Sub-Hourly Variability of Stable Isotopes in Precipitation in the Marginal Zone of East Asian Monsoon

Round 1

Reviewer 1 Report

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Comments for author File: Comments.pdf

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

Sub-hour Variability of Stable Isotopes in Precipitation in the Marginal Zone of East Asia Monsoon

This manuscript reports on isotope analyses in rainwater made with a high temporal resolution of one sample every 10 minutes. The samples were collected at Lanzhou in China which is located at the margins of the Monsoon area, the high plateau of Tibet and arid regions to the north. Nine rain events were studied including the recording of all meteorological parameters and the analysis of trajectories of winds before and during the events. Stable isotopes (deuterium and O-18) were measured using a laser-based method. The results obtained are highly interesting. Large differences were found among different events, and even during the same event. The discussion focuses mainly of the intra-event differences. The reviewer found that the paper should better discuss the differences from one event to another. For the events 1, 5 and 9 maps of trajectories of moisture are shown in Figure 4. In figure 3 it is shown that these three events are lying on completely different positions on the MWL: event 1 is close to zero for both isotopes, event 9 is very negative, and event 5 is somehow intermediate. Looking at the trajectories for these events, it is seen that moisture for event 1 travelled from northwest without crossing the highest crest of the Himalaya, while moisture from event 9 came from southwest and had to cross the Himalaya. And event 5 was subjected to both pathways. The reviewer thinks that the authors should discuss better the role of the high-altitude Himalaya region for the results obtained in this study. The very negative isotope values in event 9 are likely to be caused by snowfall on the trajectory.

The use of the deuterium excess to discuss intra-event observations is a bit misleading in this study since figure 3 shows that there is hardly any excess of deuterium since all data lie more or less on the MWL.

In conclusion, the results of this study are measured well, show significant and very interesting patterns and merit to be published in Water. The text, in contrast, is poorly written, with many unclear sentences and grammar problems. And the discussion should be rewritten as explained above. After a thorough revision of grammar and style, the paper could be accepted for publication in water, pending a few specific suggestions as stated below.

L47: and the information contained is also worth studying  à is worth being studied.

L50 ff: The referencing is very bad. Miyake (1964) misses in the list. Celle-Jeanton  is Ref. 20, and not 20,21-23. Munksgaard has no number in the text, etc.

L95 ff: The surface area of the sampler should be given.

L103: Sampling is triggered by precipitation sensor then opened the collector only the precipitation happened. Confuse sentence?

L104: two verbs in sentence: are form

L111: No verb in sentence.

Table 1 Simples? Samples

L130: formular? Equation!

Results section: The numbers in the text are too precise, instead of −8.56‰ it should be given −8.6‰

D-excess. This parameter should be defined already in the Materials and Methods section in a numbered equation. The reviewer wondered why the authors take the number 8 in this definition, and not the slope of the equation for the LMWL which is 7.48?

If one looks at Figure 3, it does not appear that many samples have excess in Deuterium. Only E6 samples may have deuterium ratios above the MWLs, in contrast the samples from event 4 all have deuterium deficit. This is not expressed in Figure 1 where for E4 the results deuterium excess are up to 10.

L194ff: This is discussion and should be moved to section 4

L198: In the later…? Just: Later,

L213: Previous researches have… Better Previous research has …

Author Response

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Author Response File: Author Response.docx

Reviewer 3 Report

Review prepared for Manuscript ID# water-844716

Dear Authors,

This manuscript presents the variability of stable isotopes in the sub-daily (sub-hour) precipitation rates in Lanzhou, China. It seems the problem is defined precisely. The structure of the manuscript looks fine as well. There is a major drawback related to the structure of sentences and the message that you are trying to communicate. I would strongly recommend seeking help from an English professional who is also relatively familiar with these subjects to address this concern to a great extent. A list of minor suggestions/comments is provided below:

Line 19: please define RH.

Line 94: please modify the caption.

Equation 1: Should not it be as 100%? Please verify.

Lines 130-131: These two lines must be edited. For instance, what is “formular”?

Line 133: “we using…”?

Figure 2: Please add some explanation related to the P intensity the other trends observed here, considering the correlation analysis in Section 3.2; for example, the dependency of P and T as well as preceding RH when you discuss the correlations?

Table 2: I did not find a complete discussion regarding the physical interpretation of positive/negative signs for these correlation coefficients. Please consider this comment.

 

Thank you, -Reviewer

Author Response

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Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

The authors responded to comments of three reviewers which all agreed on the novelty and soundness of the study. The English was impoved and some points which needed clarification were clarified better.

The study can be puslished now.

Author Response

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Author Response File: Author Response.docx