Air Quality Estimation in Ukraine Using SDG 11.6.2 Indicator Assessment
Round 1
Reviewer 1 Report
Line 9 – 27: The abstract is overly explicit of the Copernicus program and does not offer any useful information about the results or any conclusion to the study. I would suggest adding a summary of the main findings based on the SDG indicator 11.6.2.
Line 47: Please add additional references to support this claim. While I incline to agree with this statement, one should keep in mind other sources that may impact local air quality indicators.
Line 111-112: I am not sure how SDG 11.3.1 relates to this study? It is only ever mentioned here.
Line 188: Additional information on these providers would be helpful. How does this system compare to ground stations in other European countries? Please add more technical information regarding the types of sensors in use, data quality, uncertainty estimations etc.
231-234: Please rephrase the paragraph. There are a lot of other factors influencing PM concentrations. Waste generation may be one such factor however it is directly correlated with population density. Waste management may include transportation, depositing and/or elimination processes that can occur outside the oblast of origin.
241-244: please cite the study you are refereeing to
I strongly suggest adding an additional section in which the validation methodology on CAMS vs ground based data is thoroughly described! Please keep in mind to address the issue of spatial and temporal collocation of data. Is it CAMS pixel vs the overlapping ground stations or did you choose a larger area of several pixels CAMS vs the matching stations? As it stands the reader has no way of assessing how the validation effort took place. Also, what is the mean bias? I would also suggest plotting the distribution of PM values for both CAMS and ground stations and also for bias values. Further assessments can be made from this statistical analysis.
Section 4.1
Please offer a detailed explanation on the criterion of excluding statistical outliers (line 260 – 261)! Please explain how did you choose the range of acceptable values? This should be added to the validation methodology previously discussed.
Line 261: I would rephrase “all statistics was significantly improved” as this cannot be objectively said after excluding the outliers.
Line 271 – 273. I wouldn’t say that this is the only explanation for the higher PM values measured from the ground stations. Additional information about the validation method might offer further explanations!
Line 276 – 277: I would suggest adding an additional region for validation purposes, as opposed to just relying on the data from Kiev, if one would like to further extrapolate to the entire Ukraine.
I would suggest you use vertical text (in the country boxes) for figures 7 and 8.
Line 352: “4. Discussions” should be “5. Discussions”
353 – 363: This section is extremely limited and does not reflect all the results presented in this study. I strongly suggest improving this section!
Line 364 – 382: Please add some additional conclusions based on your study. How does your data compare to other European Countries? What are some of the limitations identified in this work? What are the implications of the CAMS vs ground station correlation values to the overall values of the SDG indicator 11.6.2? What do the overall values of the indicator 11.6.2 suggest about the air quality in Ukraine?
Author Response
Dear Reviewer!
Thank you for your attention to the article and valuable comments. The authors have carefully reviewed the comments and have revised the manuscript accordingly.
Please see the authors’ point-by-point responses in attachment.
Kind regards,
A. Shelestov , H. Yailymova, B. Yailymov , N. Kussul
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The paper tackles a topic of global societal interest, however the approach is more of an application of existing methodologies. Literature could be enriched with some real peer-reviewed articles instead of URL links, especially regarding air-quality monitoring/ air-pollution mapping in urban areas, and the use of high spatial resolution data. Also some basic references to previous or recent similar research projects would be useful, e.g., Sarigiannis et al., 2002, ICAROS: An integrated computational environment for the assimilation of environmental data and models for urban and regional air quality). The term CORIN is probably incorrectly used (if it alludes to the CORINE Land Cover classification); CORINE stands for CORdinate INformation on the Environment, and its mention should be justified in the text with respective references (e.g. Heymann et al,, 1994, CORINE Land Cover: Technical Guide).
Author Response
Dear Reviewer!
Thank you for your attention to the article and valuable comments. The authors have carefully reviewed the comments and have revised the manuscript accordingly.
Please see the authors’ point-by-point responses in attachment.
Kind regards,
A. Shelestov , H. Yailymova, B. Yailymov , N. Kussul
Author Response File: Author Response.pdf
Reviewer 3 Report
This manuscript presents a useful first start in collecting and synthesizing data related to population exposure to PM2.5 in the Ukraine. The authors describe some limitations of existing data and seem to use appropriate data sources to fill gaps. While the science seems sound, the manuscript requires significant text editing before it would be suitable for publication. The clarity of the manuscript would be improved with better organization and editing for the English language. The content and significance of the manuscript would be improved by more careful descriptions, in particular of methods (some of which is missing) and of statistical meaning. For example,
— the extent of existing air quality data available in the Ukraine is not clear, and should be described quantitatively. The authors state “the number of stations for air pollution measurement has significantly increased” (lines 47-55), but what does this mean? How many stations were there (x) years ago, and how many are there now? Are there any monitors outside of urban areas, and if so, how many?
— when air quality data availability are discussed, readers may not understand the important difference between a monitor and a product/service (that probably uses monitor data, or a blend of monitor and model data). While the authors do not conflate the two, organizing the introduction to clearly distinguish the different data sources is important.
— it’s not clear how much of the information in the methods section is directly relevant to the work described in this paper. At the very end of the section, it is noted that only model data are used for this paper, and as such, the information given about monitoring in this section should be replaced with details about the air quality modeling data from CAMS. It seems this section could be shortened quite a lot and combined with the “Materials” section.
— the authors state “the average annual 229 values for these years were calculated by the authors themselves” (lines 229-230). If CAMS data were unavailable for this time period, what data source(s) did the authors use? This is an important detail that should not be left out.
— in Section 4.1, the statistics could indicate that CAMS is reproducing the temporal variability in PM2.5, not necessarily the actual PM2.5 amounts. The authors are correct to note the effect of model resolution on model performance compared to monitor data. Since the health impacts of PM2.5 are a function of concentration, the authors may want to more firmly note the suitability of the CAMS data for describing health risks.
Other, smaller parts that require clarification are:
— (Abstract) admittedly I am not in the target audience, not being in an EU country, but it would be appropriate to define what SDG indicator 11.6.2 is, here.
— (Line 48) “It is the large cities that make the biggest contribution to air and air pollution” –should this be just “air pollution”?
— (Line 102) What is the difference between a public air quality monitoring network and a public network?
— (Lines 107-108) “The lack of quality national products for urban planning and monitoring of air quality indicators” —how does this statement connect to earlier statements about the increased number of monitors?
— (Line 191) does “radiation” meaning radioactive radiation, or solar or terrestrial (infrared) radiation?
— (Section 3.2) what are the other main cities?
—Discussion should be section #5 and Conclusions section #6, correct? Since the Discussion is so short, it might work to be folded in to the previous section.
— (Figure 10) the axis labels are very small and difficult to read. Could this figure be reoriented so the plots are in a 2x3 or 3x2 array, such that the axis labels might be shared and larger?
Author Response
Dear Reviewer!
Thank you for your attention to the article and valuable comments. The authors have carefully reviewed the comments and have revised the manuscript accordingly.
Please see the authors’ point-by-point responses in attachment.
Kind regards,
A. Shelestov , H. Yailymova, B. Yailymov , N. Kussul
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
The manuscript has been improved. My comments have been addressed and I recommend to publish the paper in the journal.
Author Response
Dear Reviewer!
Thank you for your attention and recommendation to publish the article.
