Ozone laminae: Comparison of the Southern and Northern Hemisphere, and tentative explanation of trends

Abstract

The measured ozone profiles often exhibit narrow layers of enhanced ozone concentration (positive laminae) or depleted ozone (negative laminae). Here we deal with the ozone laminae characteristics in the Southern Hemisphere in comparison with earlier studied laminae characteristics in the Northern Hemisphere. There are large differences between the ozone laminae characteristics in the Northern and Southern Hemisphere. The overall ozone content (deficit) in the positive (negative) laminae per profile and the number of laminae is much smaller in the Southern Hemisphere compared with the Northern Hemisphere. No detectable trend in these two lamina characteristics was found in the Southern Hemisphere contrary to a strong negative trend with a reversal to strong positive trend in the mid-1990s in the Northern Hemisphere. Pattern of trends in the ozone content in one lamina is quite different; no trend except for a slight negative trend in the Northern American sector. Some dynamical factors, mainly the degree of stability of the polar vortex, are suggested as contributing (or not) to the long-term behavior of lamina characteristics.