Analysis of Atmospheric Boundary Layer Characteristics on Different Underlying Surfaces of the Eastern Tibetan Plateau in Summer
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsPoint 1: Abstract: In the abstract section there should be a brief description of the results of the experiment. A whole paragraph is full of the results obtained from this experiment, but no description of the significance of this experiment. This section should be rewritten.
Point 2: Line 15-21: This sentence is too long!
Point 3: Line 60: Eastern part of China or Eastern Tibetan Plateau?
Point 4: Line 103-128: Tables 1-3 are positioned too far from the text. Tables should standardize the use of the three-line table format.
Point 5: Line 130: Figure 1 is positioned too far from the text.
Point 6: Line 215: Figure 1. Analysis process flow chart [29]? Is this a flow chart?
Point 7: Line 220: Is Figure 2 used in the article?
Point 8: Line 269-274: Why do Figures 4-6 only the first figure have a legend, and if the legends are the same explain it in the text. It's the same for the following.
Point 9: Line 351: Daily or hourly?
Point 10: The title of the article refers to the characterization of the atmospheric boundary layer on different underlying surfaces, but there is very little mention of the analysis of different underlying surfaces in the article, and only three sites are analyzed. Are three sites representative of that many underlying surfaces features in Figure 1? Is there a need to consider changing the title.
Author Response
Comments and Suggestions for Authors
Point 1: Abstract: In the abstract section there should be a brief description of the results of the experiment. A whole paragraph is full of the results obtained from this experiment, but no description of the significance of this experiment. This section should be rewritten.
Answer: Thank you very much for the comments. The abstract has been rewritten, please see lines 15-36. The modifications are as follows:
During The Second Tibetan Plateau Scientific Expedition and Research Program (STEP) in June 2022, utilizing the comprehensive stereoscopic observation experiment of the "Plateau Low Vortex Network," this study analyzed the variation characteristics and influencing factors of the atmospheric boundary layer height (ABLH) at three stations with different underlying surface types on the Qinghai-Tibet Plateau (QTP): Qumalai Station (grassland), Southeast Tibet Observation and Research Station for the Alpine Environment (SETORS, forest), and Sieshan Station (cropland). The analysis utilized sounding observation data, microwave radiometer data, and ERA5 reanalysis data. The results revealed that the temperature differences between the sounding observation data and microwave radiometer data were minor at the three stations, with a notable temperature inversion phenomenon observed at Sieshan Station. Regarding water vapor density, the differences between the sounding observation data and microwave radiometer data were relatively small at Sieshan Station. The relative humidity increased with height at Sieshan Station, whereas it increased and then decreased with height at SETORS and Qumalai Station. The ABLH at all sites reached its maximum value around noon, approximately 1500m, and exhibited mostly convective boundary layer (CBL) characteristics. During the night, the ABLH mostly showed a stable boundary layer (SBL) pattern, with heights around 250m. In summer, latent heat flux (LE) and sensible heat flux (H) in the eastern plateau were generally lower than those in the western plateau except at 20:00, where they were higher. Vertical velocity (w) in the eastern plateau was greater than in the western plateau. Among Sieshan Station and SETORS, LE and H had the most significant impact on ABLH, while at Qumalai Station, ABLH was more influenced by surface long-wave radiation (Rlu). These four influencing factors showed a positive correlation with ABLH. The impact of different underlying surface types on ABLH primarily manifests in surface temperature variations, solar radiation intensity, vegetation cover, and terrain. Grasslands typically exhibit a larger range of ABLH variations, while the ABLH in forests and mountainous cropland areas is relatively stable.
Point 2: Line 15-21: This sentence is too long!
Answer: Thank you very much for the comments. This sentence has been rewritten, please see lines 15-21. The modifications are as follows:
During The Second Tibetan Plateau Scientific Expedition and Research Program (STEP) in June 2022, utilizing the comprehensive stereoscopic observation experiment of the "Plateau Low Vortex Network," this study analyzed the variation characteristics and influencing factors of the atmospheric boundary layer height (ABLH) at three stations with different underlying surface types on the Qinghai-Tibet Plateau (QTP): Qumalai Station (grassland), Southeast Tibet Observation and Research Station for the Alpine Environment (SETORS, forest), and Sieshan Station (cropland). The analysis utilized sounding observation data, microwave radiometer data, and ERA5 reanalysis data.
