A Comparative Study of Cloud Microphysics Schemes in Simulating a Quasi-Linear Convective Thunderstorm Case

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The study investigated the microphysical characteristics of a quasi-linear, convective process occurring in Beijing on 30 May 2024 from multiple perspectives using diverse data sources. The research provides a detailed explanation of the microphysical processes and development patterns of this precipitation event, providing an in-depth insight for the formation of precipitation events over Beijing city. The topic and the contents of this paper fall into the scope of the journal. The structure of manuscript is well organized. The article is clearly written. Some revisions are suggested as follows:

1)     The abstract is comprehensive but could be more concise. Consider reducing the length while retaining the key findings and significance of the study.

2)     With regards to the conclusion and discussion: Currently, it reads more like a summary. It would be beneficial to place the results of this study within the broader context of previous research. Additionally, discussing how the results from this study compare to those from other frameworks would provide a deeper understanding and highlight the significance of the findings. More importantly, the discussion should include a comparison of the findings with previous studies on quasi-linear convective process and precipitation in Beijing city or adjacent regions. Highlight any novel insights or confirmations of previous hypotheses.

3)     Is it a first comparative work of microphysics scheme analysis for the quasi-linear convective process occurring in Beijing? If not, please summarize the previous related work in the introduction.

4)     Figure 4 appears slightly cluttered. To make it clearer, consider adding a new sub-figure showing the 950-hPa level at 15:00 as Figure 4(i). The current topographic map, labelled as Figure 4(i), can then be made into a separate figure to clearly shown the terrain.

5)     Line 77: a space is needed between two sentences.

6)     A space is needed between a number and its units. For example, line 295 and 296, a space is needed between 55 and dBZ. Please check the whole manuscript.

7)     In section 4.2.1, please use italic formats for the letters representing different variables.

8)     Please check the usage of English language for the full text and use scientific and popular words to enhance the readability of the article.

Comments on the Quality of English Language

The  English is well written, but the manuscript would be be benifit if the authors  reading the entire paper again to check for spelling or grammatical errors.

Author Response

Reviewer 1

The study investigated the microphysical characteristics of a quasi-linear, convective process occurring in Beijing on 30 May 2024 from multiple perspectives using diverse data sources. The research provides a detailed explanation of the microphysical processes and development patterns of this precipitation event, providing an in-depth insight for the formation of precipitation events over Beijing city. The topic and the contents of this paper fall into the scope of the journal. The structure of manuscript is well organized. The article is clearly written. Some revisions are suggested as follows:

1)     The abstract is comprehensive but could be more concise. Consider reducing the length while retaining the key findings and significance of the study.

According to reviewer’s comment, we made revisions in the abstract to be more concise. Please see the abstract.

2)     With regards to the conclusion and discussion: Currently, it reads more like a summary. It would be beneficial to place the results of this study within the broader context of previous research. Additionally, discussing how the results from this study compare to those from other frameworks would provide a deeper understanding and highlight the significance of the findings. More importantly, the discussion should include a comparison of the findings with previous studies on quasi-linear convective process and precipitation in Beijing city or adjacent regions. Highlight any novel insights or confirmations of previous hypotheses.

 According to reviewer’s advice, we added more explanations and discussions. Please see the section 1 (line 63-75) and section 6 (line 480-492). To the best of our knowledge, exhaustive examinations of the influence of diverse microphysics schemes in numerical models on the quasi-linear thunderstorms in Beijing are few. Thank reviewer very much for these comments and suggestions.

3)     Is it a first comparative work of microphysics scheme analysis for the quasi-linear convective process occurring in Beijing? If not, please summarize the previous related work in the introduction.

According to reviewer’s comment, we added previous works and the summaries in the introduction, also in the conclusions (please see line 63-75, line 480-492).

4)     Figure 4 appears slightly cluttered. To make it clearer, consider adding a new sub-figure showing the 950-hPa level at 15:00 as Figure 4(i). The current topographic map, labelled as Figure 4(i), can then be made into a separate figure to clearly shown the terrain.

According to reviewer’s advice, we revised Figure 4 and added a new separate topographic map (Figure 5).

5)     Line 77: a space is needed between two sentences.

It was added.

6)     A space is needed between a number and its units. For example, line 295 and 296, a space is needed between 55 and dBZ. Please check the whole manuscript.

It was added. Whole manuscript has also been checked.

7)     In section 4.2.1, please use italic formats for the letters representing different variables.

They were revised.

8)     Please check the usage of English language for the full text and use scientific and popular words to enhance the readability of the article.

