Beginning of Essay
Ozone measurements in the Antarctic began during the mid 1950's. In 1985, the discovery of the springtime ozone hole over the Antarctic established that our understanding of the atmosphere was far from complete. This has created a growing concern for scientists ....

Middle of Essay
.... to release chlorine. Chlorine by itself is a very stable compound, but when in the stratosphere it binds to and destroys ozone. This is a cyclic process and therefor means that one chlorine can destroy many ozone molecules (Figure 1.2) During the winter in the Antarctic the circumpolar vortex, which is a strong westerly circulation around the continent, builds in the stratosphere. This phenomenon causes the interior of the stratosphere to be cut off and the temperatures drop below -800C. This results in thin clouds forming and that enables reactions with gases containing chlorine to take place. In the spring the sun returns and the chlorine ....