Sensitivity of climate to dynamically-consistent zonal asymmetries in ozone

Previous investigations into the effect of zonal asymmetries in ozone on climate have compared simulations with prescribed 3-D ozone, in which the ozone is not necessarily consistent with the model dynamics, to simulations with prescribed zonal mean ozone. We assess the impact of zonal asymmetries in ozone by comparing a control simulation of a coupled chemistry version of the Canadian Middle Atmosphere Model (CMAM) in which the ozone and model dynamics are consistent, with a simulation in which only the zonal mean of the ozone is passed to the radiative transfer scheme. These simulations reveal a robust stratospheric zonal-mean temperature and geopotential height response to zonal asymmetries in ozone that is consistent with that identified in previous studies and of a magnitude comparable to observed trends. These results suggest that the inclusion of zonal asymmetries in ozone may be essential for the accurate simulation of future stratospheric temperature trends. Citation: Gillett, N. P., J. F. Scinocca, D. A. Plummer, and M. C. Reader (2009), Sensitivity of climate to dynamically-consistent zonal asymmetries in ozone, Geophys. Res. Lett., 36, L10809, doi: 10.1029/2009GL037246.