Individual Condensation Trails in Aircraft Trajectory Optimization

Round 1

Reviewer 1 Report

The manuscript titled “Significance of Individual Condensation Trails in Aircraft Trajectory Optimization”, by Rosenow et al., presents a method to consider the environmental impact of individual condensation trails induced by aviation. The method is clearly explained comprising six steps, from weather information to contrail radiative forcing. But it isn’t properly assessed. No experimental data is included in the manuscript, apart from a calculation example of one flight without giving much detail. Also, several conclusions are mentioned regarding aircraft speed, fuel flow, and flight height but none of them are supported by data analysis.

The main concern, as mentioned before, is the lack of results in the study. The authors explain the method in eight sheets and the results in only two. In order to assess the performance of the method, it must be tested with experimental data. For instance, statements like “Flying slowly through ice-saturated regions causes more radiative effective contrails” (lines 148 – 149) or “A tendency towards lower aircraft speeds and higher fuel flows has been identified to decrease the probability of contrails formation” (lines 347 – 348) must be supported with experimental data (flight information, meteorological fields and contrail observations). Otherwise, it is impossible to find out if the model estimations are realistic or just a theoretical calculation.

Adding to these, some parts of the manuscript needed clarification, included as notes in the attached file.

Comments for author File: Comments.pdf

Author Response

Dear Reviewer No 1,

thank you for the time you spend to improve my paper. I did my very best to consider each of your valuable comments. Please see the attached pdf file, wherein I replied to your comments.

Additionally, I organized a language editing and took over all suggestions for modification.

With kind regards

Judith Rosenow

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments:

This study considers the environmental impact of condensation trails in single trajectory optimization tools. The intent of this study is the elaboration of all significant factors deciding on the net effect of single condensation trails. Possible simplifications have been proposed for a consideration in single trajectory optimization tools. Finally, the effects of the most important impact factors, such as latitude, time of the year and time of the day, wind shear, atmospheric turbulence and their consideration in a multi-criteria trajectory optimization tool have been exemplified. The results are used for an arbitrary trajectory optimization tool with environmental optimization intents. The results are relevant and I recommend this manuscript for publication in Sustainability after addressing some minor revisions. It can be accepted, just review some sentences as described below:

Minor comments:

Page 2:

Please start the numbering of your section from 1 not 0. Please add the outline of your paper at the end of your introduction: “The rest of this study is organized as follows. In section 2…has been presented, in section 3, ….” Please revise Figure 1. It is not clear and confusing. You can use different colors. Figures 2, 3, 9, and 12: Please add different symbols or different types of line in your graphs. The conclusion is so lengthy, please split some part of that as discussion.

Author Response

Please start the numbering of your section from 1 not 0.

Thank you, I did.

Please add the outline of your paper at the end of your introduction: “The rest of this study is organized as follows. In section 2…has been presented, in section 3, ….”

Thank you, I did.

Please revise Figure 1. It is not clear and confusing. You can use different colors.

Thank you, I did my very best.

Figures 2, 3, 9, and 12: Please add different symbols or different types of line in your graphs.

Thank you, I did my very best.

The conclusion is so lengthy, please split some part of that as discussion.

Thank you, I did.

Reviewer 3 Report

The topic is very important and the paper is well structured. I don’t feel competent to judge all physics in section 2, but the summary in section 3 provides a good overview of the findings and their relevance.

My comments basically refer to language:

I doubt whether “significance” is a suitable term for the title. An alternative might be “Including Individual Condensation Trails into Aircraft Trajectory Optimization”, but other options exist and I would leave the decision with the authors.

I recommend a thorough language check by a native speaker, e.g. line 1: “contributor to global warming” (not “on”); line 16: “The term contrails summarizes…”; line 17: “water vapor emissions” (delete “exhausted”); line 68: twice “increase”; etc.

Please also check the references, e.g. 11 probably “condensation”, not “Condenstation”; 31 “Proceedings”, not “Proseedings”  

Author Response

Dear reviewer No 3,

thank you for your positive feedback on my manuscript. I considered all you comments and arranged a language editing service. I also changed the title to "Individual Condensation Trails in Trajectory Optimization". Thank you for your detailed look in the list of references and for finding some typos therein.

With best wishes

Judith Rosenow

Round 2

Reviewer 1 Report

The present version is suitable for publication