Please fully consider and address the comments in the recent re-review (copied here for your convenience):
This version of the manuscript has been improved relative to original submission, addressing several of previous reviewers comments. I commend the authors for this revision. However, while this is relevant to the scope of ACP, I have still some concerns with regards to the analysis of the results and to the evaluation of the updated emissions. I suggest minor revisions to address the following concerns before publication:

General comments
1/ I note that a particular effort has been done on the evaluation of the results but I still think that the evaluation section could be reinforced. The easiest way to see the effectiveness of the inversion is to show a gridded bias between the observations and the both the simulations using EGG or NE emissions. In this sense, you should complete the Figure S11. In addition, in my opinion, the evaluation against CrIS satellite data should be done at the regional scale in addition to the global one. It would not be an evaluation of the IASI data or of the model but of your updated emissions. It would complete the analysis of the evaluation against surface stations at least over Europe and over the US where your inversion can degrade the fit to the measurements compared to the prior EGG inventory.

2/ A comprehensive overview about the existing literature is still missing for the analysis of SO2 changes. Figure S2 is not in agreement with Krotkov et al., 2016, ACP, showing strong decrease of SO2 between 2005 and 2015 at least over Eastern US and over Eastern Europe with the OMI data themselves. These features could be explained by the choice of the authors to analyze their results for Europe or for the US as a whole but it should be discussed in the text. The section 3.2, circa p.320-340 would be more complete with analysis not only for the North China plain, even if I understand the particular interest for this region.

3/ The fact that the bi-directional exchange with surfaces is not taken into account should be mentioned. The potential impact on the inversion results should also appear in the text.

Specific comments
Line 329: “To” instead of “to”
Line 330: “NOx” instead of “NOx”
Line 329-330: The sentence is not clear. Please rephrase"

Dear authors,

Please see may responses to your questions below. If you have further questions or requests for clarifications, please ask before re-submitting. Note, these are the comments during re-review by one of the reviewers, not my own comments. I am responding here to try to answer your questions and clarify their comments.

Best,
D. Gentner

Reviewer comment #2/ A comprehensive overview about the existing literature is still missing for the analysis of SO2 changes. Figure S2 is not in agreement with Krotkov et al., 2016, ACP, showing strong decrease of SO2 between 2005 and 2015 at least over Eastern US and over Eastern Europe with the OMI data themselves. These features could be explained by the choice of the authors to analyze their results for Europe or for the US as a whole but it should be discussed in the text. The section 3.2, circa p.320-340 would be more complete with analysis not only for the North China plain, even if I understand the particular interest for this region.

Author response: We have tried to clarify that the observed decrease after 2015 is only due to our choice to present global averaged, whereas others (Krotkov et al.) have already seen decreased concentrations after 2015 (Track Changes line 369-375). As already mentioned, the reason why we chose North China Plain to investigate changes in NH3, reactants and precursor species is because the largest anomalies of SO2 and NO2 were seen there. We believe it would be beyond the scope of this paper to investigate in detail more regions in this respect, as the only reason for examining SO2 and NO2 was to explain any changes of ammonia’s reactants, which would explain change in NH3 emissions. We believe that Krotkov et al. has done a very complete analysis on SO2 and NO2 from OMI, much more detailed than what we have done in the present.

Editor's clarification: Note that the reviewer is also requesting a more comprehensive comparison to existing literature in this comment ("A comprehensive overview about the existing literature is still missing for the analysis of SO2 changes.") and is referring Krotkov et al. as an example related to Figure S2. I saw you added a short paragraph on Krotkov et al., but please make sure you have also included comparisons to any other appropriate references to put your results in context.

Reviewer comment #3/ The fact that the bi-directional exchange with surfaces is not taken into account should be mentioned. The potential impact on the inversion results should also appear in the text.

Author response: Dear Editor, please do correct me if I did not understand well this query. If you mean that we do not discuss in the text the effect of the exchange of ammonia in/out from the hypothetical box (due to atmospheric transport) that we used as a proxy to calculate emissions, then we do not agree. We have dedicated a full section (4.3 Limitations of the present study), where we explicitly state that the exchange due to transport is an issue of the selected methodology and that we believe it is fair to assume it negligible due to the very short lifetime of NH3 in the atmosphere. In case you meant something else, please be more specific and we will act on the manuscript to correct any issue.

Editor clarification: It seems to me that the reviewer is asking you to clearly state that bi-directional exchange of NH3 with the Earth surface was not considered. I don't think they are referring to atmospheric transport. Note, they also ask that "The potential impact on the inversion results should also appear in the text." Please resolve the issue and/or respond as appropriate.