Point 3: Line 60: Eastern part of China or Eastern Tibetan Plateau?
Answer: Thank you very much for the comments. It has been modified in the article, and the content modification is of great significance on the impact of the weather in China. Please see lines 52-54.
Point 4: Line 103-128: Tables 1-3 are positioned too far from the text. Tables should standardize the use of the three-line table format.
Answer: Thank you very much for the comments. Tables 1-3 have been standardised to a three-line table format and moved forward to lines 130-132.
Point 5: Line 130: Figure 1 is positioned too far from the text.
Answer: Thank you very much for the comments. Figure 1 has been moved forward to line 128.
Point 6: Line 215: Figure 1. Analysis process flow chart [29]? Is this a flow chart?
Answer: Thank you very much for the comments. Figure 1 has been renamed Figure 1. Spatial pattern of land use and stations distribution[21]. Please see line 129.
Point 7: Line 220: Is Figure 2 used in the article?
Answer: Thank you very much for the comments. Figure 2 is not mentioned in the article, it has been deleted Figure 2.
Point 8: Line 269-274: Why do Figures 4-6 only the first figure have a legend, and if the legends are the same explain it in the text. It's the same for the following.
Answer: Thank you very much for the comments. For a picture in which the legend is the same, it has been explained in the article. Please see the lines 260-261, 264-265, 291-292, 320-321 and 480.
Point 9: Line 351: Daily or hourly?
Answer: Thank you very much for the comments. Hourly variation should be referred to here. It has been corrected in this article, please see lines 374, 375 and line 391.
Point 10: The title of the article refers to the characterization of the atmospheric boundary layer on different underlying surfaces, but there is very little mention of the analysis of different underlying surfaces in the article, and only three sites are analyzed. Are three sites representative of that many underlying surfaces features in Figure 1? Is there a need to consider changing the title.
Answer: Thank you very much for the comments. Due to the complex topography and underlying surface types on the QTP, including forests, alpine meadows, sparse vegetation areas, bare soil, and farmland, the main three types are forests, grasslands, and bare land. In this study, the underlying surface types at Qumalai, SETORS, and Sieshan Station are grassland, forest, and farmland, respectively, which can be considered representative of the main underlying surface types on the QTP. Analyzing the atmospheric boundary layer characteristics at these three sites also involves a comparative analysis of the atmospheric boundary layer characteristics on different underlying surfaces. Therefore, there is no need to change the title.
Author Response File: 
Author Response.docx
Reviewer 2 Report
Comments and Suggestions for AuthorsReview of “ Analysis of atmospheric boundary layer characteristics on different underlying surfaces over the eastern Tibetan Plateau in summer " by Xiaohang Wen et al.
This manuscript reveals the characteristics of atmospheric boundary layer on different underlying surfaces over the eastern Tibetan Plateau in summer. The authors analyzed the characteristics of the vertical distributions of temperature, relative humidity, specific humidity, wind speed and vertical velocity at different stations in conjunction with the observed and reanalyzed data sets from three stations, and provided a detailed analysis of the characteristics of atmospheric boundary layer, as well as its associated daily variations of latent heat fluxes, sensible heat fluxes, and surface longwave radiation. The results showed that the above variables differed to some extent at all three stations. However, authors provide fewer summaries of the different underlying surfaces influences on atmospheric boundary layer characteristics that are the focus of this manuscript. The manuscript needs further revisions before to be published in the journal Remote Sensing. Following were comments:
1. Abstracts are too long and don't summarize the study findings well.
2. Lines 16-23, this sentence is too long. I suggest that the authors simplify this sentence to make it easier for readers to understand. Observational data are important, but it is not necessary to give all the details of the information in the abstract. They can be given in the data description section.
3. The relationship between the characteristics of atmospheric boundary layer in section 3.1 and the factors influencing the ABLH in 3.2 are not clear. For example, what is the relationship between changes in wind direction, speed and relative humidity? What is the relationship between these vertical distribution characteristics and the surface fluxes, including latent and sensible heat fluxes? It is recommended that the authors consider these issues carefully and summarize the processes and mechanisms responsible for the differences in atmospheric boundary layer characteristics and their influence factors at the three stations with different underlying surfaces.
Comments on the Quality of English LanguageSome sentences are too long to understand. I suggest that the authors simplify these sentence to make them easier for readers to understand.
