Permafrost temperature baseline at 15 m depth on the Qinghai–Tibetan Plateau (2010–2019)

• Published in: Earth System Science Data
• Main Authors: D. Zou, L. Zhao, G. Hu, E. Du, G. Liu, C. Wang, W. Li
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2025
• Subjects: Environmental sciences; GE1-350; Geology; QE1-996.5; permafrost
• Online Access: https://doi.org/10.5194/essd-17-1731-2025; https://doaj.org/article/b3df4784bccd4b47aa5990f73183069d

Ground temperature at a fixed depth is a crucial boundary condition for understanding the properties of deep permafrost. However, the commonly used mean annual ground temperature at the depth of the zero annual amplitude (MAGT DZAA ) has certain limitations for extensive application due to large spatial heterogeneity at observed depths. In this study, we utilized 231 borehole records of mean annual ground temperature at a depth of 15 m (MAGT 15 m ) from 2010 to 2019 and employed a method of support vector regression (SVR) to predict the gridded MAGT 15 m at a spatial resolution of nearly 1 km across the Qinghai–Tibetan Plateau (QTP). The SVR model predictions demonstrated an R 2 value of 0.48 with a negligible negative overestimation ( − 0.01 °C). The average MAGT 15 m of the QTP permafrost was − 1.85 ± 1.58 °C, with 90 % of the values ranging from − 5.1 to − 0.1 °C and 51.2 % greater than − 1.5 °C. The ground surface freezing degree day (FDD) was the most significant predictor ( p <0.001 ) of MAGT 15 m , followed by the ground surface thawing degree day (TDD), mean annual precipitation (MAP), and soil bulk density (BD) ( p <0.01 ). Overall, the MAGT 15 m increased from northwest to southeast and decreased with rising elevation. Lower MAGT 15 m values prevail in high mountainous areas with steep slopes. The MAGT 15 m was lowest in the headwater areas of the Amu Darya, Indus, and Tarim river basins ( − 2.9 to − 2.7 °C) and highest in the headwater areas of the Yangtze and Yellow river basins ( − 0.9 to − 0.8 °C). The baseline dataset of the MAGT 15 m for the QTP permafrost regions during 2010–2019 will facilitate simulations of deep permafrost characteristics and provide fundamental data for permafrost model validation and improvement. The dataset is openly available in the National Tibetan Plateau Data Center ( https://doi.org/10.11888/Cryos.tpdc.301165 , Zou et al., 2024b).