Comparison of Phenological Parameters Extracted from SIF, NDVI and NIRv Data on the Mongolian Plateau
, Quan Lai 1,2, Xiang Zhang 1,2 and Yusi Zhang 1,2Round 1
Reviewer 1 Report (Previous Reviewer 1)
The authors have made all the corrections highlighted in the text. They explained all the doubts were put it.
Author Response
Dear Reviewer:
Thank you for your letter commenting on our manuscript entitled "Comparison of phenological parameters extracted from SIF, NDVI and NIRv on the Mongolian Plateau" (ID: remotesensing- 2105645). At the same time, thank you for your support and encouragement, and wish you a happy life.
Reviewer 2 Report (Previous Reviewer 2)
The authors present paper Comparison of phenological parameters extracted from SIF, NDVI and NIRv on the Mongolian Plateau.
Introduction: Summarizes recent research related to the topic and establishes the research aims by demonstrating the need for investigations in the topic area - the analyses based on sun-light-induced chlorophyll fluorescence (SIF), the normalized difference vegetation index (NDVI) and the near-infrared reflectance of vegetation (NIRv)
However, Please delete paragraphs 85-87. Move it to the Study area.
Materials and Methods with Study area (Mongolian Plateau, Central AsiaData sources (Sunlight-induced chlorophyll exposure, MODIS data set, Extraction of vegetation phenological parameters, ERA5-Land climate data set, Population density data and Terrain dataset
However, please remove the paragraph 219-224. Bibliographic reference is enough
Next, Methods are presented in details: The Breaks for Additive Season and Trend algorithm (BFAST) method and Theil–Sen median trend analysis and Mann–Kendall analysis. In the same section: Detection and analysis of change points of phenological parameters,
Pearson correlation analysis and partial correlation analysis, Path analysis and Geographical detector model
Results are better understood due to illustrated with clear and informative schemes and figures. There is a very large volume of data whose trends are illustrated graphically. This is good because there is an excess of information that can lose the reader.
The discussion re-emphasises the key points and compare with related examples. However, the discussion should not simply rehash the results without critically interpreting them.
Nevertheless, statements that are exaggerated and speculation that is not supported by evidence should be avoided.
The conclusions reflect the manuscript’s content but be more than just rephrasing the discussion.
Author Response
Dear Reviewer:
We thank you for your letter commenting on our manuscript entitled "Comparison of phenological parameters extracted from SIF, NDVI and NIRv on the Mongolian Plateau"(ID: remotesensing-2105645). At the same time, I would like to thank you for making important contributions to our study by using your valuable time. We also appreciate your encouragement and support, which is very important to us. We have carefully studied the comments and corrected them in the hope of approval. The modified part is marked in red on the paper. At the same time, we will mark the page number and line number in the main answer. Please see the attachment for the main corrections and comments on the reviewers in the paper.
Author Response File: 
Author Response.docx
Reviewer 3 Report (New Reviewer)
It looks to me that tme manuscript has gone already through some review process, changes in manuscript are probably reactions to some review. I see the manuscript as beneficial, it uses data retrieved using novel approaches (GOSIF) and shows data at large scale. I am not expert in satellite data processing or interpreting, I cannot further judge the quality. Major parts of the manuscript – introduction, results, discussion look to me as good written. I have some concerns about the abstract.
In abstract I am lost between all those spring, summer, autumn data, SOS, LOS and other terms like melting snow and other facts. SIF is still SIF regardless of snow melting. There should be one significant point in the abstract as the result. There is also limit given for the abstract 200 words.
Line 57 – how can phenological factors vary with climatic factors, rather parameters can be affected with factors, and in results yield different results for different ecosystems. But from the sentence I feel the first. Similar feeling I have from line 170.
Line 58 – we do not retrieve start of vegetative period, we can identify it.
Line 65 – what is mutation of vegetation, it sounds rather like genetics.
Line 67 – what is LOS, it appears so suddenly.
Why is in abstract years 2001-2003 and later in text 2014-2016.
