Dear Authors,

Looking over the reviews and responses of your manuscript, I have only a few minor comments that you should address before publishing your manuscript as an article in Atmospheric Chemistry and Physics. Please see below.

With kindest regards,

Daniel Knopf

Minor comments:
Throughout the manuscript when discussing lambda and omega values the units are missing. You indicate both parameters are in units “K-1”. However, for a reader not familiar with this approach, Eq. (10) does not result in a parameter with this unit, but units of omega appear to be ln(s-1 cm-1)/K. This likely reflects the empirical nature of this approach (maybe an approximation). Lambda is also a proportionality factor and its units are correct. For the purpose discussing these two proportionality factors, I am fine as is in this manuscript, however, you need to elaborate on the units of omega (especially since it is different from Eq. 7 by surface area from Vali 2014), so a reader going through the math understands the approach of this method and how you can compare it to lambda.

Line 28: Typo “coefficient”.

Line 204, after Eq. 15: I believe there is an error in derived nucleation time. Should it be “….1 K min-1, and a typical lambda value of 2 K-1, a total observation time of 30 seconds is obtained.”?

Line 274: Please include newest references on this matter. Please add reference Knopf et al. (2020) to Alpert and Knopf (2016) that provides proof that surface area variance and stochasticity explains NX illite immersion freezing, also topic of this study. The issue of surface variability was also discussed in Barahona (2020) and could be mentioned in separate sentence. Knopf et al. (2020) and Barahona (2020) should be included in conclusions section on page 26.

References
Knopf, D. A., Alpert, P. A., Zipori, A., Reicher, N., Rudich, Y. (2020). Stochastic nucleation processes and substrate abundance explain time-dependent freezing in supercooled droplets. npj Climate and Atmospheric Science, 3, 2, https://doi.org/10.1038/s41612-020-0106-4.

Barahona, D. (2020). Bias-free estimation of ice nucleation efficiencies. Geophysical Research Letters, 47, e2019GL086033. https://doi.org/10.1029/2019GL086033

Dear Authors,

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

With kindest regards,

Daniel Knopf

PS: Minor typo on line 276: "the" instead of "he"