RECOVERY OF OZONE IN THE LOWER STRATOSPHERE AT THE SOUTH-POLE DURING THE SPRING OF 1994

During 1994, springtime Antarctic ozone measured at the south pole did not reach the record lows recorded during the 1993 ozone hob period when a value of 91 +/- 5 DU was observed. A low value of 102 DU was recorded on October 5, 1994, but such values were not sustained as in 1993. The recovery of total ozone in 1994 was mainly the result of moderation of ozone destruction in the 10-14 km region, probably related to diminishing stratospheric aerosol from the Pinatubo eruption, and may have also been partially related to disturbance of the vortex earlier than normal. As in 1993, ozone profiles at the minimum showed nearly complete destruction of ozone between 15 and 20 km in 1994. In this region, the rate of decline of ozone in September was at least as fast or somewhat faster than in 1992 and 1993 indicating continuing saturation of the ozone destroying chemistry, which is expected as stratospheric chlorine amounts continue to rise. As in 1993, ozone was again observed to be reduced in the 22-24 km region, suggesting that the ozone hole has now probably extended to a region unaffected prior to 1992.