Elevation‐dependent thermal regime and dynamics of frozen ground in the Bayan Har Mountains, northeastern Qinghai‐Tibet Plateau, southwest China

To investigate and monitor permafrost in the Bayan Har Mountains (BHM), north‐eastern Qinghai–Tibet Plateau, southwest China, 19 boreholes ranging from 20 to 100 m in depth were drilled along an elevational transect (4,221–4,833 m a.s.l.) from July to September 2010. Measurements from these boreholes demonstrate that ground temperatures at the depth of zero annual amplitude (TZAA) are generally higher than −2.0°C. The lapse rates of TZAA are 4 and 6 °C km−1, and the lower limits of permafrost with TZAA