There is some sort of a problem with the TC system, and I am not able to see the authors' revised manuscript today. As I'll be out of town next week, I wanted to provide some feedback based on what I can see in the responses to the referees.

It looks to me like the authors have done a good job of responding to the referees' comments, and I think the major scientific disagreements have been dealt with well. At the same time, based on the samples of the revised text that are available in the response documents, I suspect that the final manuscript will need some revisions for English and grammar. In particular:
--the response to lines 228-234 has a description of methods in present tense, while all methods should be in past tense
--In the abstract, "microscopical" should be "microscopic"
--Lines 29-33: temperature increase -> temperature increases
--Lines 37-44 : "snow grains growth" -> "snow grains' growth" or "growth of snow grains"
--Lines 50-52: should be "online coupling...has"
In the block of supplement text starting with line 34: "placed" should be "located"
... and so on.
I'm afraid I don't have time for a thorough proof-read of the manuscript, but I'd ask that the authors look carefully at their text with all revisions applied and check the grammar throughout before submitting a final draft. The manuscript is very close!

The manuscript looks good. I have a small list of edits that I saw during a quick read-through, and more may be caught during typesetting. Please make these corrections and we can get the manuscript off to the next stage!

Overall: I don’t think ‘firn’ needs to be in italics.

Line (in the change-tracked manuscript) – comment

18: detect -> identify

23: retreating -> retreat (or ‘rates of retreat’)

30: delete ‘the’

33 “light-absorbing impurities” -> “light-absorbing particles”

44 “PM” should be treated as singular (e.g. “PM reflects”)

45 relevant -> significant

345: have shown -> have been shown

346: “in a similar way as in” -> “similar to the effect of debris in “

372: “One of the samples described under microscope” : Not clear what this means.

467: “would allow to study” -> “would allow us to study”

481: “such kind of “ -> such

485 that-> those

501 “has shown” -> “has been shown”

Thanks for the thorough response, and congratulations on the paper. This looks good.