Dear authors,

I have received a review of the revised version of your manuscript by Reviewer #2. This reviewer is not fully satisfied with your revision and asks for more clarification, see below.
Please address the comments and submit a newly revised manuscript.
Best regards,
Barbara

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Reviewer #2:
The authors have significantly improved the manuscript. Their responses to the reviewers are not fully satisfactory, since they replied with “Thanks for your suggestion. We revised the manuscript accordingly” to all points raised by reviewers but did not state the lines nor the paragraph they have modified and how they changed it, which is quite frustrating when reviewing the manuscript for the second time.

In my previous review, I suggested the authors to improve the English grammar and the organization of the manuscript (especially the description of the methods). They have worked on that, but not enough from my point of view. I suggest to introduce sub-sections for each method. In addition, apart from methods 1-4, they introduced γ-method and κsca-method. What is the difference between method 3 and κsca-method?
In line 156, the authors mentioned four campaigns, but Table 1 listed up to five campaigns. It is not clear to me if the data from Wuqing and Xianghe campaigns are used or not, and for what? Why the data is not corrected? To which corrections do the authors refer?

One of my main concerns in my previous review was related with the error/uncertainties estimates of using the “new method” proposed in the manuscript. Although they have included a new dataset for testing the method, they do not quantify the errors of using this method to estimate the hygroscopicity parameter. They should address this point if they expect their method to be useful for the scientific community.

Furthermore, the authors need to make clear that the method is valid for NCP aerosols. They stated in the abstract that the method is “applicable in different sites and seasons” but they have just tested the method in another site from the NCP (probably with similar aerosol characteristics…).