Using HawkEye Level-2 Satellite Data for Remote Sensing Tasks in the Presence of Dust Aerosol

Round 1

Reviewer 1 Report

I enjoyed reading this paper. Everything including the novelty, significance of content, quality of presentation, scientific soundness, interest to the reader looks good to me. I only have minor suggestions before the publication. The paper needs to be checked in terms of typos. I suggested some of them below.

Line 37: Please correct the comma (0.22, 0.05).

Line 65: -4 should be superscript.

Line 183: sea. [48] à sea [48]

Line 185: researchwe à research, we

Line 197: PM2.5).The à PM2.5). The

Line 207: -3 should be superscript.

Section 2: I suggest putting more subtitles in Section 2 for the reader. For example, explicitly describing instruments name or method as a subtitle in Section 2.

Line 252: in the à in the, Consequentlythe à Consequently the

Line 257: datacorrectionfor à data correction for, pixelswasreceived à pixels was received

Line 367: the ratio of the

Author Response

• Dear Reviewer!

Thank you for giving us the opportunity to submit a revised draft of the manuscript “Using HawkEye Level-2 satellite data for remote sensing tasks in the presence of dust aerosol” for publication in the Atmosphere journal. We appreciate the time and effort that you dedicated to providing feedback on our manuscript and are grateful for the insightful comments on and valuable improvements to our paper. We have incorporated most of your suggestions and recommendations. Those main changes are highlighted within the manuscript (yellow). Please see below, for a point-by-point response to your comments and concerns (green highlighted). All page numbers refer to the revised manuscript file with tracked changes.

Line 37: Please correct the comma (0.22, 0.05).

Line 65: -4 should be superscript.

Line 183: sea. [48] à sea [48]

Line 185: researchwe à research, we

Line 197: PM2.5).The à PM2.5). The

Line 207: -3 should be superscript.

Line 252: in the à in the, Consequentlythe à Consequently the

Line 257: datacorrectionfor à data correction for, pixelswasreceived à pixels was received

Line 367: the ratio of the

Thank you very much for your comments! We apologize for the many typos and stuck together words (this is due to working in several versions of Word). Everything in these lines has been corrected and the rest of the text is the same.

Section 2: I suggest putting more subtitles in Section 2 for the reader. For example, explicitly describing instruments name or method as a subtitle in Section 2.

Thank you very much for your valuable recommendation. Section 2 is divided into 3 different subsections covering separately remote sensing instruments, field instruments and additional programs.

Hope we have taken into account all your comments and you will be satisfied with the new version of the paper!

Kind Regards,

Authors

Reviewer 2 Report

This article actually evaluates the HawkEye satellite data by utilizing ground-based PM measurement data, AERONET observations, and Sentinel satellite data to cross-validate the reflectance and AOT results from the HawkEye satellite. In the data processing of the HawkEye satellite, the aerosol model is set to a fixed M99 model, and the discrepancies in results are not only evident in dust aerosol but also present in significant deviations for other types of aerosols.

1. In Table 1, how are "fine", "coarse" and "percentage" defined? Additionally, the PM measurement data only covers the years 2020-2021; how were the results for 2022 obtained?
2. How is the "quality" in Table 2 selected? What are the rules or criteria adopted?
3. The lowest altitude for backward trajectory simulation is 500 meters, which cannot simulate the dust situation near the ground. It is not possible to directly compare this with the PM measurement results. It is suggested to set the backward trajectory simulation to near-ground points.
4. The content in the tables should be centered and aligned.

1. The language description requires polishing, and spaces and punctuation marks must not be omitted.

Author Response

Dear Reviewer!

Thank you for giving us the opportunity to submit a revised draft of the manuscript “Using HawkEye Level-2 satellite data for remote sensing tasks in the presence of dust aerosol” for publication in the Atmosphere journal. We appreciate the time and effort that you dedicated to providing feedback on our manuscript and are grateful for the insightful comments on and valuable improvements to our paper. We have incorporated most of your suggestions and recommendations. Those main changes are highlighted within the manuscript (yellow). Please see below, for a point-by-point response to your comments and concerns (green highlighted). All page numbers refer to the revised manuscript file with tracked changes.

