Carbonaceous matter is an important light absorption component in the aerosols and snow/ice, which has significant impacts on glacial retreat in the Tibetan Plateau, further affecting the water resource supply. 

However, there is not yet relevant study on carbonaceous matter in precipitation and snowpit at Geladaindong (GLDD) glacierized region in the source of the Yangtze River, which limits our understanding on carbonaceous matter contribution to glacier melting. 

Recently, a research group led by Prof. KANG Shichang from the Northwest Institute of Eco-Environment and Resources (NIEER) of the Chinese Academy of Sciences investigated the concentration, sources and fractionation of carbonaceous matter at Ganglongjiama (GLJM) glacier in GLDD region during the melting period in 2017. 

The scientists collected precipitation and snowpit samples during two scientific explorations in GLJM glacier at GLDD glacierized region between June and September, 2017. 

The results showed that concentrations of major ions and dissolved organic carbon (DOC) of snowpit samples were much lower than those of precipitation samples, suggesting that water soluble components could be effectively leached from the snowpit during the melting process. 

However, refractory black carbon (rBC) concentrations of snowpit and precipitation samples showed the opposite trend because rBC was likely to enrich in snowpit during the melting process. Meanwhile, DOC with high light-absorbing ability was also likely to be kept in snowpit during the melting process. 

In addition, it was found that both rBC and DOC with high light-absorbing ability began to leach from the snowpit when melting process became stronger. Therefore, rBC and DOC with high light-absorbing ability exhibited similar behavior during the melting process. 

Besides, based on relationship among DOC, rBC and K⁺ in precipitation, the main source of carbonaceous matter in GIJM glacier was biomass burning during the study period. 

This study could deepen our understanding on carbonaceous matter contribution to glacier melting. It was published in Journal of Environmental Sciences. 

Location map and sampling sites of GLJM glacier. (Image by KANG Shichang)