|This revised paper has taken into account my major comment on the first draft, in that the discussion of transport processes is now more coherent. I have a few minor comments:|
1. In response to my comment about homogeneous and heterogeneous freezing in the original manuscript the authors have added: ‘Homogeneous nucleation is the process in which droplets freeze (and no solid particle phase is involved). In the case of heterogeneous nucleation, a solid particle is needed to initiate the nucleation of an ice crystal, but can take place at much lower ice supersaturation as needed to iniate homogeneous freezing’. But the ice supersaturation is irrelevant to (immersion) freezing – i.e. when a solid particle is inside a liquid droplet the freezing process is simply a function of temperature (and the composition and structure of the nucleus). Later in the paper you do discuss deposition of ice which is indeed sensitive to supersaturation, but that is a different process to that described here. Note the typo too ('iniate').
2. The last paragraph of the introduction seems out of place, and certainly the reference to the long-term record at Garmisch-Partenkirchen is irrelevant to this paper. Reference to the earlier work of Fromm is of course relevant, and I can see you wouldn’t want to just move the text somewhere else, but it doesn’t read well here.
3. P.10 l.19 remove brackets around Mamouri and Ansmann (cite not citep)
4. P.12 l.27 I think you mean ‘from the tropics to the extratropics’
5. P.15. The new paragraph on INC is purely speculative and adds nothing to the paper. It should be removed. There is quite enough speculation in this paper already.