Editor decision and comments

Both reviewers highlighted the novelty, quality and wider importance of this paper and thus had on the scientific quality no major issues to report. However, they both noted that the paper has a lot of very technical sections which diverted the general reader from easily getting the main messages of the paper which addresses the future evolution/change of the WAIS and is of general importance and relevant not just for marine ice sheet modellers. Thus the reviewers suggested a major restructuring of the text with moving some of the technical parts to an appendix and further to improve the readability of some of the figures.
The authors have addressed these main points by the reviewers (restructuring, figures) satisfactorily and only very minor mostly technical corrections remain (see list below). The paper is now much more accessible for a wider audience although still on the long side and in parts challenging to non-specialists. The main messages (WAIS response in future), however, come through well while the approach is still explained in detail and the science done very carefully.
Thus, the publication can be accepted for publication after addressing the few minor technical/editing issues identified by the editor and listed below:

General
In the whole paper and already in the abstract (p. 2, line 7, 8, 11,…; where it first appears), the term ‘ice shelf melting’, or ‘melt rates’ is used without ever really stating that this is ice melt with/by the ocean (oceanic melt) and at the underside of the ice shelf. For experts this is certainly clear but for a more general audience this could well be confused with melt at the surface (atmospheric). The ‘oceanic’ origin of melting should be made clear within the abstract and conclusions, and explained/defined what is meant in the main text by ‘melt rates’ , (oceanic melt) somewhere at the beginning.

p 5, line 6/7 (eqn. 2): why is here ‘Ms’ used for accumulation amd ‘Mb’ for oceanic melt and later it is ‘a’ and ‘M’ respectively (p. 8, line 25 and thereafter). Make consistent.

p 8, line 24: add a space between ‘ho(x,y)’ and ‘as’.

p 9, line 1: I would rather say ‘ALBMAP is with 5km at a lower resolution…’

p. 9 line 23: ‘region of 100 m/a thickening …’. I assume this thickening is when the model is run forward, and not an observed feature. Should be made clear that when running model forward, initially there is this thickening.

p. 9 line 26: I would add ‘fields’ : ‘…to the observed velocity fields.’

p. 9 line 29: Refer to Appendix B1 at the end of this sentence)

p. 9 line 32: I do not get this phrase: ‘…Mo is somewhat INVOLVED,…???

p. 11 line 14: do you mean ‘time’-constant accumulation? Clarify.

p. 14 line 28: ‘Thwaites CAN contribute…’, I would make clearer here that ‘the modelling estimates that …’.

P 17 line 21: awkward formulation: ‘…more than twice as great WHEN THAT retreat…’, do mean ‘…as when that retreat…’

Section 3.1 (p. 14-16) and fig. 5 and 6 : in this results section in the text refers to the different experiments with the unique 4-letter names for example H/A/O/F but in the figure 5 and 6 they are labelled by the climate/ocean models so it is hard for the reader to link the text to the specific lines on the figure (without consulting tab. 1 again and again). Either change the labels in the figures or add in the text or in the caption of fig 5 and 6 what they are (see caption fig. 7; in the other sense).

p. 19 line 14: I think ‘thinning’ by s sea-level seems not a correct formulation , maybe better would be ‘…thin by an equivalent in sea-level rise of…’ or ‘…lose mass between…’.

p. 19 line 20: ‘retreat GROW’ seems awkward , maybe better would be ‘…rates of retreat increase/accelerate…’?

p. 20 line 17: I think this should be ‘Ross Ice Shelf’ and not ‘Filchner-Ronne Ice Shelf’???


Table 1 caption: maybe say ‘OCEANIC melt rate’.

Figure 5 and 6: the legend uses different names for the experiments than in text (e.g. H/A/O/F), should be adjusted or added in caption so reader can link lines in figure better with text. See comment above.

Supplementary material:
I think supplem. fig. fig9_large.pdf can be deleted seems to be doubling up fig fig7_large.pdf ????

In animations, at times some ‘islands’ of ice shelves remain, is this just an artefact visualization or of the ‘calving-scheme’ (or perhaps rather the absence of a proper calving scheme and just using a thickness threshold?



Editor, Andreas Vieli, 12th July 2015

i thank the authors for fully addressing the minor (editorial) points i had, and i can therefore accept the paper as it is for a TC.
Andreas Vieli