Dear Authors,

I've read through your proposed responses, I'm recommending major revisions to allow you sufficient time to address their comments. As well as addressing the reviewer comments as you've outlined, I have highlighted some further points they raised below.

R1 asked you to note the intake height, I see there is a disagreement about whether this leads to an overestimation but I don't see that this precludes you from noting the height in the manuscript as requested.

R3 asked about u* filtering. In your revision can you also include in your response the original plot and the plot after u* filtering in case the reviewer wishes to see the difference.

R3 suggested you combine your results and discussion, I'm happy for you to keep your manuscript as you designed it; however, can you please carefully check through the discussion and see if you can minimise repetition. I'm sure it will be better for the reader in the long run.

R3 also asked about the fertiliser - perhaps you should simply include this information in the manuscript?

Best wishes,

Martin

Dear Authors,

Three reviewers have seen your revised manuscript and they were all overwhelmingly positive. I am recommending acceptance subject to some outstanding technical corrections, listed below. Many congratulations.

Best wishes,

Martin De Kauwe

R1 commented:

The authors properly respond to the comments raised by the reviewers and made corresponding revision in the text. However, there are still several mistakes or improper places in the revised manuscript, e.g., line 111, 113, 126, the digital dates are easily confused with values, especially for line 113 "before the 16.06" which is better present as 16 June; Line 114-115, the sentence lack of logic and the values in "the 16. and the 18.6.." are typos; Lines 132-137, the size of the chamber should be noted, rather than a reference; The difference of the air temperatures in the chamber and the ambient air is better noted to make sure the flux measurements are reliable; The method used for COS flux measurements may have technical problem by using the difference of COS mixing ratios between those measured in the chamber and above the chamber because the chamber inlet was located at 0.12m above the ground where COS mixing ratio was usually much lower than those measured above the chamber. The relatively low COS mixing ratios in the chamber is not attributed to the uptake by the chamber covered area. To exactly obtain COS flux, COS mixing ratios at the inlet of the chamber and in the chamber are needed. Additionally, the relevant references are suggested to be cited to support your statement in lines 63-65, e.g., the influence of soil temperature and moisture on soil COS emission (Liu et. al., 2010, Bio geosciences 7(2):753-762).


R2 commented:

The only thing I can't seem to find is where they say what the value of the u* filter is for CO2. It's mentioned in the comments but doesn't seem to have been included in the manuscript. Once they add that, I would recommend accepting as is.

R3 commented:

Only a technical correction is needed. The fact that QCL outputs mixing ratios does not justify its correctness, as stated in the responses "The ambient COS and CO2 concentrations both originated from the QCL data, which puts out mixing ratios". As commented earlier, if the measurements were calibrated to the WMO scale, CO2 should be reported as mole fractions instead of mixing ratios, because the WMO scale (NOAA calibration gases) is reported on mole fractions.