Please consider the following changes prior to publication.

Lines 190-193: “the GC system was not set up to quantify species with known large biomass burning emission ratios (e.g. hydrogen cyanide, acetonitrile, most oxygenated organic species (Akagi et al., 2011). The chromatograms were checked for HCN and acetonitrile peaks after the campaign but those peaks were not able to be identified.” For these reasons, the description of the GC system on lines 105-111 is still inadequate. A few extra sentences in the experimental section to briefly describe the 4-channels of the GC would be helpful. At a minimum, the detectors used should be listed, particularly because the two references given (Sive, 2005 and Abeleira, 2017) disagree on whether a mass spectrometer was included on one channel or not. If no mass spectra were available (per Abeleira, 2017), what approach was used to “check” the chromatograms for HCN and acetonitrile? Did the authors rely on retention indices? Were HCN and acetonitrile standards analyzed following the study? Were they unresolved under the GC conditions used? These details would be important to note and could be stated very briefly.

Line 213: Delete ‘a’ before ‘both’.

Line 245-246: “Given the short lifetimes of these species, this indicates that the presence of the smoke either local anthropogenic or biogenic emissions of these species, or their respective rates of oxidation by OH or O3. ” There is a verb missing here.

Line 264: Change ‘ethane’ to ‘ethene’.

Line 269: Future tense (“we will”) is a little strange here. Consider changing to “we consider the remaining hypotheses below”.

Line 266: PMF has not been defined or explained. Perhaps ‘temporal trends’ or ‘time series analysis’ would be more appropriate here.

Line 383: Delete one ‘in’.

Lines 421-424: “Most hours during the 
August smoke-impacted period were associated with northwesterly flow and we found the same enhancement in O3 for a given temperature when comparing smoke-impacted observations to smoke-free observations assigned to this cluster as we found for the complete dataset (Figures S3 and 6).” The trends may be similar in Figure S3a and Figure 6, but it is still not obvious that they display the “same enhancement in O3” (10 ppbv) just by comparing box plots. 

Can you state the mean difference across the temperature bins (as described starting on line 393) for the northwesterly flow cluster to better illustrate your point? Or change ‘same’ to ‘similar’ in the quoted sentence.

Line 438: Change ‘maxima’ to ‘maximum’.

Line 473: Change ‘possibly’ to ‘possible’.

Line 477: This paragraph would fit better earlier in the section, perhaps around line 426 where the potential causes for high ozone are still being discussed.

Line 485: Change to ‘may have added’.

Line 818: Also orange and red shading indicate standard deviations.


It is recommended that the authors add the plot of the PM from the multiple ground sites that they included in their response to referee #1 as a figure in the SI.