Statistical characteristics of raindrop size distribution during rainy seasons in Complicated Mountain Terrain

Mao, Wenqian; Zhang, Wenyu; Kou, Menggang

doi:https://doi.org/10.5194/hess-2022-66

Preprints

https://doi.org/10.5194/hess-2022-66

Preprints

23 Feb 2022

| 23 Feb 2022

Status: this preprint is currently under review for the journal HESS.

Statistical characteristics of raindrop size distribution during rainy seasons in Complicated Mountain Terrain

Wenqian Mao, Wenyu Zhang, and Menggang Kou

Abstract. In order to understand the differences of raindrop size distribution (DSD) in complex mountainous terrain, the characteristics of DSD were analyzed by using the six-months observation data at the southern slopes, northern slopes and inside in Qilian Mountains. For all rainfall events, the number concentration of small and large raindrops on the inside and south slope are greater than that on the north slope, but midsize raindrops are less. The DSD spectrum of inside mountains are more variable and significantly differ from the north slopes. The differences in normalized intercept parameters of DSD for stratiform and convective rainfall are 8.3 % and 10.4 %, respectively, and mass-weighted diameters are 10.0 % and 23.4 %, respectively, which the standard deviation of DSD parameters on inside stations are larger. The differences in coefficient and exponent of Z-R relationship are 2.5 % and 10.7 %, respectively, with an increasing value of coefficient from the south slope to the north slope in stratiform rainfall but opposite to convective rainfall. In addition, the DSD characteristics and Z-R relationships are more similar at the ipsilateral stations and have smaller differences between the south slope and inside mountains.

Received: 12 Feb 2022 – Discussion started: 23 Feb 2022

Wenqian Mao et al.

Status: final response (author comments only)

RC1:
'Comment on hess-2022-66', Anonymous Referee #1, 10 Mar 2022
Raindrop size distribution and the number of raindrops is an important parameter to describe the microstructure of precipitation. Numerous studies have been carried out the statistical characteristics of DSD in different regions. Qilian mountains are the vitally important ecological protection barrier and important water source in northwest arid areas of China. In this paper, the authors select 6 sites with different backgrounds representing the southern slopes, northern slopes and inside of Qilian mountains. This study reveals the microphysical variability of precipitation in the complex topography of the arid and semi-arid regions of Northwest China, which is of great significance to solving the shortage of water resources in the arid and semi-arid regions. The manuscript is of high quality and innovative. The data are full and reliable. I suggest that it be accepted after minor revisions.

The English and grammar of the article need to be carefully revised.

How to determine the observation instruments are at the same accuracy standard in the 6 sites?

In Fig 1, the size of sites is small and unclear. Add the photos of observation station or equipment.

The research needs to further highlight the reasons for the differences between sites in the discussion and conclusion. And how is the precipitation different from other areas?

Extended discussion: Whether the change of DSD is related to other meteorological factors, such as local wind speed?
Citation: https://doi.org/10.5194/hess-2022-66-RC1
- AC1:
  'Reply on RC1', wenqian mao, 27 Jun 2022
  1. The English and grammar of the article need to be carefully revised.
  
  Thanks your comments. The language of the article have been revised
  2. How to determine the observation instruments are at the same accuracy standard in the 6 sites?
  
  Thanks your comments. The instruments are used the same type with particle size classification and velocity classification. Besides, it is also used the same data processing and quality control, which insure the same accuracy at time and particle size.
  3. In Fig 1, the size of sites is small and unclear. Add the photos of observation station or equipment.
  
  Thank you very much for your valuable comments. The fig 1 has been revised. And it also added the photos of equipment.
  4.The research needs to further highlight the reasons for the differences between sites in the discussion and conclusion. And how is the precipitation different from other areas?
  
