Figure

Maximum ozone hole area over the southern hemisphere, historically (9 September 2000) and currently (11 September 2017)

Figure Created 17 Nov 2017 Published 13 Dec 2017 Last modified 10 Jan 2019

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False-colour view of total ozone over the North (Arctic) and South (Antarctic) poles. The purple and blue colours indicate the lowest ozone presence, while yellow and red indicate higher ozone presence. Ozone concentration is commonly measured in Dobson Units. One Dobson Unit is the number of molecules of ozone that would be required to create a layer of pure ozone 0.01 millimetres thick at a temperature of 0 degrees Celsius and a pressure of 1 atmosphere.