Please address the comments of reviewer 1 listed below. Reviewer 2 was very satisfied with the progress of this manuscript and liked the 3 Figures that you added. After these changes this paper can be published in ACP.

regards,

Yves Balkanski

Comments from reviewer 1:
Reviewer 1 who had some reservations has chosen to ‘Accept the ms with additional minor comments’.
I am happy that we reached this point and let’s wait for the reviewer’s 2 comments.
Here are the ones you will need to address from reviewer 1:

The authors have included some welcome additional figures to indicate model performance over wider regions of the globe. They have attempted to address my concerns on the conclusions from this research and restructured the summary. Regarding interpolation to station location, I understand that this may not be an issue in general as the variation between adjacent grid boxes may be relatively small, especially when averaging over long timescales. Therefore, for this work interpolation is likely a minor issue. However, in my experience it is good practice to interpolate, especially in the case of comparing at polluted locations, as not to introduce unnecessary bias.

Minor edits:

Fig 3 - the legend says black circles but they appear gray.
Fig 5 - "within each panels" (remove 's')

pg12 ln 9 - "seas salt" should be "sea-salt"
pg12 ln15 & 17 - consider changing "damping" to "reducing".
pg12 ln18 - Change "We will now..." to the section number as the analysis does not happen immediately after the statement.
pg18 ln12 - extra space after "However,"
pg22 ln2-5 - Saying that the vertical profile is worse in CM3 than CM2.1 doesn't negate the fact that the seasonality is better in CM3. I think this sentence is unnecessary.
pg22 ln22 - "overestimate" rather than "over-"
pg23 - The final paragraph does not conclude well. Accounting for the temporal collocation of instruments should either be improved for this study or the statement removed. The final sentence is superfluous. Consider integrating other research ideas into relevant paragraphs within the conclusions. An adequate concluding remark, regarding the necessity to consider multiple parameters and make used of the new 3-D composition information from observations, will need adding to the previous paragraph.

The last minor comments from Reviewer 1 have been answered and changes were made to integrate the suggestion to the manuscript that is now ready to be published in ACP.

This article can now be published.

YVes Balkanski