Mesoscale Convective Systems: A Case Scenario of the ‘Heavy Rainfall’ Event of 15–20 January 2013 over Southern Africa
Round 1
Reviewer 1 Report
The manuscript analyzed the "heavy rainfall" event of 15-20 january 2013 over Southern Africa by taking advantage of observed data,satellite imagery and reanalysis data. The English is well writen. However the manuscript is more discriptive,less quantative expression. The manuscription is focusing on an event, it is much more synoptics, but less climate.
1)for a case study, the quantative or diagnostic or dynamical analysis are needed. The manuscript expressed too much qualitative. Although the writer emphasized the mesoscale convective system is so important to the heavy rainfall event,but how much the rainfall was produced by mesoscale convective system?
2)We can see the cloud belts system for the heavy rainfall event, but it is not clear how much the contribution of each subsystem is to the event.
3) Some figures quality need to be improved.
4)The section 1 and 2 need to be compressed, focusing on the mesoscale convective system and precipition.
Author Response
Reviewers # 1 and 3:
Need to compress sections 1 and 2, focusing more on mesoscale convective systems (MCSs) and precipitation.
As per the reviewers’ suggestion, these sections have been revisited and revised. We have trimmed both sections, removing repeating information and narrowed down the text to focus mainly on MSCs and precipitation. Section 1 is an introductory part, concepts of which are developed/discussed in the succeeding sections of the article.
Figure quality and grid
While we agree with the reviewers’ comments about improving the figure qualities, we reproduced some of the figures but there is no substantial difference between some of the figures. We found that enlarging some of the figures further distorts some figures (e.g. Figs. 7, 11 and 12) -becoming more faint and not easily readable. Some of the figures (e.g. Fig. 3) could not be drawn without the grid; we use NCL script to reproduce this figure and it would not be easy to overlay the graphs into (for different years) since they are of different scales.
Climatic character
We acknowledge the reviewers’ comments that we should introduce a more “climatic” character in the manuscript about MCSs, we approach this in a slightly different way in our revised paper. We introduce this concept in Section 2, where we briefly discuss their structure and climatology (pages 3–4). Since the scope of the paper is to understand the ‘heavy rainfall event” in 2013 (not generally describing MCSs), we refer the reader to some of the literature/reference material on MSCs. However, we acknowledge the fact that other readers may share this reviewer’s perspective of a more climatological character of these events (with spatial and temporal distribution and variability).
Reviewer # 2:
Justification of the study (specific focus on the 15-20 January 2013)
-The purpose of this study was to discuss the ‘heavy rainfall event’ over southern Africa in January 2013. However, our main objective was to analyse the rainfall event in relation to the observed MCSs. This event was observed throughout January, going into February 2013. We choose to focus on the period 15–20 January, being the period during which these systems were more significant over land. This period gives a better sense in dynamical aspects of MSCs and benefits amount of observation and literature report. As per the reviewer, this is stated on the abstract and elaborated in Section 3 of the text. However, we wish to highlight that our general discussion/analysis is not limited to this period only.
Description of MCSs and MCCs and restructuring of Section 2
As per the reviewers’ suggestion, this section has now been trimmed and restructured, and the terms described clearly. It is important to note that the article is about the heavy rainfall event and MCSs, whereas MCC is a subset of the former (Sec. 2.1). However, we believe it is important to highlight/describe these systems so as to help understanding their dynamics/climatology and how they can influence heavy rainfall events (especially over southern Africa). We acknowledge the importance of introducing the terms beforehand, which we have now done. Again we find it worth keeping this section separate from the introductory section to give the reader an insight of what MCSs are in more detail than just highlighting in the introduction. Some parts of this section have been rearranged or moved to relevant sections (removing unnecessary material) so as to systemize the context. The last part of Section 2 also gives importance and implication of the study and how these events can be linked to the heavy rainfall as well as important parameters to note when analysing/assessing such systems.
