Historical reconstruction and future projection of mass balance and ice volume of Qiyi Glacier, Northeast Tibetan Plateau

Abstract

Study region: Qiyi Glacier in the Qilian Mountains, northeast Tibetan Plateau. Study focus: Future glacier changes are critical to the sustainable use of regional water resources and the survival and development of the densely populated Tibetan Plateau and surrounding regions. A distributed energy-mass balance model is applied to simulate the historical and future mass balance and ice volume of Qiyi Glacier from 1980 to 2100. The aims of this study are to illuminate the spatial and temporal patterns of mass balance and energy balance, to forecast future changes of this glacier under different scenarios of CMIP6, and to identify the timing of peak ice loss. New hydrological insights for the region: Compared to the historical reconstruction, future projections show that ablation will increase, and accumulation will decrease due to less snowfall and increased net shortwave radiation that is induced by lower albedos. The average mass balance increases by a factor of 1.08, 1.67 and 2.68 under the SSP1-2.6, SSP2-4.5 and SSP5-8.5 scenarios during 2021–2100, respectively. By the end of the 21st century, Qiyi Glacier ice volume will reduce by 107.61 × 106 m3 (95.3 %) for the SSP1-2.6 scenario, and 112.12 × 106 m3 (99.3 %) for the SSP2-4.5 scenario, and will disappear entirely by 2082 for the SSP5-8.5 scenario. In all scenarios, the glacier mass loss rate will peak around 2030–2045, then decrease in parallel with the decreasing ice volume.

Keywords

• Glacier modeling
• Glacier mass balance
• Energy balance
• CMIP6
• Qiyi Glacier