Dear authors,

You have carefully and adequately addressed the reviewers' comments and suggestions. I agree that further analysis of the fluxes is beyond the scope of this study. The paper has also become less lengthy, but especially in the discussion section (5), which takes up lines 507-634 (1), I still think the paper should be shortened. I shorten the discussion section along the below recommendation to improve the readability of the paper further.

1. Please check in the manuscript that your statements on RMSE and bias also include physical units, or that it becomes clear from the text what the numbers refer to in terms of units.

2. I suggest to summarize the take-home messages of the sub-sections in the discussion into one table that compares the findings and main considerations for application of the two systems studied.

The 5 column headers would be:
Instrument; Field performance; Flexibility in application; Performance of concentrations; Performance of fluxes

The rows would be Header; mini-DOAS; HT

Each cell of this table should then have a bullet-wise concise summary of the main thing you want to say in cross-evaluating the 2 measurement techniques. The table is then your vehicle for a much more summarized discussion of the main differences between and strength-weakness analysis of the measurement methods. 127 lines of dense text is too much in the Discussion section, and I think the overall length should not be more than 50 lines.

Other than that I have no further suggestions. After you make the changes, the paper is accepted for publication in AMT.

Kind regards - Folkert Boersma

Congratulations on your paper which is accepted for publication in AMT. The Associate Editor.