#1: The authors claim that they are the first to investigate the spatial distributions of the SOA phase state over China by a regional CTM. But what about the model being applied to other parts of the world and has the authors looked into those applications and how does it differs from application of the regional CTM in those areas as compared to China?

#2: I don't know if I am missing something, but I could not find Fig. S1, S2, S3, S4, S5, S6, S7 and Table S1, S2 which are referred to throughout the manuscript.

#3: In general the figures are mostly contour plots of different parameters. A more analytical presentation of the results from the model is missing in the current form of the manuscript. The authors may try to add some statistical figures or tables in order to analyze the outcomes from the model.

#4: The conclusion section seems to be lengthy. May be the authors can think about making a separate discussions section and the conclusion section.

Specific Comment:

#5: Page 3 Line 63: What is "semi-sold"?

#6: Page 3 Line 76: Reference missing year "Maclean et al.".

#7: Page 4 Line 107:  What is the "outer domain" considered here?

#8: Page 4 lIne 115: "39 nm to 10 μm". it would be nice to use any one of units, either nm or μm.

#9: Page 9 Line 271 and Line 274: What does the author mean here by "Our previous global simulations"? Please provide proper reference.

#10: Page 10 Line 295: "(see the Method)". What "method" is referred to here?

#11: Page 10 Line 297: "The highest value is ~10–5 cm2 s–1 occurring in liquid SOA particles in the southern Tibetan Plateau (Fig. 6a).". Why is the highest value being observed at the southern Tibetan Plateau? Can the authors provide a probable reasoning for this observation?

#12: Figure 2: Figure 2g is a bit difficult to read. May be the authors can try having a different color scales for SOAX, SOA1, SOA2, SOA3 and SOA4.

#13: Figure 3: The vertical profiles of mixing timescales for organic molecules within 200 nm SOA particles at IAP site as

shown in Figure 3b seems to be more sensitive to altitude than the SOA viscosity whichis shown in Figure 3a. Can the authors provide a reasoning for this behaviour?

#14: The colorbar used in figure 8a from -45 to 45 K. But in the contour plot I can only see the values above 0 or -5. Is it possible to make these colorbar a bit more according to the range of values so as to see the variation more clearly? Same for Figure  8b and Figure 9.