Thanks. According to reviewer’s advice, we revised this section. The structure is rearranged and some descriptions are added. We hope they could satisfy reviewer.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Review of A Comparative Study of Cloud Microphysics Schemes in Simulating a quasi-linear convective thunderstorm case by Huo etc.

 

This paper tries to provide two topics. The first is to investigate the forming mechanism (mainly the evolution) of an afternoon severe storm occurred in Being on May 30, 2024. The second one simulates and explores the event using the WRF model with various microphysics schemes. These two topics do not seem related much in the paper. To me, it seems losing focus. I would recommend to either focus on one topic or make the two topics closer with reasonable scientific facts.

 

I like the detail explorations of the hydrometeor profiles with various MP schemes. The paper, however, only presents their observed facts about the vertical distributions of the hydrometeors. It does not show which outcomes from the MP scheme are more reasonable and why. Furthermore, based on my limited knowledge, for convection allowing model (3-km resolution) simulations (high-impact events as the one simulated in the paper), the Thompson scheme and the NSSL 2-moment schemes perform much better than all other schemes studied in the paper. I am wondering why the authors did not include these two schemes in their study.

 

The assessments of the simulated reflectivity and the simulated rainfall are all subjective and it lacks quantitative analysis. There are many evaluation facilities for verifying radar reflectivity and precipitations. A basic one is the neighborhood-based evaluation (or object-based evaluations for the more advanced technique). The paper will be more valuable if the quantitative analysis is added.

 

Overall, my suggestion is a major revision should be needed.

 

Minor Issues:

 

1.     It lacks a summary paragraph about each following section in the introduction.

2.     It is recommended to denote the District names with a figure, for example, Shunyi District, Fengtai District, Yanqing District etc.

3.     Line 58-59: “The total number of annual heavy rainfall event, ….. is relatively small” -> “Heavy rainfall events, …. are relatively rare.”

4.     91-92: What is the “integration time”?

5.     It is recommended to denote the observation times in the subpanels directly in Figure 1.

6.     Will it be possible to denote the two low-vortex centers in Figure 3?

7.     What is the unit “dagpm”?

8.     Line 226: “even weak convective energy”?

9.     Please describe the blue circle in Figure 4(e) or leave it out.

10.  Line 245-247: Note that NCEP is one institution under NOAA.  The WRF model is a collaborative effort among NCAR, NOAA and many research universities.

11.  Table 1, Do all three nested domains use time step 10s? What a waste of resources.

12.  Line 255: Table 1 shows number of model layers is 37. Then why was a vertical resolution of 99 sigma levels employed?

13.  Line 256-263: Could you denote which MP schemes are single-moment schemes and which ones are double-moment schemes?

14.  Line 297, 304, 307, 310 and 318: These sentences confuse me about which MP scheme performs the best according to the authors?

15.  Caption to Figure 5: Please drop the duplicated words, “with simulated with”.

16.  Line 345-353: I cannot understand the “late triggering time” description. Since the system is moving from northwest to southeast and the simulated precipitation bands appear 15 km southeast to the observed rainfall, it seems that the WRF simulations move too fast, but not being delayed?

17.  Line 408: “The right-hand columns of figure 7” -> “The rightmost columns of Figure 7”.

18.  Line 440: “Thompson scheme”?

19.  Line 456: “the observed” -> “the observations” or “the observed reflectivity”.

 

                                         

Author Response

Dear Reviewer：

We deeply thank you for the helpful comments and suggestions presenting us important guidance to the improvements of our researches and the manuscript. We have made corresponding corrections and added new descriptions and references in the revised manuscript according to the comments. The revised portions have been marked in the manuscript with blue color. The responds (blue color) to your comments are as follows.

Reviewer 2

This paper tries to provide two topics. The first is to investigate the forming mechanism (mainly the evolution) of an afternoon severe storm occurred in Being on May 30, 2024. The second one simulates and explores the event using the WRF model with various microphysics schemes. These two topics do not seem related much in the paper. To me, it seems losing focus. I would recommend to either focus on one topic or make the two topics closer with reasonable scientific facts.

We're sorry for the confusions. As stated in the title and the abstract, this article focuses on the impacts of microphysics schemes in numerical models through the comparison work. On one hand, this event was not forecasted accurately by the city meteorological service. On the other hand, the current model simulations were not "satisfactory" when compared with the observations. Therefore, in Section 3, a significant amount of space is taken up to introduce the thermodynamic conditions of the process in detail, in order to let the readers have a clear understanding of the synoptic or environmental background, which is expected to help to find out the possible reasons for the unsatisfactory simulation results of the numerical model. In fact, most work of this study is focused on the comparisons of schemes for the simulation of linear convective event. Thus, the second topic reviewer mentioned above is the topic of this study.

