The size of the Antarctic ozone hole

The size of the Antarctic ozone hole at 12:00 GMT of each day from GOME (1996-2002) and SCIAMACHY (2003-2006) Assimilated Ozone Fields. The size of the ozone hole is the area on the globe in million square km of ozone column values below 220 Dobson units (DU). DU stands for the total thickness of ozone in a given vertical column if it were concentrated into a single slab at standard temperature and atmospheric pressure – 400 DUs is equivalent to a thickness of four millimetres, for example.