Links between Teleconnection Patterns and Water Level Regime of Selected Polish Lakes
Round 1
Reviewer 1 Report
See attached file.
Comments for author File: 
Comments.pdf
Author Response
Response to Reviewers: First of all, we would like to thank the reviewers for their valuable comments. Below please find the original comments and our responses (in bold) explaining how the original manuscript was amended during the revision.
REVIEWER 1
This manuscript quantifies the relationship between lake levels in selected water bodies in northern Poland to major climate teleconnection indices that impact the region. The results show weak relationships based on linear correlation analysis; however, this in itself is not a bad thing as such analyses rarely indicate strong relationships due to the importance of local-scale conditions on water resources. Overall, I think the results of the paper and the methods used show some validity, and could be important to local water managers. Having said that, though, there are some fairly major issues that severely detract from the overall scientific impact of the results. These are briefly described below to help guide the authors in their revisions and modifications. I wavered on whether this manuscript is worthy of publication, and decided that the objectives and basic results do warrant potential acceptance if these issues are addressed; therefore, my decision is to accept the paper pending major (and substantial) revisions.
Major Comments
[1] How did the authors determine the level of the dendrogram to define groups? Sometimes it’s the second level and sometimes it’s the third. If this process is done subjectively, then the authors should remain consistent. Lines 135-136 provide some description, but don’t provide any explanation beyond a subjective determination based on geometry and an unexplained “bond distance curve”.
The description of grouping using Ward’s method was supplemented (lines: 146-158).
The level of the dendrogram was determined on the basis of a linkage distance plot. The plot shows the distance between clusters in the moment of merging. If the plot clearly shows the flattening (longer vertical line), it means that at this point the clusters are distant and it is possible point to cut off the groups. Each grouping was done separately (was independent analysis), what explain the different levels of group distinction. Each distinction was also confirmed by comparison with the Mojena rule (1977).
The linkage distance plots have been added in the figures 2, 4, 6, 8.
[2] In the plots of correlation, the shaded values appear to correspond both to the correlation coefficient and the statistical significance of the correlations. This is quite misleading, as it implies that statistical significance and correlation are themselves related. Using the t-statistic is also quite unfortunate, as it is too simplistic for this analysis. In other words, even a correlation of 0 can be significant, and in the case of this study, probably is since the sample size and underlying distributions are consistent.
The visualization could have been misleading. The plots of correlation were corrected, the levels of statistical significance are now hatched (marked with lines), and the correlation coefficients are marked with colour.
[3] More work needs to be done in describing how and why each teleconnection physically influences the region of interest. It’s good that the authors correlate the teleconnection indices to temperature and precipitation; however, they do not provide a synoptic overview of how exactly the local weather conditions change in relation to the various climate patterns. Without this overview and discussion, the paper basically lacks scientific context. Some of this information is provided in the Discussion and Conclusions section; however, as this information is central to the paper, more needs to be done.
According to the comment, in the introduction a description of correlation between circulation patterns and climate elements of the study area was added (lines: 48-58). Please check the changes in the manuscript.
[4] In lines 90-91 the authors state that they “assume” the water levels in the lakes respond to natural processes, then in lines 92-93 they provide references indicating the lakesfollow a “quasi-natural” regime. Not only is this misleading, but it is worrying since the results depend on the studied lakes having water levels driven primarily (or even solely) by climatic processes.
Thank you for drawing our attention to this problem. Statements in lines 102-106 could have been misleading, the text was verified. The regime of lakes is determined of course not only by climatic conditions, but also by the physiography of the catchment, e.g. land cover, land use, hydrogeological conditions – this aspect is now added to the manuscript.
[5] Even though northeastern Poland has a higher density of lakes, it is unfortunate that the authors didn’t choose lakes that would provide an equal distribution of points across the geographic area. As it stands, having a higher density of lakes in the eastern section of the study area potentially skews the geographic analysis. This is especially true since teleconnection indices reflect a climatic pattern; therefore, regionalscale instead of local-scale patterns are more likely to be found.
As mentioned in lines 91-98, statistical tests were carried out. On their basis, among the 75 studied lakes were selected those whose data have a homogeneous series and their mean monthly water levels do not show statistically significant trends, what results in the uneven distribution of the analysed lakes.
[6] The determination and analysis of water level regime for the selected lakes needs work (lines 102-114 and Table 1). First off, where do the regime descriptions come from (i.e., is there a citation or did the authors come up with the categories themselves)? Second, based on these regimes the authors need to provide a basic description of the water balance that controls the water levels in each lake. This would greatly enhance the usefulness of the results, as it would help to show how and why the teleconnection indices and associated climate circulation patterns influence each lake (see Comment 3 above).
Regime types of lakes, descripted in lines 116-128 and in Table 1, have been designated in the publication [48] and in the paper it was indicated as a citation.
