Evaluating Methods That Calculate Aircraft Emission Impacts on Air Quality: A Systematic Literature Review

Round 1

Reviewer 1 Report

1.       The abstract mentions the use of a systematic literature review but does not provide details on the specific methodology employed in the review process. Including a sentence on the search strategy, inclusion/exclusion criteria, and data extraction process would enhance the rigor of the study.

2.       Limited introduction as well as background of the research.

3.       SLR methodology is vaguely explained without proper research evidence. The provided research framework is a very common framework that has no new novelty for the current research.

4.       Inadequate search terms according to the scope of research. Based on title, these should include:

Aircraft emissions

Air quality

Emission calculation methods

Emission inventory

Sustainable aviation

International Civil Aviation Organization (ICAO)

Pollutant concentrations

Time-in-mode

Atmospheric conditions

Airports

Airlines

Health impacts

Ground level to 3,000 feet

5.       Methodology needs to present novelty. The current method is technically weak.

6.       Results directly provided 60 articles without clear SLR process.

7.       Authors have provided tier method for the selection of the article but this was not discussed before. Why tiers are selected now? whereas the keywords are different.

8.       The categorization of articles and the variables used for emission calculations are not based on the SLR research search. The provided methods do not make sense. Authors need to provide SLR of 60 articles as they have mentioned and then provide the methodology and relevant aspects.

9.       Results are weekly presented without any outcome or proper analysis. SLR method is based only articles without proper process that presents a weak approach to the study.

1.   No proper discussion section.

Moderate editing is required. Logical flow and comprehension is weak.

Author Response

Thank you very much for your comments. Those are really valuable. Our research team discussed all the comments and adjusted the manuscript according to your comments. 

Author Response File: Author Response.pdf

Reviewer 2 Report

The paper titled " Evaluating methods that calculate aircraft emissions: A systematic literature review " is very interesting work and the authors have shown a good effort in this review, but it still needs some minor corrections before publishing.

1- At the end of the introduction section, the authors addressed two questions, it is not suggested to write it this way, they have to address it as a solution to existing problems. not given it as a question.

2- In Fig 1 the author must check the given block diagram frames

3- In Figure 5, why did the author just give data until 2021, however, we are in 2023.

4- The author must add another section talking about the economical study and how it is impacted on the total cost.

Language is fine 

 

 

 

Author Response

Thank you very much for your comments. Those are really valuable. Our research team discussed all the comments and adjusted the manuscript according to your comments. 

Author Response File: Author Response.pdf

Reviewer 3 Report

 

 

This paper is about evaluating methods that calculate aircraft emissions, a literature review.  Not sure of the scientific benefit from such.  But method(s) to calculate aircraft emissions is(are) not known or at least shown. There is no intercomparison of the observations of the various research papers reviewed, nor even of the models that might have been used to gather the estimates ....  This paper does not read in a way to leave the reader with a notion that the title truly reflects the content of the paper. 

This is hopefully not the intent of the authors because, even though the text does read as though this paper would be about how aircraft emissions affect the climate at 3000ft. The paper is not about that much needed topic and is a literature review. 

A literature review is required for every scientific paper surely, In this case the review of the literature rules out critical contributing attributes resulting in a flawed evaluation. This may be ok depending on the true objective of this paper which is not clearly stated in the introduction.  Hence, this paper requires major revision which will likely change the title of the paper. 

 

L1, p1 of 17: The first sentence needs a reference.

 

L49-50, last sentence (p2 of 17) - replace with  'Therefore, aircraft emissions should be separately evaluated for comparison with other surface pollutant emission sources to consider the potential impacts of aircraft emissions at 30000ft.' 

Then compare the aforementioned to those from the surface and others at 30000ft when aircraft are not present at that level.    Then compare to the IPCC data.

Then need to show the frequency of momentum transfer from 3000ft to the surface.

Repeat aforementioned for under 3000ft.  

 

Figure 5, p6 of 17: Need error bars and the significance of 2012 data.  Otherwise, can't make the statements made on this page.  Not sure how relevant these are given the multiple exclusions.  Given the exclusions, and more importantly non-published data from a climatic significant period, how can you claim global issue?  Are the periods covering the no publications normal or below background or much higher?  Not knowing and then saying what you have can be very misleading to say the least.  This is another flaw.   

 

Figure 7: need to enlarge the label text sizes of all axes. 

 

p13: How are Tier3b any different than the other tiers given the uncertainties in the study?  Perform an error analysis, statistical inference tests on the Tier results so that one could at least make more appropriate conclusions or not. 

Also check references-format, published in scientific Journals. 

 

See above.

Author Response

Thank you very much for your comments. Those are really valuable. Our research team discussed all the comments and adjusted the manuscript according to your comments. 

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

1. Authors have added on the number of articles. 

2. Introduction is better than before

3. Methods have been significantly improved

4. Results are adequate

Moderate editing required

Author Response

The authors would like to thank the reviewer for the comments. They have helped to improve the paper. We appreciate their time and effort. 

Author Response File: Author Response.pdf

Reviewer 3 Report

This reviewer's comments were not adequately addressed. They were addressed though and understand author has some freedoms. 

It should not take 118 lines to have the reader understand what the particular aspect of the gap it is meant to address.  The use of operational data is good, and more usefully applied when the uncertainty interval surrounding those data are provided.  Did not see such, and thus the ability to distinguish between the tiers requires a simple statistical inference technique.  I do not see this either.  There are no error bars on the data throughout the paper.  The values used are not absolute values unless the axis label is not clearly represented.  

Figure 5 has a vertical axis label of frequency, but there is no magnitude on the labels and the only numbers shown appear to be counts?  At least add error bars on the data apparently shown in this figure and the others as appropriate.  columns in this figure? Similarly for all data points in this paper.  The latter should lend credibility on your analyses and conclusions. Simply, this ask stems from the multiple exclusions mentioned surrounding this figure and also in the paper. Given the exclusions, and more importantly non-published data (perhaps your operational data) lesson the credibility of the analysis.  Even if the result turns out to be correct.  

Need Moderate English editing.

Author Response

The authors would like to thank the reviewer for the comments. They have helped to improve the paper. We appreciate their time and effort. 

Author Response File: Author Response.pdf