Relationship between Water Temperature of Polish Rivers and Large-Scale Atmospheric Circulation
Round 1
Reviewer 1 Report
Review of “Relationship between water temperature of Polish rivers and large-scale atmospheric circulation” by Graf and Wrzesinski.
In this paper, the authors investigated the relationships between large-scale atmospheric circulations, such as NAO, AO, EA etc., and the water temperature in Polish rivers. The results showed that NAO, AO, EA and AMO indices have a generally positive correlation with air and water temperature, whereas SCAND and EWAR indices have a negative correlation.
Influence from large-scale atmospheric circulations on regional climate is an important topic, and attracts attentions from both climate community and inter-discipline research community. The research methods and the conclusions in this study are reasonable and meaningful, and the manuscript is well-written. However, I still have some comments regarding to the methods used in this manuscript. Therefore, I would recommend that the present manuscript may be accepted for publication after some major revisions.
One of my major concern is the lack of discussion on the physical mechanisms behind the relationships between the large-scale atmospheric circulations and water temperatures, especially on the spatial distributions. The authors may claim these analyses are beyond the scope of current study, however, at least some discussions must be added to make the results more convincing. Some recent literatures about influences and mechanisms from large-scale atmospheric circulations on regional climate, would provide some references to this study, and also be helpful to strengthen the motivation and importance of this manuscript, such as:
Notaro, M., W.-C. Wang, and W. Gong, 2006: Model and observational analysis of the northeast U.S. regional climate and its relationship to the PNA and NAO patterns during early winter. Mon. Wea. Rev., 134, 3479–3505
Ning, L., and R. S. Bradley, 2015: Winter climate extremes over the northeastern United States and southeastern Canada and teleconnections with large-scale modes of climate variability. J. Climate, 28, 2475-2493
Kenyon, J., and G. C. Hegerl, 2008: Influence of modes of climate variability on global temperature extremes. J. Climate, 21, 3872–3889
Ning, L., and R. S. Bradley, 2016: NAO and PNA influences on winter temperature and precipitation over the eastern United States in CMIP5 GCMs. Clim. Dyn., 46, 1257-1276
In the discussion part, the reasons about why the relationships between water temperature and atmospheric circulations are less clear than air temperature need to be strengthened.
The legends of the figures are too small.
For Figure 4 and Figure 6, the significant correlation coefficients should be marked to give the readers an idea of spatial distributions of the significant influences.
Figure 5 needs to be enlarged.
Author Response
“Relationship between water temperature of Polish rivers and large-scale atmospheric circulation”
REPLIES TO THE REVIEW – REVIEWER 1:
1. Reviewer’s comment: Influence from large-scale atmospheric circulations on regional climate is an important topic, and attracts attentions from both climate community and inter-discipline research community. The research methods and the conclusions in this study are reasonable and meaningful, and the manuscript is well-written. However, I still have some comments regarding to the methods used in this manuscript. Therefore, I would recommend that the present manuscript may be accepted for publication after some major revisions.
One of my major concern is the lack of discussion on the physical mechanisms behind the relationships between the large-scale atmospheric circulations and water temperatures, especially on the spatial distributions. The authors may claim these analyses are beyond the scope of current study, however, at least some discussions must be added to make the results more convincing. Some recent literatures about influences and mechanisms from large-scale atmospheric circulations on regional climate, would provide some references to this study, and also be helpful to strengthen the motivation and importance of this manuscript, such as:
Notaro, M., W.-C. Wang, and W. Gong, 2006: Model and observational analysis of the northeast U.S. regional climate and its relationship to the PNA and NAO patterns during early winter. Mon. Wea. Rev., 134, 3479–3505
Ning, L., and R. S. Bradley, 2015: Winter climate extremes over the north-eastern United States and south-eastern Canada and teleconnections with large-scale modes of climate variability. J. Climate, 28, 2475-2493
Kenyon, J., and G. C. Hegerl, 2008: Influence of modes of climate variability on global temperature extremes. J. Climate, 21, 3872-3889
Ning, L., and R. S. Bradley, 2016: NAO and PNA influences on winter temperature and precipitation over the eastern United States in CMIP5 GCMs. Clim. Dyn., 46, 1257-1276
REPLY: Thank you for your assessment and the suggestions put forward in the review.
The comment concerning the lack of a broader discussion on the physical mechanisms which determine relations between macroscale circulation types and air and water temperature is most apt. Indeed, as the reviewer has himself observed, this issue exceeds the scope of research conducted in connection the present paper. The main subject of analysis was the hydrological aspect of teleconnection, and in particular changes in the thermal regime of river waters viewed in a temporal and spatial approach. The issue of physical mechanisms has been given general consideration in the text of the article, specifically in the introductory part, as a background for further hydrological research into water thermal characteristics, and in the discussion. Being hydrologists, at this stage of research we did not attempt a detailed explanation of the physical mechanisms of the analysed dependences. The authors have taken the reviewer’s suggestions into consideration and supplemented the article’s “Introduction” and “Discussion”, as well as the literature concerning the physical mechanisms of macroscale circulation types and their impact on the regional climate.
