Spatio-Temporal Patterns of Warm-Season Ground Surface Temperature—Surface Air Temperature Difference over China Mainland

Round 1

Reviewer 1 Report

The expression of the article is not concise. It's a bit verbose. Too many abbreviations affect the readability of the article. Suggest the author to improve their presentation and reduce abbreviations. The link provided in the supplementary materials cannot be opened.

Author Response

Point 1: The expression of the article is not concise. It's a bit verbose. Too many abbreviations affect the readability of the article. Suggest the author to improve their presentation and reduce abbreviations. The link provided in the supplementary materials cannot be opened.

 

Response 1: Thanks for your comments. We have reduced the abbreviations in the manuscript. And the supplementary materials have been re-uploaded.

Author Response File: Author Response.docx

Reviewer 2 Report

In this study, the spatial-temporal distribution characteristics and long-term trend of GST-SAT in the warm season in China mainland are analyzed by using homogenized GST and SAT from high-density meteorological stations during 1961-2018. My recommendations are as follows.

1.       Avoid using abbreviations in keywords, unless they are well-known abbreviations, such as GDP. Using “GST-SAT” does not accurately express the meaning of ground surface temperature and surface air temperature.

2.       When “GST-SAT” appears for the first time, explain its meaning, not say it later. “GST” and “SAT” are the same, first explained in line97-99.

3.       Line 33: "in the world and China", language sickness.

4.       Line 35-41: Why was the role of soil mentioned in the introduction? The content of the soil was not said later.

5.       The research progress at home and abroad needs to be further enriched and improved. In addition, the manuscript analyzed the factors that may affect “GST-SAT” so it is necessary to supplement the research progress on influencing factors in the introduction.

6.       Data and methods, Discussion: Add subheadings.

7.       Lines 135-140: Supplement the natural environment and socio-economic factors considered in this manuscript. The manuscript explored which influencing factors and why they were chosen.

8.       Figure 2: It is best to supplement the scale bar.

9.       Figure 4: There were some years that fluctuate more and suggest that the authors describe the reasons for this.

10.   Discussions and results need to be written separately. The discussion should not only explain the results of the study, but also compare them with other studies at home and abroad, so as to sublimate the research value of this study. It was suggested that studies in other countries be added to the discussion and introduction.

Author Response

Point 1: Avoid using abbreviations in keywords, unless they are well-known abbreviations, such as GDP. Using “GST-SAT” does not accurately express the meaning of ground surface temperature and surface air temperature.

Response 1: Thank you. This is indeed a noteworthy problem. The keyword section has been modified accordingly, please see Lines 27-28 in the manuscript.

 

Point 2: When “GST-SAT” appears for the first time, explain its meaning, not say it later. “GST” and “SAT” are the same, first explained in line97-99.

Response 2: Thank you for the comment. This issue has been modified, please see Lines 58-60 in the manuscript.

 

Point 3: Line 33: "in the world and China", language sickness.

Response 3: Thank you for the correction. We rephrased the sentence, please see Line 35 in the revised manuscript.

 

Point 4: Line 35-41: Why was the role of soil mentioned in the introduction? The content of the soil was not said later.

Response 4: Soil can have an impact on ground surface temperature. Soil moisture and deep soil temperature have an important influence on climate processes, especially temperature, boundary layer stability and precipitation, through the distribution of latent and sensible heat fluxes. When soil moisture limits latent heat flux, more energy is used for sensible heating, leading to higher ground surface temperature. In turn, this can significantly affect GST-SAT. Therefore, the role of soil is mentioned in the introduction. Although the soil content is not said later, it could be mentioned as a background.

 

Point 5: The research progress at home and abroad needs to be further enriched and improved. In addition, the manuscript analyzed the factors that may affect “GST-SAT” so it is necessary to supplement the research progress on influencing factors in the introduction.

Response 5: Thank you for this suggestion. The necessary additions are added in the introduction of the revised manuscript, please see Lines 87-104.

 

Point 6: Data and methods, Discussion: Add subheadings.

Response 6: Thanks for this suggestion. The subheadings have been added to the Data and methods and Discussion sections.

 

Point 7: Lines 135-140: Supplement the natural environment and socio-economic factors considered in this manuscript. The manuscript explored which influencing factors and why they were chosen.

Response 7: The study chooses four factors including altitude, sunshine duration, precipitation and relative humidity (Line 162). The reason why we choose the four factors is that they are obtained from observation and can obtain long time series data at the same time. Although both relative humidity and precipitation are humidity factors, they are different in that relative humidity describes mainly the humidity of the air, while precipitation mainly focuses on soil moisture.

 

Point 8: Figure 2: It is best to supplement the scale bar.

Response 8: Thank you. The scale bar has been added in Figure 2.

 

Point 9: Figure 4: There were some years that fluctuate more and suggest that the authors describe the reasons for this.

Response 9: This study mainly focuses on the long-term variation trend, and the interannual variability is not the focus of attention. We mainly discuss the reasons for the strong interannual variation in the years with large fluctuations, such as the summer of 1976 and the spring of 2010. Please see Lines 263-268 in the revised manuscript.

 

Point 10: Discussions and results need to be written separately. The discussion should not only explain the results of the study, but also compare them with other studies at home and abroad, so as to sublimate the research value of this study. It was suggested that studies in other countries be added to the discussion and introduction.

Response 10: Thank you for this suggestion. The necessary additions are added to the introduction and discussion in the revised manuscript, please see Lines 87-104 and 491-505.

Observation of ground surface temperature is available in only a few countries, and observation data are temporarily unavailable. Therefore, studies on GST-SAT have mainly focused on the Chinese region. Some researchers use reanalysis data to discuss global land surface-air temperature difference. However, the surface temperature from the reanalysis data is somewhat different from the observed surface temperature. The observed surface temperature is the 0 cm soil temperature (Ground surface temperature), while the surface temperature in ERA-5 is the skin temperature (The skin temperature is the theoretical temperature that is required to satisfy the surface energy balance). The difference between the observed surface temperature and satellite remote sensing surface temperature is a question worthy of further study

Author Response File: Author Response.docx

Reviewer 3 Report

Overall, an excellent paper. Just two minor comments:

 

A brief explanation of MOST in the introduction for unfamiliar readers would be useful.

 

Line 53: 2m or 1.5m? 

Author Response

Point 1: A brief explanation of MOST in the introduction for unfamiliar readers would be useful.

Response 1: Thank you for this suggestion. A brief explanation of MOST has been added in the revised manuscript. Please see Lines 51-54.

 

Point 2: Line 53: 2m or 1.5m?

Response 2: Thank you. The data were taken from meteorological observation stations, so this is 1.5m. We have modified the manuscript.

Author Response File: Author Response.docx

Reviewer 4 Report

The explanaition of the sole formula in the manuscript has to be reworked.

In the sentence

"where ∆? is the regional average, n is the number of grids, ?? is the center latitude of the  grid, and ?? is the arithmetic mean of each grid."

"number of grids" and "center latitude of the
grid" should be replaced by formulation refering to the  "latitude of the the grid-point-box"

 

Author Response

Point 1: The explanation of the sole formula in the manuscript has to be reworked.

In the sentence "where ∆? is the regional average, n is the number of grids, ?? is the center latitude of the grid, and ?? is the arithmetic mean of each grid."

"number of grids" and "center latitude of the grid" should be replaced by formulation referring to the "latitude of the grid-point-box"

 

Response 1: Thank you for this suggestion. We have reworked the formulae in the manuscript. Please see Line 206.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

The revised manuscript is significantly improved. Authors have responded my concerns. I think it is acceptable for publication.