Table of contents

December 2012 - Volume 67 - 12

Cover image

Cover image expansion

Satellite map showing a severe depletion or ‘hole’ in the ozone layer over Antarctica on October 2, 1987. The hole is probably due to pollution of the atmosphere by chlorofl uorocarbons (CFCs). First seen in 1980, the ‘hole’ has grown in severity. It reaches a maximum in October, the Antarctic spring. It is visible here as the white & pink area covering Antarctica (outlined in white) & beyond. Australia, southern Africa & part of South America are also outlined. The colours represent Dobson units, a measure of atmospheric ozone. The map was made from data obtained by the Nimbus-7 weather satellite.