Decadal Dynamics of Air Temperature on the Southern and Northern Slopes of the Kunlun Mountains, Qinghai‐Tibet Plateau, and the Topographic Modulation Effects

Topographic conditions are key factors governing surface energy distribution in high‐alpine mountainous areas, determining the dynamic variations of local climate and the thermal state of permafrost, which holds profound implications for understanding global climate system responses in extreme terrestrial environments. However, the in situ thermal impact mechanisms on air temperature and permafrost under complex topographic configurations require further investigation. Based on a decadal (2015–2024) in situ observational dataset of near‐surface air temperature and deep ground temperature on the southern and northern slopes of the Kunlun Mountains, this study evaluates the asymmetric variations and decoupling effects between near‐surface thermal conditions and the underlying permafrost. The results demonstrate that: (1) Comprehensive topographic configurations modulate the expected distribution patterns of air temperature. Influenced by cold‐air pooling, the cold‐season air temperature on the southern slope remains consistently lower than that on the northern slope. However, such near‐surface atmospheric thermal characteristics do not strictly determine the subsurface thermal evolution. (2) The near‐surface air temperature and ground thermal processes are decoupled. Although the Thawing Degree Days (TDD) are comparable between the two slopes, the Ground Thawing Degree Days (GTDD) on the southern slope is approximately four times that of the northern slope. Under conditions of intense heat input, the downward geothermal flux on the southern slope noticeably deepens the permafrost Active Layer Thickness (ALT). (3) Against the backdrop of generalized climate warming, the high‐intensity effective heat input during the warm season drives permafrost degradation. By 2024, the ground temperatures at depths of 8 and 15 m on the southern slope increased by 0.21°C–0.29°C and 0.19°C–0.20°C, respectively, compared to 2015, which noticeably exceeds predicted levels. This reflects the high sensitivity of local permafrost to heat input. This study provides critical in situ evidence for correcting topographic thermal offsets in high‐alpine land surface models.