Dear Amy,

thanks for submitting a revised version of the manuscript and the detailed point-by-point replies to the referee comments. Referee #1 recommends the paper for publication subject to a number of minor revisions, which are listed in the pdf report.

In addition, I have read your replies carefully and ask you for the following final modifications to your manuscript:

- In his first major comment, reviewer #2 has asked for clarifications on the implementation of the prognostic IN tracers. Your explanations in lines 260-264 of the replies are illuminative; please add them also to the paper itself.
- Reviewer #2 also asked for clarifications on the value of 5.8/liter. I think your explanations on this important point should be further expanded. In the manuscript, you have added text from line 806 onwards which reveals that the initial N_IN is a sum over all bins, i.e. it equals N_IN given by eq. (2) evaluated at the temperature the coldest bin (-20.2°C). Please state so explicitly in the text. Also, please add what the temperature range for the IN bins was based on. (See also the related question by reviewer #1). According to Fig. 1, the temperature does not reach down to -20.2°C in the initial profile – does is decrease to this value later in the simulation?
- Check the page numbers for Abdul-Razzak & Ghan in the reference list.
- Reference Cziczo et al: Saatho -> Saathoff

Best regards,
Corinna

Dear Amy,

thanks for the submission of the revised version. I ask you for the following additional changes in the description of the technical implementation of the IN scheme, because this is crucial to make your results reproducible.

All line number refer to the track-changed document.
- line 311: “above” should be “below”
- line 314: “(by multiplying the activation tendency in equation (1) by 0.5)” as well as the justification of this ad-hoc assumption has been deleted, but I think this detail is important and should be kept in the manuscript.
- line 337: insert “of” before “the coldest bin”
- Also at line 337, you should give here the information provided in the replies, namely that -20.2°C is the coldest temperature reached in the reference run.
- I actually suggest to add “at -20.2°C” after “5.8 L-1” in line 334, because IN concentrations should always be given together with the conditions which they refer to. (If you had chosen to extend the temperature bins down to e.g. -22°C, this value would have been different.)

Best regards,
Corinna