Antarctic Ozone Hole a Record Low in October

NOAA’s measurements of ozone at South Pole registered a record low for the month of October. This year, the average amount of ozone measured by a Dobson instrument at South Pole in the second half of October was 114 Dobson Units (DU), or 60 percent below the pre-ozone hole conditions. The October ozone average has historically been based on 15-31 October levels, and is an indicator of the amount of ozone depletion directly over South Pole. Ozone column amounts lower than the minimum thickness of 220 DU are deemed as the threshold for onset of an “ozone hole” each austral spring. Much of this is driven by depletion at altitudes between ~13 and 21 km high, where ozone is removed almost completely.

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