Results and Discussion
According to the reviewer, the section should be divided into two (Results and Discussion). While we acknowledge the comment, we find it not easy to separate this section since we discuss each part of the results as we present. However, we have subdivided the results into subsections as recommended, under subtitles: ’Rainfall distribution’, ‘temperature and wind pattern’ and ‘clouds and precipitation’ in Section 5.
Conclusions
In acknowledging the reviewer’s comments about shortening this section, we have summarized this section, trying to focus on the study conclusions and/or implications only. However, we find it worth to highlight the limitations of the study here rather under discussion. Our view is that it is worth having this at the end so that the reader can have an idea of how it could be improved or other possible future work in the same area.
- We have revised all the sections, starting with abstract up to conclusions to be consistent and concise with the study
- Citations have also been incorporated where necessary to support the argument, and defining/describing important terms.
- Repeated statements/sections have been removed or rephrased. Figure qualities (e.g. Fig. 4 re-drawn without grids) or rearranged. Figure captions incorporated as per the reviewer’s comments
- Overall, the breath of the article has been trimmed to make it more concise.
Thank you,
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The manuscript offers a good idea about studying the part and parcels of Mesoscale Convective Systems in a specific heavy rainfall event. However, it lacks substantial clarity in explaining its rationale and formulation of objectives. Other major problem I see in this manuscript are lack of proper description in methods, unorganized results, and a general description about implications of the study at a broader level of heavy precipitation scenarios. I also observed several long complicated sentence structures, out of context paragraphs, and lack of references when necessary. Here, I have tried to give some general comments about the sections and specific comments as far as possible (mostly in description of some specific methods, results, and ways to discuss them).
Abstract
P1L16: Please justify about why you focused only on 15-20th for the heavy precipitation month of January 2013.
P1L22: Short elaboration needed on how the rainfall data, satellite imagery and re-analysis data was used. Also, what is re-analysis data?
P1L22 How much correlation is substantial?
P1L26: One or two lines need to be added reflecting the study’s implications on a much broader scale
1. Introduction
P1L31 Reference?
P1L31-37 Some terms need to be clarified with definition for eg. lows, fronts, MCSs ITCZ, and quasi-stationary high pressure systems.
P1/P2L37-49 What are the authors basing all the information on? Citations needed for each piece of information. Also, I observed a shift in explaining about precipitation from Southern Africa initially to Africa (in L43/44) and then two hemispheres (L45). The explanation should be broader to narrower (not narrower to broader). So, please reorganize accordingly.
P2L46 which region?
P2L47-49 The two currents should be defined well. Also, why are they influencing climate in opposite directions?
P2L57-60 References?
P2L77-81 It is still not clear why the authors chose this particular heavy event for their study? Okay they have presented a few examples about the consequences of extreme rainfall and floods just above – but why this event specifically?
P2L79 remove ‘try’? Also, how do the authors know that the event’s evolution was related to MCS cycle before analysis? What parameters did they check to build such a relationship?
Although, mesoscale convective systems seem to be the focus of the paper, they have not been introduced beforehand. I understand that there is a long separate section regarding MCSs but I still think they should be introduced beforehand to systematize the context.
L81-85 Instead of showing how the paper is organized, I recommend that the authors briefly put what parameters they have used to address their objectives, the methods followed, and the scope of the study.
2. Mesoscale convective systems
For 2.1: I strongly recommend the authors to cut all the unnecessary information and focus keeping only the information which is important for this study. It also occurs to me that the authors are describing the MCS (L88-107) as well as providing justification for this study (L108-126 and L156-162) together. This is not a helpful scenario for the reader. Please provide the justification of studying MCS in the previous introduction section. I think this whole section can be shortened and fit into the introduction systematically and it will provide better justification for the study as well. Continuity is very important which is completely missing here.
P3L101-107 References?
For 2.2: Again the authors are mixing the description if MCS, MCC and providing some justification regarding the study.