2. Reviewer’s comment: In the discussion part, the reasons about why the relationships between water temperature and atmospheric circulations are less clear than air temperature need to be strengthened.
REPLY: The authors have taken the reviewer's suggestions into consideration and supplemented the article’s “Discussion” accordingly.
3. Reviewer’s comment: The legends of the figures are too small.
REPLY: The legends of the figures have been enlarged.
4. Reviewer’s comment: For Figure 4 and Figure 6, the significant correlation coefficients should be marked to give the readers an idea of spatial distributions of the significant influences.
REPLY: In Figs. 4 and 6, significant coefficients of correlation have been described in the legend and marked with the appropriate colour. The quality of the figures has been improved.
5. Reviewer’s comment: Figure 5 needs to be enlarged.
REPLY: Fig. 5 has been enlarged.
REPLY: In accordance with the reviewer’s suggestion, the structure of the article has been changed by the addition of a chapter entitled “Conclusions” and the rewording, shortening and supplementation of the chapters “Abstract”, “Introduction”, “Results” and “Discussion”.
Attention: Language editing has been carried out by the “Ultra” Translation Agency in Poznań, Poland.
The authors would like to thank the Reviewer for their helpful and constructive comments, which greatly contributed to improving the quality of the paper.
Reviewer 2 Report
Broad comments
The research was carried out reliably, using the available data and appropriate tools. It responds to established research questions.
My main reservations concern the broadly understood structure of the article.
As for the sections: Introduction, Materials and Methods, and Results, I have no objections. The authors introduce the reader into a problem in detail, present the methodology and logically run through the thicket of results.
Nevertheless, in my opinion, the end of the article lacks short and/but synthetic conclusions. It seems that the abstract has taken over this role. The information in the abstract is too detailed and too long.
As to the Discussion section, which is supposed to summarize research and analyse studies conducted by other researchers, this part is partially a repetition of the Results section (too many numerical detail). Personally, I think that discussion with other research studies should be conducted at a higher level of generality, unless it would refer to specific numerical values obtained parallel by other authors.
Specific comments
In the subsection on the Research area, the authors often mention minor rivers in Poland, forgetting perhaps that not all readers would be able to place them on the map. E.g. page 5, lines 205-206: The authors write: "Also prominent, however, is a group of rivers without any connection, and these include e.g.: Przemsza, Kłodnica, Brynica." Where are these rivers? Why were these mentioned? Is their choice accidental? Is there any spatial pattern in correlation? Any specific areas where these correlation coefficients are high and other where there is no correlation at all? In my opinion, such information seems to be more valuable than listing river names.
I do not want to discuss whether to use the name Wielkopolska Region or Greater Poland (page 10, line 307). However, for the comfort of a foreign reader, I recommend to additionally insert an approximate location of the region in Poland (e.g. the western part of the country).
Page 10, lines 303-323. When it comes to AMO, SCAND and EAWR indicators, there are no references to the figures that would definitely facilitate the perception of the text.
Author Response
“Relationship between water temperature of Polish rivers and large-scale atmospheric circulation”
REPLIES TO THE REVIEW – REVIEWER 2:
1. Reviewer’s comment - Broad comments
The research was carried out reliably, using the available data and appropriate tools. It responds to established research questions.
My main reservations concern the broadly understood structure of the article.
As for the sections: Introduction, Materials and Methods, and Results, I have no objections. The authors introduce the reader into a problem in detail, present the methodology and logically run through the thicket of results.
Nevertheless, in my opinion, the end of the article lacks short and/but synthetic conclusions. It seems that the abstract has taken over this role. The information in the abstract is too detailed and too long.
As to the Discussion section, which is supposed to summarize research and analyse studies conducted by other researchers, this part is partially a repetition of the Results section (too many numerical detail). Personally, I think that discussion with other research studies should be conducted at a higher level of generality, unless it would refer to specific numerical values obtained parallel by other authors.
REPLY: Thank you for your assessment and the suggestions put forward in the review.
REPLY: In accordance with the reviewer’s suggestion, the structure of the article has been changed by the addition of a chapter entitled “Conclusions” and the rewording, shortening and supplementation of the chapters “Abstract”, “Introduction”, “Results” and “Discussion”.
2. Reviewer’s comment - Specific comments:
In the subsection on the Research area, the authors often mention minor rivers in Poland, forgetting perhaps that not all readers would be able to place them on the map. E.g. page 5, lines 205-206: The authors write: "Also prominent, however, is a group of rivers without any connection, and these include e.g.: Przemsza, Kłodnica, Brynica." Where are these rivers? Why were these mentioned? Is their choice accidental? Is there any spatial pattern in correlation? Any specific areas where these correlation coefficients are high and other where there is no correlation at all? In my opinion, such information seems to be more valuable than listing river names.