Author Response
Comments and Suggestions for Authors
Review of “ Analysis of atmospheric boundary layer characteristics on different underlying surfaces over the eastern Tibetan Plateau in summer " by Xiaohang Wen et al.
This manuscript reveals the characteristics of atmospheric boundary layer on different underlying surfaces over the eastern Tibetan Plateau in summer. The authors analyzed the characteristics of the vertical distributions of temperature, relative humidity, specific humidity, wind speed and vertical velocity at different stations in conjunction with the observed and reanalyzed data sets from three stations, and provided a detailed analysis of the characteristics of atmospheric boundary layer, as well as its associated daily variations of latent heat fluxes, sensible heat fluxes, and surface longwave radiation. The results showed that the above variables differed to some extent at all three stations. However, authors provide fewer summaries of the different underlying surfaces influences on atmospheric boundary layer characteristics that are the focus of this manuscript. The manuscript needs further revisions before to be published in the journal Remote Sensing. Following were comments:
- Abstracts are too long and don't summarize the study findings well.
Answer: Thank you very much for the comments. The abstract has been rewritten, please see lines 15-36. The modifications are as follows:
During The Second Tibetan Plateau Scientific Expedition and Research Program (STEP) in June 2022, utilizing the comprehensive stereoscopic observation experiment of the "Plateau Low Vortex Network," this study analyzed the variation characteristics and influencing factors of the atmospheric boundary layer height (ABLH) at three stations with different underlying surface types on the Qinghai-Tibet Plateau (QTP): Qumalai Station (grassland), Southeast Tibet Observation and Research Station for the Alpine Environment (SETORS, forest), and Sieshan Station (cropland). The analysis utilized sounding observation data, microwave radiometer data, and ERA5 reanalysis data. The results revealed that the temperature differences between the sounding observation data and microwave radiometer data were minor at the three stations, with a notable temperature inversion phenomenon observed at Sieshan Station. Regarding water vapor density, the differences between the sounding observation data and microwave radiometer data were relatively small at Sieshan Station. The relative humidity increased with height at Sieshan Station, whereas it increased and then decreased with height at SETORS and Qumalai Station. The ABLH at all sites reached its maximum value around noon, approximately 1500m, and exhibited mostly convective boundary layer (CBL) characteristics. During the night, the ABLH mostly showed a stable boundary layer (SBL) pattern, with heights around 250m. In summer, latent heat flux (LE) and sensible heat flux (H) in the eastern plateau were generally lower than those in the western plateau except at 20:00, where they were higher. Vertical velocity (w) in the eastern plateau was greater than in the western plateau. Among Sieshan Station and SETORS, LE and H had the most significant impact on ABLH, while at Qumalai Station, ABLH was more influenced by surface long-wave radiation (Rlu). These four influencing factors showed a positive correlation with ABLH. The impact of different underlying surface types on ABLH primarily manifests in surface temperature variations, solar radiation intensity, vegetation cover, and terrain. Grasslands typically exhibit a larger range of ABLH variations, while the ABLH in forests and mountainous cropland areas is relatively stable.
- Lines 16-23, this sentence is too long. I suggest that the authors simplify this sentence to make it easier for readers to understand. Observational data are important, but it is not necessary to give all the details of the information in the abstract. They can be given in the data description section.
Answer: Thank you very much for the comments. This sentence has been rewritten, please see lines 15-21. The modifications are as follows:
During The Second Tibetan Plateau Scientific Expedition and Research Program (STEP) in June 2022, utilizing the comprehensive stereoscopic observation experiment of the "Plateau Low Vortex Network," this study analyzed the variation characteristics and influencing factors of the atmospheric boundary layer height (ABLH) at three stations with different underlying surface types on the Qinghai-Tibet Plateau (QTP): Qumalai Station (grassland), Southeast Tibet Observation and Research Station for the Alpine Environment (SETORS, forest), and Sieshan Station (cropland). The analysis utilized sounding observation data, microwave radiometer data, and ERA5 reanalysis data.
- The relationship between the characteristics of atmospheric boundary layer in section 3.1 and the factors influencing the ABLH in 3.2 are not clear. For example, what is the relationship between changes in wind direction, speed and relative humidity? What is the relationship between these vertical distribution characteristics and the surface fluxes, including latent and sensible heat fluxes? It is recommended that the authors consider these issues carefully and summarize the processes and mechanisms responsible for the differences in atmospheric boundary layer characteristics and their influence factors at the three stations with different underlying surfaces.
