Temporal Synchrony in Satellite-Derived Ocean Parameters in the Inner Sea of Chiloé, Northern Patagonia, Chile

Round 1

Reviewer 1 Report (Previous Reviewer 3)

Dear Authors,

The manuscript has been substantially revised and improved in quality, but there are still some parts that need to be written in more detail, especially in the "Result" section. The authors may adapt the content according to the comments below.

Review report on “Long-term synchrony in satellite-derived ocean parameters in northern Patagonia, Chile” by Richard Muñoz

 

1.      The description of Figures 1A and 1B needs to be supplemented with the data used.

2.      Lines 176-183: The meaning of the time series in Figure 2(c) needs to be explained in detail. And combine the spatial characteristics of Figure 2 (a) and (b) to give an example of the meanings of the high and low values of those years.

3.      Lines 184-190: As in the previous paragraph, more explanation is needed. In addition, I would suggest drawing the time series of different Modes in Figure 2(c) and Figure 3(c) separately, because the line segments are too overlapping to be recognized.

4.      Lines 191-200: You can't just say that they are "important", you should speculate on the reasons behind these figures.

5.      Lines 201-216: The same problem, need to explain the meaning of "synchrony".

6.      Abstract: The description here is too general, and the abstract should contain very specific research results. It should be written what kind of characteristics the specific synchrony results represent.

Author Response

Attached is a letter in which we respond to the indications of both  point by point.

Author Response File: Author Response.pdf

Reviewer 2 Report (New Reviewer)

In this study, the authors performed wavelet analysis of 20 years long time series of satellite-derived chlorophyll-a and turbidity in the large gulf in Chile. They report different statistical relations chlorophyll-a and turbidity between the northern and southern parts of the gulf.

In the present form, this research looks like a statistical processing of satellite data with vague connection with ocean science. The authors made a good job in mathematics, but this analysis requires interpretation in terms of physical and/or biogeochemical oceanography. In other words, the authors are encouraged to make more effort in (1) describing the oceanographic reasons of the obtained statitical dependences and differences and (2) put the findings into a broader context, i.e., clearly demonstrate why the applied methodology provides new understanding of ocean processes, what is the exact contribution and advantage of this study and this method to the existing methods in ocean science. Finally, in order to follow the best practice in ocean science, the authors are encouraged to support their findings by in situ data and/or numerical modelling of the study region.

Author Response

Attached is a letter in which we respond to the indications of both  point by point.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report (New Reviewer)

The manuscript was improved and could be pbblished in the current form

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

The manuscript contains 43 percent plagiarism, and the methodology portion is not properly presented, the imf1,imf2, and imf3 not defined or how it is obtained as chl a signals not mentioned. Wavelet coherence equations simply copied.  Why is the HHT analysis chosen for the study area? is not represented in the article. Since the time series analysis is only estimated for a period of 1.04 years. nFLH, rrs 645 methods are not described and properly linked. line 235 figure number not mentioned. The high chlorophyll variability including negative is not addressed for both northern and southern Patagonia with reference to PDO,MAI, SAM and river discharges are not properly correlated. Though the study has results proper articulation is not carried.

Reviewer 2 Report

The paper discusses the patterns of temporal variability of remote-sensed bio-optical characteristics of the Inner Sea of Chiloé and their connections with environmental conditions. As a result, significant patterns in ocean color dynamics were obtained.
Unfortunartely, the hypothesis presented by the authors, "We hypothesize that the strength of the synchrony between environmental characteristics varies... etc." remained unresolved. No discussion of influence of bottom topography and river discharge is presented. In general, the paper lacks well-grounded conclusions.

Basically the authors are trying to research synchrony between remote-sensed reflectance and its derivative parameters, which they will find, obviously. It would be of much more interest if the authors could show the coherence between bio-optical characteristics and river discharge or climatic indices. Such results will make it possible to draw conclusions about the mutual influence of climate and bio-optical characteristics.
Climatic and river discharge data are presented, but not used apart from showing them in Figure 8. There is no discussion of the influence of, for example, a certain variability of a certain index on Chla.

Specific comments:

The title: "Long-term synchrony in satellite-derived ocean parameters in northern Patagonia, Chile"
The observed synchrony has a 1year period, is it long-term?
Probably it is better to name the water body under study, i.e. "in the Inner Sea of Chiloé, Northern Patagonia, Chile"

Figure 1B: numbes on the scale are shifted with respect to color squares, it would look nicer if they fit the color changes.

Line 87 "The ISC is part of an inner sea..." ISC _is_ the inner sea, not a part of it, right?