  Thanks your comments. According to the characteristics of raindrop size distribution (DSD) in Qilian Mountains, we find there are some similarities in different sites, which different from other areas. This is mainly due to melting of tiny, compact graupel, and rimed ice particles (relative to large, low-density snowflakes). Besides, there are also some similarities in different areas, such as the basic law of stratiform and convective rainfall reflecting in the raindrop size distribution. However, it still exists some differences, especially in the DSD parameters, because they have different altitudes and geographical environments. Based on the suggestion and above description, we have supplemented the discussion section. In order to better illustrate the precipitation difference between Qilian Mountains and other areas, we will choose representative site in Qilian Mountains to compare with other areas despite a brief mention of Z-R relationship and classification of precipitation types in this article.
  5.Extended discussion: Whether the change of DSD is related to other meteorological factors, such as local wind speed?
  
  Thanks for your tips. DSD can reflect the microstructure of precipitation. But it involves a series of microphysical and physical processes from rain generation to falling. There are more researchers to explore the possible factors about the change of DSD. And we will continue to think about the contribution of local wind speed on the change.
  
  Citation: https://doi.org/10.5194/hess-2022-66-AC1
RC2:
'Comment on hess-2022-66', Anonymous Referee #2, 14 Apr 2022

The authors investigate the characteristics of the raindrop size distribution(DSD) over the complex mountainous terrain Qilian Mountains which are sensitive to climate change in recent decades. Such a study is very helpful to increase the knowledge of the precipitation regimes over the arid and semi-arid region. Overall, the studyÂ is written well in terms of science and techniques, and can be accepted and published after minor revision. More comments are as follows:

1)On line 18, the âwhichâ had better to be replaced with âwhileâ.

2)The period on line 32 should be updated with English style.

3)The period before (SR) should be removed on line 50.

4) âin southeastâ should be updated as âin the southeastâ.

5) âresults fromâ had better be replaced with âmeasurement inâ on line 56.

6) Insert a blank space between the number and unit on line 57.

7)â vary from locationâ had better be replaced with âvary withâ, or âvary from location to locationâ.

8) The equation ï¼1ï¼on line 139 shows up suddenly and suffers from discontinuity in the context. Similar case can be seen for Eq. (7) on line 169.

9) âwithâ or âbyâ should be added after the word âcalculatedâ on line 149.

10) Refine the sentence on 167-168.

11) Replace âto be well fittedâ with âto well fitâ on line 167.

12) Refine the sentence on line 174-175.

13)Add legends for different color points, and add descriptions for the rectangles in grey line in the subfigures in Fig.7.

13) âwith the rain rate class risingâ can be refined as âas the rainfall rate increasesâ.

14) Refine sentence on line 478-479.

15)âFig 1â needs to be considered for better presenting sites information.

16) The differences from different sites can be described more clearly in the Conclusion section.

17) Some key raindrop parameters can be reported in the Analysis section, such as 3.4 Section reflecting the differences in different rain types.

18) Line 320: âbased on the classification ideas of Chen and Saurabhâ, Saurabh is not shown in the part of classification method. Please check this sentence.

19) Check the accuracy of the subscripts in the manuscript.

Citation: https://doi.org/10.5194/hess-2022-66-RC2
- AC2:
  'Reply on RC2', wenqian mao, 27 Jun 2022
  1)On line 18, the “which” had better to be replaced with “while”.
  
  Thanks for your advice. We have revised the conjunction.
  2)The period on line 32 should be updated with English style.
  
  Thanks for your advice. We have revised the parentheses with English style.
  3)The period before (SR) should be removed on line 50.
  
  Thanks for your advice. We have deleted the period.
  4) “in southeast” should be updated as “in the southeast”.
  
  Thanks for your advice. We have updated this statement in the whole manuscript.
  5) “results from” had better be replaced with “measurement in” on line 56.
  
  Thanks for your advice. We have replaced the expression.
  6) Insert a blank space between the number and unit on line 57.
  
  Thanks for your advice. We have inserted a blank between the number and unit in the whole manuscript.
  7)” vary from location” had better be replaced with “vary with”, or “vary from location to location”.
  
  Thanks for your advice. We have revised as “vary from location to location”
  8) The equation on line 139 shows up suddenly and suffers from discontinuity in the context. Similar case can be seen for Eq. (7) on line 169.
  
