Dear Authors

Thanks you for your revised version of manuscript tc 2015-196. Your new version is significantly improved. However, I contacted the referees with specific questions and they indicated that several of your changes did not quite respond to their objections.

In general, I do find your paper of high scientific quality, of great originality, and I will be happy to accept it for publication in The Cryosphere. However, it is probably in your interest, in the interest of the journal and in the interest of our wide readership that some aspects be clearer or explained with a bit more detail and with more rigor. I will just focus here on the point that caused significant dissatisfaction with the reviewer.

Your treatment of uncertainties appears unsatisfactory and your response to point 2 by Dr. Dumont does not really address the elements she raised. Your response is essentially “We believe…”, and I get the feeling that the main effect of your changes is to sweep the difficulty under the rug rather than actually try to improve your text. I very strongly recommend that you address the uncertainty issue in this paper, even though subsequent papers may also add further detail. Furthermore, the observed decrease in grain size is not really addressed, while the growth of sublimation crystals may be a possible interesting hypothesis. Their formation may be favored by the accumulation of impurities near the surface which will modify the profile of energy absorption and of temperature. While I understand that you may not want to significantly expand your paper on that subject, throwing in a few interesting ideas or suggestions, possibly developed in subsequent papers, would be in order.

Regarding a simple request by referee 1, it would probably be still useful to mention clearly in the introduction that the radiative forcing referred to is always by LAISI. Sometimes you mention “radiative forcing by LAISI” and sometimes just “radiative forcing”, but you never explicitly equate both terms. This may be ambiguous to non-specialists and I therefore recommend that you state clearly that when you mention radiative forcing, it is by LAISI.
Addressing these issues should not take too much time. I will be happy to accept your paper once you have addressed appropriately these simple requests.

Best regards,

Florent Domine

Dear Authors,

Thank you for your corrections. I am now pleased to accept your paper for publication in The Cryosphere. Your paper will be an excellent contribution to our journal and I thank you for submitting your work to The Cryosphere.

There is just one very minor presentation detail that you may want to correct in proof. On p. 12, line 10 you mention a hypothesis by “co-author Painter”. Please either add a reference or mention (unpublished results) or something similar at that spot.

Best regards

Florent Domine