Full title: 'Consideration of lifetimes of tracers for the determination of stratospheric age spectra and the Brewer-Dobson Circulation (COLIBRI)'

The mean age of air is a powerful tool to diagnose the Brewer-Dobson Circulation. By consideration of multiple source gases the mean age of air can be better constrained. Stratospheric sinks on non-inert source gases, however, have to be considered.