PCLM-D-25-00013

Machine Learning-Based Assessment of Aerosol Optical Depth over Ghana, West Africa Using MODIS Satellite Data.

PLOS Climate

Dear Dr. Aryee,

Thank you for submitting your manuscript to PLOS Climate. After careful consideration, we feel that it has merit but does not fully meet PLOS Climate’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

The manuscript has been evaluated by two reviewers, and their comments are appended below and attached. The reviewers have raised a number of detailed concerns relating to the narrative, methodology, policy implications and validation presented in your work. We recommend that you consider these comments carefully, and revise your manuscript accordingly.

Please submit your revised manuscript by May 04 2025 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at climate@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pclm/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

Please include the following items when submitting your revised manuscript:

• A rebuttal letter that responds to each point raised by the editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.
• A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.
• An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

We look forward to receiving your revised manuscript.

Kind regards,

Jason Morgan

Staff Editor

PLOS Climate

Journal Requirements:

1. Please note that PLOS Climate has specific guidelines on code sharing for submissions in which author-generated code underpins the findings in the manuscript. In these cases, we expect all author-generated code to be made available without restrictions upon publication of the work. Please review our guidelines at https://journals.plos.org/climate/s/materials-and-software-sharing#loc-sharing-code and ensure that your code is shared in a way that follows best practice and facilitates reproducibility and reuse.

Additional Editor Comments (if provided):

[Note: HTML markup is below. Please do not edit.]

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Does this manuscript meet PLOS Climate’s publication criteria? Is the manuscript technically sound, and do the data support the conclusions? The manuscript must describe methodologically and ethically rigorous research with conclusions that are appropriately drawn based on the data presented.

Reviewer #1: Yes

Reviewer #2: Partly

**********

2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: Yes

**********

3. Have the authors made all data underlying the findings in their manuscript fully available (please refer to the Data Availability Statement at the start of the manuscript PDF file)?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception. The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: No

**********

4. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS Climate does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

**********

5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: GENERAL COMMENTS

This paper presents a comprehensive assessment of Aerosol Optical Depth (AOD) levels over Ghana from 2003 to 2019 using MODIS satellite data and predictive modeling approaches. The study employs multiple linear regression (MLR) and artificial neural network (ANN) models to estimate AOD levels and introduces an innovative hybrid approach by leveraging the ANN architecture to construct the MLR model. The analysis reveals significant spatial variations in aerosol levels, with the southwestern region exhibiting elevated levels attributed to biogenic emissions and mining activities. The study provides valuable insights into air quality monitoring in Ghana, where ground-based observation networks are sparse.

The paper is well-written and contributes meaningfully to environmental health and air quality monitoring. However, some areas require further elaboration, particularly regarding methodology, policy implications, and validation strategy.

I have several specific comments that may help improve the clarity and impact of the paper.

SPECIFIC COMMENTS

• Page 2-4, Lines 55-130: The study mentions the health implications of air pollution but does not explicitly link AOD levels to specific health outcomes, such as respiratory or cardiovascular diseases. Expanding this could strengthen the paper's relevance to public health.

• Page 2-4, Lines 55-130: While the introduction mentions that the ANN model architecture was used to construct the MLR model, the novelty of this hybrid approach should be clarified. How does it differ from traditional MLR or standalone ANN methods? Have similar approaches been applied in other regions?

• Page 4-6, Lines 158-194: The text highlights the sparse monitoring of air pollution in Ghana but does not discuss specific limitations of MODIS AOD data, such as retrieval errors due to cloud cover or algorithm assumptions. Consider including a brief discussion of these limitations.

• Page 6-7, Lines 196-235: The selection of meteorological variables used as input to the models should be described in more detail. Were variables like relative humidity, temperature, and wind speed selected based on a specific criterion, such as correlation with AOD levels?

• Page 14, Lines 342-378: The spatiotemporal distribution analysis would benefit from clearer visualization. Consider adding maps or graphs to illustrate annual or seasonal trends in AOD levels across Ghana.

• Page 14, Lines 342-378: While the southwestern region is identified as having higher aerosol levels, the paper could further explore the role of surface mining operations in contributing to this phenomenon. Are there specific hotspots identified that align with known mining sites?

