Light-absorbing impurities (LAIs), including black carbon (BC), mineral dust, brown carbon, and others in snow, have been recognized as important contributors to anthropogenic climate change since the 1980s, which are the second most important contributor to global warming only after CO2 due to its strong light absorption. 

Previous studies showed that BC and dust deposition in glaciers represented a threat to water resources in mountainous region, especially in the arid Central Asia. Therefore, the studies on the glacier surface snow albedo reduction and enhanced melting by LAIs have important implications for the regional hydrology and water demands in the mid-latitudes. However, studies on LAIs in Central Asian glaciers beyond the Tibetan Plateau are still sparse. 

Recently, scientists from the Northwest Institute of Eco-Environment and Resources of Chinese Academy of Sciences (CAS), together with researchers from famous universities and research institutes at home and abroad, estimated the contribution of BC and dust to glacial melting in Central Asia. This study focused on BC and dust in snow samples collected from the Muz Taw glacier located in the Sawir Mountain to investigate the climate effect of LAIs on glacier melting in Central Asia. 

In this study, scientists constrained the concentrations of both BC and dust, the albedo reduction, radiative forcing and estimated of recent glacier melting. Furthermore, the potential sources of the LAIs deposited on the glacier are also addressed. 

The study results showed that BC and dust concentrations in Muz Taw glacier snow varies but falls into the range of reported data from the Third Pole region. Besides, simulation using the Snow Ice and Aerosol Radiation (SNICAR) model indicates that the combined effect of BC and dust reduces the snow albedo by approximately 6.24% to 50.4% relative to clean snow.  

This study strengthen the important role of BC and dust in glacier melting in Central Asia, and further highlights the potential benefits of mitigation of BC emissions. This study has been published in the Science of the Total Environment in an article entitled “Effects of black carbon and mineral dust on glacial melting on the Muz Taw glacier, Central Asia”. 

Contact: 

ZHANG Yulan 

E-mail: yulan.zhang@lzb.ac.cn 

State Key Laboratory of Cryosphere Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China.