REPLY: The authors agree with the reviewer’s observation that for readers unfamiliar with the territory of Poland, the location of small rivers is made difficult by the fact that map contents (including descriptions of rivers) are generalised – Fig. 1. However, this generalisation was necessitated by a technical limitation imposed on the presentations of stations, rivers and the very results of research – Figs. 4 and 6. The text of the article has been altered and generalised in relation to the contents of maps.
Among others, the following sentence has been supplemented: Lower water temperatures are also registered in the rivers of the Upper Silesia region (in the vicinity of Katowice, Fig. 1).
Further, the article’s “Results” and “Discussion” have also been changed, and now include data on the correlation between river water temperature and air temperature.
3. Reviewer’s comment: I do not want to discuss whether to use the name Wielkopolska Region or Greater Poland (page 10, line 307). However, for the comfort of a foreign reader, I recommend to additionally insert an approximate location of the region in Poland (e.g. the western part of the country).
REPLY: The text has been altered and supplemented: … was also determined for rivers in Greater Poland, (in west-central Poland), and the lower Odra … .
4. Reviewer’s comment: Page 10, lines 303-323. When it comes to AMO, SCAND and EAWR indicators, there are no references to the figures that would definitely facilitate the perception of the text.
REPLY: The text has been supplemented by the addition of figure numbers.
The SCAND and EAWR indices displayed considerably weaker and negative correlations with river water temperature – Fig. 4A.
In the negative phase, river water temperatures are higher by 0.1–0.4°C, while in the positive phase they are lower by 0.1–0.2°C – Fig. 4B.
Attention: Language editing has been carried out by the “Ultra” Translation Agency in Poznań, Poland.
The authors would like to thank the Reviewer for their helpful and constructive comments, which greatly contributed to improving the quality of the paper.
Reviewer 3 Report
See attached file.
Comments for author File: 
Comments.pdf
Author Response
“Relationship between water temperature of Polish rivers and large-scale atmospheric circulation”
REPLIES TO THE REVIEW – REVIEWER 3:
1. Reviewer’s comment: General Comments and Suggestions for Consideration.
While I realize that air temperature has great effects on water temperature, the paper spends about an equal amount of space to both air and water temperature. So, I would suggest either modifying the title of the paper to include both air and water temperature, or be a bit more generic and just talk about temperature in general and how atmospheric temperature is affected by atmospheric teleconnections like the 6 that are looked at. Or simply focus on water temperature if that is the ultimate goal. The abstract talks about how the relationship between teleconnections and air temperature is much clearer than water temperature; and so again, perhaps that might want to guide the focus of the paper.
REPLY: Thank you for your assessment and the suggestions put forward in the review.
In the authors’ opinion, a climatic background in the form of air temperature is important for an analysis of temporal and spatial water temperature changes and the connections thereof with teleconnection patterns, and this has been duly presented in the paper. An incidental benefit is that the reader is provided with additional information about the relations between air temperature and macroscale circulation types. Taking the reviewer’s suggestions into consideration, the authors have precised the objective of the study, focusing on the determination of the impact of teleconnection patterns on temporal and spatial changes in river water temperature in Poland. The authors have stressed that as regards this part of Europe, the impact of certain of them is only rarely discussed in topical literature. There are no studies for the territory of Poland that would concern relations between macroscale circulation types and river water temperature.
2. Reviewer’s comment: The abstract should be a bit more succinct, but should also note some more specific conclusions that give the reader a better picture of what was found.
REPLY: The authors have taken the reviewer's suggestions into consideration by correcting and supplementing the contents of the “Abstract”.
3. Reviewer’s comment: As noted in the Introduction, if “…the thermal characteristics of river waters are impacted first and foremost by air temperature…”, then why not focus on air temperatures which have clearer relationships to the teleconnections? So for instance, on lines 193-194, what part of the high water temperatures of the Upper Silesia attributed to anthropogenic factors, and what part is attributed to the NAO or AO? Pardon, the pun, but that just muddies the waters and is confusing. It would seem easier to tease out a climate signal from the changes in atmospheric temperatures and what those affects are on river temperature.
- If in fact river water temperature does have a lot more anthropogenic effects than air temperature (should of anthropogenic climate change), then I think you are opening yourself open to criticism about how you tease out things like pollution, river management, river bed management, etc. So, what is affecting the river temperature in 2017 – is it the NAO, or is it increased effluents added? So, again, focusing primarily on air temperature may be a cleaner approach.