• Page 12, Lines 512-581 The conclusion states that the hybrid MLR-ANN model outperformed other models, but the performance metrics (e.g., R², RMSE, MAE) are not explicitly provided in the main text. Consider including these metrics in a table to substantiate the claim.

Reviewer #2: I have uploaded my review as an attachement.

**********

6. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

Do you want your identity to be public for this peer review? If you choose “no”, your identity will remain anonymous but your review may still be made public.

For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: No

Reviewer #2: Yes: Dr. Julius Fenn

**********

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step.

Attachments

Attachment

Submitted filename: Review Comments.docx

Attachment

Submitted filename: Review PCLM-D-25-00013-1.docx

Machine Learning-Based Assessment of Aerosol Optical Depth over Ghana, West Africa Using MODIS Satellite Data.

PCLM-D-25-00013R1

Dear Dr. Jeffrey N. A. Nii Armah Aryee,

We're pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

Within one week, you'll receive an e-mail detailing the required amendments. When these have been addressed, you'll receive a formal acceptance letter and your manuscript will be scheduled for publication.

An invoice for payment will follow shortly after the formal acceptance. To ensure an efficient process, please log into Editorial Manager at https://www.editorialmanager.com/pclm/ click the 'Update My Information' link at the top of the page, and double check that your user information is up-to-date. For billing related questions, please contact billing support at https://plos.my.site.com/s/.

If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they'll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact climate@plos.org.

Kind regards,

Muhammad Irfan Ashraf, Ph.D

Academic Editor

PLOS Climate

Additional Editor Comments (optional):

The manuscript presents an interesting and timely study, addressing an important issue using emerging machine learning techniques. The research is well-designed and methodologically sound. The revised version is accepted for publication in PLOS Climate, pending compliance with the journal's editorial and formatting requirements and reviewers suggestions if any.

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: All comments have been addressed

Reviewer #3: All comments have been addressed

--------------------

2. Does this manuscript meet PLOS Climate’s publication criteria? Is the manuscript technically sound, and do the data support the conclusions? The manuscript must describe methodologically and ethically rigorous research with conclusions that are appropriately drawn based on the data presented.

Reviewer #1: Yes

Reviewer #3: Yes

--------------------

3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #3: Yes

--------------------

4. Have the authors made all data underlying the findings in their manuscript fully available (please refer to the Data Availability Statement at the start of the manuscript PDF file)?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception. The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #3: Yes

--------------------

5. Is the manuscript presented in an intelligible fashion and written in standard English?<br/><br/>PLOS Climate does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #3: Yes

--------------------

6. Review Comments to the Author<br/><br/>Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: Reviewer Comments – Second Round Review

Manuscript Title: Machine Learning-Based Assessment of Aerosol Optical Depth over Ghana, West Africa Using MODIS Satellite Data.

Manuscript Number: PCLM-D-25-00013R1

I have reviewed the revised manuscript. I appreciate the thoughtful revisions, and the effort made to address all concerns raised during the first round of review.

General Assessment

The manuscript has improved significantly and now meets the standards of clarity, methodological rigor, and relevance expected for publication. The authors have addressed all my previous comments adequately, including:

• Enhancing the clarity and organization of the methodology section

• Providing additional data and analysis to support key claims

• Improving the readability of figures and captions

• Citing relevant recent literature and situating the findings appropriately within the existing body of work

I do not have any additional substantive comments at this stage.

Recommendation: Accept as is

The manuscript is ready for publication in its current form.

Reviewer #3: This article is very well written. I have some suggestions if you would like to incorporate.

Please carefully red the article and try to provide as much sources as possible like references of epidemiological studies (Line 53-54) are missing. Reference is also missing in Line 109.

Moreover in your manuscripts in some places you have mentioned that detail is given in Section. Please clearly indicate in which section like (Line 65 and Line 93).

--------------------

7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

Do you want your identity to be public for this peer review? If you choose “no”, your identity will remain anonymous but your review may still be made public.

For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: No

Reviewer #3: No

--------------------