Slowdown in the CFC-11 atmospheric concentration decay
related to emissions from non-reported forbidden production
CFC-11 is one of the most important chlorofluorocarbons (CFCs) in the Earth’s atmosphere. CFCs are chemicals exclusively emitted to the atmosphere by human activities.
When CFC-11 is transported into the stratosphere, it is photolyzed, releasing chlorine atoms that catalytically destroy stratospheric ozone, which protects the biosphere from harmful UV radiation. Analysis of the last 20-years ground-based FTIR time series of CFC-11 from the NDACC stations Jungfraujoch (46°N) and Lauder (45°S) confirms the slowdown in the CFC-11 atmospheric concentration decay, related to emissions from non-reported forbidden production. This study further demonstrates that the ground-based FTIR instruments are a useful complement to in situ and satellite measurements, providing relevant information to the Montreal Protocol on Substances that Deplete the Ozone Layer.
