Implications of a Large River Discharge on the Dynamics of a Tide-Dominated Amazonian Estuary

Round 1

Reviewer 1 Report

I wrote some comments on the manuscript

Comments for author File: Comments.pdf

Author Response

I think this particular paper presents a very interesting topic and is generally well written. The figures needs to be improved. Also, several parameters need to be explained as already noted by one of the reviewers. A large number of important references were used, however, they must be corrected in the configuration according to the instructions. Finally, I recommend the acceptance of the submitted paper, after minor revisions (according to the reviewers' comments and the references' correction concerning the format).

 

A: Thank you very much for your thoughtful general evaluation of the manuscript. We improved the figures on the manuscript, added more explanation about the parameters and other aspects of the results and discussion sections and, corrected the references according to the instruction’s format. Furthermore, our native North American co-authors performed a new review of the writing, and we believe to have corrected grammar errors, and made the text more fluid. All the comments were certainly useful for making the manuscript clearer.

 

Comments from the reviewers:

-Reviewer #1

Comments and Suggestions for Authors: I wrote some comments on the manuscript.

A: Thank you for all your effort to help us towards a better manuscript. We believe to have properly addressed all your concerns. Co-authors also perform additional improvements on the text in general and we hope that this manuscript can be accepted for publication soon.

Author Response File: Author Response.pdf

Reviewer 2 Report

Generally, and interesting and a paper warranting publication. But would benefit by a revision of the text, and a careful look at improving some of the figures.

Comments for author File: Comments.pdf

Author Response

Comments and Suggestions for Authors: Generally, and interesting and a paper warranting publication. But would benefit by a revision of the text, and a careful look at improving some of the figures.

 

Overall evaluation.

This M/S examines the salinity and sediment dynamics of Gurupi river/estuary under

conditions of high and low fluvial discharge. It is based on extensive and careful observations made at multiple sites within the estuary encompassing almost the full range of salinities. The estuary is potentially in the receiving zone of sediments delivered by the Amazon River plume and transported along the coast. It makes a useful contribution to knowledge not only through this examination, but also by setting the results in the context of estuarine parameter space and estuarine classification, and thus facilitating comparisons with other studied systems.

In my view this M/S warrants publication in “Water” after addressing the points listed below to the Editor’s satisfaction. These are mainly minor matters of syntax and grammar so require minor modifications to the M/S. Further attention needs to be directed towards some of the Figures, and the mention of mangroves in the Abstract and in the Keywords needs to be reconsidered as the discussion of the role of mangroves in the text is extremely limited, and not strongly linked to the tidal dynamics of sediment transport.

A: We have performed an extensive review of the manuscript following your comments. Thank you for the constructive comments. We corrected the inadequate words, rewrote the sentences requested, improved the figures and checked the grammar, giving the reader a substantially clearer view of our study. We believe to have addressed most of your comments. Thanks again for your review.

 

• 19 whereas?

A: It was slightly rephrased for clearness.

 

• 54 Should this be “1.5 X 10⁶” ?

A: Yes, sorry for this slip. We corrected that. Thank you for notice.

 

• 57 “has” not ”have”

A: OK, we corrected that.

 

• 71”regress” is not the right word. What is an “inactive bluff”?

A: Sorry for this slip. We rephased the sentence for clearness, changing the words “regress” and “inactive bluff”.

 

• 74 Figures 1 and 2. I suggest that these Figures need to be revisited as they contain similar information. It would be helpful to the reader to include some of the details from Fig.2 ( station numbers and transect locations) in the larger Fig.1c. The Gurupi should be indicated in Figure 1a. The axes in Fig. 2 (top right hand corner) need to be labelled and show units, and thus dispense with the little box in the lower right hand corner of Fig. 2. The bathymetric profile would be more informative if distance upstream was also indicated. I don’t think station numbers were referred to in the text.

A: Thank you for your observations. Figures 1 and 2 were improved. We believe the figures are much clearer now. Thank you for your suggestions. We add some information in both figures, and made all changes you suggested. They look substantially better now. Thank you again.

 

• 84 “homonymous” is archaic and should be replaced. Why not just name the mountain?

A: You are right. We rephrased it and indeed include the “Gurupi Range Mountains”.

 

• 88 January to August.

A: OK, we corrected that.

 

• 113. “…using a Sea and Sun model 90m CTD , which was…”.

A: OK, we corrected that as well. Thank you.

 

• L,117 I think more details are required on the number of casts made an the interpolation procedure. How was the turbidity converted into SSC?

A: We include more details on methods to describe how turbidity was converted for SSC and believe that it is clear now. Thank you again.

 

• 130. datasets.

A: OK, we corrected that.

 

• 136-138. “fibre”, sentence needs to be revised. “Traverse surveys were processed…”

A: Thank you. It was revised and slightly rephrased for clearness.

 

• 146-147. QRev undefined and relationship to F not made explicit.

A: OK. We rephrased it and provided complementary explanations about it.

 

• 150 Delete “posteriorly”.

A: We have deleted it. Thanks.

 

• 151, Equation (3) needs punctuation to separate the individual equations.

A: OK, we corrected that.

 

• 159. “…applied in …”

A: Thank you for noticed that. It was corrected.

 

• 176. “….Shapiro-Wilk test. As the data…”

A: OK, we rephrase it.

 

• 178. “… was adopted for the analysis…”

A: OK, we corrected that. Thank you

 

• 181. Delete “According to its morphology”

A: Thank you, this section was substantially rephrased.

 

• 179. “with” not “within”

A: OK, we corrected that.

 

• 200-201. “The observed salinity levels varied between …“

A: Thanks, it was rephrased.

 

• 202. “.. and remained constant further up stream…”

A: OK, we rephrase it. Thank you for notice that.