  Thanks for your advice. We have added some contexts before the both equations to improve the continuity
  9) ”with” or “by” should be added after the word “calculated” on line 149.
  
  Thanks for your advice. We have added the word “by” after the word “calculated” and checked the similar problems.
  10) Refine the sentence on 167-168.
  
  Thanks for your advice. We have refined as “And it has better fitting capability than M-P distribution on the broader variation of DSD fluctuations, including the middle rain drops, especially on small and large rain scale”.
  11) Replace “to be well fitted” with “to well fit” on line 167.
  
  It shown as the above response.
  12) Refine the sentence on line 174-175.
  
  Thanks for your advice. We have refined as “Although, the gamma distribution is commonly accepted, the normalized gamma distribution has also been widely adopted with its independent parameters and clear physical meaning as follows”.
  13)Add legends for different color points, and add descriptions for the rectangles in grey line in the subfigures in Fig.7.
  
  Thanks for your advice. We have updated the legends and descriptions in Fig 7.
  13) “with the rain rate class rising” can be refined as “as the rainfall rate increases”.
  Thanks for your advice. We have refined it and checked in the whole manuscript.
  14) Refine sentence on line 478-479.
  
  We have refined as “Above all, the proposed classification of stratiform and convective rainfall is suitable for Qilian Mountains, which is applicable to the precipitation in the arid and semi-arid regions.”.
  15)”Fig 1” needs to be considered for better presenting sites information.
  
  Thanks for your advice. We have changed Fig 1 with bigger size of sites and smaller areas in the map, which better presents the sites information.
  16) The differences from different sites can be described more clearly in the Conclusion section.
  
  Thanks for your advice. We have revised Conclusion section, which described the differences from four aspects including different rainfall rates and types, as well Z-R relationship.
  17) Some key raindrop parameters can be reported in the Analysis section, such as 3.4 Section reflecting the differences in different rain types.
  
  Thanks for your advice. We have considered some key raindrop parameters, but there are six sites showing the values, which makes it hard to choose site or the average values of sites. We will add the key parameters of typical site to report the differences in different rain types. And we also prepare another manuscript chosen one site to indicate the differences with other areas. We think it will be more clearly reported with some key raindrop parameters’ values.
  18) Line 320: “based on the classification ideas of Chen and Saurabh”, Saurabh is not shown in the part of classification method. Please check this sentence.
  
  Thanks for your comment. “based on the classification ideas of Chen and Saurabh” should be revised as” “based on the classification ideas of Chen et al. (2013) and Das et al. (2018)””
  19) Check the accuracy of the subscripts in the manuscript.
  
  Thanks for your comment. We have revised the subscripts in the whole manuscript.
  
  Citation: https://doi.org/10.5194/hess-2022-66-AC2
RC3:
'Comment on hess-2022-66', Anonymous Referee #3, 30 May 2022
General comment

The English is not up to the standard of a journal like EGU-HESS. The manuscript absolutely needs to be checked and improved on this aspect as for some instances, the reader would be confused and can only guess what the authors wish to say. In addition to this, the manuscript has a high frequency of occurrence of typo on units, punctuation and itemization. It thus needs a careful proofreading either by the authors or an external reviewer. I find it hard to concentrate on the content of the paper, and thus would suggest that the authors improve that aspect first, and then submit a revised version that could be reviewed for assessing the content. I thus suggest a major revision based on this comment only.

The study is based on the HSC-OTT Parsivel2: the authors refer to the OTT and HSC manufacturers of the instrument. It is unclear if this is the exact same instrument as the OTT Parsivel2 found extensively in the DSD literature, or if it is a slightly different version. It would be good if the author can provide more information on this.

It would be important to make the DSD data available on a repository. This is predominantly the norm now in the new DSD studies and would help advance science. This is not mandatory as part of the HESS policy (I suppose), but it should be encouraged nevertheless.

Specific comments

I only list a few comments here, but the manuscript needs absolutely a careful proof reading by a professional editor, or a careful editing by the authors, so that the reviewers can concentrate on the content of the paper.

