|Review the revised version of Anderson et al., TC, September 2020|
This is a revised version of a paper that was initially made of 3 parts. Part A and B have been merged into this single manuscript and part C will be re-submitted elsewhere. I do not know how part C will evolve but I applaud the merging of part A and B in a more complete article. I feel that most of my earlier comments were correctly addressed.
At this stage my only major comment is that the paper is lengthy (especially the supplement) so anything that can contribute to make it shorter and easier for the readers will be welcome.
Maybe this is the result of the merging of two previous manuscripts (not a funny thing to do, I must admit) but I found the article rather long in particular the discussion. See example of repeated statements in my technical comments. Authors should aim at streamlining the article, especially the discussion. And the conclusion also: A 12 bullet point conclusions is not a nice way to end up the paper. Cannot the authors find 4 or 5 main findings that would be the take home message for the readers, the reasons why they would then cite this study. The same applies to the supplement. Make this supplement more concise, better organized so that the reader can navigate through.
L23 "across our study area, the lower 8 km of the glacier". So that the "study area "is unambiguously defined”.
L25. is it synonymous of the "study area" as defined above? Not clear again.
L34. The recently published (maybe after the authors submitted?) debris inventory by Herreid & Pellicciotti should be cited I think:
Herreid, S. and Pellicciotti, F.: The state of rock debris covering Earth’s glaciers, Nature Geoscience, doi:10.1038/s41561-020-0615-0, 2020.
L48. "compelling" what?
L93. I could count only two questions.
L147 "the sites where we"
L153. delete "a"
Figure 6. Is it wise to have the bare ice point of the same color as the curve fitted to the sub-debris measurements? It confused me.
L354. Remove first occurrence of "rates"
L379. This should be a full sentence.
L381. Reference needed here for Changri Nup. Maybe tell that Changri Nup is small (to re-emphasize the added value of your study of examining a large glacier, the largest debris-cover studied so far I think).
This comparison to published work could be moved to the discussion by the way.
L389. "In Figure 11, we"
Also 8+26 = 34% What process is responsible for the remaining 66%? Authors are loosing their readers here (at least me…)
L392. "26 (20 , 40 )%" Unclear notation. What 20 and 40% correspond to. Need to be explained/defined.
L397. Do authors mean "below" rather than "above"?
L434. Help retaining? Help to retain?
L460. Before application “to” different glaciers
L482. Seems like a repetition of the same statement 2 lines above. Try to be more concise when possible.
L488. Again exact repetition of a statement L484. This lack of concision is a pity, as it makes the readers (reviewer...) nervous.
L501. I must say I am not found of this exercise. I do not feel we learn much from it.
L503. This is as reduction factor of 10 or a multiplicative factor of 0.1
L519. useful sentence???
Conclusion. Again lack of concision. The conclusion should extract the main message and not a list of 12 bullet points… For me the main message is that for the largest debris-covered glaciers studied so far, despite a very high density of ice cliffs compared to others studied glaciers, their contribution to the tongue-wide ablation is moderate. To be a bit provocative, maybe our community should spend more energy estimating spatial pattern of debris thickness than ice cliffs density.
L535. "near the terminus near the margin" strange formulation.
L568. Is not "vital" a bit strong???
Authors should use the same font throughout the text of the supplement, organize the different sections clearly for easier navigation, e.g., increase a bit the line spacing also.
Not providing a line-numbered supplement seriously complicated the life of referee who was almost exhausted when he started to review this part of the article…
Reducing the size of the supplement file (55 Mo) should be possible without loosing readibility.
Fig S3. Dead ice portion. Above or below 5 cm/day? For me dead ice is almost stagnant.
Fig S4 "repeated measurements"
Fig S5. Why not showing directly the difference instead of two set of points?
Fig S6. It is not clear how the others studies were selected. I think it would be very useful to add the data from a previous compilation made by Kraaijenbrink et al. in their Supplementary
Figure S5. Your compilation would gain exhaustivity.
Kraaijenbrink, P. D. A., Bierkens, M. F. P., Lutz, A. F. and Immerzeel, W. W.: Impact of a global temperature rise of 1.5 degrees Celsius on Asia’s glaciers, Nature, 549(7671), 257–260, 2017.
I do not see the point of having some figures repeated both in the main and in the supplement (Fig 16 and 17 at least).
Fig S17-S35. Cannot these sensitivity tests be summarized in one or two paragraphs? Do the authors really need to show all figures?