Dear author, co-authors,
I have checked carefully your response to the reviewers comments as well as the revised version of the ms. It seems that you made a good effort to address all the raised issues and have introduced substantial modifications to tackle the comments/suggestions for changes. I have considered to invite again one of the reviewers to check if they feel that all the comments have been properly addressed but actually one of them already followed carefully the review process and checked your response and indicated that the paper has substantially improved. In addition, I have checked again the revision and found some last minor issues that I would like you to address before I can accept the ms for publication in ACP.

Minor correction; Bakwin et al. (2004) adjusted the CO2 concentration at 30 m height increasing it by 2.5 ppm to estimate in summer.....
Line 240; Checking the revised ms, in particular on the introduced modifications in section 2.5, which has substantially changed I noticed that you introduce there the two footprint methods; the second is mentioned after an extensive introduction of method number 1. I would therefore suggest to change the text to: “We used two footprint methods. The first method is based on determining an equally-weighted circular footprint centered at the tall tower. The area within each circular footprint was equally weighted, therefore fraci is the fraction of land cover type i within a certain radius around the tall tower.”
What do you mean here with equally-weighted?? Is fraci constant (but different from 1/6) for the different radii or is it 1/6 so that each land cover type contributes 1/6 to the total footprint (read that later on there is more explanation about how fraci is determined but the way it is now put here is confusing).
Further textual modification: “The second footprint method we applied derives the footprint from the Stochastic Time-Inverted Lagrangian Transport model (STILT, Lin et al., 2003).”
In your reference to the EDGAR dataset you initially refer to it as EDGAR and then continue to EDGAR42 reflecting the fact that you used version v4.2 of EDGAR. Refer consistently to this emission dataset after you have chosen your abbreviation for this one.
In your discussion you have included a short statement about how the fluxes of EDGAR/the data compare to the emission/fluxes from a national inventory, the one by EPA; “The GHG inventory developed by EPA (EPA inventory) was based on more country-specific emission factors or models...”.
What is missing here is a short introduction statement that explains that to further analyse the significance of the underestimation of the EDGAR emissions, that you have also included a the National scale EPA inventory in your analysis to determine some plausible explanations for this underestimation and to appreciate the uncertainty in the top-down and bottom-up approaches compare to the differences between different available emission inventories. Your statement now comes too much out of the blue.

Regards, Laurens Ganzeveld

Dear authors, co-authors, I have checked your response to the last round of minor comments and your modifications in the ms and do accept now the paper for publication in ACP,

Regards, Laurens Ganzeveld