Author Response
Dear Reviewer:
Thank you for your letter commenting on our manuscript entitled "Comparison of phenological parameters extracted from SIF, NDVI and NIRv on the Mongolian Plateau"(ID: remotesensing- 2105645). At the same time, I would like to thank you for using your valuable time to contribute to our research. These comments are very valuable for the modification and improvement of our paper and have important guiding significance for our research. The revised part is marked in blue in the manuscript. And for the main changes, we marked the specific line number. Please see the attachment for the main corrections and comments on the reviewers in the paper.
Author Response File: Author Response.docx
This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.
Round 1
Reviewer 1 Report
In this manuscript, the response of phenological parameters to climatic factors is analysed.The analyses based on several index, namely, sun-light-induced chlorophyll fluorescence (SIF), the normalized difference vegetation index (NDVI) and the near-infrared reflectance of vegetation (NIRv).
The results show that SIF and NIRv can retrieve more details of the vegetation dynamics and identify mutations earlier. This study was applied in Mongolian Plateau is located in Central Asia
This manuscript has introduction, study area, methodology, results and discussion and bibliography.
Reading the manuscript becomes difficult because it analyzes a lot of data and correlates a lot of information.
Comments for author File: 
Comments.pdf
Author Response
Dear Reviewer:
Thank you for your letter commenting on our manuscript entitled "Comparison of phenological parameters extracted from SIF, NDVI and NIRv on the Mongolian Plateau" (ID: remotesensing-2004248). At the same time, I would like to appreciate you for making use of your valuable time to contribute to our study. We also appreciate your encouragement and support, which is very important to us. Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our studies. We have studied comments carefully and have made correction which we hope meet with approval. The revised part is marked in bold green on the manuscript. Please see the attachment for the main corrections in the paper and the responses to the reviewers' comments.
Author Response File: Author Response.docx
Reviewer 2 Report
The authors present paper Comparison of phenological parameters extracted from SIF, 2NDVI and NIRv on the Mongolian Plateau. The manuscript is well-written and nicely presented, as well.
Introduction: Provides a clear idea of phenology of the Mongolian Plateau.
Anyway, the however paragraphs 50-59 express the authors' own ideas because there is no citation and it would be better to move them to the Discussion.
The statement of 41 is repeated at 121.
Objective 1 (93-94) is repeated at 112-114
144,145, 154, 171, 214, 219 should be moved at References
331-336 the phrase is redundant
Results The results contain too many details that do not belong here. maybe in discussions: for example 334-338 the phrase should be deleted; there is no result.
Discussions are too limited in contrast with the results. So, this section needs to be developed.
The conclusions reflect the objectives very briefly but well.
Author Response
Dear Reviewer:
We thank you for your letter commenting on our manuscript entitled "Comparison of phenological parameters extracted from SIF, NDVI and NIRv on the Mongolian Plateau" (ID: remotesensing-2004248). At the same time, I would like to thank you for making important contributions to our study by using your valuable time. Your keen and thorough analysis has benefited us a lot. At the same time, your detailed and professional comments are very valuable for the modification and improvement of our paper and have important guiding significance for our research. We also appreciate your encouragement and support, which is very important to us. We have carefully studied the comments and corrected them in the hope of approval. The modified part is marked in bold red on the paper. At the same time, we will mark the page number and line number in the main answer. Please see the attachment for the main corrections in the paper and the responses to the reviewers' comments.
Author Response File: Author Response.docx
Reviewer 3 Report
This paper retrieved the SOS and EOS based on SIF, NDVI and NIRv. The correlations between these phenological parameters and snow-related factors, precipitation, temperature, soil moisture and population density were also analyzed. The following issues are worth considering.
1. Line 23, and 792, LOSSIF, whether there are spelling errors?
2. Line 162, and 170, Please clarify the specific method of resampling.
3. Line 187, Format problem.
4. Line 222, Please provide expansion for “BFAST”.
5. Line 233, “SIF from 2003-2020”, why? Line 146, GOSIF data sets from 2001 to 2020.
6. In section 2.3.1, I think it is difficult to understand these formulas. For example, what does “t” mean? Do αi and αj have the same meaning? What is the meaning of their table below? And so on. Therefore, it is suggested that the authors further clarify these formulas.
