SPRINGTIME STRATOSPHERIC OZONE OVER MARAMBIO, ANTARCTIC DURING 1990-1998 Analysis of Ozone Sonde Data In Relation To the Phase and Position of Polar Vortex

摘要

It is not possible to draw definitive conclusions about the possible early start of the ozone loss at outskirts of the SH polar vortex from this data set only. It can nevertheless be said that if there occurs chemical depletion, it has not changed remarkably during 1990-1998. Some signs of negative ozone trends can be seen in this data set supporting the suggestion of an early start of ozone depletion. Interestingly they occur in the edge region rather than inside the vortex. During the period of strongest chemical depletion in September, October and November the overall linear trend of ozone inside the vortex has been negative (about 0,1 ppmV/year or 17 %/year on average) on the 475 K and the 435 K surfaces. The overall negative trend of ozone on all surfaces under scrutiny is characterised by a strong decline from 1990 to 1993, where after ozone has not declined. If there had been similar linear trends of ozone outside and inside the vortex and linear dependence between mixing ratio of ozone inside and outside the vortex, it would have been a piece of evidence in favour of significant mixing of ozone poor air masses through a strong polar vortex edge. This nevertheless was not the case.