Dear Ilaria Tabone and co-authors,
This manuscript received three critical but in general supportive and positive reviews on the initial version of the manuscript that highlighted the novelty and relevance of the modelling investigation on paleo ice sheet dynamics and related controls for the NEGIS area., The issues/weaknesses identified by the first round of reviews mainly concerned: (i) a more rigorous discussion/comparison with geologic evidence, (ii) lack in detail of model description/assumptions and forcing experiments and (iii) the performance/validity of the model (for example to reproduce present ice stream dynamics).
The authors addressed these major and all minor editing issues very effectively and satisfactorily within their and this manuscript, which has also been confirmed by the re-review below. Thus the revised manuscript is now very close to be accepted and soon ready for publication. There are still a couple of minor editing/language issues I spotted (in line with the comment of the re-review below on English language and editing issues) and that need addressing before final publication (see list below).
Please also acknowledge the referees (2 anonymous and referee Kerim Nisancioglou) in the acknowledgments.
I congratulate the authors for their very interesting paper and also would like to thank them for their thorough revisions and excellent handling of the revision process and thorough .

Best regards
The editor, Andreas Vieli, 20 June 2019

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Re-review comment
The authors have done a very good job in replying to the reviewers comments, in particular by adding more details on the model including spin-up and comparison to previous published work. Nearly all reviews comments have been taken into account.

The discussion is also much improved. The English could be improved, in particular in the new edited text, but overall the quality of the article is very good with enhanced insight into the model work behind the main conclusions. I have no further comments and recommend the article is accepted for publication.



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Minor language/editing/technical issues (by editor)
(page numbers and line numbers refer to newest revised document)

- Please carefully proofread the final manuscript again and check for English language (it should be the authors duty to do this!).
- I suggest to use the units for temperature (air) more consistently, currently it is rather mixed between Kelvin ([K] as in methods on p. 5-7 and on p.9 line 20/21) and Celsius ([C] as on p. 9 line 9, 32 ).

p. 2 line 1: 'A LARGER stability…' 'larger sounds awkward maybe change to 'Enhanced stability of …'
p. 2 line 8: rephrase to '…has been suggested to be more resistant to increasing …'
p. 3 line 14: the symbol 'H' should be italics.
p. 5 line 18: adjust formulation: '…lack of data for basal melt…this assumption is considered as the most reasonable approach.
p. 5 line 32: delete 'far': '…at a mean distance of 40km from the shelf break.'
p. 6 line 12: verb in plural: 'rates …not only HELP… but subsequently TRIGGER a slight INLAND grounding line retreat.'
p. 6 line 22:formulation: '…to the inland shows a bedrock depth of 100-200m' or '…to the inland shows a 100-200m bedrock depth '
p. 6 line 27: formulation: 'The effect of submarine melt applied to…' or 'The effect of variable submarine melt rates applied to…'
p. 7 line 6: awkward sentence, please rephrase, ???' ….simulates … as well demonstrates that….'???
p. 7 line 6: awkward formulation: '…as a further retreat inland…', maybe rephrase to '…as further inland retreat …'
p. 7 line 14: 'glacier' should be singular as 'fronts' is already in plural: '…outlet GLACIER fronts
p. 7 line 19: '…was as FAR inland as…'
p. 7 line 32: '…of northeast Greenland…' or '…of the NEGIS…'
p. 9 line 2: 'could cause FURTHER INLAND retreat'.
p. 9 line 9 and line 32: why here suddenly 'Celsius' units are used (before always Kelvin)
p. 9 line 12-13: awkward formulation: do you really mean 'durable'? or rather: '…that such continuously high … is unrealistic/exaggerated'.
p. 10 line 1: do you really mean 'fairly' (in the sense of treated fairly?) or rather 'fairly well'?
p. 10 line 2: '…oceanic conditions OVER long timescales.'
p. 10 line 8: again 'fairly' seems not appropriate here, '…our simulations represent the present state of the GIS reasonably well'.
p. 10 line 10: '…which are not ADEQATELY represented…'
p. 10 line 11: delete the 'as': '….located farther inland than observed.'
p. 10 line 15: awkward wording: '…is not ADEQUATELY RESOLVED,…'
p. 10 line 17: awkward wording: do you mean: '…the fast flow features of the tributary that … '
p. 10 line 19: awkward wording: 'catching'??? maybe replace by 'draining/covering'
p. 10 line 26: delete stream, is already within NEGIS : '….of the NEGIS is probably…'
p. 10 line 26: : delete 'still': '…to low spatial …' (or '…insufficiently low'…
p. 10 line 33: 'THE model behaves REASONADBLY WELL in simulating…' or 'THE model behaves satisfactory in simulating…'
p. 11 line 5: wrongly cited:' Alvarez-Solas et al. (2019)….'
p. 11 line 21: awkward wording: '…CONSTRAIN the effect of the atmosphere in this ??phenomenon??...'. is phenomenon the right word here? Maybe just delet 'in this phenomenon'

Fig. 2: some scale (spatial distance) would be useful in this figure
Fig. 3 caption:
p. 20 Line 1: 'SIMULATED evolution of the NEGIS grounding lines (COLOURED LINES)….'
p. 20 line 3: 'THE dashed black line

Fig. 4: again some spatial scale would be useful in the figure (or some description in the caption e.g.: '…the shown sector spans an area of ???km by ???km…'
p. 21 line 3, In caption: 'THE grey thin….'

Fig. 5 caption: 'SIMULATED ice flux …'

Fig. 6 caption, p. 23 line 4: 'The black LINE on the side map….' (it is a line not a contour).