Dear authors,

please consider comments raised by a reviewer on your revisions. There is particular concern that you can not fully link the formation of nanoparticles to PM2.5, and the referee has raised a couple of comments on your revisions.

best regards, Thomas Karl

Dear authors, the manuscript has significantly improved and addressed concerns by the reviewers. A couple of grammar issues could be improved in the final version. br, Thomas Karl


For example: reference to time should always be at the very end or beginning of a sentence:

The particle and ion number size distribution measurements were conducted in January and February 2020 on the roof of the Chinese Academy of Meteorological Sciences building (CAMS) on the Chinese Meteorological Administration campus.

CORRECT:

The particle and ion number size distribution measurements were conducted on the roof of the Chinese Academy of Meteorological Sciences building (CAMS) on the Chinese Meteorological Administration campus between January and February 2020.

Conclusion:

In this study, we presented changes in the NSD of particles and charged ions measured in January and February 2020 to reveal the influence of emission reduction on NPF events.

BETTER:

In this study we present changes in the NSD of particles and charged ions measured between January and February 2020. These observations reveal the influence of emission reduction on NPF events.

NEXT: The nucleated particles entered accumulation mode by the secondary aerosol formation

change to: The nucleated particles entered accumulation mode by secondary aerosol formation...