Line 126 units upper script

Line 131 starting with (1) is inappropriate here.

Line 131 to 142 you could cite Jaffrain et al. (2011) and Guyot et al. (2019) here:

Jaffrain, J. and Berne, A.: Experimental quantification of the sampling uncertainty associated with measurements from PARSIVEL disdrometers, J. Hydrometeorol., 12, 352–370, https://doi.org/10.1175/2010JHM1244.1, 2011.

Guyot, A., Pudashine, J., Protat, A., Uijlenhoet, R., Pauwels, V. R. N., Seed, A., and Walker, J. P.: Effect of disdrometer type on rain drop size distribution characterisation: a new dataset for south-eastern Australia, Hydrol. Earth Syst. Sci., 23, 4737–4761, https://doi.org/10.5194/hess-23-4737-2019, 2019.

Line 138 do no use “can’t” in abbreviated form

Line 157 following equationS

Line 174 add references on the parameterisation of the DSD

Figure 1 is not up to the standards in terms of resolution

Section 3.1 could you provide a summary of the data of each site in terms of the number of samples before and after quality control, and DSD stats (see for example in Angulo-Martinez et al. 2015 or Guyot et al. 2019).

Angulo-MartiÌnez, M., and A. Barros, 2015: Measurement uncertainty in rainfall kinetic energy and intensity relationships for soil erosion studies: An evaluation using PARSIVEL disdrometers in the Southern Appalachian Mountains. Geomorphology, 228, 28-40.

Line 127 spacing between value and units

Figure 3 space between Z and (dBZ); missing “.” at the end of the figure caption

Figure 11: it would be good to add results from the literature as well on this graph so we can compare the value of the coefficients found in that paper with data from elsewhere (mountainous region, DSD from China in particular).

Line 516 Bringi et al.: which year?
Citation: https://doi.org/10.5194/hess-2022-66-RC3
- AC3:
  'Reply on RC3', wenqian mao, 27 Jun 2022
  Response to general comments:
  1.Thanks for your comment and the opportunity. We have revised some long or confused sentences, which will be easier to understand. Besides, we checked all the subscripts, units and format in the manuscript and revised them. So, we sincerely hope that the manuscript can move forward in the journal.
  
  2.Thanks for your advice. The DSG4 disdrometer is produced and sold by Huatron (China), including the sensor is mainly created from OTT Messtechnik (Germany). Essentially, there is not much difference between them.
  
  3.Thanks for your affirmation and recognition. We will try our best to improve the expression of manuscript.
  
  Response to specific comments:
  Line 126 units upper script.
  
  We have revised as “m s^-1” and checked the whole manuscript.
  Line 131 starting with (1) is inappropriate here.
  
  We replaced the period before (1) with a colon, and then continued (2), (3), (4), (5) with a semicolon.
  Line 131 to 142 you could cite Jaffrain et al. (2011) and Guyot et al. (2019) here:
  
  Jaffrain, J. and Berne, A.: Experimental quantification of the sampling uncertainty associated with measurements from PARSIVEL disdrometers, J. Hydrometeorol., 12, 352–370, https://doi.org/10.1175/2010JHM1244.1, 2011.
  Guyot, A., Pudashine, J., Protat, A., Uijlenhoet, R., Pauwels, V. R. N., Seed, A., and Walker, J. P.: Effect of disdrometer type on rain drop size distribution characterisation: a new dataset for south-eastern Australia, Hydrol. Earth Syst. Sci., 23, 4737– 4761
  Thanks for your advice. We have read the two articles and cited them in this part.
  Line 138 do no use “can’t” in abbreviated form.
  
  Thanks for your advice. We have revised the expression form
  Line 157 following equations.
  
  Thanks for your comment. We have revised as “equations”.
  Line 174 add references on the parameterisation of the DSD.
  
  Thanks for your advice. We have added the reference from Zhang et al. (2019).
  Figure 1 is not up to the standards in terms of resolution.
  
