Variations in Albedo on Dongkemadi Glacier in Tanggula Range on the Tibetan Plateau during 2002–2012 and Its Linkage with Mass Balance

摘要

Albedo, which impacts the surface heat budget of a glacier, is a dominant factor governing snow and ice melt variability. We analyzed variations in albedo on the Dongkemadi Glacier (92°4.94′E, 33°05.88′N) using MODIS daily snow albedo products. The results show that the summer albedo over the accumulation zone and the ablation zone all presented a decreasing trend from 2002 to 2012, and both precipitation and summer temperature were critical factors that impacted variations in the albedo of the glacier. We linked the albedo variation with the measured mass balance of the glacier and found that 2006 and 2010 were high-melt years at the Dongkemadi Glacier, with lower albedo and a more negative mass balance. The area around the equilibrium line altitude (ELA) on the glacier was very sensitive to albedo feedback. The albedo change rate reached approximately -34% when the summer average temperature increased about 1 °C and the summer precipitation declined 94.5 mm. We built a linear model between the annual lowest albedo and the annual mass balance of the Xiao Dongkemadi Glacier, one branch of the Dongkemadi Glacier. This model was used to evaluate the annual mass balance of another branch of the Dongkemadi Glacier, the Da Dongkemadi Glacier. The mass balance of the Da Dongkemadi Glacier was significantly negative in 2006 (-768.7 mm w.e.) and 2010 (-696.9 mm w.e.). This work indicates that the glacier surface annual lowest albedo may be a reasonable proxy for evaluating the inter-annual variability of the mass balance of the glacier.