|I have read this manuscript with great interest, along with the review comments and the responses by the authors. However, but I like the approach and consider this as a very valid contribution to understand permafrost distribution in large and more or less inaccessible areas, and actually to check the validity of numerical models. I also admit having a “euro-centric” view on this matter, and I also see the problem of transferring this other areas, however, in my opinion this is justified in this case. I also see that reviewers ask to use models to check the validity of the RG inventory; however, it should be vice versa, as the authors also did in the manuscript. The discussion boils down to some major questions:|
1. Are RG good indicators for PF? I think a large part of the scientific community working with this topic will answer a clear yes.
2. Is a RG inventory something scientific valuable publishable in the Cryosphere? I again think, yes, at least a large and significant work as done here.
3. Does such a RG inventory indicate the quality or validity of modeling approaches? Again, yes. The IPA map is a “manually” drawn map, the map is good at places where there has been good observations, and very limited to useless other places. The scale of which this map was produced makes it more or less useless for mountain areas. So it is no surprise that the RG inventory from this study differ quite a lot from the IPA map boundaries. The PZI is based on a quantitative independent approach, and has of course also its limitations. But future approaches will follow similar lines, including re-analysis data, remote sensing data etc., and these approaches will normally have a better resolution than the IPA map. Here, the result of this study will be a very valuable data set.
4. Is the identification of RG from GoogleEarth reliable? Well, here one can of course have a large discussion. I think the authors give a good description of how they identified the RGs, they made an extensive manual. There are certainly misinterpretations; however, the data set is statistically large enough to justify the observed pattern.
5. Are RG related to permafrost limits? This is now thoroughly discussed in the manuscript. Often, and in steep mountains, they may show lower limits, because RG produce a cool anomaly in relation to the surrounding because of air convection in the course blocky material. But this is of course not the case everywhere, and there may be processes in these central-Asian mountains, which are not known or good investigated, and which may counter-act this assumption.
This in mind, I have some minor comments to the manuscript. I understand the reviewers that the manuscript is partly hard to follow, especially for an audience not familiar with the topic:
• First of all, I think the discussion and conclusions should be separated, it is better to combine results and discussion, and then give clear conclusions in some points. So I would move discussions points from chapter 6 to the results, rename the chapter to “results and discussion” and finally give clear conclusions. Maybe also the “Background” chapter to a large degree could be a discussion. I mean, you give an introduction, which is quite lengthy, then a lengthy background, and then you start methods. This is probably one reason the paper is hard to follow. Consider revising, but maybe it is better this way, so you should check that at least.
• Chapter 7 I would remove out of the main manuscript and include before, after or inside the acknowledgement.
l. 43: Reference there maybe to some general publication, e.g. IPPC or similar
l 57: “e.g.” Bolch, there are several
l. 145: Please give an explanation why RG forms a sort of “thermal anomaly”
l. 186 ff. This could be also moved in to a discussion section
l. 216: Again, a discussion point
In conclusion, the authors for the first time provide an inventory of RG distribution over a vast area in central Asia. RGs are the only visible expression of mountain permafrost, thus this information is very valuable for validating former and future modeling exercises of permafrost in high-mountain areas. With that, this paper should be published, maybe after addressing some of the minor comments.