#Monit montreal series#

Today, these assessments form the basis for amendments and adjustments to the Montreal Protocol, the most recent of which was agreed upon in Montreal in September 2007. These assessments provided the basis for the UNEP-led negotiations for conclusion of the Vienna Convention on the Protection of the Ozone Layer (1985) and its Montreal Protocol (1987). Ground-based measurements play an essential role, both for trend studies in various regions of the world and also for ground-truthing of satellite measurements. They are based on the achievements of hundreds of scientists, from both developed and developing countries and on contributions from many national agencies.

#Monit montreal series#

This discovery was made in 1985 by British scientists performing ground-based measurements from the Halley station at 76°S, where ozone observations had been carried out since 1956.ĭuring the last 20 years, WMO, in collaboration with the United Nations Environment Programme (UNEP), has coordinated the preparation of a series of scientific assessments, the most recent of which was published in early 2007. It was not until the mid-1980s, however, that we obtained convincing evidence of ozone destruction as demonstrated by the dramatic ozone decline in the Antarctic spring. These data started to be analysed carefully when, in the early 1970s, scientific findings highlighted the potential of chlorofluorocarbons (CFCs) and halons to destroy ozone with serious environmental implications. At present, more than 70 agencies in some 50 WMO Member countries are contributing ozone observations to WMO’s Global Atmosphere Watch (GAW), providing data essential for understanding the state of, and changes to, the ozone layer. Isolated ozone observations were made in the 1920s, but systematic measurements began only about 50 years ago. They determine the temperature structure of the stratosphere and, by absorbing harmful ultraviolet radiation, safeguard life on this planet.

Ozone molecules are concentrated in the stratosphere mainly between altitudes of 10 and 40 km.