1. In Table 1, how are "fine", "coarse" and "percentage" defined? Additionally, the PM measurement data only covers the years 2020-2021; how were the results for 2022 obtained?

Thank you very much for your valuable question. The percentage of fine and coarse particles was calculated automatically based on dust meter «Atmas» measurements. Unfortunately, we did not fully understand the remark about temporary coverage, since, based on Table 1, the four dates under study refer to 2022. Based on your comment (number 3), we subsequently removed this information.

2. How is the "quality" in Table 2 selected? What are the rules or criteria adopted?

Thank you very much for your question. A detailed description of this issue is described in lines 382-385. The main reasons of bad measurements quality were glint and cloudiness. In the Table 2, the “Quality” column presents the percentage of high-quality pixels after the culling (filtering) procedure. Unfortunately, the percentage of quality data after this filtering at 05.11.2021, 17.02.2022 and 17.05.2022 was only 1-2%

3. The lowest altitude for backward trajectory simulation is 500 meters, which cannot simulate the dust situation near the ground. It is not possible to directly compare this with the PM measurement results. It is suggested to set the backward trajectory simulation to near-ground points.

You are absolutely right, our dust meter is located on the roof of the MHI RAS Institute at an altitude of approximately 100 m above sea level. We constructed return HYSPLIT  trajectories for all the studied dates and, unfortunately, in more than half of the cases it was not possible to confirm the transfer specifically from the Sahara in the surface layer. Nevertheless, the presence of dust was confirmed at altitudes of 500 m and higher (up to approximately 5 km). Subsequently, we decided to remove this data from Table 1 in order to avoid errors and uncertainties, and only limit ourselves to measurements with a hand-held spectrophotometer SPM, which takes measurements in the atomosphere column.Thank you!

4. The content in the tables should be centered and aligned.

Thank you very much for your comment. We took this into account and corrected it

We also apologize for the many typos and stuck together words (this is due to working in several versions of Word 2003, 2007 and 2010).

Hope we have taken into account all your comments and you will be satisfied with the new version of the paper!

Kind Regards,

Authors

Author Response File: Author Response.docx

Reviewer 3 Report

This study shows that the aerosol model used by HawkEye underestimates the Angström parameter and thus introduces errors in the derived product. They provide very useful information for those who use satellite data. The paper would be better if you could indicate the uniqueness of this study.

The following modifications are proposed.

Equations are not numbered.

There is no space between words in some places.

Author Response

Dear Reviewer!

Thank you for giving us the opportunity to submit a revised draft of the manuscript “Using HawkEye Level-2 satellite data for remote sensing tasks in the presence of dust aerosol” for publication in the Atmosphere journal. We appreciate the time and effort that you dedicated to providing feedback on our manuscript and are grateful for the insightful comments on and valuable improvements to our paper. We have incorporated most of your suggestions and recommendations. Those main changes are highlighted within the manuscript (yellow). Please see below, for a point-by-point response to your comments and concerns (green highlighted). All page numbers refer to the revised manuscript file with tracked changes.

The paper would be better if you could indicate the uniqueness of this study.

Thank you for your advice, we are very pleased with the attention to our work. We noted the relevance and that this work was carried out for the first time in the lines 134-138.

Equations are not numbered.

Thank you very much for your comment. We took this into account and corrected it

There is no space between words in some places.

We also apologize for the many typos and stuck together words (this is due to working in several versions of Word 2003, 2007 and 2010).

Hope we have taken into account all your comments and you will be satisfied with the new version of the paper!

Kind Regards,

Authors

Round 2

Reviewer 2 Report

Thank the authors for the earnest responses, which have resolved my doubts. The revised manuscript is more logically sound and the content is more accessible. Personally, I believe that the revised manuscript meets the requirements of the journal and recommend it for acceptance pending publication.

Reviewer 3 Report

The manuscript has been revised well.