REPLY: The authors are aware of the fact that the thermal characteristics of river waters are impacted first and foremost by air temperature, and could perform such analyses for the territory of Poland. However, due to the lack of studies concerning relations between teleconnection patterns and river water temperature in Poland, they did not take up this topic. No such studies have yet been conducted at this level. Simple analyses of the impact of air temperature on water temperature are performed in large numbers on various temporal and spatial scales, and the authors have mentioned this fact in their review of the literature.
The drawing of conclusions as to the significance of macroscopic, regional and local factors (the latter connected with anthropopressure) for shaping the features of the thermal regime of waters is very important, but at the same time difficult, and for this reason it did not constitute the subject of analysis for the adopted spatial scale of the study. The authors are aware of the problem of anthropogenic changes in water thermal characteristics, however such research was not anticipated for the study. At this level of analysis it is not possible to answer the question concerning the extent to which higher temperatures of river waters in Upper Silesia are brought about by anthropogenic factors or are connected with teleconnection patterns. Research into the run-off regime of rivers confirms that some rivers have regimes which have been anthropogenically transformed, which manifests itself, for example, through increased run-off and considerable pollution caused by the discharge of mine waters, e.g. in Upper Silesia. The research conducted took into consideration all rivers, with a full series of water temperature observations in Poland, with the intention being to analyse the influence of impact patterns irrespective of the degree of anthropogenic transformation of river systems. As regards rivers impacted by anthropopressure, which factor has been confirmed in the literature, the results of research demonstrated the completely different character of relations with macroscale circulation types.
4. Reviewer’s comment: Six teleconnections seems like a lot to focus on in one paper, and so perhaps pick the two most important ones (e.g., NAO and AO), and then focus on those, with a mention of the other four.
So, for instance, use Figure 4 for all six teleconnections and their coefficients of correlation, and then pick two to focus on from there.
REPLY: The authors selected 6 teleconnection patterns, the impact of which on hydroclimatic conditions (to a greater or lesser degree) had been previously confirmed for this part of Europe (references in the literature), however none of them were researched in relation to the aspect of river water temperature. The authors considered that an analysis of correlation conducted for all selected patterns and river water temperature values would constitute a good synthesis of the circulatory conditions extant in Poland, enabling an assessment of their impact on water thermal characteristics.
5. Reviewer’s comment: Also, the color bar legend for Figure 4 is unreadable – I do not have a clue as to what the colors represent there. I have the same comment for Figs 3, 5, and 6; they are extremely hard to read.
REPLY: The legends of the figures and the figures themselves have been enlarged. In Figs. 4 and 6, statistically significant coefficients of correlation have been described in the legend and marked with the appropriate colour. The quality of the figures has been improved.
5. Reviewer’s comment: The study seems to include both annual and monthly values, but I would suggest focusing on something more applicable which would be on a seasonal basis, and so I think it would be better to focus on changes for Winter (DJF), Spring (MAM), Summer (JJA), and Autumn (SON), rather than mixing monthly and annual analyses. Seasonal analyses have the added benefit of looking at change throughout the year with having to see 12 analyses vice 4.
- So in Figure 2, I could see perhaps two four-panel plots that show seasonal average air temperatures and seasonal average water temperatures; or just water temperatures if you want to stay true to the title of your paper.
REPLY: In the authors’ opinion this is an interesting suggestion, and indeed the approach is commonly used in research into the seasonality and variability of hydrometeorological elements in the average annual cycle. It would appear, however, that research on a monthly scale provides the most detailed information. The results of seasonal research with reference to certain teleconnections may actually lead to erroneous determinations and conclusions. For example, in the case of NAO and AO (Fig. 5) the strongest relation occur in winter and only in one spring month (March). A seasonal analysis would demonstrate a strong relation for the entire spring season. The situation is similar for AO – stronger relations have been demonstrated for September, and in the seasonal approach a stronger relation would have been determined for the entire autumn period. For this reason analyses were conducted on a monthly scale.
6. Reviewer’s comment: Typically in climate studies, things are couched in terms of anomalies (or departures from a set long term, usually 30-year, set of normal. Therefore, I would suggest selecting a standard 30-year period like 1981-2010, and then see what happens on a seasonal basis from there.
REPLY: A valuable observation for climate research, however this is not a commonly applied principle. Hydrological research conducted by the authors made use of the multiannual period 1971–2015, this because it constituted the longest available observation series of river water temperature in Poland. Measurement series were taken from data from the standard network of hydrological and meteorological observations of the Institute of Meteorology and Water Management – National Research Institute (Warsaw, Poland).
7. Reviewer’s comment: In line with that, I would avoid talking about things like average annual air temperature over Poland (line 179); frankly, from a climatological point of view the average annual temperature in Poland is not important; it would be far more important to see departures (or anomalies) from that value. So, then it would be nice to see (perhaps seasonally) two fourpanel charts showing temperature anomalies for each season under the two most critical teleconnections.