Moreover, in the Table 1 the elements of the water balance of lake catchments (outflow and precipitation) were added.
[7] The last paragraph of the manuscript illustrates some of the major shortcomings of this research, including the need for non-linear statistical analysis. Although the results of this paper using linear correlations are a viable first step, there are still a lot of assumptions and statistical simplifications that detract from the overall impact of the results. Also, within this section there is no mention of how these results could be used by the broader scientific community (i.e., water management), which is absolutely critical to put this paper into scientific context.
Conclusions have been supplemented with the above-mentioned issues (lines: 459-464). Please check the changes in the manuscript.
Reviewer 2 Report
The work presented for the review is extremely interesting due to the subject matter and methods used. The purpose of the work was to determine relationships between lake water levels and indices of macroscale atmospheric circulations.
The abstract is written well. Keywords I would suggest a little change. Instead of abbreviations AO, NAO, EA, SCAND maybe it's worth saving as “indices of macroscale atmospheric circulations”. The word “Poland” seems unnecessary.
The introduction is written well, the literature selected correctly.
In chapter Materials and Methods I would suggest in Figure 1, check the stations that measure the air temperature and the amount of atmospheric precipitation. In Table 1, I did not have a few hydrological measures, among others the water exchange rate in the lake, the O'hle index, the Schindler index, or the index “n”, determining the retention capacity of the lake. I also lacked information on the catchment area of the lakes studied.
The obtained results are described very well and supplemented with a great graphic material. In this part of the work I just lacked a larger description of the connections of precipitation to the obtained results.
Chapter Discussion and conclusions I would break down into two: discussions and conclusions. In the conclusions I would like to read what the authors discovered in their work. At the moment the discussion prevails over the conclusions and it is difficult to find them in the text. The discussion itself would be complemented by a larger number of quoted references. At the moment, the description is largely a discussion with yourself.
In summary, I think that the work is written very well and requires only a few additions and corrections. Therefore, it should be accepted for publication in the journal Water.
Author Response
Response to Reviewers: First of all, we would like to thank the reviewers for their valuable comments. Below please find the original comments and our responses (in bold) explaining how the original manuscript was amended during the revision.
Reviewer 2
The work presented for the review is extremely interesting due to the subject matter and methods used. The purpose of the work was to determine relationships between lake water levels and indices of macroscale atmospheric circulations.
The abstract is written well. Keywords I would suggest a little change. Instead of abbreviations AO, NAO, EA, SCAND maybe it's worth saving as “indices of macroscale atmospheric circulations”. The word “Poland” seems unnecessary.
The introduction is written well, the literature selected correctly.
In chapter Materials and Methods I would suggest in Figure 1, check the stations that measure the air temperature and the amount of atmospheric precipitation. In Table 1, I did not have a few hydrological measures, among others the water exchange rate in the lake, the O'hle index, the Schindler index, or the index “n”, determining the retention capacity of the lake. I also lacked information on the catchment area of the lakes studied.
The obtained results are described very well and supplemented with a great graphic material. In this part of the work I just lacked a larger description of the connections of precipitation to the obtained results.
Chapter Discussion and conclusions I would break down into two: discussions and conclusions. In the conclusions I would like to read what the authors discovered in their work. At the moment the discussion prevails over the conclusions and it is difficult to find them in the text. The discussion itself would be complemented by a larger number of quoted references. At the moment, the description is largely a discussion with yourself.
In summary, I think that the work is written very well and requires only a few additions and corrections. Therefore, it should be accepted for publication in the journal Water.
According to the comments, keywords have been verified.
In the Figure 1 the meteorological stations were marked.
Table 1 was supplemented with the area of the lake catchment, the Ohle index, the Schindler index and the elements of the water balance of lake catchments (outflow and precipitation).
In the Results section the connections between precipitation and the obtained results are now better described (lines: 353-357). Please check the changes in the manuscript.
The “Discussion and conclusions” section has been divided into two separate sections. The “Discussion” section has been supplemented with the new text and citations. Please check the changes in the manuscript.
Round 2
Reviewer 1 Report
I think the new version of the manuscript has substantially improved relative to the original version, and I thank the authors for their work in responding to my suggested revisions. I see no major issues in the manuscript now (some minor issues are described below).
Lines 56-57 - I don't understand this one-sentence paragraph. Should this be included as part of the previous paragraph or as part of the next paragraph?
Line 376 - "Mississippi" is misspelled at the beginning of the line, and "River" should be capitalized as it is a proper noun.
Line 401 - Please replace "indexes" with "indices".
There are several more spelling and grammar issues within the manuscript, but a careful proofread by a native English speaker should take care of them.
Author Response
We are thankful for your comments, they has helped us to improve the paper. We also corrected mentioned minor issues.
