Dear authors,

I have checked your replies to the reviewers and the related changes in the manuscript and come to the conclusion that you have considered their comments appropriately. Therefore I accept your paper for final publication in ACP. However, I have a number of minor items, mainly of technical nature, that I would like to ask you to consider when submitting your manuscript in final form for publication:

Line 20, where Kovacs et al is mentioned: please note that the SF6 destruction in the mesosphere has been discussed and modeled much earlier - see reddmann et al., 2001 (Full reference:Reddmann, T., R. Ruhnke, and W. Kouker (2001), Three-dimensional model simulations of SF6 with mesospheric chemistry, J. Geophys. Res., 106(D13), 14525–14537, doi:10.1029/2000JD900700.). You might wish to cite and discuss the implication of this paper for your study.

Line 83: Since you refer here to a ten-years data record, the publication by Haenel et al., 2015 would be more appropriate as reference for the MIPAS data set, since in this publication the first data set on age of air covering the full 10-years mission time has been published (full reference:Haenel, F. J., Stiller, G. P., von Clarmann, T., Funke, B., Eckert, E., Glatthor, N., Grabowski, U., Kellmann, S., Kiefer, M., Linden, A., and Reddmann, T.: Reassessment of MIPAS age of air trends and variability, Atmos. Chem. Phys., 15, 13161-13176, https://doi.org/10.5194/acp-15-13161-2015, 2015.).

Fig. 2: The quality of this figure (resolution) should be improved.

Table 5: the footnote referring to the "$" footnote sign is missing.

Best regards,
Gabriele Stiller