Monitoring Changes to Arctic Vegetation and Glaciers at Ny-Ålesund, Svalbard, Based on Time Series Remote Sensing
Round 1
Reviewer 1 Report
The authors responded to all of my revisions in an excellent manner. i recommend the publication of the work
Author Response
Thanks to reviewer for the valuable work to our research paper. Thank you again.
Reviewer 2 Report
Thank you for taking my initial comments into consideration. This version of the manuscript is significantly improved. In particular, the methods are much more clearly explained, and I have a much better sense for how the study was conducted overall. I have a few minor comments which I think should be considered before publication. I have indicated the line numbers according to the revised manuscript below.
Overall, the manuscript is too long (22 figures is really excessive for this journal, in my opinion). There are too many diversions, which distract from what I think could be an important and interesting message: vegetation and glacier changes, and their potential linkages.
L75: The study uses six Landsat images, so you should just say that instead of referring to them as phases (which is vague and potentially misleading).
L125: what exactly is the nominal resolution of Gaofen-2 images?
L152: Is "correction error" the RMSE? If so, please specify that.
L154-L157: Could you provide a bit more detail on the UAV platform and flight characteristics? This would be very helpful for others interesting in UAV remote sensing in Arctic regions. What type of UAV platform (drone) was used? What was the time of flight? Was a ground station used for georeferencing? What type?
L198-199: If these are indeed the values that were used for the remainder of the study, you should remove "For example" in this sentence.
L203-204: Redundant - you've already described the data used in this study. Perhaps you could specify whether you used Landsat, Gaofen-2, or both, however.
L252-253: What value of k did you eventually use in this study? Did you obtain a global estimate for k, or was this done on an image-by-image basis?
L336-339 and Figure 10 - Interesting observations. I wonder if you could (briefly) mention this in the abstract as one of the potential drivers of vegetation change. Currently, the abstract mainly attributes change to urban expansion, while it may be interesting to point out some of these more subtle implications of climate change and vegetation dynamics.
Figure 11: What are the units used in this map? ∆NDVI over the entire study period?
Figure 12: I think there are too many figures in this paper. Consider reducing the number of figures, and I suggest that this one could be the first to go. I don't think a box plot is a great way to analyze changes over your study area, as it may mask actual, important changes at local scales.
Figure 14: I cannot interpret this figure. It would be better as a 6-panel figure with a scatterplot for each year.
FIgure 22: I don't think this figure is necessary. In fact, along with the paragraph preceding it, it is distracting me from the overall message of the paper. I suggest removing this figure and the entire discussion on spatial resolution before it, and dedicating the discussion section to the significance of your results. In particular, I'm missing a discussion on the significance of vegetation change in your study area, and how (or if) it is actually linked with glacier change. You alluded to that in your results (talking about bryophytes), but never really followed up on that point.
Author Response
Please see the attachment for the response to the valuable comments of the reviewer.
Author Response File: 
Author Response.pdf
Reviewer 3 Report
See comments on attached comments and submission pdf; some grammatical edits and removed sentences. The figures are good, but many need minor edits such as improving legibility by making labels larger. The most major suggested edits include moving some sentences from discussion to introduction and including reference to the (Norwegian) Svalbard glacier inventories.
Comments for author File: Comments.zip
Author Response
Response to comments: Thank the reviewer for the modification on the grammar and some wrong/misleading sentences. The authors totally followed the comments of grammatical edits and the sentences removements in the pdf attachment file. And some Figures were improved by making the labels larger, such as Figure 15 and Figure 20. In figure 15 (the new version) the north arrow and the scale bar were enlarged, and the longitude and latitude coordinates were removed because they are too crowding and not necessary. In figure 20 (the new version) the terrain of 5 selected glaciers at the bottom of the figure was removed because they are not helpful to this paper.
