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ozone is an invisible upper atmospheric

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gas that protects all forms of life on

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earth for most of the sun's damaging

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radiation

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damage and suppression of the immune

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system

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the harvesting of fish and plant life

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are also affected

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a vast amount of aquatic life has its

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beginnings in the oceans near antarctica

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false color imagery of the south pole

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from nasa's nimbus-7 satellite provides

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scientists with a road map of daily

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changes in the ozone

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by tracking this imagery for the past

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nine years they have discovered a trend

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each spring over antarctica a hole in

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the ozone develops and it has been

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getting larger year by year

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to date as much as 50 to 60 percent of

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the ozone in this area has been lost

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these discoveries prompted a coordinated

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including some 150 scientists and

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engineers from nasa the national oceanic

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and atmospheric administration national

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science foundation and industry worked

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together for four months to study this

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alarming environmental issue

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scientists used ground-based instruments

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and launched balloon-borne payloads to

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sample air chemistry at mcmurdo station

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in antarctica

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at the same time nasa's dc-8 flying

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laboratory studied the lower atmosphere

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making long missions from punta arenas

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chile into the area of ozone depletion

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nasa's high-flying er-2 plane carrying a

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single pilot and a handful of sampling

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instruments flew directly into a layer

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of atmosphere where the ozone was

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depleted

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a number of activities contributing to

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ozone loss have been pinpointed by the

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scientific and policy community

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no longer do canned aerosol products

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contain chlorofluorocarbons or cfcs but

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these harmful gases still get into the

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atmosphere because they are used as

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refrigerants fire retardants foam

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blowing agents and solvents

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as long as this persists ozone will

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continue to be lost

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initial findings from the summer's ozone

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expedition verify that there is a

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complex interplay between cfcs

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chlorine-containing gases and the

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meteorology in certain parts of the

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world

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ice crystals in the upper atmosphere

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convert the gases into a by-product that

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destroys ozone

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these ice crystals usually only form in

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the atmosphere of the south pole because

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it gets so cold this may explain why

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other parts of the world aren't

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dramatically affected by the depletion

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scientists still do not understand all

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the mechanisms of change but thanks to

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the work of so many we will soon have a

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more complete understanding of ozone

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loss and its threat to the world

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environment

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in the early 1990s a new generation of