7. Line 335, “for”?
8. Section 3.1, From the results, the author may not consider the spatial distribution of vegetation. How does spatial distribution affect the results? Does the result without considering spatial distribution have scientific significance? Why did the author not consider changes in other vegetation types? What is the significance of finding these breakpoints?
9. Section 3.2, What is the accuracy and uncertainty of phenological parameters?
10. Line 430, Figure 3?
11. Line 464-465, Therefore, as the altitude increased, LOSSIF was significantly shorter, LOSNDVI slowly increased, and LOSNIRv was significantly longer. It seems contradictory here, why? What conclusions should readers draw from this result? Is NIRv not suitable for extracting phenological parameters?
12. The words in Figure 5 are too large to fit the text. Some words in Figure 6 are too small to be seen clearly. To make matters worse, there are two figures with the same figure number, both of which are Figure 6.
13. Line 560, Figure 6 a?
14. In Figure 8, The meaning of many abbreviations is not clear, which may cause confusion for readers. Please expand in the caption. What is the meaning of the sub graph?
15. Line 561-562, The spring snow melting period showed a more significant negative correlation with SOSNDVI and SOSNIRv. How to understand the word negative? I think both readers and I may be confused. Please clarify the relationship between snow cover and SOSNDVI and SOSNIRv in detail.
16. The conclusion needs further improvement. The current conclusions and results are similar. What should we do when the results from different remote sensing data are inconsistent? Will EOS appear in summer?
17. This manuscript is very long and has done a lot of work. However, it seems that no work is deep enough. I recommend that the author study each question thoroughly and form conclusions with scientific value.
Author Response
Dear Reviewer:
Thank you for your letter commenting on our manuscript entitled "Comparison of phenological parameters extracted from SIF, NDVI and NIRv on the Mongolian Plateau" (ID: remotesensing-2004248). At the same time, I would like to thank you for using your valuable time to contribute to our research. These comments are very valuable for the modification and improvement of our paper and have important guiding significance for our research. We also appreciate your encouragement and support, which is very important to us. We have carefully studied the comments and corrected them in the hope of approval. The revised part is marked in bold blue in the manuscript. And for the main changes, we marked the specific line number. Please see the attachment for the main corrections in the paper and the responses to the reviewers' comments.
Author Response File: Author Response.docx
Round 2
Reviewer 2 Report
Dear Authors,
Thank you for your comments. Good luck in your work!
Author Response
Dear Reviewer:
We thank you very much for your constructive and important comments, which have made great contributions to our work. At the same time, we would also like to thank you for your encouragement and support, which is very important to us. Finally, we wish you success in your work and a happy life.
Reviewer 3 Report
The quality of the revised manuscript has been improved. However, there are still two issues that the author did not give a satisfactory explanation. (1) What is the accuracy and uncertainty of phenological parameters? This issue may be relevant to the scientificity of this manuscript. (2) Line 162, and 170, Please clarify the specific method of resampling. For example, 1km to 5km, this means that 25 pixel values are resampled to one pixel value, what is the algorithm for this?
Author Response
Dear Reviewer:
Thank you for your letter commenting on our manuscript entitled "Comparison of phenological parameters extracted from SIF, NDVI and NIRv on the Mongolian Plateau" (ID: remotesensing-2004248). At the same time, I would like to thank you for using your valuable time to contribute to our research. These comments are very valuable for the modification and improvement of our paper and have important guiding significance for our research. We also appreciate your encouragement and support, which is very important to us. We have carefully studied the comments and corrected them in the hope of approval. The revised part is marked in bold blue in the manuscript. And for the main changes, we marked the specific line number. Please see the attachment for the main corrections in the paper and the replies to the reviewer's comments.
Author Response File: Author Response.docx