I believe all of Section 2 can be summarized and fit into the introduction section such that there is a continuity in introducing the MCS, providing justification for the study, and finally setting up the objectives.
Also missing in Section 2 is how the ‘heavy rainfall events, in January 2013 can be linked to the MCSs and MCCs specifically.
3. The heavy rainfall of 2013
P5L220 It is not clear why is the period 15 – 20 January focused in the study?
P5L221 These locations should be indicated (by stars or abbreviations) inside the map in Figure 1. The figure can be enlarged for this purpose.
P5L227 What is Albany Atmos? Please clarify
This section describes more about the heavy rainfall in January 2013 and its consequences. However, the role of MCS and MCC in the rainfall has not been provided. Can you provide some details on this?
4. Data and Methods
P7L255 Are these examples of satellites or techniques? Elaborate on Maximum Spatial Correlation and SEVIRI? Also, is MASCOTTE part of SEVIRI? If yes please point out, if not why are you keeping it here? Elaborate on MASCOTTE more than saying it is an automated method. Also how does the automated method work specifically?
P8L274 misleading in what way?
P8L280 Which similar approach are the authors talking about?
The authors have not described about how the satellites and radar data/ images were specifically in this study, rather they focus more on general description of the satellites and instruments.
P8289 Can you describe on other aspects of the data obtained? For eg. Which station? What’s the period of the data? What was the method of collection? Same with satellite imagery? Also, needed is a study area map showing Botswana and its stations? An explanation of why Botswana was chosen as the study location also needs to be given.
P8L292 What do you mean by ‘Reanalysis data’
P8L303-307 What do you mean by atmospheric circulation? I believe it has not been introduced before. Also, a systematic introduction of all these output parameters, how are they relevant to the study, and how will the statistical and satellite data help to find them is essential here.
5. Results and Discussion
The main problem with this section is that many methods have been described here along with the results. This should be eliminated completed. Furthermore, I strongly recommend the authors to separate this section into ‘Results’ and ‘Discussion’ section so that the readers can focus only on the results while reading the results and then focus on meaning, implications and any comparison of the results with other studies in the discussion section. In doing so, the authors must be careful about not repeating the results while writing the discussion. It’s further recommended to divide results into subsections. For eg. L309-324 can go under tone subsection (probable title: Distribution of Rainfall) and L328-366 can be another subsection (probable title: Geopolitical height and SLP), likewise throughout the results section.
P8L309-315 and L317-319 These lines do not present results, they are more relevant for methods section where the data can be described and a line about using bar graphs for comparison of annual rainfall can be added.
P8L316 Why did Gaborone receive less rainfall than others when 2013 was supposed to be a heavy rainfall year?
P9L324 How can you deduce about the whole subcontinent when the results are from 5 stations within a country (with 1 contrasting result)?
Figure 3 is not clear at all. I think it will be much better if the figures are horizontally placed on over other such that they have a common caption for each axes with equal range of vertical axis. Please also remove the grid lines
L328-330 These are methods. Also, a description on geopotential height and SLP required.
P9 L332 What does positive anomaly infer to? Why negative anomaly was not found? What happens in case of negative anomaly? (discussion section inputs).
Figure 4: Please enlarge all figures – for enlarging the numbers in both the axes to see them clearly. Also the captions below the numbers are not very small and not clear as well. It can also be a good idea to abbreviate the countries in the figure.
P10L355-366 Most of the results here need an explanation of what they essentially are in the methods section.
P11L373 What is deep convective cloudiness?
Fig 6: a short explanation of what omega means is required
Fig 7: Same problem as Fig 4. Also, please explain in the caption OLR about what? Which date? Which location? In facts same problems in Figures 8-12 and their captions.
Rest of the results and discussion section has similar issues as I explained in my first general paragraph.
One more problem I had with this section is that but I did not notice discussion about implications and importance of your study and how your study fills the missing gap about specific instances of heavy rainfall studies in the general literation. Also in your study mostly explanation is missing about what is the importance of the results, what is the reason behind getting those results.
