Figure 4: Area extent of the Antarctic and Arctic ozone holes.
From: Quantifying the ozone and ultraviolet benefits already achieved by the Montreal Protocol
The area of the ozone hole is defined as the area with column ozone<220 DU. (b) The observed area of the Antarctic ozone hole from 2007 to 2014 estimated from OMI data (black symbols). (a) For the Arctic, the observed ozone hole area is near zero in all years. The figure also includes the ozone hole areas calculated from model runs MP (blue) and NoMP (red).
