Permafrost on the Tibetan Plateau (TP) is controlled by high-elevation and the complex hydrothermal processes and energy balance on the ground surface. To successfully model or map permafrost distribution, it is necessary to parameterize near-surface air or land-surface temperatures (Ta or LST) to ground surface temperature (GST) at local-, meso-, or macro-scale. Here, a long-term experimental observation (November 2010 to December 2018) was conducted for understanding the differences between Ta and GST at a plot with 26 sites at Chalaping to the south of the Sisters Lakes in the Source Area of the Yellow River, northeastern TP. Results show that GST varies considerably within an area of about 3.5 km2 under the combined thermal influences of surface vegetation, soil moisture conditions, and microtopography. Mean annual GST (MAGST) ranged from -0.55 to -3.02 degrees C, with an average of -1.35 +/- 0.63 degrees C. The surface offset varied from 1.01 to 3.90 degrees C, with an average of 2.72 +/- 0.70 degrees C. The difference between monthly Ta and monthly GST decreased from 4.64 +/- 2.09 degrees C in January to 1.09 +/- 1.34 degrees C in July and then gradually increased to 5.61 +/- 2.53 degrees C in November. The active layer thickness (ALT) calculated with the ground-surface thawing index ranged from 0.85 to 1.95 m, with an average of 1.51 +/- 0.33 m. Annual freezing N-factors and annual thawing N-factors were averaged at 0.58 +/- 0.12 and 1.31 +/- 0.28, respectively. Although weakly, hourly and daily GST values are positively correlated to NDVI, while ALT negatively correlated with NDVI. This study demonstrates the complex thermal regimes on the ground surface, even within a small area despite the relatively consistent topography. It will likely facilitate the parameterization of the upper thermal boundary of permafrost modeling or mapping on the TP where the landscapes are characterized by extensive presence of dwarf alpine meadow and alpine steppe, further contributing to the study in ecosystem feedbacks to the regional climate change.

来源平台：AGRICULTURAL AND FOREST METEOROLOGY