South Pole Minimum Ozone Profiles
1986 to 1993 Min Ozone profiles. Total ozone column amount in Dobson Units are recorded just under each date
Zero Ozone Baselines are shown as vertical lines. Notice from the figure that the 1986 minimum profile in green does not go to zero at any altitude, 1987 (blue) reaches zero just at 17 km, and 1993 (blue) is zero from about 14 to 19 km.
1994 to 2001Min Ozone profiles.
Since 1986, NOAA/CMDL has launched ozonesondes at Amundsen-Scott South Pole Station to monitor the development of the annual ozone hole over
Antarctica. About 70 ozonesondes are launched each year at South Pole. This chart shows the minimum ozone profiles measured each year from 1986 to
1999. The minimum typically occurs in early October. However, in 1999, 90 Dobson Units was measured on September 29th , which is about 10 days
earlier than normal.
In mid August, about 6 weeks before the minimum occurs, the ozone profile over South Pole Station generally has a well-defined peak in ozone
concentration occurring at 18 kilometers. The total column ozone is about 250 DU. Throughout September, though, total ozone drops rapidly at a rate of
3-5 DU per day. Nearly all of the ozone destruction centers around the ozone peak in a layer from 14 to 22 km. The record minimum of 89 DU was
observed on October 12, 1993. Since that year the 14 to 22 km layer has consistently shown near complete ozone destruction. When the first sign
of recovery of the yearly ozone hole does occur, it will likely be observed as a decrease in the thickness of the layer where near complete ozone destruction
occurs (primarily in the upper part of the 14-22 km layer) and also as a reduction in the rate of ozone destruction during September (Hofmann et al.,1997).
Hofmann, D. J., S. J. Oltmans, J. M. Harris, B. J. Johnson, and J. A. Lathrop, Ten years of ozonesonde measurements at the south pole: Implications for
recovery of springtime Antarctic ozone, J. Geophys. Res., 102, 8931-8943, 1997.
Web page original source http://www.cmdl.noaa.gov/ozwv/ozsondes/spo/spmin.html