 

• 206-207. “… the salinity levels were higher during the dry season than in the rainy season.”

A: OK, we rephrase it.

 

• 209-210. “ The salinity reached ~0 at 40 km…”

A: Thanks, we rephrase it.

 

• 216-217. This sentence can be simplified and made more direct. Don’t need “ considering

A: OK, we rephrase it.

 

• the average of the period…”.

A: OK, we rephrase it.

 

• 218. “ …also differed between…”

A: OK, we rephrase it.

 

• 219 delete “whereas” and start a new sentence “Local…
• A: Thank you, we have edited that paragraph.

 

• Figure 3. At line 413 it is note that the Morphology did not change substantially seasonally. Yet comparing the dry and wet season longitudinal profiles suggests that there are seasonal changes. Perhaps a comment is warranted?

A: Thank you, this is very important observation and we wrote an entire paragraph with clarifications on that. Indeed, no substantial seasonal changes were observed in the estuarine morphology. On the other hand, the water level, especially in the upper estuary, does change seasonally, giving the impression that the upper estuary is much deeper during the rainy season from middle to upper estuary, but actually the water column is bigger, not the bottom deeper. Besides, the effort of following the channel thalweg and perform the CTD casts does not always run smoothly, so that the seasonal transects might differ slightly and give the impression of important morphological changes. We have tried to put it in an appropriate manner in the manuscript. Thank you again.

 

• 231. delete “Regarding” . “…observed during…”.delete “the observed value”.

A: OK, we deleted and rephrased the sentences.

 

• 244-246. Something wrong with this sentence. Needs to revised removing the second “SSC”.

A: Thank you for your comment. We removed the second “SSC” and rephased the sentence.

 

• 250. “Salinity was… and reached… “
• A: OK, we rephrase it.

 

• 255. flushing or draining not “washing”. “…salt-rich…” not “salt reach”

A: Thank you for the correction. We changed “washing” for “flushing” and “salt reach” for “salt-rich”.

 

• 266-267. Q seems to be undefined but appears to be the discharge. Perhaps specify it. Are the cited values correct? It seems physically impossible for the estuary to be accumulating water at such a rate during the dry season. Are these instantaneous or average values/?

A: Thank you very much. The numbers were not correct indeed… We found an inconsistency in the used MatLab routine, and the numbers are now correct, being few orders of magnitude smaller than before and really making sense now. In matter of fact, water is being accumulated or lost due to evapotranspiration during the dry season, and exported to the ocean during the rainy season.  

 

• 271 replace “e” with “and”.

A: OK, we corrected that.

 

• 275. replace “ presented significative values ranging” with “ranged”.

A: OK, we corrected that.

 

• 287 replace “within” by “with a”.

A: OK, we corrected that.

 

• 300. delete “opened”.

A: OK, we deleted that.

 

• 317 delete “In an overview.. ‘ and rephrase starting sentence to”’

A: OK, we deleted it and rephased the sentence.

 

• 328. “was” not “were’.

A: OK, we corrected that.

 

• 329-330 delete “We noticed that” , and “its concentrations of suspended sediments” and replace with “SSC”.

A: OK, we deleted that and slightly rephrased the sentence.

 

• 337-338. reformulate the sentence to “ It is difficult to establish whether… “.

A: OK, we reformulated the sentence.

 

• 340. Delete “order of “. Is “insignificant” the right word? This points toa deeper problem for this paper- there is no discussion of the uncertainty in the fluxes, hence this element of the discussion is deficient.

A:Thank you, we have change this and other words, as well as added some discussion on the uncertainties among used methods and calculations

 

• 346-348.This sentence needs to be reformulated. I think you are trying to say that the Gurupi wet season flows and the ebb phase dominance inhibits the transport of ARP sediments into the estuary?

A: Thanks, you are right, and so we rephrase most of this section for clarification.

 

• 354. “…expansion of…”.

A: OK, we corrected that.

 

• 355. delete” also highlight” replace with “note”.

A: OK, we corrected that.

 

• 358. replace “by” with “due to”.

A: OK, we replaced that.

 

• 367. Replace” the gravity action upon “ by “acting”.
• A: OK, we replaced that.

 

• 375-378. I found this paragraph difficult to understand, rewrite to make it clearer.

A: OK. We rephrased it and provided complementary explanations.

 

• 397-398. The meaning of this sentence is unclear ( at least to me). I think the message is that tidal wave propagation can have different forms.

A: Sorry for the misunderstanding. We rephrased the sentencer for clearness.

 

• 404-409. This paragraph is mainly a discussion of generalities. This component needs to be decreased and more emphasis given to the specific case of the Gurupi with numerical comparison to other estuaries.

A: We agree. This part of the text was mostly re-written with the help of all co-authors and we believe this point was satisfactorily addressed. Thank you.

 

• 412-413. See earlier comment re the longitudinal shape of the estuary.

A: Thank you again. We include explanations on that early in the manuscript as you suggest. We think that it was clarified.

 

• 422. Please specify the actual equation so it can be used by others as well as the R2value.

A: That is fine. We have included the equation, beside the R² value.

 

• Figure 7. The description of the various estuaries is too faint.

A: We agree that the description of other estuaries was too superficial. We include few more information, however, it was in a certain way, intentional, as we recently publish a paper with a comparison of those estuaries, including a detailed description of them and it seemed redundant to include it here again. I hope

 

• 458. Perhaps here is the place to discuss the experimental uncertainties?

A:

 

•  
• These need to be curated. I noticed problems at lines 493, 598,

A: Sorry for this slip. We corrected the mentioned lines and check the other to make sure there is no additional errors.

 

 

 

Author Response File: Author Response.pdf