TY  - Data
T1  - A new permafrost thermal state map based on enthalpy change on the Qinghai-Tibet Plateau
A1  - Ji Hailong
A1  - NAN Zhuotong 
DO  - 10.12072/ncdc.permafrost.db7696.2026
PY  - 2026
DA  - 2026-08-04
PB  - National Cryosphere Desert Data Center
AB  - Permafrost thermal state represents the stored “cold energy” in the ground and is a crucial metric for assessing permafrost changes. However, the widely used mean annual ground temperature (MAGT) has inherent limitations because it overlooks the thermodynamic contribution of ground ice. To address this issue, we proposed an alternative metric based on enthalpy change (ΔH′), which comprehensively considers ground temperature and ground ice content, corresponding to the theoretical heat absorption required for the complete thawing of permafrost. Compared with MAGT, ΔH′ provides a more uniform scale and higher discernibility in characterizing potential permafrost duration, making it more suitable for representing permafrost thermal state. Using high-resolution gridded datasets, we re-mapped the spatial distribution of permafrost thermal state across the Qinghai-Tibet Plateau (QTP) based on ΔH′ and quantitatively analyzed the spatial discrepancy between the two metrics. The results indicate that MAGT overestimates the permafrost thermal stability in the western QTP and underestimates it in the southeastern QTP as well as in areas surrounding lakes in endorheic basins. Details regarding the metric's calculation, evaluation, spatial distribution characteristics, and the attribution of spatial discrepancies with MAGT are provided in the associated paper. This dataset provides the ΔH′ distribution map for permafrost across the QTP. The data are distributed in GeoTIFF format using the WGS84 coordinate system, with pixel values representing ΔH′ (unit: GJ/m2, 1 GJ=109 J). Within the study area, the minimum value is −1.33 GJ/m2, the maximum value is −0.04 GJ/m2, the mean value is −0.84 GJ/m2, and the standard deviation is 0.13 GJ/m2. More negative values indicate higher permafrost thermal stability.
DB  - NCDC
UR  - https://www.ncdc.ac.cn/portal/metadata/e70737b0-9cbf-4189-b8d6-dd6935414d4c
ER  -