Dear Authors,

The two reviewers appreciate your revision to address their comments on the earlier version of the manuscript and think that the revised manuscript is much improved. However, they still have several comments related to the structure of the manuscript, and more seriously both are concerned with the writing of the paper, e.g., the grammar errors, typos, inappropriate words,... Please make more efforts, e.g., by asking helps from native English speaker or language edit service to meet the high standard of ACP.

Xiaohong Liu

Dear authors,

I read through your manuscript carefully, and would appreciate your efforts to improve the manuscript following the reviewers' comments, particularly the language writing.

While I read your manuscript I have some comments/questions. Please address/ correct them before submit your manuscript for publicaition.

1. Page 2. Line 21. change "observational" to "observed".
2. Page 2. Line 35-36. remove "that contributes...YRMB area"
3. Page 3. Line 43. remove "traffic"
4. Page 3. Line 60. "As of late"? do you understand what you mean
5. Page 4. Line 69. "The emissions factor includes ...". This statement is not correct. "chemical production and transformation" should not be counted in emissions.
6. Page 6. Line 106. add "of" in-between "one which"
7. Page 7. Line 139. change "coupled offline with" to "driven by"
8. Page 8. Line 161-162. It worths to give a bit more detail on the performance for different variables and sites for people who do not know much about the Taylor diagram.
9. Page 9. Line 169-170. Please explain how you determine the residence time
10. Page 9. Line 172. add "as" after "considered"
11. Page 9. Line 179. "h" to "hour"
12. Page 9. Line 184-186. "The primary PM2.5 emission data..." Does MEIC provide PM2.5 emissions? or emissions for BC, SO2,..
13. Page 11. Line 214. remove "apparent"
14. Page 12. Line 249. "precipitation could impact the emissions". How can precipitation impacts the emissions?
15. Page 17. Line 350. change "exhibited" to "shown"
16. Page 17. Figure 7a. Where do the PM2.5 concentrations (color contour in Figure 7a) come from?
17. Page 20. Line 412. move "in the YRMB area" to behind "the PM2.5 concentrations"
18. Page 21. Line 425. Cite Gao et al. (2011) which had used the WRF-Chem to study the contributions of regional transport and other aerosol processes (emission, wet scavenging) to air pollution reduction in Beijing Olympic.
Gao, Y., X. Liu, C. Zhao, and M. Zhang (2011), Emission controls versus meteorological conditions in determining aerosol concentrations in Beijing during the 2008 Olympic Games, Atmospheric Chemistry and Physics, 11, 12437-12451.