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Despite projections of extreme reduction in glacier volume in the Qilian Mountains by the end of the century, comprehensive studies of regional glacier-wide mass and energy balance characteristics remain lacking. This study undertook a comparative analysis of the surface energy and mass balance characteristics of Laohugou glacier No. 12 (LHG glacier) in the Shule River Basin (western Qilian Mountains) and Bailanghe glacier No. 21 (BLH glacier) in the Heihe River Basin (middle Qilian Mountains) based on in situ measurements from September 2020 to August 2021. During the cold season (September-April), precipitation was greater on the BLH glacier than on the LHG glacier. This resulted in a more positive mass balance on the BLH glacier during the cold season, and less melting in May-June owing to the higher incoming shortwave radiation. During the ablation season (May-August), snowfall was greater on the LHG glacier owing to its higher elevation, while melting was also greater owing to the anomalously low cloud fraction during summer 2021. The annual mass balance was notably more negative on the LHG glacier than on the BLH glacier at the same elevation below 5000 m, whereas the annual glacier-wide mass balance was just slightly more negative on the LHG glacier than on the BLH glacier because most of the area in the LHG glacier is at higher elevation. The equilibrium line altitude varied between 4900 and 5100 on the glaciers of Qilian Mountains during recent two decades, which signified that only 5.8-25.5% of the total glacier area is within the accumulation zone in the Heihe River Basin; thus, further global warming will place the regional glaciers in a very vulnerable position.

来源平台：CLIMATE DYNAMICS