Improving Forecast of Severe Oceanic Mesoscale Convective Systems Using FY-4A Lightning Data Assimilation with WRF-FDDA

Round 1

Reviewer 1 Report

The topic and study is interesting and important in the society, and deserve to publish in the journal. However, I have some comments and suggestions for improving the quality of the manuscript and study. 

 

1. In the last paragraph of the introduction, the purpose of the study is not clear and solid enough, author should emphasize the originality of the current study and why it is important.
2. Section 2, for radar data, please provide the details of quality control for radar data. It seems to me that observations of radar data in Figs 5 and 7 have significant ground clutters. 
3. For the study of data assimilation, it is very weird that there is no equations at all in the entire manuscript. Authors should include the forward model (observation operator) of assimilating lightning data, and provide the details of the assimilation process. In addition, the definition and equation of FSS score is need. 
4. Please justify the reason of selecting these two cases. Are they similar or different cases? 
5. Please justify that only 34 model-level is applied in this study. Compare to horizontal resolution, vertical resolution seems low. 
6. Even though appendix define the abbreviations, there is no connection of  experimental designs and "ASML" and "CTRL" in the content. 
7. For model validation, it is not convinced that only FSS score is applied to quantitative evaluation of these two cases. Different forecast skill score for model verification would be necessary. 
8. How to select the black boxes in Figs 6 and 8? 
9. Since this study focused on convective systems, it is desired to see and examine the results and performance of vertical structure. Current figures only provide 2D horizontal features to the study.  

Author Response

Dear reviewer,

Please find our response in the attachment.

Best regards.

Author Response File: Author Response.docx

Reviewer 2 Report

Dear Authors,

Please find attached my comments

Best regards

Comments for author File: Comments.pdf

Author Response

Dear reviewer,

Please find our response in the attachment.

Best regards.

Author Response File: Author Response.docx

Reviewer 3 Report

Improving Forecast of Severe Oceanic Convective Systems Using FY-4A Lightning Data Assimilation with WRF-RTFDDA

Hao Sun, Haoliang Wang , Jing Yang, Yingting Zeng , Qilin Zhang, Yubao Liu, Jiaying Gu, Shiye Huang

Summary

The authors present two case studies showing the impact of assimilating high resolution lightning data into a regional model for forecasting non-typhoon convective events over the South China Sea. A previous study showed that a LDA scheme nudging graupel mixing ratio and potential temperature based on lightning is most effective at improving convection. The authors employed this scheme in their regional model. The study is well written and shows clear improvement of the forecast over the control experiment when lightning data is assimilated through graupel mixing ratio and potential temperature nudging. My only comment is that the authors run only 2 cases. It would have been better if at least one season of cases could have been run to provide better statistics on this method. I recommend publication after fixing minor grammatical errors and addressing minor points of confusion in the text. 

Major comments:

Lines 203-205 - Can the authors clarify what the 1 hour interval is in the diagram? Is this the output time interval? 

Line 229 - Do the authors mean Convection 1? Fig. 6a shows a small red contour in the CNTL in the region of Convection 1. 

Fig. 6 - Please add the red ellipses of Convection 1, 2, 3 to Fig. 6a and c to ease in these comparisons. Why just contour the 1.5 m/s updraft value? Are you saying that within that contour the ASML updrafts increase to as much as 9 m/s? Is the small red contour in panel a 1.5 m/s? In the text (line 228) you state the maximum value for the CNTL is 1.2 m/s. Please clarify.

Fig. 8 - Please add red ellipses to all panels. 

Fig. 9 - There are no negative times in this panel though that would be the preferred way to display these results. I recommend leaving the caption and fixing the x-axis to have -2, -1, 0, 1, 2, etc. for Simulation Time.

Minor edits:

Line 42 - suggest deleting “for assimilation”.

Line 52 - suggest replacing “applied” with “made available”.

Line 83 - suggest changing to “when they are advected towards land.”

Lines 83-84 - suggest changing to “one of the most frequently effected regions in the world to be devastated by”.

Line 128-129 - change to “Wang et al. [29]).”

Line 134 - looks like a circle not an ellipse?

Line 153 - change to “Wang et al. [29].”

Line 155 - suggest changing to “ten summer severe convective events over the SCS” or “convective events for ten summer seasons over the SCS”. Did you simulate ten summers or ten events in the summer season? Please clarify and adjust wording as needed.

Line 158 - change to “relatively”.

Lines 160, 161- change to “Wang et al. [29]”

Line 171 - suggest changing to “cases that occurred over the South China Sea were selected”.

Line 175 - suggest changing to “were merged into a squall line”.

Line 177 - suggest changing to “developed over several hours”.

Line 179 - suggest changing to “moved north and dissipated over a period of 5 hours”.

Line 201 - suggest changing to “between parent and inner nests was used”.

Line 216 - change Fig. 5 to Figure 5.

Line 218 - change to “better captured by ASML than CTRL”.

Line 221 - delete “in good”.

Line 222 - change to “were not well simulated by”.

Line 224-225 - Move “(Fig. 6)” to end of this sentence following “environments” or change text to “were analyzed in Figure 6 to demonstrate”.

Lines 236-237 - revise to “Conversely, convergence regions of the observed convective systems were not accurately simulated by the CNTL partly contributing to the poor simulations of these systems in this simulation.” If this is not exactly what is intended, please revise as needed. The current sentence is confusing and not grammatically correct.

Line 268 - change “does not” to “is not”.

Line 274 - change to “more accurately”.

Line 283 - change to “in ASML to be around”.

Line 284 - remove “were”.

Line 288 - change to “convergence”.

Line 295 - remove “Nevertheless,”.

Line 370 - change to “partly explained by the deviations of the initial convergence in the regions”.

 

Author Response

Dear reviewer,

Please find our response in the attachment.

Best regards.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Authors did lots of effort to revise the manuscript based on previous suggestions and comments. I have no further suggestions and agree to accept the manuscript in the current version. 

Author Response

Dear reviewer,

Please find our response in the attachment.

Best regards.

Author Response File: Author Response.pdf

Reviewer 2 Report

Dear Authors,

Thank you for the complete review of your manuscript. I include here some points that should be solved before the acceptance of the research:

• "Severe convective weathers"? Please change to "Weather"
• L74: Which is the degree of improvement using LDA?
• I think that your answer should be included in the text "The spatial resolution of LMI (7.6 km) is lower than that of the inner domain (3 km). Previous studies found that the lower resolution of satellite-based lightning detection may lead to a larger spatial extent of convective systems compared to the observations [30,44]. However, benefits will still be obtained by assimilating such data, especially for marine areas not covered by high-resolution radar detection as indicated by the results of this study."
• Please, clarify what kind of convective organization are you referring to with the term "Convective System" (see, for instance, Pacey, G. P., Schultz, D. M., & Garcia-Carreras, L. (2021). Severe convective windstorms in Europe: Climatology, preconvective environments, and convective mode. Weather and Forecasting, 36(1), 237-252.)
• I think you should add this point in your manuscript, to clarify the reader's point of view: "The outer domains of the two oceanic convective cases are the same while the inner domains are different. This is because the convective cells are preferred to be covered in the inner domain in the whole simulation period, and the positions and development directions of convective cells are different in the two cases. Therefore, the coverage of the inner domains in the two cases are slightly different."

Best regards

Author Response

Dear reviewer,

Please find our response in the attachment.

Best regards.

Author Response File: Author Response.docx