The new manuscript has significantly improved.
However, one important issue remains: the DC is closely associated with sources (this is the argument you use in the introduction) and an apportionment needs to be shown and compared to. The argument that you use while claiming that the Sandradewi et al (2008) source apportionment cannot be used (that AAE_wood burning too variable) is weak. The method clearly depends on the assumed (!) AAE_wb and AAE_ff values and a sensitivity analysis need to be performed. Zotter et al. (2017) have shown both the influence of the choice of AAE and the sensitivities and have validated the values using C14. Please add the Sandradewi et al. source apportionment for comparison and perform a sensitivity analysis.

Please take the comments of reviewer 1 into account in the updated manuscript. You find them attached below.
Best regards, Ernest Weingartner

Requested revisions from Reviewer 1:

The Authors have addressed the review comments appropriately. The statement on SOA production in winter not being relevant might need toning down, as there are night-time mechanisms for SOA production involving nitrogen chemistry that are effective in SOA production.

One issue remains: the DC is closely associated with sources, as mentioned in the article. Source apportionment should be performed and compared to, for reference.

The Sandradewi et al (2008) method clearly depends on the assumed (!) Angstrom exponent values for "wood burning" and "fossil fuel": AAE_wb and AAE_ff, and a sensitivity analysis needs to be performed. Zotter et al. (2017) have shown both the influence of the choice of AAE and the sensitivity to this choice and have validated the AAE values using C14. The Authors should add the Sandradewi et al. source apportionment for comparison and perform a (quick) sensitivity analysis.

the introduction needs to be adapted, especially the sentence:
...
Given the uncertainties associated with values of Alpha for woodsmoke for our
study, we did not perform the source apportionment analysis similar to that presented by (Sandradewi et al., 2008a).
...

References

Sandradewi, J., Prevot, A. S. H., Szidat, S., Perron, N., Alfarra, M. R., Lanz, V. A., Weingartner, E., and Baltensperger, U.: Using aerosol light absorption measurements for the quantitative determination of wood burning and traffic emission contributions to particulate matter, Environ. Sci. Technol., 42, 3316–3323, doi:10.1021/es702253m, 2008.

Zotter, P., Herich, H., Gysel, M., El-Haddad, I., Zhang, Y., Močnik, G., Hüglin, C., Baltensperger, U., Szidat, S., and Prévôt, A. S. H.: Evaluation of the absorption Ångström exponents for traffic and wood burning in the Aethalometer-based source apportionment using radiocarbon measurements of ambient aerosol, Atmos. Chem. Phys., 17, 4229-4249, https://doi.org/10.5194/acp-17-4229-2017, 2017.