Spatiotemporal Variations of Soil Temperature at 10 and 50 cm Depths in Permafrost Regions along the Qinghai-Tibet Engineering Corridor

Round 1

Reviewer 1 Report

  The manuscript evaluated the applicability of soil temperature datasets by using the in-situ soil temperature in the permafrost region along the Qinghai-Tibet highway. Overall, the manuscript is well, I recommend it publication before minor revision.

 

Special comments:

 

1. What is the mean of abbreviation “OBS” in Figure 2 and 3?

 

2. In Figure 4, the authors show soil temperature in four seasons. However, I cannot find the definition of seasons, in other words, the winter means “Nov. to Jan” or “Dec. to Feb.”.

 

3. Line 219 to 220, “...with the best simulation results....is GLDAS-Noah...”. Why? Is the rank 1 more, the results better? Please show more details.

Author Response

Dear Reviewer:

Thank you very much for your advice and help, please see the attachment for detailed response.

Author Response File: Author Response.docx

Reviewer 2 Report

The manuscript submitted for review provides an expert analysis of ground temperature within the active layer. The authors look at a strip of land along the Qinghai-Tibet Highway with a width of about 200 km and analyse the usefulness of MERRA-2, GLDAS-Noah, ERA5-Land, and CFSR&v2 soil temperature reanalysis datasets. In a further step, they revised GLDAS-Noah soil temperature data and examined the 330 spatial and temporal evolution of soil temperature at 10 and 50 cm depths. Direct measurements verify the data in 9 boreholes distributed along the highway in permafrost areas and seasonally frozen soil. The essence of the work done is the proposed methodology for validating the data and improving its accuracy. The authors use additional variables such as NDVI, SD and DEM.

I have no severe objections to the submitted manuscript. However, I express doubts about whether terrain analyses with a horizontal resolution of 250 m (MODIS Terra/Aqua Vegetation) and 0.05° (SRTM) can be compared at all to direct measurements of ground temperature, the result of which strongly depends, as the authors note in the text, on local conditions, including soil structure and moisture. Nevertheless, the paper has methodological value.

There needs to be more clarity over terminology in the first part of the manuscript. Measurements at depths 10 and 50 cm below the ground surface are not taken within the permafrost but the active layer. The text should be reviewed and corrected in this regard.

Author Response

Dear Reviewer:

Thank you very much for your advice and help, please see the attachment for detailed response.

Author Response File: Author Response.docx