Dear Andreas Alexander and co-authors,
Your manuscript received two detailed and critical reviews that both the novelty of the data and the relevance for subglacial process research on cold based glaciers (so permafrost and glacier research) and confirm that the manuscripts seems to be well within the scope of TC. Both reviews were in general positive but also indicated a few aspects that should be improved which in brief encompass a better placing into existing literature, better explaining of the sensor measurements and improving the discussion.

The raised points seem according to the author response well addressable and if revised the paper has a good chance to be accepted. I therefore ask the authors to undertake the planned revisions and submit the revised document.
Please address all the raised points by the referees and provide a point by point response and explain how you addressed these points (potentially a track change version may be helpful).

Andreas Vieli, editor
19 Aug 2020

Dear Andreas Alexander and co-authors,
Your manuscript received 2 detailed largely positive reviews that highlighted the novelty of the data from subglacial conduits in a polythermal/cold based/permafrost regime and the discussed implications on erosion of subglacial channels. The referees also indicated that the data and findings of this manuscript would be of interest to a broad community of glacier and permafrost researchers.
Besides some rather minor editing corrections the referees also raised some more substantial points which in brief mainly concerned:
- the research in the manuscript should be better placed in to the context of the literature
- the instrument setup should in places be clarified
- the discussion of the results should be better linked to the collected evidence, and

These points and some additional comments by the editor (from the access review response) have in the revised manuscript been addressed satisfactorily or justified. Thus this manuscript is very close to be accepted for publication. There are just a few minor points from the editor's side which are listed below and should be addressed by the authors before publication.
I congratulate the authors for their very interesting contribution and for their cooperation in the review and revision process.

Andreas Vieli, editor
11 Oct 2020

Minor corrections/editing issues
(lines refer to revised manuscript)

Fig. 5: '…the sediment temperature SENSOR was buried…' (the 'sensor' was missing).
Fig. 6-9: I would find it useful to add a zero degree horizontal orange line, for the right orange scale. I accept that the authors do not want to use just one temp. scales, but a zero line would help as a reference.

Fig. 11: I struggle a bit with this conceptual figure: i) why is there no mouling chabnnel in. the top left summer figure? Is this to illustrate the case of no subglacial waterflow? But why should this be, I assume it needs water to have a channel there ii) related, is a subglacial channel without water flowing realistic in summer (see comment referee 2), iii) it would be quite useful to see what temperature regime there is (where is it cold/warm…) and potentially in which direction the air is expected to flow (see also comments by referee 2).
Anyway, this figure should be clarified a bit, perhaps just describe the 4 situation (and differences) clearly in the caption.

Dear Andreas Alexander and co-authors,
The revisions of your revised manuscript addressed all the rather minor issues listed by the editor and in particular the schematic figure 11 is now much easier to follow.
Thus, I am happy to announce that this revised manuscript can now be accepted and I congratulate the authors for this interesting contribution to TC and thank for their cooperation during the reviewing process.
Best regards
Andreas Vieli, the editor