Tropical Cyclone Wind Field Reconstruction and Validation Using Measurements from SFMR and SMAP Radiometer

Round 1

Reviewer 1 Report

This work represents an important step-forward for the research in the climate change, especially considering the increasing impact of extreme marine events. Here, a reanalysis on the tropical cyclones was performed through the representation in ERA5 (European Centre for Medium-Range Weather Forecasts Reanalysis 5th Generation) and IBTrACS (International Best Track Archive for Climate Stewardship) during the period of 2018-2020. The method followed in this work showed an accurate representation of the asymmetric structure of tropical cyclones, with a following reconstruction of the typhoon wind field for the case where the reanalyzed wind speed underestimates the field data. The aspect about the underestimation of storm surge is an important topic, which authors have addressed with a good approach.

I have few questions that can improve this work.

In the section 2.4, it is possible to explain better the definitions of tropical cyclone position for the ERA5 reanalysis and IBTrACS. Are tropical cyclone positions defined in the same manner? This is important if you assessed the position deviation.

Considering the sentences for the storm surge assessment in the abstract and in introduction section, some reference concerning the effect of tropical cyclone must be inserted in the Discussion section. You can consider the literature works that described the impact of storm waves on the coasts, which determined flooding and erosion.

Other few comments are highlighted in the attached pdf file.

Kind regards.

Comments for author File: Comments.pdf

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

This paper compares the wind field of tropical cyclones with data provided by ERA5 and IBTrACS. The results of this comparison revealed the strong underestimation of the cyclon intensity by the ERA5 data. Moreover, reconstructed wind fields based on parameters of tropical cyclones have been compared with data from two radiometers, SFMR and SMAP. The number cases employed is noticeable, 94 cases belonging to cyclones with varied intensities. However, the authors have selected some cases to compare the wind profiles provided by SFMR, ERA5 and reconstructed profile by ERA5. The information handled by the authors is noticeable and improving the knowledge about this subject is necessary, since cyclones have a noticeable impact on the environment and structures built by the men. A good description of cyclones is useful to minimise their impact. Consequently, this paper merits to be published in Remote Sensing after the introduction of some minor changes.

Is Equation (1) suggested by the authors? In affirmative case, the authors should indicate the reasons for its form. In negative case, the authors should introduce the corresponding reference.

The discussion section should contrast the paper results with those from other authors or studies. Most of the references are placed in the introduction. Perhaps, the authors should consider to divide them. Some references should be reserved for the discussion section.

Figures 7, 8, 9 and 12 show the contrast of varied wind profiles. The agreement is qualitatively valued. However, some numerical estimator that quantifies the contrast would improve the paper.

Minor remarks.

The paper should be revised by an English native teacher.

Line 133. “…the advantages… are discussed”.

Line 165-166. Perhaps “…the most important of the parameters…”.

Line 213. Revise the sentence “. ratio…”.

Line 233-236. Since this information is included in Fig. 2, it should not be repeated.

Line 257. Improve the sentence. Perhaps “…Hart [14] indicated that the reanalyses…”.

Line 262. Supress “that”. The sentence should be “Figure 5 shows the scatter…”.

Figure 5. The colour scale presents negative values. Moreover, a unit for the scatter density should be introduced in this and similar figures along the paper.

Figures 7, 8, 9, and 12. Indicate the figure that corresponds to the profile before reconstruction and after reconstruction. Perhaps with labels such as (a), (b), (c)…

Line 337. Replace “it is can be” by “it can be”.

Line 338. Replace “winds is agreed” by “winds agreed”.

Figure 10 (a). If this figure corresponds to the situation before the reconstruction, the Y axis title should be modified.

Figure 11 (d). Replace “Befere” by “Before”.

Line 444-445. Remove “The authors would like to thank the reviewers for their useful suggestions”, since it is included in the acknowledgements section.

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

The manuscript concerns a critically relevant and scarcely studied topic.

The number of studied events is enough to justify the results of the research. In addition, the time frame is adequate and completely up-to-date.

Line 55-58. The authors properly refer to the importance of the study of the spatial representation of cyclones. The authors list the essential components necessary to require such representation. However, they do not mention the rain field produced by these phenomena. Although this paper only takes into account the wind fields; for the idea to be correct in this paragraph, it would be necessary to add the rain fields produced by cyclones, since they also produce damage, not only the winds.

doi.org/10.1002/joc.7335

The parameters that the authors operate in their methodology are very important and should be explained in detail. These parameters are fundamental in the development of the methodology and the results. For example, the units of the radius of the maximum wind speed (RMW) are unknown. It is necessary to read Jourdain et al., [21] and determine the units represent kilometers. In this presented work are these similar units used?

The authors clearly mention the parameters to be used, but not their units (lines 112-113).

Table 1. It is known that the US Agency proposes and is widely used the scale of intensities presented in the table. However, a reference is necessary, since there are different updates of these values.

According to the methodology proposed by the authors, there should also be an arrow from the blue block to the green block, correct?

Line 109. Equation (1) is fundamental to the research results. However, none of the variables have units. Additionally, the variable "ratio" is defined until line 227. The definition of "ratio" should be before equation (1). A table with the description of each variable, its units, its reference, etc., would be desirable.

Another fundamental part of the research is just the use of the "ratio". The authors mention they used a value of 1.3, however the authors refer to a range of 1.1 to 1.5. I consider all the research to be of high quality. The results are very useful. But I understand everything was performed with ratio =1.3 could the authors perform a sensitivity analysis with different ratio values?

Lines 222 and 223 what is the meaning of "cm"?

Figure 2 is unnecessary. What this figure shows is already described in the paragraph preceding the figure (lines 232-236).

Line 241. Is the value of 43.8 km meaningful?

Lines 253-259. This section is more of a discussion than a methodology or results.

Line 267. Figure 5, I suppose that the meaning of R is the correlation coefficient. However, R is not defined until line 307.

All the work is very good, the results excellent. The manuscript should be published after providing the observations referred to in this review.

Author Response

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Author Response File: Author Response.pdf