Line 117 "We considered the stations in the Puelo and Futaleufu Rivers (Figure 1B)..." Figure 1B does not show the Futaleufu River.

Line 159 "...equals zero if the time series [see details in 44]." Looks like something is missing in this sentence.

The Methods section require the explanation of how will these methods be used and what for. Why is the HHT used if the wavelet analyses gives the same result and even more?

Results section: it will be more clear if the authors keep to the same terms when discussing variability. Cycles/year or year-1? Frequency or period? Just make it uniform across the whole paper. Same for the figures: why figures 2 - 4 show frequencies and 5 - 7 show periods?

Subscripts to Figures 2-4: "Darker colours indicate greater power..." "The color scale (blue to violet) shows the strength of the energy" Isn't it the same statement?

The reference to the Figure 7 goes before the references to the figures 5 and 6, therefore Figure 7 must be Figure 5 and the consequent number changed as well.

Figure 5 "Vertical white lines delimit the time period where there are common time synchrony." Common how? What is the proof that the synchrony is the same?

Line 217 "...variability of external forcing, which in turn, imposes an annual/semi-annual temperate regime [31]. " This sentence is unclear. What is "annual/semi-annual temperate regime"? Or it is supposed to be "temperature"?

Line 235 "the lowest discharges during austral summer (Figure ??D,E)." Is it Figure 8?

Line 236 "Our results are consistent with the temporal patterns observed by Flores et al. [30] and Vásquez et al. [29], in which there is a marked seasonal variability in river discharges (Puelo and Futaleufú rivers) and an asynchronous variability between Chla and nFLH. Previous studies have shown that the river discharges and autotrophic biomass (measured as satellite Chla and nFLH) cycles in northern Patagonia are associated with large-scale climatic variability through the PDO, MEI and SAM indices, from intra-seasonal to inter–annual timescales [e.g. 30,31,55]."
And how are the results in this paper different from the previous studies? What new effects are observed? Please explain in more detail.
The spectral coherence between rever discharge and Rrs could provide a sound explanation of the two peaks with 1year and 0.5year period of Rrs variation.

Line 303 "When we examined the coherence between chlorophyll–a and turbid river plumes controlled by the effect of MEI with PWC..." What does "controlled by the effect of MEI" mean? How is this control expressed?

The Discussion section is very general, it barely concerns the results of the presented work.

The main conclusion about synchrony between Chla and Rrs is obvious. The spatial synchrony appears to be more interesting, but it requires the research of climatic and river influence.

Reviewer 3 Report

Review report on “Long-term synchrony in satellite-derived ocean parameters in northern Patagonia, Chile” by Richard Muñoz et al.

  The authors try to use some optical parameters to understand the long-term characteristic changes in northern Patagonia, Chile. However, the structure of the manuscript is so disorganized that the reviewers cannot even summarize what the authors are trying to convey. The main suggestions can be seen from the following points.

1.      Introduction section needs to add more details, including the environmental characteristics of the research area (Inner Sea of Chiloé (ISC) in northern Patagonia) and adjacent waters. Some previous studies have been mentioned [27-30], but it is still not enough for readers to understand the environmental background here. In addition, the connection between the synchrony of these ocean optical properties and environmental conditions (e.g. temperature, salinity, river discharges, Colored Dissolved Organic Matter, Chl-a) needs to be presented more concretely. The main purpose of the authors' study and expected results are still unknown.

2.      "2.0.1." to "2.0.5." This is a very strange wording, please correct it.

3.      Lines 87-99: The author should be able to draw a 3D cross-sectional diagram to present these complex environments and water masses.

4.      The author should replace the original HHT and wavelet formulas with the parameters used in this study, otherwise there is no need to write the known two subsections.

5.      Line 101-114: The physical meaning of the parameters used should be briefly stated.

6.      Line 188-195: Figure 7 should not be mentioned before Figures 5 and 6.

7.      Line 172: Where is the northern and southern border of the ISC? The authors do not mention it, and Figure 1B does not show it. Obviously, the whole result needs to wait for the authors to clarify the scope before further review. On the other hand, I suggest that the author first provide the results of EOF before doing the HHT and wavelet analysis.

8.      The structure of the entire Discussion obviously needs to be rewritten. On the one hand, it is usually not recommended to use HHT and wavelet analysis. For a complex water area, the author needs to clarify the dynamic problem first, rather than linking to the climate field problem, because it is easier lead to misjudgment and excessive interpretation. The impact of SAM, PDO, and ENSO on this area should be placed in the subsection of result, and readers should be told why these changes in climate characteristics are sufficient to affect this small area. The author mixes all kinds of things together to discuss in this chapter, making it very messy.