Modeling the Impact of Late 20th Century Stratospheric Ozone Changes: Sensitivity to Different Ozone Forcing Data Sets
P. Young1, S. Solomon1, B. Hassler1, G. Bodeker2, R. Portmann1 and J. Lamarque3
1NOAA Earth System Research Laboratory, 325 Broadway, Boulder, CO 80305; 303-497-4711, E-mail: paul.j.young@noaa.gov
2Bodeker Scientific, Alexandra, New Zealand
3National Center for Atmospheric Research, Boulder, CO 80307
Several climate model studies have addressed the role that 20th Century Antarctic ozone depletion has played in observed changes in both stratospheric and tropospheric climate: Polvani et al. (2011) have even suggested that the ozone depletion was the dominant driver of 20th Century climate changes in the Southern Hemisphere. However, the great majority of climate model studies have used either the ozone data set of Randel and Wu (2007) or the related one of Cionni et al. (2011), which do not capture the depth of the ozone hole. This issue has recently been addressed by developing a new ozone data set, drawing on the extensive database of observations collated by Hassler et al. (2009): the Binary DataBase of Profiles (BDBP). The BDBP data were used to develop a comprehensive statistical model to produce a spatially and temporally continuous data set suitable for global climate models.
We will show a series of climate model simulations to illustrate the sensitivity of the modeled ozone-hole signal to the ozone data set employed, comparing the Randel and Wu, Cionni et al., and BDBP-based data. Results will be presented in the context of existing studies to determine the importance of the climate model ozone data set for studying the impact of 20th Century ozone depletion.
Figure 1. Latitude-time plots of column (250-5 hPa) anomalies for the (a) Randel and Wu (2007), (b) Cionni et al. (2011) and (c) BDBP-based climate model ozone data sets, in Dobson Units (DU). Anomalies are computed relative to the 1979-2005 climatology for each data set.