Balloon-borne Ozonesonde Profile Measurements at South Pole Station Show an Upward Trend
Abstract
Balloon-borne electrochemical-concentration cell (ECC) ozonesondes launched at South Pole station have been tracking the development of the yearly Antarctic ozone hole for 32 years with regular balloon launches beginning in 1986. The unique central location (90˚ S) provides an optimum site to observe the rapid and severe ozone depletion from chlorine-catalyzed chemistry that occurs each September to mid-October. Figure 1 shows the 32 year ozonesonde record divided into four 8-year periods; the median total column ozone (TCO) is computed in 5 day intervals. The 1994-2001 period represents the severe ozone hole period near the peak in effective stratospheric chlorine. The last two 8-year medians show signs of ozone recovery with 10-20% higher TCO during mid-September to October compared to 1994-2001. The 55 year Dobson Spectrophotometer measurements (during sun-up period) began in 1963. The white median line, with 30-70% and 10-90% statistical envelopes, represents an approximate view of future ozone hole recovery using the 1963-1981 pre-ozone hole years as the norm. The Dobson 8-year median data line for 1978-1985 shows the period when the ozone hole was beginning to drop below the 220 DU ozone hole metric. The July 31, 2018 profile shows a normal TCO at 255 Dobson Units with indications of slight depletion beginning in the 16-19 km altitude layer. By the 2018 Fall Meeting, the 2018 ozone hole will have come and gone and will be reported as part of this presentation.
Figure 1. Total column ozone in Dobson Units (DU) measured at South Pole by ozonesondes in 8 year intervals beginning in 1986 and with a Dobson spectrophotometer in the 1978-1985 (before ozonesonde measurements began) and the 1963-1981 Dobson median (white line) which represents an approximation of full recovery to pre-ozone hole conditions. Daily direct Dobson sun measurements begin mid-October at sunrise and continue through to March 1 (dusk) with occasional moon observations during the dark months.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.A41I3074S
- Keywords:
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- 0340 Middle atmosphere: composition and chemistry;
- ATMOSPHERIC COMPOSITION AND STRUCTUREDE: 0341 Middle atmosphere: constituent transport and chemistry;
- ATMOSPHERIC COMPOSITION AND STRUCTUREDE: 3305 Climate change and variability;
- ATMOSPHERIC PROCESSESDE: 3334 Middle atmosphere dynamics;
- ATMOSPHERIC PROCESSES