Seasons Effects of Field Measurement of Near-Ground Wind Characteristics in a Complex Terrain Forested Region

Round 1

Reviewer 1 Report

This manuscript investigates the seasons effects of field measurement of near-ground wind characteristics in a complex terrain forested region, providing a new perspective for studying near-ground wind characteristics in the forest region. The manuscript is well-written, and the topic is relevant from both scientific and technical perspectives. Consequently, I recommend it for publication in Sustainability. However, some minor revisions are necessary.

 

Specific comments

(1)    Figures 6-9. The author should modify the wind speed division labels.

(2)    Whether the bimodal trend of lateral PDF distribution in section 3.3.3 should be related to the trend of lateral turbulence intensity with wind speed in section 3.3.1. An adequate analysis should be provided.

(3)    Section 3.5. The authors should further analyze the vertical spatial coherence in Figures 70-73.

(4)    Section 4. The authors should indicate the bimodal trend of the lateral PDF distribution in the second article of the conclusions.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

The study has assessed the effect of seasons on wind profiles from the perspective of wind turbine designing in forested areas. The work is interesting and I take the view that it is useful to relevant communities in the field of blade designing, optimization of wind turbines, structural analysis, and fatigue loading. However, some defects in the paper should be amended before being published in Sustainability which are as follows:  

1- A nomenclature should be provided and all parameters and abbreviations in the texts, figures, and equations should be placed there. 

2-In the introduction, the abstract, and Section 2.3, please note that the characteristics extracted for different seasons play a key role not only in designing optimal blades to gain better performance but also in assessing the structural response.  It could make the paper more intriguing for readers. 

3-Section 2 started with pictures in the first place. Please displace it with written issues.

4-From lines 130 to 131, it has been claimed that the error between gained data and real data is about 4.54%. It is worth providing a chart and comparing them on that. 

5-In Figure 3, the wind history has been indicated in 120 minutes for Spring, Summer, Autumn, and Winter. However, the mean temperature and the wetness of the weather have not been taken into consideration. If they have been factored in, a table would be provided to present and discuss.  

6-In line 201, it has been described that the reference point has been set to 35m. Please explain the reason behind that and why other points have not been considered for reference points.

7-For Figure 5, the differences between field measurements and different power-law exponents should be described based on thermodynamics and fluid mechanics reasoning.

8- In line 233, it was described that the differences between temperatures in summer, autumn, and winter are large, however as I can see in your analysis in line 229, the wind direction of 270° to 300° in autumn and winter has been reported. Please express why by having temperature discrepancies in autumn and winter the wind direction has remained fixed for both conditions. 

9- As I see from Figure 22-25, by changing the seasons as the temperature and canopy differs turbulence intensity changes when we move from warmer season toward colder seasons. It is worthwhile to describe why it occurs like that in that part. 

10-From lines 378 to 386, it has been mentioned that " the greater the vertical-to-longitudinal ratio, the hotter the climate and the denser the canopy, and the greater the lateral-to-longitudinal ratio, the colder the climate and the sparser the canopy". 

First, please consider the vertical-to-lateral ratio. Afterward please describe why they are sensitive to the canopy presence, along with temperature discrepancies.

It means that the reasons behind the issue regarding vertical, lateral, and longitudinal ratios should be expounded on.

11- Also I suggest that in the discussion, describe the effect of wetness on variation of different results like turbulence intensity.  

The paper needs reevaluation after providing the revised version. 

 

 

The quality of English is good. However, there are some long sentences and they lag in reading fluency. It is suggested to split them into shorter ones to be more simple and understandable. 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

 

Seasons effects of field measurement of near-ground wind 2 characteristics in a complex terrain forested region

The study presented by authors contains a lot of scientific results which are the result of measurements of the mean and turbulent atmospheric characteristics. The manuscript is well structured and demonstrates a high scientific level. However, I have a number of suggestions which may improve the manuscript.  

-Abstract. Line 13. Authors use the word or the part of word «complex» use twice: «complexity due to complex» we recommend rephrase the sentence.

- Line 260, subsection 3.3.1. «According to Equation (7), the turbulence intensity decreases with increased wind 260 speed».  I think it's worth talking about the relative intensity of turbulence as the real turbulent fluctuations in the wind speed in the surface layer of the atmosphere tend to increase with the increasing mean wind speed.

 

- The analysis of figures which demonstrate the variation in turbulence intensity with wind speed (for example, figure 10) show that one may observe clouds of points rather than some strict dependencies. I recommend authors to clarify the atmospheric conditions for which the dependencies of  relative turbulence intensity on wind speed were obtained (clear sky, perhaps, the repeatability probability of cloudiness at different heights in the atmosphere and so on).

 

-Analysis of seasonal variations of K and C coefficients. Analysis of figures 74 and 75 shows that difference between summer and other seasons is more pronounced for Coh (uu) for coefficient C. Please clarify in more details with what physical reasons  this behavior is connected.

- The spectra of turbulence are characterized by different power-laws usually. The spectral behavior and  formation of turbulent fluctuation in different spectral ranges  depends on a lot factors including wind speed regimes, temperature stratifications, impact of mesoscale and large scale atmospheric disturbances.    It is possibly to discuss (in introduction) the features  of formatting fluctuations in the interrelations with different atmospheric factors. It is possible that the following papers will be interesting for you:

i) doi:10.1088/1755-1315/211/1/012023 (In this paper authors provide universal dependencies of relative turbulent energy on the height above the earth`s surface (from measurements at the meteorological mast) (figure 3).

ii) https://doi.org/10.3390/atmos12101347 (authors provide the ratio of the turbulent to the mean kinetic wind energy components from minisodar measurments)

iii) https://doi.org/10.1007/s10546-015-0079-8, https://doi.org/10.3390/atmos10110661

-Turbulent integral length scales which are plotted on the figures 58 – 69 have not units.  Please add units or at least indicate units in the captions of figures.  Also you use excessive rounding (excessive accuracy) for turbulent integral length scales. Please correct.

 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

The authors have reformed, addressed, and justified all the recommendations/suggestions. Therefore, now, the paper is suitable for publication. 

Reviewer 3 Report

    Authors have made corrections and we recommend the manuscript for publication.