Dear Lei Zheng and co-authors

Your manuscript "Recent changes in pan-Antarctic surface snowmelt detected by AMSR-E and AMSR2" received two reviews where both reviewers suggested to accept after major revisions.

I want to thank you already for the addressing the comments raised in your author's response and revised version which will now again be considered by the reviewers.

Additionally, I would appreciate it if you could further comment on my comments below in the response/revised version to upload.

Best regards,
Stef Lhermitte

Editor comments (page/line numbers based on revised manuscript):
1. p6L22 "if we assume": what happens if you don't make this assumption. How much do the results change? What impact does this assumption has on the final outcome.
2. p9 + table 2: please also add uncertainties (+- x days) on the observed trends and indicate how these uncertainties were calculated. If the uncertainties are in the same order of magnitude as the trends, the trends do not mean much.

Dear authors,

First I want to apologise for the long period since submitting your revised version and this feedback. We had difficulties finding reviewers (and R1 & R2 were no longer available), so I, as an editor, have taken an additional in-depth look at the paper and responses.

Based on this in-depth look, I suggest to reconsider your work after major revisions, where I ask you to specifically look at the robustness of the methods (also indicated by R1), since I think I cannot accept the paper if no more insights on the robustness etc. are provided.

I have added some detailed comments in the pdf in attachment and also would advice you to take the following major remarks into account:

1. I agree with R1 that Figure 1 does not directly conveys a clear message to your paper. I would recommend to either remove it (if Kang already showed that DAV is superior) or redesign (e.g. by showing a time series of single channel vs. DAV for different types of snowpacks) it such that it is clear that DAV method is superior. Currently, it is not very clear what the added value within the story is.
2. Accuracy of the method: you indicate accuracies/Kappa-coefficients between Tair and satellite melt of 0.79 and 0.51 (for DAV) and 0.82 and 0.60 (for DAV_ice). Based on these values I doubt if these are strong enough to warrant any later interpretation of the trends (especially for the more chaotic EMO (see next point))? Please clarify this and take this uncertainty along if you later want to use the DAV signal for melt interpretations
3. I agree with R1 that the early melt onset seems very much random early effect with little physical meaning and/or impact. Therefore, I wonder if the regression on these time series have any physical meaning? I would definitely consider removing the trend analysis of the EMO
4. You only introduce the trend regression in the results (which should already be done in the methods) and it is completely unclear how the trends (already indicated by R1) were observed and where their uncertainty comes from. Is it on a per-pixel basis and afterwards spatially merged (and how?) or first spatial merging and then trend-analyses? How were the uncertainties calculated, etc?
5. I have my severe doubts about the physical meaning of the trends (especially for the EMO, which seems very stochastic (as also indicated by R1)). I would reconsider removing all trend analyses from the paper and or add more clarity on the methods (how did you do the patio-temporal averaging?)
6. The comparison with the atmospheric indices should already be introduced in the results/methods sections and not left until the discussion.

If you have additional questions, please do not hesitate to get back to me.

Best regards,
Stef

Dear Lei Zheng and colleagues,

First I want to apologise for the long period since submitting your revised version and this feedback as Covid-limitations have provided some delay.

I have now revised the updated version of your manuscript and still have some comments that need to be addressed before we can accept the paper.

I have attached my main comments below and as comments in the attached pdf.

If you have additional questions, please do not hesitate to get back to me.

We look forward to receiving your revised version.

Best regards,
Stef Lhermitte

Separate comments:
- Please have your text revised by a native English speaker. The quality of the written English can still be strongly improved
- In your revised version you do not discuss the effect of the DAV melt uncertainty on the later interpretations of the melt. What would be the effect of accuracy/Kappa's of 0.82 and 0.60 (for DAV_ice) on the later interpretations? Please include this uncertainty and discuss this in more detail in your revised document

Dear Lei Zheng and colleagues,

Thank you for providing the revised version and author's response to the minor revisions of tc-2019-234 "Recent changes in pan-Antarctic region surface snowmelt detected by AMSR-E and AMSR2". Your response to most of the comments is adequate and therefore I recommend to accept the paper. Congratulations!

Before final publication, however, I would like to ask you to check if you can make the significant regions in Fig 7+8 more clear to the reader? Currently the black points are difficult to see and seem to correspond to dark blue/red (except when zooming in a lot).

Best regards, thanks again for submitting to the Cryosphere,
Stef Lhermitte