Comparison of observed stratospheric ozone and temperature time series with chemistry-climate model simulations. Part II: Profiles at selected stations

We report on the comparison of ozone and temperature long-term observations (30+ years) from about ten northern mid-latitude stations (WOUDC and NDSC databases) with simulations by two different versions of the fully coupled ECHAM4 chemistry-climate model. One version by MPI Mainz/Hamburg includes the middle atmosphere up to about 80 km altitude, whereas the other version by DLR Oberpfaffenhofen focuses on the upper troposphere/ lower stratosphere and ends at about 30 km altitude. Simulations of both models are 40-year transient runs accounting for effects of quasi-biennial oscillation (QBO), 11-year solar cycle, observed sea-surface temperatures, volcanic aerosol, as well as gradually increasing source gases (CFCs, CO2, N2O, CH4, ...). Both models reproduce the results from the observations quite well. Observations and models show negative trends in ozone and temperature throughout the lower stratosphere (-2 to -4%/decade, -0.7 K/decade). The largest ozone depletion is observed and modelled in the upper stratosphere (-8%/decade). QBO and 11-year solar cycle related variations show similar seasonal and vertical patterns in the lower stratosphere for observations and models. However, model results show less variation from station to station than is observed.