Monthly mean total ozone, October 1991.
© National Aeronautics & Space Administration / Science & Society
Coloured graph produced by NASA showing, in dobson units, the distribution of ozone in the Earth's ozone layer. The ozone hole (a thinning of the ozone) over Antarctica is clearly visible. A dobson unit is the basic measurement used in ozone research, and concerns the thicknes of ozone. It is named after G M B Dobson, one of the first scientists to conduct research into atmospheric ozone.