Dear authors. I tend to share the opinion of the initial reviewers that the amount of new information on ozonolysis of alpha-pinene presented in this study is not very high. However, given the that reviewer #1 agreed with the extensive revisions you have done, and requested no changes I am reasonably comfortable with approving this manuscript for publication in ACP.

Figures: Some of the color choices are not optimal in my opinion, such as the pale colors in Figures 3, 4 and 7 (as well as S11). I understand the authors want to keep colors consistent but this comes at the expense of a poor contrast. Likewise, the pale symbols in Figure 6 are very hard to see, another color scheme could improve it. Finally, there is no need for using hatched bars in Fig 8, this color choice is distracting attention from the actual data shown in the figure.

I have minor corrections listed below.
"m/z" is typically italicized, not sure if they do it in ACP
L12: neutral ((NH4)2SO4)/acidic (H2SO4+((NH4)2SO4)) -> neutral (NH4)2SO4) and acidic (H2SO4+((NH4)2SO4))
L19,20: abundance -> peak abundances
L26: complex -> complex set
L68: Pre-existing -> Previous
L113: consider breaking this long paragraph into several shorter ones, it is hard to read
L142: m/zs -> m/z values
L142: sec -> s
L212: hr -> h
:482: be decomposed -> decompose
L574: mz223 and mz279 -> m/z 223 and m/z 279