Monitoring of the atmospheric ozone layer and natural ultraviolet radiation: Annual report 2015.

This report summarizes the results from the Norwegian monitoring programme on stratospheric ozone and UV radiation measurements. The ozone layer has been measured at three locations since 1979: in Oslo, Tromsø/Andøya and Ny-Ålesund. The UV measurements started in 1995. The results show that there was a significant decrease in stratospheric ozone above Norway between 1979 and 1997. After that the ozone layer stabilized at a level ~2% below the 1979-1989 average. However, there are large inter-annual variations and in 2015 the average ozone level was close to the 1979-1989 average values at all three Norwegian stations.