Introduction to the Special Issue of Atmosphere-Ocean—Proceedings of the Twenty-Second QOS / Introduction du numéro spécial d'Atmosphere-Ocean – Comptes-rendus du vingt-deuxième SQO

The twenty-second Quadrennial Ozone Symposium (QOS) was held in Toronto in August 2012, a year that marked a number of anniversaries of events related to the study of ozone and connected to Canada. These include the 50-year anniversary of the founding of the World Ozone Data Centre (now the World Ozone and Ultraviolet radiation Data Centre; WOUDC) by Environment Canada scientist Carleton Mateer; the 30-year anniversary of the delivery of the first commercial Brewer Ozone Spectrophotometer to Thessaloniki in Greece; the 25-year anniversary of the signing of the Montréal Protocol on Substances that Deplete the Ozone Layer (a protocol to the Vienna Convention for the Protection of the Ozone Layer) in Montréal; and the 20year anniversary of the introduction of the Ultraviolet (UV) Index in Canada. These anniversaries speak to the strong commitment that Canada has had to ozone measurement and ozone science. The twenty-second symposium is also notable for another reason—it was the first QOS to take place after the discovery of the first Arctic ozone hole (Manney et al., 2011). A number of papers were presented addressing that event. The QOS2012 saw nearly 300 scientists and students come together to share their research in Toronto. Attendees from 30 countries contributed more than 200 abstracts; 213 posters and 105 oral talks were presented. There are 15 papers in this special issue of Atmosphere-Ocean.