Hi,

Thank you for taking the reviewers' comments into account and for your thorough revision of the manuscript. I think the paper has been improved and reads very well now. Before proceeding with publication, I have the following minor remarks:

- p.1 (abstract): "all measurement in the Network are performed by *ground-based* remote sensing techniques" (just to be clear for a general readership).

- p.13: "Copernicus Atmosphere Monitoring Service" (not "Atmospheric").

- p.31-32 (section 4.2): in spite of the revision and reference to (Thorne et al., 2017), I am afraid that the section remains somewhat obscure because it is either too short or too long. Figure 15 is especially very hard to understand fully: the meaning of lines in the matrix is unclear and the terms "comprehensive", "baseline" (etc...) are not really used in the plain English sense. In the end, I suggest either to add a few paragraphs in order to explain better the maturity matrix or to remove Figure 15 and make the same point (NDACC is a mature network) more qualitatively and refer to (Thorne et al., 2017) for details.

- some figures are low quality, please revise. This is not only an issue with e.g. the DPI output, but mainly with the fact that some graphics (especially Figs 1 and 3) are originally slides designed for projection on a large screen. In the paper, the use of tiny fonts and of many colours does not work too well. Could you try revise/simplify some of the Figures?

Thank you for the final corrections brought to the manuscript.