REPLY: The values provided in line 179 are intended to supplement the text of the article with a description of the test area. Deviations of annual temperatures in various phases of all teleconnections from average values for the years 1971–2015 have been presented in Fig. 4, and for selected months in Fig. 6.
7. Reviewer’s comment: Sections 3 and 4 are frankly quite a slog to read through and I think that a lot of what is presented could be more easily summarized in a few tables that would cut down considerably on the amount of text.
REPLY: In accordance with the reviewer’s suggestion, the contents of the chapters “Results” and “Discussion” have been reworded, shortened and supplemented.
8. Reviewer’s comment: Finally, the addition of a section 5, Conclusions, would be good in order to present a succinct and well-summarized discussion about what was found, and more importantly, what was the significance of these findings.
REPLY: In accordance with the reviewer’s suggestion, the structure of the article has been changed by the addition of a chapter entitled “Conclusions” and the rewording, shortening and supplementation of the chapters “Abstract”, “Introduction”, “Results” and “Discussion”.
9. Reviewer’s comment: While mention is made about what software analysis and graphic packages that were used (something I am not sure is required unless you make the coding available), there is no mention made of where the data results are stored (web site address) and if they are available or not.
REPLY: Raw data was obtained from the collections of the Institute of Meteorology and Water Management – National Research Institute (Warsaw, Poland).
Data concerning teleconnections were obtained from the Climate Prediction Centre of NOAA (CPC NOAA) (http://www.cpc.ncep.noaa.gov/data/teledoc/telecontents.shtml).
The provision of access to the results of research in any other form has not been anticipated.
Attention: Language editing has been carried out by the “Ultra” Translation Agency in Poznań, Poland.
The authors would like to thank the Reviewer for their helpful and constructive comments, which greatly contributed to improving the quality of the paper.
Reviewer 4 Report
This paper is a simple analysis of non-linear correlations between climate indices and water temperature. There is no novelty in the methodology. The only novelty in this application is the fact that it has perhaps not been done in Poland. However in most papers, this would be summarized in one paragraph, with a table of correlations. I do not think that such basic applications warrant publication.
Author Response
“Relationship between water temperature of Polish rivers and large-scale atmospheric circulation”
REPLIES TO THE REVIEW – REVIEWER 4:
Reviewer’s comment: This paper is a simple analysis of non-linear correlations between climate indices and water temperature. There is no novelty in the methodology. The only novelty in this application is the fact that it has perhaps not been done in Poland. However in most papers, this would be summarized in one paragraph, with a table of correlations. I do not think that such basic applications warrant publication.
REPLY: Thank you for your review.
While the authors concur that the methodology which they utilised in their research is neither very complicated nor innovative, they consider that the scope of research, which was conducted on a rich body of hydrometrical material covering daily water temperature values for the years 1971–2015 at 96 stations located on 53 rivers in Poland, is worth emphasising. Daily air temperature values for 43 meteorological stations were also taken into account. It is the authors’ opinion that from a hydrological point of view the study contributes much new information concerning the temporal and spatial relations between teleconnection patterns and river water temperature in Poland. These dependences have been similarly identified for elements of the hydrological regime of lakes (ice phenomena, temperatures, water levels) and rivers (run-offs), however not many studies are devoted to the thermal characteristics of river waters, particularly on the regional scale, and the authors have noted this fact in the “Introduction” and “Results”. The reviewed paper is the first such broad study of the issue to be undertaken not only in Poland, but also in this part of Europe, and without a doubt possesses a certain informational and utilitarian potential, which fact the authors have stressed when outlining the objectives of the paper and in its “Conclusions”. There exists a specific need within the scientific community for works of this type, touching upon hydrological and environmental issues. The results of research presented in the paper demonstrate the complexity of processes occurring in rivers, the course of which depends on numerous factors that exert their influence on both the regional and the local scale. This knowledge is of importance in the context of observed climate change and increasing anthropopressure, and the transformations of river ecosystems caused thereby,which fact the remaining reviewers have duly noted.
Round 2
Reviewer 1 Report
The authors have successfully addressed all my concerns.
Author Response
REPLIES TO THE REVIEW – REVIEWER 1:
We thank very much the Reviewer for taking time and effort in reading and analyzing our manuscript entitled “Relationship between water temperature of Polish rivers and large-scale atmospheric circulation". We are very grateful for all of the valuable comments, both general and detailed ones, which allowed to improve the manuscript.
1. Reviewer’s comment: English language and style are fine/minor spell check required
REPLY: In accordance with the Reviewer’s suggestion, the language and style of the text have been edited. Language editing has been carried out by the “Ultra” Translation Agency in Poznań, Poland.
Reviewer 3 Report
While the authors addressed all of my comments in their responses; I
really did not see those responses reflected in the body of the
manuscript. Frankly, I continue to not find the paper to contribute
much to the literature from a climatological perspective. Yes, while I
suppose that the impact of global teleconnections on Polish water and
air temperature may have not been done before, but from a global climate
standpoint, I simply do not find it to add anything significant to the
literature.
