Thank you for providing a very comprehensive response to both reviewers’ comments and a clear explanation of the changes you have made. I am satisfied that you have addressed their concerns satisfactorily, except for one issue regarding uncertainties for which I am asking further clarification. There are also a number of minor technical issues that need sorting out. Once these have been addressed I will be happy to accept publication of this manuscript in ACP

Regards,
Claire

Minor Revision
Section 2.3.2. You were asked by reviewer #1 to explain how the uncertainties were calculated. For the NMHC measurements there were 2 instruments, one run by LCSE at LHVP and one run by AIRPARIF at Les Halles. In your response to the reviewer you explained that there was insufficient information provided by AIRPARIF to quantify the uncertainties, however you did not explain how the uncertainties in the LHVP data were calculated. The second paragraph is on the Les Halles data and the last sentence states that the analytical uncertainty of “all” data was estimated. It is not clear if this refers to the LHVP data and based on your response to the reviewer, I would expect the uncertainties in the LHVP and Les Halles data to have been derived differently. Also since you lacked sufficient information from AIRPARIF to quantify the uncertainties, you should make this clear in the text. When you say that the uncertainties were estimated to be 15% in agreement with previous studies, it is not clear if they were set at 15% to be in agreement or somehow estimated to be 15% which happened to be in agreement with previous studies.

Technical Issues
1) Page 6, line 18. Relative Humidity should be all in lower case letters.
2) Page 7 lines 29 and 31 “back trajectories”.
3) Page 8 line 26 “ranges”.
4) Page 8 lines 27-28 “Despite this limitation”.
5) Page 10, line 25. Please define w/w in the text.
6) Page 12, line 17 “composition of VOCs”.
7) Page 12, line 32 “on VOC trends”.
8) Page 12, line 33 “As OVOCs are”, “to observe different”
9) Page 15, line 2 “good indicators of”.
10) Page 15, line 21 “passenger cars”.
11) Page 19, line 11 “shallower”.
12) Page 22, lines 18-19 “These kinds of emissions have been”.
13) Page 22, line 29 “temperatures recorded …. were”.
14) Page 24, line 14 “and the rest of the world”.
15) Make sure axes labels are large enough. I have concerns over those for Fig. 7c and Fig. 10.
16) Fig. 13 in the caption which pie chart is which (left and right).

Dear Alexia,

Thank you for clarifying the uncertainties in the GC-FID measurements. I would just like to suggest a minor change to the English. I realise the some of the bits that I am changing came verbatim from my comments, but the language I used was rather colloquial to emphasise my point rather than suitable for scientific literature. Please change the last 2 sentences in section 2.3.2 to something more like: "We were unable to perform a comprehensive calculation of uncertainties due a lack of sufficient information provide to us by AIRPARIF. However, based on previous experimental tests, the NMHC measurements were provided by AIRPARIF with an accuracy of  +/- 15 %, which is the same level of uncertainty as we calculated for the LSCE GC-FID data."

I realised that the font sizes of some figures had been increase in the previous version, but I am still concerned that for some figures the font size is too small. Please ensure that at the production stage the figure text is readable.

Regards,
Claire