Dear Jesper Sjolte and co-authors,

Thank you for submitting your manuscript (CP-2019-136) to Climate of the Past. Your paper has been reviewed by two reviewers who both see merit in the new methodological approaches developed in this paper. Both also make helpful suggestions for improvements, and your author comments have provided some details on the revisions you plan to make based on these reviewer comments.

I would like to invite you to submit a revised manuscript that addresses the reviewer comments. In particular, please ensure that the manuscript is framed as being a methodological paper rather than an examination of a new set of reconstructions (including revising the title and abstract, as well as the main text). I also share the reviewers concerns that uncertainties are not fully described in the text and figures, and I encourage the authors to consider this more fully (and more fully than so far indicated in the author response letters). While I agree that a detailed comparison with other reconstructions and climatic interpretations of the new reconstructions are beyond the scope of this study, I do think that in establishing and testing the new approach it is critical to compare your new reconstructions to some of the existing Arctic/NH reconstructions in order to help establish your methodological approaches and the similar/different results they display.

I hope that this guidance is helpful and look forward to receiving a revised manuscript. Please include with this revised submission a response to reviewers document that details the revisions made based on each of the review comments.

Sincerely,
Nerilie Abram

Dear Jesper Sjolte and co-authors,

Thank you for responding to the reviewer comments and submitting a revised version of your manuscript to Climate of the Past. I am satisfied that the reviewer comments have been addressed well and I am pleased to accept your manuscript for publication with minor revisions. Please address the following editor comments in preparing a revised manuscript:

*Please carry out a thorough proof reading of the article to fix typographical errors in the text

*Figure 14: I’m not convinced that the pre-1500 comparison is reliable. The scaling of this lower resolution data does not appear to be appropriate and so it would seem better to only compare the reconstructions from 1500 onwards.

*Figure 14 and 15: It would be helpful to have a consistent approach to the moving correlations. e.g. in figure 14 all of the moving correlations are shown but there is no indication of significance. In figure 15 the moving correlations are only shown where they are significant.

*Figure 3, Figure 4 and Table 3: I don’t think that it is appropriate to give mean correlations only for significant correlations. This doesn’t give an accurate reflection of the skill of the reconstructions, and will also be affected by the relative size of regions of positive and negative correlations. Suggest restricting this only to reporting the number of grid cells with significant correlations. Alternately, reporting the maximum correlation values would be more informative.

*Table 3: The arrangement of Table 3 is difficult to follow. Please group summer/JJA and winter/DJF categories near to each other. I’ve already suggested not reporting the mean of significant correlations, but if these are kept or swapped for reporting maximum correlations please also group the correlations and # grid cell information for each parameter together.

*Please consider archiving the code associated with this paper to aid with promoting FAIR data practices. For example, as this paper is about a reconstruction method it would be helpful for the community for the code associated with the method to be archived and made accessible on a platform like github.

Please let me know if any of this isn’t clear. I look forward to receiving your revised manuscript.

Sincerely,
Nerilie