1Department of Physics, University of Toronto, Toronto, Ontario, Canada
2Cooperative Institute for Research in Environmental Sciences University of Colorado/NOAA Earth System Research Laboratory, Physical Sciences Division, Boulder, CO, USA
Received: 01 Nov 2011 – Published in Atmos. Chem. Phys. Discuss.: 14 Dec 2011
Abstract. In a recent paper Hu et al. (2011) suggest that the recovery of stratospheric ozone during the first half of this century will significantly enhance free tropospheric and surface warming caused by the anthropogenic increase of greenhouse gases, with the effects being most pronounced in Northern Hemisphere middle and high latitudes. These surprising results are based on a multi-model analysis of CMIP3 model simulations with and without prescribed stratospheric ozone recovery. Hu et al. suggest that in order to properly quantify the tropospheric and surface temperature response to stratospheric ozone recovery, it is necessary to run coupled atmosphere-ocean climate models with stratospheric ozone chemistry. The results of such an experiment are presented here, using a state-of-the-art chemistry-climate model coupled to a three-dimensional ocean model. In contrast to Hu et al., we find a much smaller Northern Hemisphere tropospheric temperature response to ozone recovery, which is of opposite sign. We suggest that their result is an artifact of the incomplete removal of the large effect of greenhouse gas warming between the two different sets of models.
Revised: 15 Feb 2012 – Accepted: 23 Feb 2012 – Published: 07 Mar 2012
McLandress, C., Perlwitz, J., and Shepherd, T. G.: Comment on "Tropospheric temperature response to stratospheric ozone recovery in the 21st century" by Hu et al. (2011), Atmos. Chem. Phys., 12, 2533-2540, doi:10.5194/acp-12-2533-2012, 2012.