It is formed by the reaction that sunlight has on oxygen. ... Scientists discovered in the 1970's that chemicals that we had been using regularly were damaging the earth's protective layer. ... Chemicals such as bromine, nitrous oxide, which is found in fertilizers, have also been found to damage the ozone. ... Which is cold enough to create polar stratospheric clouds, in these clouds a reaction between the chemicals takes place and converts the inactive chlorine and bromine to more active forms. ... This satellite, which orbits the earth at about 600 km, measures ozone variations...

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• Approx Pages: 4
• Grade Level: High School