybe six weeks or so, and where we see at least 40 percent ozone depletion. We've seen a few of those over the Arctic. Those are very large, they cover several thousand kilometers at least. But we've also seen another type of ozone hole, which is very different from what is seen in Antarctica. These are very small ozone holes, maybe a thousand kilometers across. They usually only last a few days."

Ozone exists naturally in the stratosphere--that's a layer about 50 kilometers or 30 miles thick high above the earth. Its purpose is to filter the sun's harmful ultraviolet, or UV, rays. But some industrial chemicals make their way into the stratosphere and destroy ozone faster than nature can replenish it. The result is a thinning of the ozone layer. Nowhere are such gaps more obvious than over the South Pole, where too much UV light has been linked to increased skin cancer among people in southern Chile and Argentina.

Such problems are now likely to occur among people in the Arctic. Bruce Hicks is the director of NOAA's Air Resources Lab in Boulder, Colorado.

HICKS: "So now we're starting to get a little bit worried. The problem I see coming is that because the number of people is higher and because the latitude is higher we are likely to have a larger potential health hazard than we have in the Southern Hemisphere."

Skin cancer is the most talked about result of too much UV light. But there are other health hazards. Elizabeth Weatherhead.

WEATHERHEAD: "UV is also known to cause cataract damage. In the Arctic we get an awful lot of ocular damage from UV. We can expect to see even more ocular damage if people don't take proper precautions to protect themselves. In addition, UV is known to suppress the immune system of human beings. It makes us more susceptible to disease and the diseases we get are more likely to be severe."

Scientists say increased UV radiation also could have serious consequences for the Arctic environment. John Cullen is a professor of oceanography at Dalhouse University, in Halifax, Nova Scotia. He's studied UV light's effects on the Antarctic Ocean's food chain.

CULLEN: "A concern that exists and remains is that some species of phytoplankton might be affected more by UV radiation than others and the potential exists that increased UV from ozone depletion might alter species composition of phytoplankton in the Antarctic. Going up the food chain there is a certain amount of research that's been done looking at the effects of other organisms in the ocean, including the bacteria that process food in the ocean, that help to recycle food, and also the larval stages of fish and eggs. We know that UV radiation affects the DNA of these organisms and can interfere with their reproduction and survival."

Complicating matters are scientists' understanding of just how ozone is destroyed. They know that cold temperatures in the stratosphere trigger the chemical reactions that break down ozone. But the stratosphere has been particularly cold in recent years and scientists want to know why. One theory, ironically, is global warming. Elizabeth Weatherhead explains.

WEATHERHEAD: "For all the solar radiation that comes in, all of that either ends up being bounced out immediately or re-radiating out as thermal energy. If we trap more of that thermal energy in the lower layer, then that means less of that thermal energy will be trapped or grabbed onto by the stratosphere. So the stratosphere will cool as the troposphere warms."

Researchers caution that while holes in the Arctic ozone layer are serious, they do not yet compare with ozone losses seen over the South Pole. Still, they say it's time to focus more research on the effects of increased UV light on the region's people and the environment before the problem gets worse.

OUTRO: For Arctic Science Journeys, this is Debra Damron reporting from Fairbanks, Alaska.