An Investigation of GNSS Radio Occultation Data Pattern for Temperature Monitoring and Analysis over Africa

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Dear Authors,

Thank you for submitting your paper titled "An Investigation of GNSS RO Data Pattern for Climate Change Monitoring and Analysis over Africa."

The current paper is both interesting and scientifically valuable. It is well-written, and the results are generally well-presented.

That said, I would like to share some minor and major concerns for your consideration.

Minor Concerns: To streamline the feedback, I have provided my detailed comments in the attached PDF file.

Major Concerns:

1. In Section 3.1 of your results, you have analyzed only five missions for spatial analysis, whereas other sections mention and analyze additional missions. Please clarify this discrepancy and include an explanation in the paper.

2. In Section 3.3 (Seasonal Variations), you focus on temperature variations; however, the title of your paper suggests a broader focus on climate change. I recommend either adjusting the title to better reflect the scope of the study or elaborating on why temperature was specifically chosen as a parameter. Additionally, please specify how and where the temperature data was derived.

I hope you find this feedback helpful. Please address these points accordingly.

Once again thank you for your time and efforts for this manuscript.

Yours sincerely,

Reviewer

Comments for author File: Comments.pdf

Author Response

Good day.

1. The missions selected for investigation in this research endeavour, namely CHAMP (2001-2007), COSMIC-I (2006-2019), and COSMIC-II (2020-2023), were aimed at acquiring datasets that comprehensively encompass the temporal span of 2001 to 2023. while datasets from other missions were used to address the data gaps within the study period.
2. The title has been modified.
3. Thank you for your patience and understanding.

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

The study provides valuable insights into the use of GNSS RO data for climate monitoring in Africa, addressing a critical gap due to the continent's limited ground-based stations. The comparison of different missions (e.g., METOP, COSMIC) adds practical value for future research. With Major revisions to improve clarity, methodology details, and figure presentation, it would be suitable for publication. 

Major comments

1.The introduction effectively highlights the challenges of climate monitoring in Africa but could better emphasize the novelty of using GNSS RO data in this context. 

2. more details on the Python scripts or tools used for processing would enhance reproducibility.
3. The temporal analysis could be strengthened by including statistical tests to validate the significance of seasonal trends.
4. The spatial analysis figures (e.g., Figures 3–7) should include axis labels and units for better interpretation
5. The seasonal temperature variations (Figures 9–31) are comprehensive but somewhat repetitive. Consider adding a summary table or heatmap to highlight key trends (e.g., regions with the most significant temperature changes).
6. Clarify the criteria for selecting specific GNSS RO missions (e.g., why CHAMP, METOP, COSMIC were chosen over others).
7. Provide more details on the Python libraries or packages used for spatial analysis (e.g., `PySAL`, `scipy`).
8. The discussion could better contextualize the findings by comparing them with similar studies in other regions (e.g., Asia, South America).
9. Address potential biases or uncertainties in the GNSS RO data (e.g., signal interference, coverage gaps).
10. The references are comprehensive, but some citations (e.g., [39–61]) are overly broad. Consider citing specific studies for key claims (e.g., temperature trends, RO data accuracy).

Minor comments

   - Page 1: "Tape of the Paper" should likely be "Title of the Paper." 

   - Page 5: "Biplays" should be "Ripley’s" in the figure captions. 

   - Ensure all figures are high-resolution and legible in the final version. 

   - Define all acronyms (e.g., LEO, ROE) at first use for clarity.

Author Response

Good day,

1.        The reason why in section 3.1 where five missions were analysed for spatial analysis, is that the missions selected for investigation in this research endeavor, namely CHAMP (2001-2007), COSMIC-I (2006-2019), and COSMIC-II (2020-2023), were aimed at acquiring datasets that comprehensively encompass the temporal span of 2001 to 2023, while other missions was employed to mitigate certain data deficiencies that occurred throughout the study period.

2.        The title of the paper was adjusted to ‘An Investigation of GNSS Radio Occultation Data Pattern for Temperature Monitoring and Analysis over Africa’

3.        The details of the python tool used was discussed in section 2.1

4.        The spatial analysis figures axis was also labeled.

5.        Heatmaps were also inserted

6.        The introduction was also improved

7.        The agreement of the findings of the research was also looked into. 

Corrections were made in the manuscript.

Thank you for your patience and understanding.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Dear Authors,

Thank you for submitting the revised version of your work. Your manuscript is well-structured and highly relevant to the scope of NDT Journal. I appreciate the efforts you have made in addressing the previous comments and refining the clarity and coherence of your research.

The methodology is robust, and the results are presented in a clear and well-organized manner, contributing valuable insights to the field. The discussion effectively interprets the findings, and the conclusions are well-supported by the data.

I have no further concerns, and I believe this paper will be a valuable addition to the journal. Congratulations on your work!

Best regards

Author Response

Dear Academic Editor,.
Thank you for your support, patience, and understanding. The following is my reply:
1. The equations have been checked, and corrections have been applied.
2. The sub-figure labels are also corrected.
3. The Moran's I decimal place values were also corrected.
4. The time given for the author will not be enough for the correction in section 3.2 (seasonal variation) due to the fact that the processing of this section takes several days before yielding the output results.
5. The new section 3.3 Heatmap is also corrected. The Python script for both the seasonal variation and the heatmap is currently processing for the correction. but it takes days to process due to the dataset size.
Please i need more time to improve section 3.2 and 3.3.
Thank you.

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

The new manuscript is well written and merit to publish.

Author Response

Dear Academic Editor,.

Thank you for your support, patience, and understanding. The following is my reply:

1. The equations have been checked, and corrections have been applied.

2. The sub-figure labels are also corrected.

3. The Moran's I decimal place values were also corrected.

4. The time given for the author will not be enough for the correction in section 3.2 (seasonal variation) due to the fact that the processing of this section takes several days before yielding the output results.

5. The new section 3.3 Heatmap is also corrected. The Python script for both the seasonal variation and the heatmap is currently processing for the correction. but it takes days to process due to the dataset size.

Please i need more time to improve section 3.2 and 3.3.

Thank you.