Changes in Ground Freeze-Thaw Characteristics Based on ERA5-Land Surface Temperature Calculations and Soil Organic Carbon Data

The data is comprised of four primary components.The first component is the 0-7cm soil temperature data from the ERA5-Land dataset. This dataset originally has an hourly temporal resolution and a 9km spatial resolution. For this project, the data were resampled to 1km using the Google Earth Engine (GEE) platform to extract daily 0-7cm soil temperature data for 36 sampling sites in the river source region of the Tibetan Plateau from 2011 to 2023（Table 1,sheet 1）. Additionally, it includes 5 cm below-ground temperature data monitored from 2011 to 2023 via five field-built meteorological stations (Table 1, sheet 2).The second component was used to validate the applicability of the ERA5-Land dataset. This was done by processing the daily data from the first component into monthly averages and comparing them with 5cm monthly average soil temperature data collected from our own field-based weather stations(Table 2).The third component includes the soil freeze-thaw index（Table 3, sheet 1,2）, period（Table 3, sheet 3,4), and frequency（Table 3, sheet 5）, all calculated from the ERA5-Land data. It also contains NDVI data （Table 3, sheet 6）for the 36 sampling sites from 2011 to 2023, which was extracted from the MOD13A2 product via GEE.The fourth component consists of data on soil organic carbon and its corresponding environmental factors, which were obtained through field and laboratory experiments. These include vegetation characteristics (cover, height, aboveground biomass), soil physicochemical properties, and calculated freeze-thaw characteristics (Table 4).