Reconstruction of the mass balance of Muztag Ata No. 15 glacier, eastern Pamir, and its climatic drivers

Abstract

The mass-balance of Muztag Ata No. 15 (MZ15) glacier in the eastern Pamir is reconstructed between 1980 and 2012 using an energy-based mass-balance model. The results show that this glacier has been characterized by obvious interannual mass-balance changes during 1980–2012 with a slightly positive mass balance during 1998–2012. Precipitation in the ablation season is a primary driver of these mass-balance fluctuations. Distinct changes in the mass-balance of MZ15 glacier between 1980–1997 and 1998–2012 are thought to be associated with changes in the regionally averaged meridional wind speed and corresponding precipitation in the ablation season. The negative and positive mass-balance phases during 1980–1997 and 1998–2012, respectively, were associated with northerly and southerly wind anomalies in the eastern Pamir and their corresponding decreasing and increasing precipitation. These changes in circulation appear to be linked to the mid-latitude climate. Finally, contrary to the variation of most glaciers on the Tibetan Plateau, glaciers in the Karakoram-western Kunlun-eastern Pamir appear to have retreated more slowly over the past 10 years than during the 1970s-2000. This contrasting trend may be caused by different changes in snowfall and different topography factors in different regions under warming and increased precipitation.

Keywords

• climate change
• glacier modeling
• ice/atmosphere interactions
• mass-balance reconstruction
• mountain glaciers