The manuscript is very nearly ready for publication, and is subject to only minor revision based on the remaining comments from two reviewers, as summarized below and in the reviewer’s comments.

Reviewer #1 suggests the addition of the nitrate radical production rate, k(NO2+O3)*[NO2]*[O3] to figure 3 either in place of the NO2 trace or in addition to it. This is a good suggestion that the authors should implement presuming the O3 data are available. Please also take the reviewer’s suggestion for the discussion of the Rollins et al. results on page 20 into account. This section of the manuscript would also benefit from correlations to the NO3 production rate rather than to NO2 alone.

Reviewer #3 suggests several small but important addition to the paper, mainly related to the description of experimental methodology. Some details are requested in section 2.1, and these questions should be addressed. The reviewer asks several questions regarding methodology in sections 2.2 and 2.5. A response to the editor for both questions will be sufficient, although the authors are encouraged to include any of the details of this response in the manuscript. The reviewer also suggests a change in the title, to add the phrase “in Denmark.” This is a reasonable suggestion (the phrase could be added where the reviewer indicates, or alternatively at the end of the title), since the analysis is certainly specific to the region in which the measurements occurred. The title change should be at the discretion of the authors, however.

The authors have been thorough and responsive through two rounds of reviewer comments. They have answered all comments satisfactorily. The manuscript is now ready for publication in ACP.