Author Response
REPLIES TO THE REVIEW – REVIEWER 3:
Comments and Suggestions for Authors:
While the authors addressed all of my comments in their responses; I really did not see those responses reflected in the body of the manuscript. Frankly, I continue to not find the paper to contribute much to the literature from a climatological perspective. Yes, while I suppose that the impact of global teleconnections on Polish water and air temperature may have not been done before, but from a global climate standpoint, I simply do not find it to add anything significant to the literature.
REPLY: We thank very much the Reviewer for taking time and effort in reading and analyzing our manuscript entitled “Relationship between water temperature of Polish rivers and large-scale atmospheric circulation". We are very grateful for all of the valuable comments, both general and detailed ones, which allowed to improve the manuscript.
All of comments and remarks were again considered carefully; the general comments allowed to revise our ideas concerning the studied issue and they are essential for our future studies).
The authors have provided detailed responses to the entirety of comments and suggestions put forward by the reviewer in Round 1 of their replies to the review. In the present Round, their responses concern fundamental changes introduced into the structure and contents of the manuscript.
Changes made:
1. The authors have modified the structure of the following chapters: “Materials and Methods”, “Source Materials”, “Research Area”, “Results”, and “Discussion”. Major revisions have been made in particular to the “Results” and “Discussion” sections. Individual paragraphs of the text have been redrafted or supplemented, and also reordered thematically.
2. The methodological part has been supplemented with information on the data used in analyses, and also by the addition of a description of the macroscale circulation types utilised in research.
3. The section “Introduction” has also been supplemented, this by the verification and detailing of the assumptions and objective of research.
4. In response to comments made by the Reviewer, the analysis and interpretation of relations between water temperature and macroscale types of atmospheric circulation have been strengthened by the inclusion of seasonal relations (for the research period 1971–2015), duly presented in the section “Results”. The adoption of these assumptions entailed the elaboration of new maps presenting temperature correlations (for all teleconnection patterns) and deviations in the individual phases of various indices.
In accordance with the Reviewer’s suggestion, detailed analyses of seasonal deviations of water temperature values from average values for the years 1971–2015 were conducted in various phases of circulation types for two selected indices: the Arctic Oscillation (AO- and AO +) and the East Atlantic pattern (EA- and EA+). These specific indices were selected for detailed analysis on the basis of results concerning the percentage share of positive and negative coefficients of correlation of seasonal indices with water temperature values.
The results of analyses of annual teleconnections have been retained in the work, while the volume of analyses concerning monthly correlations has been reduced by the transferral of a portion of the graphical materials to the Appendix.
In the present form, the results are clearly presented and more cohesive.
5. The “Conclusions” present the main conclusions following from the analysis conducted thereby, these concerning the temporal and spatial character of relations between the temperature of water in Polish rivers and macroscale types of atmospheric circulation. The analysis was based on the determination of the annual and seasonal activity and intensity of influence of macroscale types of atmospheric circulation on the development of water temperature in rivers.
6. In accordance with the Reviewer’s suggestion, the language and style of the text have been edited. Language editing has been carried out by the “Ultra” Translation Agency in Poznań, Poland.
We provided a record of changes introduced to the manuscript, according to all Reviewers’ suggestions.
Reviewer 4 Report
I am still of the opinion that this manuscript lacks originality in its methodological approach. Water is supposed to publish "original research papers, critical reviews and short communications". I will leave it up to the Editor to decide if the manuscript falls in the first category. Should the answer be yes, I believe that more information is needed on the water temperature measurements and their precision. I have mad a few more comments in the annotated manuscript attached.
Comments for author File: Comments.pdf
Author Response
REPLIES TO THE REVIEW – REVIEWER 4:
Comments and Suggestions for Authors
I am still of the opinion that this manuscript lacks originality in its methodological approach. Water is supposed to publish "original research papers, critical reviews and short communications". I will leave it up to the Editor to decide if the manuscript falls in the first category. Should the answer be yes, I believe that more information is needed on the water temperature measurements and their precision. I have mad a few more comments in the annotated manuscript attached.
REPLY: We thank very much the Reviewer for taking time and effort in reading and analyzing our manuscript entitled “Relationship between water temperature of Polish rivers and large-scale atmospheric circulation". We are very grateful for all of the valuable comments, both general and detailed ones, which allowed to improve the manuscript.
All of comments and remarks were considered carefully; the general comments allowed to revise our ideas concerning the studied issue and they are essential for our future studies
1. Reviewer’s comment: The research design can be improved and the methods must be adequately described.
REPLY: As regards the improvement of the research design, the manuscript has been redrafted as regards the assumptions and objective of research. Specifically, its contents have supplemented in the “Introduction”, this by the verification and detailing of the assumptions and objective of research.
