A set of methods to evaluate the below-cloud evaporation effect on local precipitation isotopic composition: a case study for Xi'an, China

Xing, Meng; Liu, Weiguo; Hu, Jing; Wang, Zheng

doi:https://doi.org/10.5194/acp-23-9123-2023

Articles | Volume 23, issue 16

https://doi.org/10.5194/acp-23-9123-2023

© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

https://doi.org/10.5194/acp-23-9123-2023

© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 23, issue 16

Research article

|

18 Aug 2023

Research article |

| 18 Aug 2023

A set of methods to evaluate the below-cloud evaporation effect on local precipitation isotopic composition: a case study for Xi'an, China

Meng Xing, Weiguo Liu, Jing Hu, and Zheng Wang

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Final revised paper (published on 18 Aug 2023)
Supplement to the final revised paper
Preprint (discussion started on 23 Aug 2022)
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Interactive discussion

Status: closed

RC1: 'Comment on acp-2022-576', Anonymous Referee #1, 12 Sep 2022

The comment was uploaded in the form of a supplement: https://acp.copernicus.org/preprints/acp-2022-576/acp-2022-576-RC1-supplement.pdf

Citation: https://doi.org/10.5194/acp-2022-576-RC1
RC2: 'Comment on acp-2022-576', Anonymous Referee #2, 16 Dec 2022

The comment was uploaded in the form of a supplement: https://acp.copernicus.org/preprints/acp-2022-576/acp-2022-576-RC2-supplement.pdf

Citation: https://doi.org/10.5194/acp-2022-576-RC2
AC1:
'Comment on acp-2022-576', Meng Xing, 17 Feb 2023
To ACP Editorial Office
Dear editor:

I hope this letter will find you well, and thanks for processing our manuscript “A comparison of two methods to quantitatively evaluate the effect of below-cloud evaporation on the precipitation isotopic composition in the semi-arid region of the Chinese Loess Plateau” (MS#acp-2022-576, note that we have changed the manuscript title to “A set of methods to evaluate the below-cloud evaporation effect on local precipitation isotopic composition: a case study in Xi’an, China”).

In the past two months, we have carried out multiple rounds of revisions in light of the comments we received from the reviewers. We have revised the manuscript in three major areas:

1) We changed the title to “A set of methods to evaluate the below-cloud evaporation effect on local precipitation isotopic composition: a case study in Xi’an, China”. In fact, our manuscript consists of two parts: one is to use the ΔdΔδ-diagram to qualitatively identify the below-cloud processes in our site, and another is to compare two methods that are used to quantitatively evaluate the below-cloud effect on the local precipitation isotopic composition. The new title contains the two topics.
2) We used method 1 and method 2 to represent the two methods, and clearly pointed out the main differences in the methods.

3) We have shortened the content in the ΔdΔδ-diagram part and added content in the methods comparing part.

Appended to this letter is our point-by-point response to the comments raised by the reviewers. The comments are quoted, and our responses are followed in blue.

We look forward to hearing from you at your earliest convenience.

Best regards,

Meng Xing

Authors:
Meng Xing^1,2*, Weiguo Liu^1,2,3*, Jing Hu^1,2, Zheng Wang^1,2

*Corresponding Authors：xingmeng@ieecas.cn; liuwg@loess.llqg.ac.cn
State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an, 710061, China

CAS Center for Excellence in Quaternary Science and Global Change, Xi'an, 710061, China.

University of Chinese Academy of Sciences, Beijing, 100049, China
Citation: https://doi.org/10.5194/acp-2022-576-AC1
- AC2: 'Reply on AC1', Meng Xing, 17 Feb 2023
  
  The comment was uploaded in the form of a supplement: https://acp.copernicus.org/preprints/acp-2022-576/acp-2022-576-AC2-supplement.pdf
  
  Citation: https://doi.org/10.5194/acp-2022-576-AC2

Peer review completion

AR: Author's response | RR: Referee report | ED: Editor decision | EF: Editorial file upload

AR by Meng Xing on behalf of the Authors (17 Feb 2023) Author's response Author's tracked changes Manuscript

ED: Referee Nomination & Report Request started (27 Feb 2023) by Eliza Harris

RR by Anonymous Referee #1 (01 Mar 2023)

Suggestions for revision or reasons for rejection

The manuscript by Xing et al. has significantly improved. However, there are still some minor issues as well as a lot of technical issues that should be considered before publication.

General technical issues:
“eq.” should be written in capital letter throughout the manuscript and supplement (thus “Eq.”, see ACP guidelines)

There should be a colon or full stop after Figure [Number], thus e.g “Figure 1:” or “Figure 1.” instead of “Figure 1”

Specific comments:
P1, L60ff: It is still not clear why the two methods improve our understanding. Please clearly state what is improved. What do we derive from these methods? Which method is better? Are both methods well suited to investigate below cloud processes or are there some restrictions for one or the other method? This should be clearly stated in the abstract.

P4, L128: What do you mean with “initial signal”? Is this found in the delta diagram?

P9, L272: Why does tis function need to be determined? Why is this correction necessary?

P11, L354: What is meant here with “updraft” and “downdraft”?

P11, L366: What is SPSS? What does this p value mean? Why has this value been chosen. This should be clarified in the manuscript.

P13, L423-424: Sentence is not clear. It may be that there is just a “the” missing, but what exactly is meant with two monthly equilibrated water vapour values? Are this values observed on a two monthly basis or derived (averaged?) over two years?

P19, L581ff: Clearly write what the differences are. To make these more clearly I would suggest to write that the same input parameters as for method 1 have been used except precipitation amount.

P21, L646: Be more precise. Have been added quadratically to what?

P21, L652: Change the order of the sentence parts so that it reads: Before exploring……it is important…. since ……….