Answer: Thank you very much for the comments.
In general, The factors influencing the height of the atmospheric boundary layer include:
Topography: The height and complexity of the terrain affect the development and ABLH. For example, rugged mountainous areas often result in lower atmospheric boundary layer heights, while flat areas may have higher atmospheric boundary layer heights.
Surface Temperature: Variations in surface temperature directly impact the height of the atmospheric boundary layer. Warmer surface temperatures during the day increase the atmospheric boundary layer height, while cooler surface temperatures at night decrease it.
Solar Radiation: The intensity and distribution of solar radiation also influence changes in the height of the atmospheric boundary layer. Regions with intense radiation typically have higher atmospheric boundary layer heights.
Vertical velocity and Horizontal Wind: Vertical velocity and horizontal wind in the atmosphere significantly affect the height of the atmospheric boundary layer. Upward velocity increases the boundary layer height, while downward velocity decreases it.
Surface Features: Surface features including vegetation cover and water distribution also affect the height of the atmospheric boundary layer. Dense vegetation areas typically have lower ABLH.
The three representative sites selected in this study represent alpine grassland, forests, and mountainous croplands areas.
Qumalai Station, located in the hinterland of the QTP, has flat terrain. Influenced by intense daytime surface heating, vigorous vertical convection develops, increasing the surface sensible heat flux and the temperature gradient in the atmospheric boundary layer. This gradient promotes the development of convection, resulting in the highest boundary layer height among the three stations, which can be sustained until evening. The cooling effect from nighttime surface radiation is evident, leading to the lowest boundary layer height.
SETORS Station has a forested underlying surface, resulting in the lowest atmospheric boundary layer height among the three stations during the day. This is due to the dense vegetation reducing direct solar energy reaching the surface, which lowers the surface temperature and limits the upward extent of the atmospheric boundary layer. Additionally, the dense vegetation increases surface roughness, reducing wind speeds within the canopy layer and slowing vertical diffusion, contributing to the lower boundary layer height.
Sieshan Station is situated in a lower-altitude mountainous cropland area with less intense solar radiation and less dense vegetation compared to SETORS station. This results in a moderate increase in surface temperature and an atmospheric boundary layer height between that of forests and grasslands.
Table 4 also shows that surface latent heat, sensible heat, and net radiation have the highest correlation with the ABLH at SETORS station. This is because the dense vegetation releases a significant amount of latent heat during evapotranspiration, which raises the surrounding air temperature, aiding in convection development. This convection transports warm air upward, increasing the ABLH. At Sieshan Station in the cropland area, vertical velocity has the most significant impact on boundary layer height, possibly due to local circulations formed by complex terrain elevating the boundary layer height, with latent and sensible heat contributions being less dominant factors.
The characteristics of the atmospheric boundary layer height on different underlying surface types in the Qinghai-Tibet Plateau can be summarized as follows:
Grassland: grassland underlying surfaces are typically located in plateau areas with relatively flat terrain. During the day, warm surface temperatures increase the ABLH, while cold surface temperatures at night decrease it. Due to significant surface temperature variations, the boundary layer height experiences a large range of fluctuations, and it is relatively stable as it is less influenced by solar radiation and terrain.
Forest: The ABLH in forested areas is generally lower. This is because dense vegetation reduces direct solar radiation reaching the surface, resulting in lower surface temperatures. This, in turn, reduces the temperature gradient in the lower part of the atmospheric boundary layer, limiting its upward extent. Dense vegetation also increases surface roughness, slowing down vertical diffusion and contributing to a lower boundary layer height.
Cropland Areas: Underlying surfaces in mountainous cropland areas are relatively flat, with weaker solar radiation and lower vegetation cover. As a result, the boundary layer height falls between that of forests and grasslands. The increase in surface temperature is not as intense, leading to a relatively stable atmospheric boundary layer height.
In general, the influence of different underlying surface types on the ABLH is primarily reflected in surface temperature variations, solar radiation intensity, vegetation cover, and terrain. Grasslands typically exhibit a larger range of boundary layer height variations, while forests and mountainous agricultural areas are relatively stable.
Please see lines 339-371, 443-450, 525-545.
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsI have no further comment.
Reviewer 2 Report
Comments and Suggestions for AuthorsI have no more comments.
