Dear Dr. Ehn and Co-workers,

thank you for submitting your responses. Both reviewers strongly support your study but raised some issues regarding the manuscript organization and data interpretation.

I recognized that you chose not to follow Review #1's advice to apply a statistical analyses, because of the limitation of available data. You also chose not to follow Reviewer #2's advice to concentrate on one physical process related to suspended particles, because you believe the relationships are too complex. I believe this is justifiable, but I wonder if interpretations will consequently remain difficult. We will see. Your approach to associate particle characterization with freshwater inputs via oxygen isotopes sounds promising and could help.

Overall I recognized that you offer a thorough revision of the manuscript. I am confident this should take care of most if not all of the raised issues.

Please be invited to upload your revised manuscript. It will be send back to 1-2 reviewers for a second round of review.

With kind regards
Tina Treude

Dear Dr. Ehn and Co-workers,

the referees had a close look at your revision and both agree that the manuscript has significantly improved. However, both still suggest some minor adaptations, which I believe you should be able to implement. Referee #1 advises to remove any interpretations that should only be made after applying a multivariance analysis. Referee #2 has mainly technical comments.

Please provide a detailed point-by-point response to the reviewers and how you implemented their comments. Please submit your revised manuscript with all new edits highlighted.

Let me know if you have any questions
With kind regards
Tina Treude

Dear Dr. Ehn and Co-Authors,

thank you for the submission of the revised manuscript. I am satisfied by your responses to the referees and your revision improved the clarity of the manuscript. I consider it acceptable subject to one technical correction:

Please remove the weblink in the Figure 9 caption (and any other weblink should I have missed it). Weblinks are not permanent and subject to change, while your publication will last much longer. Hence, a weblink could become invalid in the future. Please replace the weblink with a permanent citation.

With kind regards
Tina Treude