The analysis was based on the determination of the annual and seasonal activity and intensity of influence of macroscale types of atmospheric circulation on the development of water temperature in rivers functioning in the moderate climate zone, and on the identification of the month (months) in which the effect of teleconnection patterns on changes in water temperature is greatest. Particular emphasis was placed on ascertaining the circulatory determinants of deviations of annual, seasonal and monthly water temperature in various phases of the studied circulation types from average values for the years 1971–2015, and on establishing their statistical significance. Special attention was paid to anomalous situations when weather models in the researched part of Europe change, which may lead to the disruption of models of the river thermal regime.
The analysis and interpretation of relations between water temperature and macroscale types of atmospheric circulation have been strengthened by the inclusion of seasonal relations (for the research period 1971–2015), duly presented in the section “Results”. The adoption of these assumptions entailed the elaboration of new maps presenting temperature correlations (for all teleconnection patterns) and deviations in the individual phases of various indices.
Detailed analyses of seasonal deviations of water temperature values from average values for the years 1971–2015 were conducted in various phases of circulation types for two selected indices: the Arctic Oscillation (AO- and AO +) and the East Atlantic pattern (EA- and EA+). These specific indices were selected for detailed analysis on the basis of results concerning the percentage share of positive and negative coefficients of correlation of seasonal indices with water temperature values.
The results of analyses of annual teleconnections have been retained in the work, while the volume of analyses concerning monthly correlations has been reduced by the transferral of a portion of the graphical materials to the Appendix.
In the present form, the results are clearly presented and more cohesive.
The authors have stressed that the results obtained thereby, which concern the distinguishment of the character of teleconnections and their influence on the temperature of river waters, are the first and to date only results elaborated on such a broad spatial scale using these specific statistical methods and forms of spatial analysis (supplemented with graphical images in the form of maps of the spatial distribution of temperature correlations and deviations in various index phases) for this part of Europe (Poland). They may be utilised as an initial database – elaborated on the basis of long-term observations of the temperature of lotic waters – for further research conducted on various spatial scales.
Detailed information:
1. The authors have modified the structure of the following chapters: “Materials and Methods”, “Source Materials”, “Research Area”, “Results”, and “Discussion”. Major revisions have been made in particular to the “Results” and “Discussion” sections. Individual paragraphs of the text have been redrafted or supplemented, and also reordered thematically.
2. In the section “Materials and Methods” we have supplemented information on the water and air temperature data utilised in the analyses, this as regards the following: types of sensors, frequency of measurements and precision, and also added a description of the circulation types that were taken into consideration in macroscale research.
3. The section “Introduction” has also been supplemented, this by the verification and detailing of the assumptions and objective of research.
4. In accordance with the Reviewer’s suggestion, the language and style of the text have been edited. Language editing has been carried out by the “Ultra” Translation Agency in Poznań, Poland.
Reviewer’s comment in the manuscript:
1.Reviewer’s comment: So, there are spatial differences but you used the average for the country henceforth, which refers to the following fragment of text:
“Values of indices determined as averages for the whole country are very well correlated with indices for individual regions (the best correlation occurs for central Poland), and thus they may be used to assess the tendencies of climate circulatory features. Circulation indices on the regional scale excellently characterise the variability of weather conditions in Poland, which is caused by the differing forms of circulation”.
REPLY: Usage was made of the average annual temperature, which reflects average thermal conditions in the country and informs of the macro- and mesoclimatic diversification of the area. In Poland, regional differences in air temperature are brought about by oceanic influences (western part) and continental influences (eastern part). The landscape and hypsometric diversity of Poland is another factor that significantly impacts the development of air temperature on the regional and local scale.
A description of the test area was supplemented with a characterisation of changes occurring in seasonal air and river water temperature values.
2.Reviewer’s comment: The reviewer proposed that the description of the objectives of research be proofread.
REPLY: The authors have modified the text in accordance with suggestions made.
It was: As regards this part of Europe, the impact of certain of them is only rarely discussed in topical literature. There are no studies for the territory of Poland that would concern relations between macroscale circulation types and river water temperature.
Is: With regards to this part of Europe, the impact of certain teleconnections is only rarely discussed in topical literature. There are no studies for the territory of Poland that would concern relations between macroscale circulation types and river water temperature.
3. Reviewer’s comment: More information is needed on the water temperature data. Types of sensors, frequency of measurements, precision, etc.
REPLY: The information has been supplemented in the section “Materials and Methods”.
REPLY: In light of the uncertainty as to the confirmation of the normal distribution of the measurement series, it was considered as appropriate to make use of Spearman’s rank-order correlation. During elaboration of the database use was also made of Pearson’s coefficient of linear correlation, however the results which it provided were weaker, and thus the selection was made as above. Spearman’s rank-order correlation (utilised in the study) constitutes a measure of the monotonic statistical dependence between random variables, and also of the non-linear dependence. Spearman’s rank-order correlation test, used in the study, is a non-parametric test, while correlation is rank-based. The analysis makes it possible to correlate variables that have a non-normal distribution with each other at the order and quantitative level, and at the same time remains largely unsusceptible to outliers.
