Dear Authors,

I am happy to accept your manuscript for publication after you have addressed the few minor revisions given below.

With best regards,

Daniel Knopf

Minor revisions:

Page 2, line 6: If you cite Zobrist et al., 2007, wouldn’t it be fair to also cite these studies on this topic: Cantrell, W.; Robinson, C. Geophys. Res. Lett. 2006, 33, L07802, Knopf and Forrester, J. Phys. Chem. A 2011, 115, 5579–5591 ?

Page 3, line 24 following: “Therefore,…”. When reading the text, I had the impression you talk about immersion freezing (IMCA/ZINC) but then you argue with contact ice nucleation for particles < 40 nm. Maybe I am just missing something. The section title mentions IMCA/ZINC which are the immersion freezing experiments and Figure 1 is discussed.

Page 4, line 27 & Page 9, section 4: Figure 2: The median freezing temperatures are given. I believe it would be very beneficial to also plot the uncertainties such as 10 and 90 percentiles (or 25, 75, or 20, 80 percentiles). I would not be surprised that for some data sets, the trend is within the scatter/uncertainty of the freezing data. I am aware, that it may be difficult to derive for all data the percentiles (and this depends on the number of data points as well). In this case, maybe use experimental uncertainty (temperature error, etc.).

Page 9, line 16: I assume you meant Fig. 2?

Page 20, B3: I believe Appendix B3 is not referred to in the main text.

Technical correction:
Page 4, line 6: “…supercooled liquid particle…”

Dear Authors,

I am happy to accept your manuscript as an article in Atmospheric Chemistry and Physics.

With kindest regards,

Daniel Knopf