Long-term ozone trends in Northern mid-latitudes with special emphasis on the contribution of changes in dynamics

• Published in: Physics and Chemistry of the Earth, Parts A/B/C
• Main Authors: Staehelin, Johannes, Mäder, Jörg, Weiss, Andrea K., Appenzeller, Christof
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2002
• Subjects: stratospheric ozone; long-term trends; dynamics; tropopause pressure; statistical modelling; Antarc*; Antarctica
• Online Access: https://doi.org/10.1016/S1474-7065(02)00027-X

Monitoring indicates that stratospheric ozone strongly decreased in the polar regions, most seriously over the Antarctica. It is widely accepted that polar ozone loss is caused by heterogeneous processes activating halogen radicals which originate from the man-made release of ozone depleting substances. Significant ozone decrease peaking in winter/spring also has been observed in mid-latitudes. It started around the beginning of the 1970s. In this paper we review recent studies which indicate that not only long-term trends in chemical composition but also long-term changes in the dynamical structure of the atmosphere have significantly contributed to the ozone decrease over mid-latitudes. Such changes most strongly affected the ozone shield in the lower stratosphere and over Europe. However, they also influence ozone over the entire extra-tropical Northern hemisphere.