Numerous studies concerning the dependence between times series of water and air temperature have shown that the relationship between variables is not ideally linear. First and foremost, this is connected with the fact that water temperature, as opposed to air temperature, has a lower limit and cannot attain a value of less than 0oC, even during periods of long-term frost. During the summer season, when air temperature is high, the temperature of water in the river does not increase linearly, this because of the intense loss of thermal energy in processes of evaporation and emission of long-wave radiation:
Caissie D., El-Jabi N ., Satish M. G., 2001, Modelling of maximum daily water temperatures in a small stream using air temperatures, Journal of Hydrology, 251, 14 – 28.
Mohseni O., Stefan H. G., Erickson T. R., 1998, A nonlinear regression model for weekly stream temperatures, Water Resources Research, 34, 2685 – 2692.
Neumann D. W., Rajagopalan B., Zagona E.A., 2003, Regression Model for Daily Maximum Stream Temperature, Journal of Environmental Engineering, 7, 667–674.
Graf, R. A multifaceted analysis of the relationship between daily temperature of river water and air. Acta Geophys. 2019, 67, 3, 905–920
5. Reviewer’s comment: with reference to the sentence in the section “Results” – How does that compare with the precision of the instruments?
“In the negative NAO phase the temperature of the majority of rivers is usually 0.3°C lower than average, while in the positive phase it is slightly, i.e. 0–0.3°C, higher than average.”
REPLY: The accuracy of river water temperature measurements at stations with automatic and manual meters equals 0.1°C. This issue has been presented in detail in the section “Materials and Methods”.
6. Reviewer’s comment: Is this a word “baric gradients”? with reference to the sentence:
“The activity of atmospheric circulation follows from the stronger baric gradients over Europe in the cool season of the year.”
REPLY: the concept (term) “baric gradients” is commonly used, however in the present topical context the authors have replaced it with the phrase “pressure gradient”.
We provided a record of changes introduced to the manuscript, according to all Reviewers’ suggestions.
Round 3
Reviewer 3 Report
Accept
Author Response
Dear Reviewer,
Thank you once again for your valuable comments and the final acceptance of our paper for publication.
Reviewer 4 Report
I reviewed the manuscript for a third time (!). There are still two major outstanding issues highlighted in the comments made on the pdf file.
1) It seems to me if the authors are using a combination of spot measurements and daily means calculated from high frequency automated temperature measurements. If this is the case, the spot measurements are likely biased in comparison with daily means from the automated probes. This needs to be clarified and/or addressed.
2) see also my comment on the statistical test for homgeneity.
Comments for author File: Comments.pdf
Author Response
I reviewed the manuscript for a third time (!). There are still two major outstanding issues highlighted in the comments made on the pdf file.
Response to the Reviewer: Thank you very much for your comments with the suggested changes and amendments made on the pdf file. All of them have been considered.
Regarding the two issues:
1) It seems to me if the authors are using a combination of spot measurements and daily means calculated from high frequency automated temperature measurements. If this is the case, the spot measurements are likely biased in comparison with daily means from the automated probes. This needs to be clarified and/or addressed.
Response to the Reviewer: Thank you for the remark. Indeed, detailed information on the temperature measurements may be confusing to the Readers. Daily values of water and air temperature measurements used in our paper are published on the official web-page of the Institute of Meteorology and Water Management-National Research Institute (IMGW-PIB). The data are verified by the Institute and according to it they are homogenous and comparable. Water temperatures shown in the IMGW-PIB publications are based on the point measurements taken daily at the depth of 0.4 meters below the water surface at 6:00 UTC. Mean daily air temperature results from eight measurements and is calculated according to the method: (T00 + T03 + T06 + … + T21)/8. The hours are given in the UTC time. The text in this section of the paper has been improved.
2) see also my comment on the statistical test for homgeneity.
Response to the Reviewer: The Alexandersson test is a statistical tool for detection of a step change in mean value in normally distributed time series that identifies the change point. The test may be applied to log-normally distributed hydrological series where normality is achieved by logarithmisation. Sometimes, for example mean and maximum annual flows are subject to this distribution [Gumbel E.J., 1958; Katz R.W., Parlange M.B.,Naveau P., 2002].The traditional test for equality of means is a competitor of the Alexandersson test, but it requires knowledge of the change point.
Gumbel, E. J. (1958). Statistics of Extremes. New York: Columbia University Press.
Katz, R. W., Parlange, M. B., Naveau, P. (2002). Statistics of extremes in hydrology.
Advances in Water Resources 25, pp. 1287-1304.