P23, L707ff: As in the abstract, also here in the conclusion a clear message should be provided. When should one use method 1 and when method 2? Which of the two methods is better or are the same result derived?

Technical corrections:
Title: in Xi´an -> for Xi´an

P2, L40: delete “a” rephrase as follows: …based on two-years of synchronous observations of precipitation……

P2, L46: add “the” -> By using the

P2, L58: add “we found that” -> Through the sensitivity test we found that relative humidity ……

P2, L60: “following” is not the right term here. I would suggest to rephrase as follows: Therefore, by applying the two methods, the diagnosis of below-cloud processes and the understanding of their effects on the precipitation isotopic composition can be improved.”

P4, L105: rephrase as follows: “…..and a slope lower than 8.0 points to a non-equilibrium fractionation, such…….” Further, I am not sure if it rather should non-equilibrium fractionation process.

P4, L120 and 122: add “the” before delta-diagram (twice) and LMWL (once).

P4, L125: works -> work

P4, L139: frame is not the correct term here. Rather “region” or “area”. What is meant here with “simple”?

P5, L155: Change sentence to: However, so far these have not been systematically compared.

P6, L178: remove “year”

P7, L206: delete “a”

P7, 207: Since the measurements are performed based on samples I would rather write “analysed” than “measured”.

P7, L216: same here

P7, L224 and 225: Spaces are missing. You could also write VSMOW-GISP (Vienna Standard Mean Ocean Water – Greenland Ice Sheet Precipitation).

P7, L277: This sentence is not clear and I would suggest to rephrase as follows: To correct the instrument drift, the instrument was repeatedly calibrated with the laboratory standards after analysing 8 samples.

P9, L298: lead to -> encounter

P9, L300: a -> the

P10, L310: add “the” -> of the equilibrium

P10, L330: variations -> variation

P11, L341: isotope -> isotopic

P11, L344: is able to calculate -> can be calculated

P11, L349: Be more precise. Which method? Method 1 or method 2?

P11, L352: isotopically -> isotopic

P11, L357: more works need to -> more work is needed to

P11, L358: delete “the”

P11, L375: the LWML is -> the LMWL is defined as……. (or can be calculated by…….)

P11, L376: same here for LWVL

P11, L376: add “the” -> based on the per-precipitation-event water vapour

P12, L378: of LMWL -> of the LWML

P12, L378: are 8.0 and 10.0…… -> have a slope of 8.0 and 10.0….

P12, L382: little -> somewhat

P12, L378: of LMWL -> of the LMWL

P12, 383: may also relate to -> may also be related to

P12, L388:which -> where; Further, I would suggest to write “with the former being generally more negative when the latter”

P12, L391: add “being” -> composition being more positive

P12, L397: add “the” -> the precipitation

P13, L400: add “the” -> with the observed

P13, Figure 3 caption: dash-dot -> dash-dotted

P13, L409: Add in which figure.

P13, L413: deviation -> deviate

P14, L429: clearly state which one? From the isotope composition?

P14, L444: richer -> more

P15, L466: event happens -> events happen

P15, L467: corresponds -> correspond

P15, L492: move “the” behind “in”

P16, L493: scope is not the correct term here. It should rather read “area of” or “region of”.

P16, L496: works -> work

P16, L500: “rich” is not the correct term. Use “valuable”.

P16, L506: The section header should rather read “Quantitative evaluation of the below-cloud evaporation effect derived from the two methods”.

P16, L508, L509 and L510: range -> ranges

P16, L513: delete “a”

P16, L514 and L515: in -> for or better write “derived from”

P16, L514 and L515: delete “+-“ before standard deviation

P17, L523: show -> appears

P17, L528: could not -> can not or better write “is always positive” instead of “be a negative number”.

P17, L538: when the -> for

P19, L583: test -> tests

P19, L591: at -> to

P19, L597: have positive impact -> have a positive impact

P20, L629: deciding -> determining

P21, L643: section 2.4 -> Sect. 2.4

P21, L645: add “used“ -> above used input parameters

P21, L645: in -> for

P22, L691: add “the” -> of the local RH

P23, L692: validates -> evaluates (?)

P23, L705. difference -> differences

P23, L707: add “we found that” after sensitivity analysis

Supplement:
General: Add page numbers

eq. -> Eq.

Specific comments:
sentence after Eq. 14: add “the” -> the average

P6: What is Q1 and Q2?

Appendix D, second paragraph: cloud base follows -> cloud base that follows
vertical distribution of what?

Paragraph after Eq. 22: add “the” twice -> denotes the scale height of the atmospheric water vapour

can use eq. 14 to calculate -> can be calculated by using Eq. 14

Appendix E: in the two -> by the two

defined -> derived (?)

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RR by Anonymous Referee #2 (13 Apr 2023)

ED: Reconsider after major revisions (19 Apr 2023) by Eliza Harris

AR by Meng Xing on behalf of the Authors (12 Jun 2023) Author's response Author's tracked changes Manuscript

ED: Referee Nomination & Report Request started (27 Jun 2023) by Eliza Harris

RR by Anonymous Referee #2 (30 Jun 2023)

ED: Publish subject to technical corrections (13 Jul 2023) by Eliza Harris

AR by Meng Xing on behalf of the Authors (17 Jul 2023) Author's response Manuscript

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Short summary

The below-cloud evaporation effect (BCE) on precipitation largely impacts the final isotopic composition. However, determining the BCE effect remains poorly constrained. Our work used a ΔdΔδ diagram to differentiate the below-cloud processes. Moreover, by comparing two different computing methods, we considered that both methods are suitable for evaluation the BCE, except for snowfall events. Overall, our work compiled a set of effective methods to evaluate the BCE effect.