Authors,

Thank you for your revised manuscript and detailed responses to the reviewer questions. Most of the comments have been sufficiently dealt with, however, I have a few additional requests that I would like to see you process before the manuscript is accepted. See below for these minor points.

Regards,

Alex Huffman

- Add a sentence summarizing your response to Response #1 from Reviewer #1, e.g. stating that the 97% threshold was operational in nature and that your usage of this value is already more conservative than what Cornman et al. suggests may be required.

- Related to Comment #2 from Reviewer #2: The way I read this question, the reviewer is not asking so much about the sampler height in relation to the mountain, but also in relation to the height of the trees as well. Also, I clicked on the link that you included in the response document, and now I can easily see that the measurement site was in what I would consider to be at least semi-urban in nature. I think describing it only as “a mountainous, forested area of Seoul” does not immediately describe what must surely be heavy influence from the populated areas. Please add some more explanation here, i.e. that the site has influence from airflow from the large populated area/city as well as influence from the non-populated and forested regions in the mountains area within the metropolitan area. Is there also a citation that you can add that discusses characterization of the site and aerosol types that can be sampled there? The reviewer suggested making a simple schematic diagram of the relative topography of the sampling site in order to show the height of the trees and buildings related to where the sampler was placed. Given the complexity of the types of land cover types in the immediate area, it could indeed be useful to the reader. If you decide to make the additional figure, you can place in the supplement and only refer to it briefly.

- I specifically asked Reviewer #2 about her/his opinions of the updates to the manuscript. S/he responded with a further comment on Response #6:
The dimensional analysis made by the author is correct, however the reviewer still finds a discrepacy when considering units rather than dimensions.
The authors, in fact, specify that Vd (the units of which are not stated in the paragraph, but it is expressed in cm s-1 in paragraph 3.3) is a ratio between a flux in (CN cm-2 month-1, page 5 line 22) and a concentration (in CN m-3, page 5 line 23).
By substituting these units in eq. 1 we will have that:
cm s-1 = (CN cm-2 month-1) * (m3 CN-1)
the reviewer fails to understand how it is possible to obtain a Vd in cm s-1 on the left side when the units for time on the right side are in months and the length units are mismatched in the two terms on the right side (cm vs. m). While the reviewers agree that both s and months are dimensionally consistent (as being both times, T) and cm and m are consistent by being both lengths (L), they’re far from the same! So either a scaling has been applied to both fluxes (in order to convert them from CN cm-2 month-1 to CN cm-2 s-1) and concentrations (in order to convert them to CN m-3 to CN cm-3), either Vd cannot be expressed in terms of cm s-1. If these scalings have been applied, then please explicitate that, otherwise please correct the magnitudes of terms in order for them to be in consistent units and not only in consistent dimensions.