   If possible, we will use more microphysics schemes and seek more data or the AI models to carry out more detailed analyses in the future to improve the forecast accuracy of such weather processes.

We hope reviewer could accept the arrangement of current article.

 I like the detail explorations of the hydrometeor profiles with various MP schemes. The paper, however, only presents their observed facts about the vertical distributions of the hydrometeors. It does not show which outcomes from the MP scheme are more reasonable and why. Furthermore, based on my limited knowledge, for convection allowing model (3-km resolution) simulations (high-impact events as the one simulated in the paper), the Thompson scheme and the NSSL 2-moment schemes perform much better than all other schemes studied in the paper. I am wondering why the authors did not include these two schemes in their study.

The analyses of cloud-particle microphysical vertical profiles in this paper are all carried out based on the output results of the model. The radar images used in this paper are the composite radar graphs downloaded from official websites, however, the vertical structure data, such as radar reflectivity and microphysical parameters of each column (or pixel), were inaccessible from public website. Due to the lack of vertical data, the judgment of which scheme is the best can only rely on the our experiences by comparing the images to make an indirect evaluation, and the quantitative comparison of radar images, the MP, cannot be achieved at present. We hope that this work could be approved by the reviewer.

Since the precipitation observation data of this event are rich, we have quantitatively compared and analyzed the precipitation results according to the reviewer's comments. Based on these comparison results, some corresponding conclusions are given in the article. Please see new figure 8 and revised section 4.2.2.

The selection of the five microphysics schemes in this paper is mainly based on the following considerations: (1) the comparison between single and dual moment schemes; (2) from previous works about the comparisons of microphysics schemes; and (3) we hope that the simulation results can be compared with the radar reflectivity factor. However, some of the microphysics schemes in the WRF model, for example, the NSSL scheme mentioned by the reviewer, do not provide calculations of the reflectivity factor. In addition, the reviewer mentioned the Thompson scheme (mp_physics=8), and we actually did simulations using this scheme. However, the results seem to be not so good (see the simulation results of radar reflectivity factor in the following figure, the left figure is Thompson scheme, and the right figure is Goddard scheme, mp_physics=7). Hope reviewer could accept it.

Figure left: Thompson scheme; right: Goddard scheme

 

The assessments of the simulated reflectivity and the simulated rainfall are all subjective and it lacks quantitative analysis. There are many evaluation facilities for verifying radar reflectivity and precipitations. A basic one is the neighborhood-based evaluation (or object-based evaluations for the more advanced technique). The paper will be more valuable if the quantitative analysis is added.

 Agree with reviewers' comments. As described in the previous response to above comment, we have added quantitative comparisons in the revised manuscript. Please see new figure 8 and section 4.2.2.

Overall, my suggestion is a major revision should be needed.

 

 Minor Issues: 

1. It lacks a summary paragraph about each following section in the introduction.

According to reviewer’s advice, we added a summary paragraph in the introduction (please see line 98-104).

2. It is recommended to denote the District names with a figure, for example, Shunyi District, Fengtai District, Yanqing District etc.

According to reviewer’s comments, these District names were added in Figure 2.

3. Line 58-59: “The total number of annual heavy rainfall event, ….. is relatively small” -> “Heavy rainfall events, …. are relatively rare.”

They were revised according to reviewer's advice.

4. 91-92: What is the “integration time”?

It should be integral time. The rainfall accumulated in 1 minute is recorded.

5. It is recommended to denote the observation times in the subpanels directly in Figure 1.

They were added in Figure 1 according to reviewer's advice.

6. Will it be possible to denote the two low-vortex centers in Figure 3?

According to reviewer’s comments, we add some words about the centers in the caption of Figure 3.

7. What is the unit “dagpm”?

The decameters of geopotential height.

8. Line 226: “even weak convective energy”?

Sorry for that. It was deleted.

9. Please describe the blue circle in Figure 4(e) or leave it out.

It was described in the figure4 caption and text (please see line 236).

10. Line 245-247: Note that NCEP is one institution under NOAA.  The WRF model is a collaborative effort among NCAR, NOAA and many research universities.

Sorry for that. The sentence was revised according to reviewer's advice (please see line 268-270).

11. Table 1, Do all three nested domains use time step 10s? What a waste of resources.

Yes.

