Articles | Volume 25, issue 19 
            
                
                    
            
            
            
        https://doi.org/10.5194/acp-25-12513-2025
                    © Author(s) 2025. This work is distributed under the Creative Commons Attribution 4.0 License.
                Evaluating urban methane emissions and their attributes in a megacity, Osaka, Japan, via mobile and eddy covariance measurements
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- Final revised paper (published on 09 Oct 2025)
- Preprint (discussion started on 03 Feb 2025)
Interactive discussion
Status: closed
            Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor
                | : Report abuse 
            
        - RC1: 'Comment on egusphere-2024-3926', Anonymous Referee #1, 24 Feb 2025
- RC2: 'Comment on egusphere-2024-3926', Anonymous Referee #2, 01 Apr 2025
- RC3: 'Comment on egusphere-2024-3926', Anonymous Referee #3, 11 Apr 2025
- AC1: 'Reply to reviewers' comments on egusphere-2024-3926', Masahito Ueyama, 19 May 2025
Peer review completion
                AR: Author's response | RR: Referee report | ED: Editor decision | EF: Editorial file upload
            
        
                        AR by Masahito Ueyama  on behalf of the Authors (19 May 2025)
                             Author's response 
                             Author's tracked changes 
                             Manuscript 
                    
                
                        ED: Referee Nomination & Report Request started (13 Jun 2025) by Rebecca Garland
                    
                
                
                            RR by Anonymous Referee #3 (17 Jun 2025)
                        
                    
                        ED: Publish as is (30 Jun 2025) by Rebecca Garland
                
                             
                            
                          
                    
                 
                            
                          
                    
                        AR by Masahito Ueyama  on behalf of the Authors (01 Jul 2025)
                    
                 
 
                           
                 
                 
                 
                 
                 
                     
                     
                     
                    
Review of Manuscript:
Title: Evaluating urban methane emissions and their attributes in a megacity, Osaka, Japan, via mobile and eddy covariance measurements
Author(s): Masahito Ueyama et al.
MS No.: egusphere-2024-3926
MS type: Research article
Does the paper address relevant scientific questions within the scope of ACP? YES
Does the paper present novel concepts, ideas, tools, or data? YES
Are substantial conclusions reached? YES
Are the scientific methods and assumptions valid and clearly outlined? YES
Are the results sufficient to support the interpretations and conclusions? YES
Is the description of experiments and calculations sufficiently complete and precise to allow their reproduction by fellow scientists (traceability of results)? YES
Do the authors give proper credit to related work and clearly indicate their own new/original contribution? YES
Does the title clearly reflect the contents of the paper? YES
Does the abstract provide a concise and complete summary? YES
Is the overall presentation well-structured and clear? YES
Is the language fluent and precise? YES
Are mathematical formulae, symbols, abbreviations, and units correctly defined and used? YES
Should any parts of the paper (text, formulae, figures, tables) be clarified, reduced, combined, or eliminated? NO
Are the number and quality of references appropriate? YES
Is the amount and quality of supplementary material appropriate? YES
Recommendation:
Accepted!
In my opinion, this is an excellent paper!
Temporal and spatial variability of greenhouse gas exchange between the atmosphere and various ecosystems is one of the most critical problems of global climatology/ecology/environmental science. Despite the growing number of measurement sites worldwide, it should be noted that (for various reasons) their number in cities is insufficient. And yet, cities are such intensive sources of GHGs to the atmosphere! In addition, the existing urban sites mainly focus on measuring carbon dioxide fluxes, and long-term measurements of methane fluxes are still few (the results of only a few long-term measurement campaigns in the UK, Poland, Japan, or Italy have been published). Thus, it should be emphasized that the research results presented in the manuscript are valuable to knowledge of urban methane emissions.
The article presents the results of a detailed planned research experiment during which measurements were made using the EC method and during mobile measurements with methane concentration sensors installed on a car and a bicycle. The study is written clearly, and the Authors describe the results in detail. Noteworthy is the detailed description of the methodology and the extensive discussion of the results' quality (and their comparison with inventories). Some discrepancies in the results obtained from mobile measurements by car and bicycle are also discussed in detail by the Authors. The Authors also devoted much attention to estimating CH4 flux components, which I consider the most critical achievement in the presented study.
I have only two comments:
P4, figure 4 should be more detailed (larger?). In the current figure, the differences in development, and especially the EC footprint, are poorly visible!
P6L168 – should be (Vickers and Mahrt, 1997)