6. Conclusions
The conclusions are overly long. Please shorten this section. Focus only on explaining the major conclusions and implications. For eg. L477-485 can be removed, L513-524 they should go under the discussion section, etc.
Author Response
Reviewers # 1 and 3:
Need to compress sections 1 and 2, focusing more on mesoscale convective systems (MCSs) and precipitation.
As per the reviewers’ suggestion, these sections have been revisited and revised. We have trimmed both sections, removing repeating information and narrowed down the text to focus mainly on MSCs and precipitation. Section 1 is an introductory part, concepts of which are developed/discussed in the succeeding sections of the article.
Figure quality and grid
While we agree with the reviewers’ comments about improving the figure qualities, we reproduced some of the figures but there is no substantial difference between some of the figures. We found that enlarging some of the figures further distorts some figures (e.g. Figs. 7, 11 and 12) -becoming more faint and not easily readable. Some of the figures (e.g. Fig. 3) could not be drawn without the grid; we use NCL script to reproduce this figure and it would not be easy to overlay the graphs into (for different years) since they are of different scales.
Climatic character
We acknowledge the reviewers’ comments that we should introduce a more “climatic” character in the manuscript about MCSs, we approach this in a slightly different way in our revised paper. We introduce this concept in Section 2, where we briefly discuss their structure and climatology (pages 3–4). Since the scope of the paper is to understand the ‘heavy rainfall event” in 2013 (not generally describing MCSs), we refer the reader to some of the literature/reference material on MSCs. However, we acknowledge the fact that other readers may share this reviewer’s perspective of a more climatological character of these events (with spatial and temporal distribution and variability).
Reviewer # 2:
Justification of the study (specific focus on the 15-20 January 2013)
-The purpose of this study was to discuss the ‘heavy rainfall event’ over southern Africa in January 2013. However, our main objective was to analyse the rainfall event in relation to the observed MCSs. This event was observed throughout January, going into February 2013. We choose to focus on the period 15–20 January, being the period during which these systems were more significant over land. This period gives a better sense in dynamical aspects of MSCs and benefits amount of observation and literature report. As per the reviewer, this is stated on the abstract and elaborated in Section 3 of the text. However, we wish to highlight that our general discussion/analysis is not limited to this period only.
Description of MCSs and MCCs and restructuring of Section 2
As per the reviewers’ suggestion, this section has now been trimmed and restructured, and the terms described clearly. It is important to note that the article is about the heavy rainfall event and MCSs, whereas MCC is a subset of the former (Sec. 2.1). However, we believe it is important to highlight/describe these systems so as to help understanding their dynamics/climatology and how they can influence heavy rainfall events (especially over southern Africa). We acknowledge the importance of introducing the terms beforehand, which we have now done. Again we find it worth keeping this section separate from the introductory section to give the reader an insight of what MCSs are in more detail than just highlighting in the introduction. Some parts of this section have been rearranged or moved to relevant sections (removing unnecessary material) so as to systemize the context. The last part of Section 2 also gives importance and implication of the study and how these events can be linked to the heavy rainfall as well as important parameters to note when analysing/assessing such systems.
Results and Discussion
According to the reviewer, the section should be divided into two (Results and Discussion). While we acknowledge the comment, we find it not easy to separate this section since we discuss each part of the results as we present. However, we have subdivided the results into subsections as recommended, under subtitles: ’Rainfall distribution’, ‘temperature and wind pattern’ and ‘clouds and precipitation’ in Section 5.
Conclusions
In acknowledging the reviewer’s comments about shortening this section, we have summarized this section, trying to focus on the study conclusions and/or implications only. However, we find it worth to highlight the limitations of the study here rather under discussion. Our view is that it is worth having this at the end so that the reader can have an idea of how it could be improved or other possible future work in the same area.
