Comments by Keding Lu on behalf of the TOAR-II Steering Committee on:

Hemispheric differences in ozone across the stratosphere-troposphere exchange region

Rodrigo J. Seguel (corresponding author), Charlie Opazo, Yann Cohen, Owen R. Cooper, Laura Gallardo, Björn-Martin Sinnhuber, Florian Obersteiner, Andreas Zahn, Peter Hoor, Susanne Rohs

This manuscript was submitted to ACP as part of the TOAR-II Community Special Issue

https://doi.org/10.5194/egusphere-2024-3719

Discussion started: 13 Dec 2024

This review is by Keding Lu, member of the TOAR-II Steering Committee. The primary purpose of these reviews is to identify any discrepancies across the TOAR-II submissions, and to allow the author teams time to address the discrepancies. Additional comments may be included with the reviews.

While members of the TOAR Steering Committee may post open comments on papers submitted to the TOAR-II Community Special Issue, they are not involved with the decision to accept or reject a paper for publication, which is entirely handled by the journal’s editorial team.

General comments

The differences bettwen the NH and SH mid-latitude UTLS ozone concentrations are of high interest for both the global radiative forcing and the global ozone budget studies. This paper provide timely analysis on a super valuable dataset on the mid-latitude SH UTLS measurements which could open a window of this demanding topic.

This manuscript has already received two thorough and critical reviews from two anonymous referees regarding the scope, scientific analysis and structure of the paper and I don’t have anything to add. Nevertheless, I would agree with the two reviewers that the significant different sample size could be a point to further address of which in this case the two ozone sonde observations in SH could be considered.

Overall, for my responsibility, I just found no discrepancies between the conclusions and the findings of other papers submitted so far to the TOAR-II Community Special Issue.

Technical comments

1. The term ‘ozone’ is sometimes depicted as ‘O₃’ in both text and figures, maybe the authors can choose ‘O₃’ in all the figures while ‘ozone’ in the text, in addition, the font style might be synchronized too.
2. The lead author Rodrigo J. Seguel is also a member of the TOAR Steering Committee who are familiar with all the TOAR-II technical requirements. I would like to advertise herein again that TOAR-II has produced two guidance documents to help authors develop their manuscripts so that results can be consistently compared across the wide range of studies that will be written for the TOAR-II Community Special Issue. Both guidance documents can be found on the TOAR-II webpage: https://igacproject.org/activities/TOAR/TOAR-II.  The two guidance documents are “The TOAR-II Community Special Issue Guidelines” and “Guidance note on best statistical practices for TOAR analyses”. This message might be useful for the reviewers and readers to consider.