A recent ACP paper by B. Hassler and co-authors compares three vertically-resolved ozone data sets, the data set of Randel and Wu (2007), Cionni et al., (2011) and Bodeker et al., (2013). All three data sets represent multiple-linear regression fits to vertically resolved ozone observations and cover at least the period from 1979-2005. They find that the main differences among the data sets result from the underlying regression models used, which use different observations and include different basis functions. Climatologies, trends and calculated stratospheric ozone radiative forcing are compared between the three data sets as well. Find the full abstract here.