- We have revised all the sections, starting with abstract up to conclusions to be consistent and concise with the study
- Citations have also been incorporated where necessary to support the argument, and defining/describing important terms.
- Repeated statements/sections have been removed or rephrased. Figure qualities (e.g. Fig. 4 re-drawn without grids) or rearranged. Figure captions incorporated as per the reviewer’s comments
- Overall, the breath of the article has been trimmed to make it more concise.
Thank you,
Author Response File: Author Response.pdf
Reviewer 3 Report
The paper, "Mesoscale Convective Systems: A case scenario of the ‘heavy rainfall’ event of 15–20 January 2013 over Southern Africa" is in my opinion very good. It considers an in depth study regarding the heavy rainfall event that occurred over the period. I did not see a detailed treatment of modeling studies but considering the length of the paper, I can accept to take it as is.
Author Response
Reviewers # 1 and 3:
Need to compress sections 1 and 2, focusing more on mesoscale convective systems (MCSs) and precipitation.
As per the reviewers’ suggestion, these sections have been revisited and revised. We have trimmed both sections, removing repeating information and narrowed down the text to focus mainly on MSCs and precipitation. Section 1 is an introductory part, concepts of which are developed/discussed in the succeeding sections of the article.
Figure quality and grid
While we agree with the reviewers’ comments about improving the figure qualities, we reproduced some of the figures but there is no substantial difference between some of the figures. We found that enlarging some of the figures further distorts some figures (e.g. Figs. 7, 11 and 12) -becoming more faint and not easily readable. Some of the figures (e.g. Fig. 3) could not be drawn without the grid; we use NCL script to reproduce this figure and it would not be easy to overlay the graphs into (for different years) since they are of different scales.
Climatic character
We acknowledge the reviewers’ comments that we should introduce a more “climatic” character in the manuscript about MCSs, we approach this in a slightly different way in our revised paper. We introduce this concept in Section 2, where we briefly discuss their structure and climatology (pages 3–4). Since the scope of the paper is to understand the ‘heavy rainfall event” in 2013 (not generally describing MCSs), we refer the reader to some of the literature/reference material on MSCs. However, we acknowledge the fact that other readers may share this reviewer’s perspective of a more climatological character of these events (with spatial and temporal distribution and variability).
Reviewer # 2:
Justification of the study (specific focus on the 15-20 January 2013)
-The purpose of this study was to discuss the ‘heavy rainfall event’ over southern Africa in January 2013. However, our main objective was to analyse the rainfall event in relation to the observed MCSs. This event was observed throughout January, going into February 2013. We choose to focus on the period 15–20 January, being the period during which these systems were more significant over land. This period gives a better sense in dynamical aspects of MSCs and benefits amount of observation and literature report. As per the reviewer, this is stated on the abstract and elaborated in Section 3 of the text. However, we wish to highlight that our general discussion/analysis is not limited to this period only.
Description of MCSs and MCCs and restructuring of Section 2
As per the reviewers’ suggestion, this section has now been trimmed and restructured, and the terms described clearly. It is important to note that the article is about the heavy rainfall event and MCSs, whereas MCC is a subset of the former (Sec. 2.1). However, we believe it is important to highlight/describe these systems so as to help understanding their dynamics/climatology and how they can influence heavy rainfall events (especially over southern Africa). We acknowledge the importance of introducing the terms beforehand, which we have now done. Again we find it worth keeping this section separate from the introductory section to give the reader an insight of what MCSs are in more detail than just highlighting in the introduction. Some parts of this section have been rearranged or moved to relevant sections (removing unnecessary material) so as to systemize the context. The last part of Section 2 also gives importance and implication of the study and how these events can be linked to the heavy rainfall as well as important parameters to note when analysing/assessing such systems.
Results and Discussion
According to the reviewer, the section should be divided into two (Results and Discussion). While we acknowledge the comment, we find it not easy to separate this section since we discuss each part of the results as we present. However, we have subdivided the results into subsections as recommended, under subtitles: ’Rainfall distribution’, ‘temperature and wind pattern’ and ‘clouds and precipitation’ in Section 5.
