The Ozone Layer is a layer of ozone in the stratosphere which defends the earth from ultraviolet (UV) rays of the sun. 90% of the ozone in our atmosphere is in the highest regions of the stratosphere. A decrease of the concentration of ozone in the stratosphere was first reported in 1974, and the decrease was linked to the presence of man-made compounds. Most of the damage was mainly in the Polar Regions especially Antarctica.
The Ozone Hole is not technically a hole, but instead, it is an area of low concentrated ozone. When the gas becomes less concentrated, only ozone molecules decrease, but it does not affect the size of the hole. One column of less than 220 Dobson units (measurement of ozone concentration) was not observed until 1979. Evidence suggested that ozone was lost from chlorine and bromine compounds. The "hole" is roughly 10 miles thick with the bottom of the layer about six miles above the poles. Scientis Joseph C. Farman showed that hole was getting bigger since the 1960's meaning the areas of low concentrations were increased while areas of dense concentrations decreased.
The main Ozone Hole is in the Antarctic, but recent research has showed that there might be a hole over the Artic Circle. Similar to the Antarctic Hole, the Artic Hole showed high levels of chlorine. Scientists have used spectrometer from Antarctica to Greenland in January 1988 and found high levels of chlorine dioxide and low levels of nitrogen oxide. Another piece of evidence is AASE (Airborne Artic Stratospheric Expedition) flights; with 31 flights to the northern polar vortex, the expedition found distrubed levels of chemistry. Levels of chlorine monoxide has been found to be highly elevated with other flights. The low nitrogen and high chlorine levels show similar conditions as the Antarctic Ozone Hole.
| Diagram of the concentration levels of ozone over Antarctica. |
| The ozone hole over Antarctica in 3D!!!!! |
