A Field Measurement Based Wind Characteristics Analysis of a Typhoon in Near-Ground Boundary Layer

Round 1

Reviewer 1 Report

Authors provide the results of the study of the wind in the near ground layer of the atmosphere by means of the analysis of mast measurements of ultrasonic anemometers and vane-type anemometers. Principally, the manuscript contains the results of analysis of interesting data of measurements. However, there are a number of disadvantages in the manuscript.

• There is a term climate in the title of the manuscript. I suggest to rename the manuscript as authors use a short enough time series and term climate is not suitable.
• Authors use the term turbulence intensity. I assume that authors mean turbulence strength.
• Also I suggest to accent the attention on the fact that the study concerns the periphery of typhoon. These corrections should be done in the text.
• Authors calculated the energy spectra of atmospheric turbulence including small scales with low energy enough. So it is important to indicate the accuracy of the measurements of the wind speed and air temperature in the lines 73 – 74.
• Formula 3. The parameter in the left part of the classical wide used formula should be in the power 2 (sigma^2).
• I suggest to add the dependence of the distance of the typhoon center from the site of the measurements on time in the figures 6-8 (+fig 11,12).
• «Fig.10 shows the wind profiles for different wind speeds during Typhoon “Maria”, indicating that the wind profile significantly varies with the wind speed.» The shown profiles in the figure 10 are approximately straight line i e the the variations of the wind speed with height are imperceptible.  It is better to replot the figure 10 or explain what criterion indicates that the wind profile significantly  varies with the wind speed (do you mean mean wind speed?).
• - Also I recommend you to view the following papers to cite it where the results of the ultrasonic anemometers measurements are discussed:

- https://0-www-mdpi-com.brum.beds.ac.uk/2073-4433/10/11/661

-https://0-www-mdpi-com.brum.beds.ac.uk/2073-4433/10/8/460

• Spectra of turbulence in the figures 28- 30. Firstly you should to add the confidence interval at the spectra calculated.
• Secondly, please explain the following your result. Usually, the accuracy of the measurements of wind speed by the ultrasonic anemometers depends on the average wind speed and approximately equal to (~0.1+0.02V) 0.2 m/s (5 m/sec) – 0.5 m/s (20 m/sec). Your spectra are corresponds to the frequencies >0.1Hz. So, power spectral density of fluctuations at the frequency 1 Hz is equal to 0.01 (m/s)^2.  So, the amplitudes of 1 Hz and higher fluctuations are low (the accuracy of the measurements of very small scale turbulence is not high) I think to cut off the  frequencies higher than 1 Hz. Moreover you may apply the filtering wide used spectral technics (at different frequencies) in order to obtain more representative spectra (or smooth out the spectra by another methods). In  the analysis of the spectra you may use the results:
• https://www.spiedigitallibrary.org/conference-proceedings-of-spie/9292/92920T/Optical-turbulence-and-different-parameters-of-airflow/10.1117/12.2074609.short?SSO=1
• https://0-rmets-onlinelibrary-wiley-com.brum.beds.ac.uk/doi/10.1002/qj.3301

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Reviewer 2 Report

Field measurement data and a systematical analysis of data statistics are presented for Typhoon Maria in this study. The work especially the presented data will be useful for the community. The organization and written English is good. Some minor suggestions are below.

1. More recent studies on field-measured typhoon data and associated statistical analysis should be added in the literature review, e.g., "Evolutionary power spectral density of recorded typhoons at Sutong Bridge using harmonic wavelets" by Wang et al. in 2018 and "An analytical framework for the investigation of tropical cyclone wind characteristics over different measurement conditions" by Li et al. in 2019.
2. Since the authors highlighted the nonstationary approach for wind characteristic analysis, it may be good to mention the study by Tao et al. "Comparative study of the wind characteristics of a strong wind event based on stationary and nonstationary models". 
3. "tth" on line 111 should be fixed.
4. It's probably a good idea to present some wind fluctuation time histories in Sect. 3.2.
5. It is important to carefully examine the potential reasons of outlier data around 14:00 (e.g., in Fig. 11 and Fig. 16).
6. It's probably a good idea to first present the analysis results of autocorrelation functions before presenting Fig. 22.
7. The PSDs obtained in Sect. 4.3 are based on which segment of the field-measured data? It's probably a good idea to present the changes of PSDs based on various data segments.

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Round 2

Reviewer 1 Report

Authors have performed a wide analysis of the atmospheric turbulence structure in the surface layer. We found that the results based on the experemental are interesting. Before publication the following flaws must be corrected:

- Figure 23. It is necessary to add units for the abscissa axis.

-Line 82. «...with the wind speed range: 0~65m/s, accuracy….». It is a well-known fact that measurements taken with ultrasonic anemometer have the disadvantage. Namely, the measurement area is a air volume between the emitters and turbulent characteristics are nor local. Moreover, the accuracy of ultrasonic anemometer is not so high as 0.01 m/s. The value 0.01 m/s corresponds to the sampling rate (resolution). Please, check it in «Wind Speed Specifications» (http://www.gillinstruments.com/products/anemometer/windmaster-pro.html). So, I suggest replace the word «accuracy» to resolution. At the same time, I would like to note that such anemometers are widely used for turbulence studies. Therefore, this remark does not fundamentally affect the results.

- Figure 30. «Power spectra of the longitudinal wind component» Also I suggest to cut off the spectra above the frequency 1Hz.

- Please rename the title Reference to References

-References. It is advisable to add doi to papers in References.

- You should correct References № 27 and 28:

[27] Shikhovtsev A., Kovadlo P., Lukin V., Nosov V.,Kiselev A., Kolobov D., Kopylov E., Shikhovtsev M., Avdeev F. Statistics of the Optical Turbulence from the Micrometeorological Measurements at the Baykal Astrophysical Observatory Site. Atmosphere 2019, 10, 661. https://0-doi-org.brum.beds.ac.uk/10.3390/atmos10110661

[28] Nosov V., Lukin V., Nosov E., Torgaev A., Bogushevich A. Measurement of Atmospheric Turbulence Characteristics by the Ultrasonic Anemometers and the Calibration Processes. Atmosphere 2019, 10, 460. https://0-doi-org.brum.beds.ac.uk/10.3390/atmos10080460

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Reviewer 2 Report

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