Carbonaceous aerosols not only alter atmospheric radiation balance but also accelerate glacier melt by reducing the albedo of ice and snow surfaces. However, due to the heterogeneity of carbonaceous aerosols, identifying their sources and assessing their environmental impacts pose significant challenges. Carbon isotope (δ¹³C, Δ¹⁴C) technology is an effective tool for identifying the sources of carbonaceous aerosols. 

The Tibetan Plateau is one of the richest glacier areas outside of Antarctic and the Arctic. Due to global warming, most glaciers in this region rapidly retreating, and the impact of carbonaceous particles deposited on glacier surfaces cannot be ignored.  

Prof. KANG Shichang's research team from the Northwest Institute of Eco-Environment and Resources of the Chinese Academy of Sciences (CAS) revealed unique stable carbon isotopes characteristics of carbonaceous aerosol endmembers on the Tibetan Plateau.  

This work was published in Environmental Science & Technology on May 23. 

The researchers collected particulate matter samples from fossil fuel emissions (traffic and coal combustion), and biomass combustion emissions (yak dung and wood), as well as surface soil samples in the Tibetan Plateau. By analyzing the δ¹³C characteristics of total carbon (TC), water-insoluble particulate carbon (WIPC), and elemental carbon (EC) in the samples, they found significant differences in the δ¹³C values of carbonaceous aerosol endmembers between the Tibetan Plateau and other regions.  

Due to the high altitude and thin air, particulate matter from fossil fuel combustion in this region has more negative δ¹³C values compared to other regions. The unique fuel types used here result in particulate matter from biomass fuel combustion having more positive δ¹³C values compared to other regions.  

Furthermore, significant differences in δ¹³C values exist among different carbon components (TC, WIPC, EC) in yak dung combustion and traffic emissions due to varying combustion efficiency. However, no significant differences are observed among different carbon components in coal and wood combustion emissions. The δ¹³C values of fine particulate topsoil (less than 20μm) are influenced by changes in regional surface vegetation types.  

The study enhances the understanding of the emission characteristics of carbonaceous aerosols on the Tibetan Plateau and helps accurately identify their sources in the Tibetan Plateau and its surrounding areas. It provides data to assess the impact of carbonaceous aerosols on cryospheric melting and climate effects.