Impact of Blue Space Geometry on Urban Heat Island Mitigation
Round 1
Reviewer 1 Report
please see the attached file
Comments for author File: 
Comments.pdf
Author Response
We would like to thank the reviewers for their contributions and the time spent providing useful feedback on our manuscript. Below is our response to their comments.
Reviewer 1
“Introduction: the description of the work should be improved & Introduction: the novelty of the work should be emphasized and not summed up in a single sentence”
In response to these comments, we have included a new paragraph at the end of the Introduction to highlight the novelty of the study and its objectives (lines 104-112).
“A section with acronyms is required”
Following the reviewer’s comment, an Abbreviations section is added in the end of the paper (line 710).
“More details should be given about CFD toolbox OpenFOAM”
We have added a new line (line 155-156) following this comment to refer to the OpenFOAM documentation and source code. We are not going into many details in the text as OpenFOAM is internationally acknowledged and well-documented.
“Line 163: A building with a height of 1.5 metres is not realistic”
The choice of the 1.5 m height was made on the basis of reproducing the experimental configuration of the outdoor urban scale model of COSMO (see Kanda et al. 2006 & 2007, Syafii et al. 2017). The simulation was set up in such way so that the dimensionless numbers are the same as in an unscaled case, ensuring the reproduction of the same dynamics according to the Reynolds analogy principle. For instance, the Richardson number, the dimensionless number that expresses the ratio of the buoyancy term to the flow shear term, is representative of observed urban flows, as mentioned also in Ampatzidis et al. (2020).
“Conclusion: this section could be improved by: a) Restating the research question anf the major findings; b) Telling the reader what contribution the study has made to the existing literature; c) Highlighting any limitations of the study; d) Stating future directions for research/recommendations.”
We agree with the reviewer that the Conclusions can be improved; thus, we have modified them where necessary to address all the points suggested. Particularly: (a) Lines 631-633 of the Conclusions already restate the main aim of the paper. (b) Lines 670-673 and the newly added 691-693 highlight the contribution of the paper to the existing literature. (c,d) A subsection is added in the Results and Discussion section, as per the Instruction for Authors, providing a range of identified limitations and suggestions for future work (see lines 615-629).
Reviewer 2 Report
The work investigate the influence of blue space (surface waterbodies ) size and shape on the in-canyon flow structure, temperature, and water vapour distribution by CFD. Effects on Pollutant transport, evaporative cooling, urban heat island mitigation are identified. The paper is well-structured with sound calculation. The findings are meaningful and significant. Some minor comments.
1. The definition of green and blue space should be introduced in the beginning of the paper.
2. the results are somewhat lengthy. try to shorten if possible.
3. any validation with field monitoring can support the findings?
Author Response
We would like to thank the reviewers for their contributions and the time spent providing useful feedback on our manuscript. Below is our response to their comments.
Reviewer 2
“The definition of green and blue space should be introduced in the beginning of the paper”
Green and blue spaces are types of Nature-Based Solutions that are defined in lines 32-34. Following the reviewer’s comment we have also added some examples of green and blue spaces in lines 35-36.
“the results are somewhat lengthy. try to shorten if possible”
Following the reviewer’s comment we have reread and assessed the Results section trying to identify and remove any unnecessary commentary. However, we still feel the reported discussion is adequate to support our conclusions and in accordance with the number of figures and the information that needs to be conveyed to the reader. Also, the total number of pages is not excessive compared to recently published articles in Climate (e.g. see Palash et al. (2023) and Balcha et al. (2022)).
“any validation with field monitoring can support the findings?”
We are particularly pleased with this comment because it allows us to emphasise once again a peculiarity and the innovative content of this work: to the best of the authors' knowledge, there is no numerical or experimental work in the literature dealing with water evaporation and heat transfer from surfaces in urban contexts similar to those analysed here. However, a validation of the evaporation model was conducted against measurements for evaporating plane water surface in the previous work Ampatzidis et al. (2022), while the validation of motion fields was conducted against wind tunnel experiments of urban flows. This information has been added in the modified manuscript, at lines 170-171.
