Monitoring of the atmospheric ozone layer and natural ultraviolet radiation: Annual report 2013.

This is an annual report describing the activities and main results of the monitoring programme “Monitoring of the atmospheric ozone layer and natural ultraviolet radiation” for 2013. In 2013 the ozone values above Norway were close to the long-term mean at all sites. A clear decrease in the ozone layer above Norway during the period 1979-1997 stopped after 1998 and the ozone layer above Norway now seems to have stabilized.