About 90% of ozone is found in the stratosphere, which is 6 to 30 miles above the earth's surface. Stratospheric ozone is beneficial because of the UV absorption. The lower region of the atmosphere, the troposphere, extends up to 6 miles above the earth's surface. The tropospheric ozone, however, is detrimental to the environment and is commonly found in urban areas because of the condensed locality of burnt fossil fuel. Tropospheric ozone pollutes air in urban areas, but ironically provides ultra-violet protection.
Scientist used their new technology and recorded ozone level findings. Chlorofluorocarbons, (CFCs) were discovered in high concentrations over Ireland that originated in London. Testing in the North Atlantic unexpectedly showed CFC concentration. The detection of CFCs was not expected in the North Atlantic because the area was uncontaminated by urban pollution. England then funded a program for scientist to set up a new testing station in an area that was entirely unpolluted. Antarctica was the new testing position decided upon. Annual monitoring showed that ozone would decrease by 35% during the months between September and December.
The hole may only last a couple months, but these are critical months. After four months of complete darkness, the Artic relies on the sunlight to awaken dormant plants and animals. Eight weeks later the hole moves from the Artic and covers New Zealand and Australia. This hole is three times larger than the United States. The ozone is depleted during these frigid months because winter winds create a swirling pattern of air that will trap air for several months. Water mixes with the circling air, forming crystals. These crystals in turn collect the ozone depleting materials. In effect, the harmful elements (namely chlorofluorocarbons) get soaked up in a sponge, creating an extreme potency in a local area. .
It took forty years after CFC production to determine the negative effect CFCs have and to discover the process of how CFCs deplete the ozone layer.