The Quadrennial Ozone Symposium (QOS) held on line on October 3-9, 2021 was a great success with 341 registered participants from various countries around the world.

It was the first online meeting of QOS history. Up to 230 participants connected to the various sessions of the Symposium. There were still about 140 connections during the last session on Saturday 9 October.

During the opening session on Sunday, October 3rd, 2021, the Dobson and Farman awards were given to Dr. William Ball and the SBUV-MOD team of NASA, as previously announced.

Press Release: The International Ozone Commission, on the 34th anniversary of the Montreal Protocol, reports successes and remaining challenges for understanding ozone layer recovery

September 16th is the International Day for the Preservation of the Ozone Layer, celebrating the 1987 anniversary of the Montreal Protocol on Substances that Deplete the Ozone Layer. The Montreal Protocol is the globally ratified treaty that controls the production and consumption of ozone depleting substances (ODSs) and many replacements for these substances.