Conclusions
In acknowledging the reviewer’s comments about shortening this section, we have summarized this section, trying to focus on the study conclusions and/or implications only. However, we find it worth to highlight the limitations of the study here rather under discussion. Our view is that it is worth having this at the end so that the reader can have an idea of how it could be improved or other possible future work in the same area.
- We have revised all the sections, starting with abstract up to conclusions to be consistent and concise with the study
- Citations have also been incorporated where necessary to support the argument, and defining/describing important terms.
- Repeated statements/sections have been removed or rephrased. Figure qualities (e.g. Fig. 4 re-drawn without grids) or rearranged. Figure captions incorporated as per the reviewer’s comments
- Overall, the breath of the article has been trimmed to make it more concise.
Thank you,
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
The authors have modified the manuscript accoring to my suggestions.I think this work gave us a typical case on MCS in Southern Africa.The work is of importance of heavy rainfall forecasting . Its potental to us is to understand the future heavy rainfall change under the global warming.
There is a word"climatogy". Should it be "climatology"?
There is one more caption of "Fig. 12"
Author Response
There is a word "climatogy". Should it be "climatology"?
Response: Agree to the comment, the word should read "climatology" and has been corrected
There is one more caption of "Fig. 12"
Response: Not quite clear with the comment, but I guess it meant to talk about 'rephrasing the caption in Fig. 12'..?
However, the caption has been re-phrased in the figure
Reviewer 2 Report
The revised version of the manuscript is definitely an improvement over the first version. However, some issues still remain. First of all, I would have liked that the authors made a systematic point by point response addressing my comments and showing corresponding changes in the exact Pages and Lines – this would make it much easier for me to locate the changes and/or read their rebuttal if they did not agree with my suggestion.
P3L126-128 looks like some issue with paragraph and heading of paragraph mixing together.
The introduction and study rationale has been improved and made more continuous and clearer.
However, I did not see any improvement on many sections of the results which I thought were definitely methods (for eg. L285-293, 300-301, 311-315, 419-428, etc). Please recheck on this
In the conclusions sections, I do not think limitations are conclusive statements, they should be part of discussion. Conclusions are summary of major findings and how they are important.
Author Response
The revised version of the manuscript is definitely an improvement over the first version. However, some issues still remain. First of all, I would have liked that the authors made a systematic point by point response addressing my comments and showing corresponding changes in the exact Pages and Lines – this would make it much easier for me to locate the changes and/or read their rebuttal if they did not agree with my suggestion. Comments have been addressed in the section required (changes are reflected in the pdf file built on the journal web page). The cover letter was also sent (together with revised version) highlighting the changes and rebuttals where appropriate.
P3L126-128 looks like some issue with paragraph and heading of paragraph mixing together.
We agree with the comment on this point. This statement talks about the impacts of severe weather systems (& their consequent benefit –in the form of rainfall); it should be under subsection 2.2, rather than 2.1.
The introduction and study rationale has been improved and made more continuous and clearer.
No comment
However, I did not see any improvement on many sections of the results which I thought were definitely methods (for e.g. L285-293, 300-301, 311-315, 419-428, etc). Please recheck on this.
These are results sections. Our view is that it is worth (before discussing), highlighting what we present (e.g. figure/graph, table, variable etc.) and why we show or discuss these so as to lead the reader, rather than just discussing results. It is worth pointing out what each section or subsection of the results/discussion is about. We only highlight (in the methodology section) what we shall discuss. These lines do not discuss the methods here, but lead the reader into what the section is about.
In the conclusions sections, I do not think limitations are conclusive statements, they should be part of discussion. Conclusions are summary of major findings and how they are important.
As per the reviewer’s comment, this section is restructured and the limitations are moved to the discussion section.
