Editor’s comment on Jones et al.
acp-2015-818

The authors have done an excellent job in addressing the reviewers’ comments. There are only a few issues remaining. After these are addressed satisfactorily, I will be happy to accept this article for publication. All pages and line numbers below are in reference to the “Response to reviewers”/tracked changes version of the manuscript.

General comments:

In your response to reviewer #2, you have added the comment “No QBO-like oscillation can be detected in the 10-year time span.” It would be helpful in your model description section to discuss whether your model has a QBO and how well it does in representing this oscillation.

Regarding your response to John Dykema, point #4, McCusker et al. should be cited in the manuscript, and there should be a comment that you have confirmed their results (along the lines of what you wrote in the reply to this review). I know there is a more detailed description to this effect in supplemental material, but a short mention in the manuscript itself would be appropriate.

Specific comments:

Page 29, line 1: I’m not sure “maximize” is the right word, as it implies you did a sensitivity study. I recommend replacing “maximize” with “ensure a long”.

Page 29, lines 5 and 7: Replace “radiation” with “radiative flux”.

Page 29, lines 4-21: In this paragraph, it is unclear as to why the TOA net radiative flux is not 0 in the preindustrial control simulation. Is this due to insufficient model spinup? Some clarity is needed here.

Page 29, line 16: Add “adjusted” before “Radiative Forcing” (there are many different kinds of radiative forcing).

Page 29, lines 27-28: I’m not sure what is meant by “reasonable”.

Page 29, lines 28-30: This is essentially what MacMartin et al. (2014, Climate Dynamics) and Kravitz et al. (2014, ERL) suggest, albeit done slightly differently. Citations would be appropriate here.

Page 31, lines 1, 3, 5, 7, and 8: Change “radiation” to “radiative flux”

Page 31, lines 11-12: This is what Hansen et al., 1997 (JGR) found – the times where instantaneous and adjusted radiative forcing strongly differ are when there is a large heating affecting the tropopause. A citation here would be appropriate.

Page 32, line 31: Describe the SmR experiment so the reader doesn’t need to refer to the other paper.

Page 34, lines 16-18: It’s a little more complicated than just the surface radiative imbalance. See Muller and O’Gorman (2011, Nature Climate Change) and O’Gorman et al. (2012, Surveys in Geophysics). The missing part here is that it’s not just the surface – you need to account for energy flux entering/leaving the entire atmospheric column.

Page 36, line 8: Again, define/describe SmR.

Page 37, line 24: Similar comment – don’t make the reader have to read an entirely different paper just to understand this one experiment.

Page 38, line 19: I think “zonally-homogeneous” might be the wrong word, as that implies it doesn’t vary with longitude. I assume you mean that you want the cooling not to vary with latitude?

Page 39, Lines 28-32: Your response to John Dykema’s comment (#1) was more thorough than your response here. I would like to see a mention of how aerosol microphysics AND interactions with radiation/circulation are both important.

Page 40, lines 19-20: Kravitz et al. (2012) showed this for only one of their scenarios. Your description needs to be qualified here so as not to give the wrong impression.

Page 41, lines 10-22: In your response to John Dykema (#6), you mention that deposition of titania on snow would also have a climatic impact, but this is not mentioned here. I would like to see some lines about that as well.

Caption of Figure 6: “Stippling” is misspelled.

Kravitz et al. (2014) should refer to this paper: http://iopscience.iop.org/article/10.1088/1748-9326/9/4/044006/meta

Other than that, the manuscript is in great shape.