Ozone Trends and the Ability of Models to Reproduce the 2020 Ozone Concentrations in the South Coast Air Basin in Southern California under the COVID-19 Restrictions

Round 1

Reviewer 1 Report

The paper is well written, accurate in the formulation of the problem and the investigation. The modelling tools used are most appropriate for the case study.

As far as I am concerned the paper can proceed to be published

Author Response

Thank you very much for reviewing.

Reviewer 2 Report

While somewhat limited in scope, I find this is a nice study design with interesting and important results on the impacts of COVID-19 lockdowns and meteorology on ozone concentrations in the SoCAB, and on the ability of a 4-km resolution WRF-CMAQ model in representing such changes. The overall writing and grammar is acceptable as well.  However, my main issues are how the paper is structured, where many sections need to be moved (or removed) and reformatted to improve the overall readability.  Also, the quality of some of the figures need to be improved, and there is need for further discussion and clarifications in the analysis and main text.  Please find my detailed comments in the attached PDF.  

Comments for author File: Comments.pdf

Author Response

Thank you for your review. Please see the attachment.

Author Response File: Author Response.docx

Reviewer 3 Report

This manuscript applied CMAQ to reproduce ozone trends in the South Coast Air Basin (SoCAB) of southern California under the COVID-19 Restrictions. The data also seem reliable and the scope is also suitable for the Atmosphere. I think this study is interesting and meaningful, and suitable for publication after minor revisions.

• Introduction: Lines 112-124, I would suggest the authors remove this part to Section 2 Methods.
• Table 2: I am curious about the reason of highlighting some numbers by the red color.

Author Response

Thank you for reviewing. Based on your comment and another review I determined lines 112-124 to be redundant and removed them. I also added a footnote to Table 2 to describe the reason for highlighting some number in red.

Reviewer 4 Report

Please see uploaded file

Comments for author File: Comments.pdf

Author Response

Thank you for your review. Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 4 Report

Please see uploaded file

Comments for author File: Comments.pdf

Author Response

Please see the attachment

Author Response File: Author Response.docx