12. Line 255: Table 1 shows number of model layers is 37. Then why was a vertical resolution of 99 sigma levels employed?

The 37 layers is refer to the input ERA5 reanalysis data layer. Sorry for that. We revised Table 1 to avoid such confusion.

13. Line 256-263: Could you denote which MP schemes are single-moment schemes and which ones are double-moment schemes?

According to reviewer’s comments, we add some words about the schemes. Please see line 282-284.

14. Line 297, 304, 307, 310 and 318: These sentences confuse me about which MP scheme performs the best according to the authors?

We're sorry for that. These sentences explain the performances of the five schemes from different perspectives. We revised some statements and hope reviewer could accept them (please see line 331-333, line 412-414, line 520-521).

15. Caption to Figure 5: Please drop the duplicated words, “with simulated with”.

They were deleted. Sorry for that.

16. Line 345-353: I cannot understand the “late triggering time” description. Since the system is moving from northwest to southeast and the simulated precipitation bands appear 15 km southeast to the observed rainfall, it seems that the WRF simulations move too fast, but not being delayed?

The model forecasts rainfall later than it actually occurs. It might be that the simulation of precipitation from development to maturity in the model were slower than it actually was. In other words, the model considered the event to be at developing stage while it should actually be at a mature stage. The immature system passed the city center pushed by the wind before it rained. Therefore, the model should be lagging behind. We hope reviewer would accept our viewpoints.

17. Line 408: “The right-hand columns of figure 7” -> “The rightmost columns of Figure 7”.

It was revised.

18. Line 440: “Thompson scheme”?

It was Morrison. We're sorry for that.

19. Line 456: “the observed” -> “the observations” or “the observed reflectivity”.

 It was revised.

 

 

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

This manuscript compares the performance of five cloud microphysical schemes in simulating a convective storm event in Beijing. The method is clearly described, and the content is well presented. I recommend the manuscript for publication with minor revisions.

Comments on the Quality of English Language

In general, the article is well-written, though there are several minor grammatical errors and inappropriate descriptions throughout the manuscript. For example, in line 83, the phrase 'strengthening Beijing's capability...' is not commonly used. Additionally, in line 134, the word 'formidable' is more likely to be used in a newspaper than in a scientific manuscript when describing storm intensity. I suggest the authors revise the manuscript and correct these inappropriate usages before proceeding with publication.

Author Response

In general, the article is well-written, though there are several minor grammatical errors and inappropriate descriptions throughout the manuscript. For example, in line 83, the phrase 'strengthening Beijing's capability...' is not commonly used. Additionally, in line 134, the word 'formidable' is more likely to be used in a newspaper than in a scientific manuscript when describing storm intensity. I suggest the authors revise the manuscript and correct these inappropriate usages before proceeding with publication.

We deeply thank you for the helpful comments and suggestions. We have made corresponding corrections according to your advice (please see line 33-36, 52-53, line 96-98, line 154-155, etc.). We hope they meet your approval.

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

I would like to thank the authors for their reply to my initial comments. I agree that the paper is ready for publication.

However, I still maintain that the scientific soundness of this paper is significantly diminished due to the lack of quantitative analysis.

Additionally, I do not agree with the authors' conclusions regarding the Thompson scheme and the NSSL 2-moment scheme in their reply. First, the NSSL MP scheme does indeed include reflectivity outputs; the authors may not have accessed the correct version of the package. Second, the simulation results of radar reflectivity from the Thompson scheme, as presented in their reply, are questionable. There appears to be an issue that needs to be addressed.

Author Response

Thank reviewer for the valuable comments and approval. We acknowledge that the simulation outcomes of the Thompson scheme raise concerns and we will proceed to investigate potential causes for this discrepancy.

Currently, we are utilizing WRF version 4.4, according to the official WRF user guide, the radar reflectivity calculations are detailed as:

"do radar ref =1: compute radar reflectivity using microphysics-specific parameters in the model. Works for mp physics = 2,4,6,7,8,10,14,16."  The NSSL scheme (identified by mp physics=17,18) was not initially considered due to its absence in our selection list. In light of the reviewers' suggestions, we have plans to include simulations with this scheme in our subsequent work. Given time constraints and other logistical factors, we kindly request the reviewers' understanding and endorsement of our current manuscript.

Looking ahead, we intend to undertake separate simulations and comprehensive analyses for both the NSSL and Thompson schemes. According to reviewer's comments, we added some words about this in the 'Conclusions and Discussions' section, highlighted in red. We hope they meet your approval.