  Thanks for your advice. We have revised Figure 1 and chosen bigger the size of sites.
  Section 3.1 could you provide a summary of the data of each site in terms of the number of samples before and after quality control, and DSD stats (see for example in Angulo-Martinez et al. 2015 or Guyot et al. 2019).
  
  Angulo-MartiÌnez, M., and A. Barros, 2015: Measurement uncertainty in rainfall kinetic energy and intensity relationships for soil erosion studies: An evaluation using PARSIVEL disdrometers in the Southern Appalachian Mountains. Geomorphology, 228, 28-40.
  Thanks for your advice. We have added the number of samples before and after quality control in different sites.
  Line 127 spacing between value and units.
  
  Thanks for your comment. We have added the space and checked the whole manuscript.
  Figure 3 space between Z and (dBZ); missing “.” at the end of the figure caption.
  
  Thanks for your advice. We have added the “.” and corrected the wrong figure caption in the corresponding words.
  Figure 11: it would be good to add results from the literature as well on this graph so we can compare the value of the coefficients found in that paper with data from elsewhere (mountainous region, DSD from China in particular).
  
  Thanks for your advice. We are preparing another manuscript chosen one site to indicate the differences with other areas. We think it will be more clearly reported with some key raindrop parameters’ values, as well the Z-R relationships. So, in this article, we compared with some common relationships which are widely used in numerical model.
  Line 516 Bringi et al.: which year?
  
  Thanks for your comments. We have added the year. It is Bringi et al. (2003).
  
  Citation: https://doi.org/10.5194/hess-2022-66-AC3
  - EC1: 'Reply on AC3', Matjaz Mikos, 24 Jul 2022
    
    Dear Authors,
    it is really essential that the revised manuscript has been read by a native speaker prior to sending back the revised version of the paper. Long sentences are sometimes hard to be fully understood which lowers the quality of a paper. Please, follow this Reviewer's suggestion.
    
    Citation: https://doi.org/10.5194/hess-2022-66-EC1
AC4:
'Comment on hess-2022-66', wenqian mao, 22 Jul 2022

The raindrop spectrum is one of the most important elements in precipitation observations, which can reflect the interconnection between dynamics and microphysics of rain formation in clouds. It also can provide many parameters to describe the microstructure and evolutionary characteristics of precipitation, which has become a hot issue. Qilian mountains as the vitally important ecological protection barrier and water source in northwest arid areas of China, we are particularly interested in the differences over different sites, which can help us to understand the precipitation characteristics. This paper reveals the similarities and differences of precipitation with six sites verified by large domestic field trials in Qilian mountains, which is of great significance to considering the shortage of water resources in the arid and semi-arid regions. The data is precious, reliable and systematic. For the paper, the language has been further improved and the characteristics of precipitation are highlighted. Of course, based on the reviewee’ suggestions, it also further improved, such as the first figure, language and some details.
Additionally, this is my first time to submit in HESS. And I am not sure what to expect or what to do in terms of the process. If there is any question, please don’t hesitate to contact me.

Citation: https://doi.org/10.5194/hess-2022-66-AC4
- EC2: 'Reply on AC4', Matjaz Mikos, 24 Jul 2022
  
  Dear Authors,
  language is basically very important, firstly for the selected reviewers to easily understand the technical content, and be able to comment on it straightforward - this is not an easy task if the language used is vague. Many non-English speaking authors are using copy-editing help from native speakers or even professional copy-editing services. Please, decide which option fits you the best. And secondly, the language is also important for users - readers of scientific papers, to be able to understand and use the scientific information conveyed in the paper for their further applications or research.
  Kind regards, Matjaž Mikoš
  
  Citation: https://doi.org/10.5194/hess-2022-66-EC2

Wenqian Mao et al.

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Short summary

DSD characteristics significantly vary to reflect microphysical characteristics. We choose Qilian mountains and select 6 sites representing southern, northern slopes and inside. To thoroughly investigate discrepancies, DSD characteristics and Z-R relationships are analyzed based on continuous observations in rainy season. The goal is to obtain the finer precipitation of mountains and improve the accuracy of QPE, which would contribute to developing cloud water resources in mountainous areas.


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