Dear Authors,

thank you for your thorough revision of your manuscript. I will not send the manuscript back to referees but rather ask you to only correct the minor/technical issues listed below.
After they are properly addressed, I will be happy to accept the manuscript for publication in ACP.

Best regards
Barbara Ervens

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l. 99: Also figures in the supplement should be referred to in order. Thus, Figure S8 should not be cited right after Figure S2. Please renumber the figures accordingly or change when they are referred to in the text.

l. 121: (0 h days) - Is this a typo or is there anything missing? Please clarify.

l. 186: Specify ‘small enough’ (for what or for which assumptions?)

l. 197 – 198: ‘Increasing pH and ε(NO3−) and decreasing ε(NH4+) by the increase in fixed NH3 level become flatten over the 5 ppb of NH3 (Figs. 5b, d, and f), …’
This sentence does not read well and thus the meaning is not clear. Clarify and reword.

l. 302: SOR only refers to the sulfur oxidation ratio. Is this meant here or do refer by ‘higher oxidation ratio’ also to the higher fraction of nitrate that is formed from precursors NOx? I suggest either simply adding ‘sulfur’ to ‘ratios of sulfur oxidation’ or clarifying that NOx//nitrate is included, respectively.

l. 326: replace ‘particle’ by ‘particles’

l. 331: replace ‘colder temperature’ by ‘lower temperature’

l. 332: replace ‘help’ by ‘lead to’ or ‘cause’

l. 343: Usually the units of the effective Henry’s law constant H* are the same as for the physical Henry’s law constant (e.g. M/atm or mol/kg/atm) as
H* = H (1+ Ka/[H+]) whereas Ka is the acid dissociation constant
Thus, the units are not clear unless you define Ks differently. Maybe all what is needed is to add correct units to Ka (or to H*, respectively).

l. 392: the increase from 3 to 22 microg/m3 is closer to 7 times than 8 times. Please replace ‘8’ by ‘7’ accordingly.

Fig. S5: What are the blue and red frames?

Dear Authors,

many thanks for your careful revisions. I am happy to accept your paper for publication in ACP.

Sincerely
Barbara Ervens