Black carbon (BC) is a major component of tiny soot particles generated by the incomplete combustion of raw coal, diesel oil, gasoline and biomass fuel, which largely absorbs sunlight radiation. The deposition of BC on snow and ice impacts the local and regional climate by altering solar radiation balance through snow albedo change and associated albedo positive feedback effect. 

In recent years, there has extensive studies been focused on BC and other light-absorbing impurities in the cryosphere and atmosphere because of their strong climate effects and radiative forcing. 

However, the detailed mechanism of physiochemical processes of insoluble light-absorbing impurities (ILAIs) in snowpack is yet to be fully understood and is still a topic of active research. Besides, systematic investigations of ILAIs in snowpack of glaciers on the Tibetan Plateau (TP) are rare. 

Recently, for the first time, scientists from the Northwest Institute of Eco-Environment and Resources of Chinese Academy of Sciences systematically conducted the integrated analysis of measured and modeled concentrations of ILAI in snowpack and atmosphere at surface over the four glaciers on the TP, to obtain a comprehensive understanding of the physicochemical process of ILAIs in snowpack and the performance of current-generation 3D atmospheric chemical models in simulating the deposition of ILAIs in surface snow. 

Based on extensive field observations and measurements of ILAI concentrations in snow/ice from four glaciers on the TP, scientists evaluated model performance, post-depositional processes of ILAIs in snow/ice, spatio-temporal pattern of ILAIs, optical properties of BC in snowpack, as well as chemical composition and morphology of individual particles in glacier cryoconite, and tentatively proposed possible schemes for the parameterization improvement and optimization of atmospheric chemistry models. 

Besides, the scanning electron microscopy (SEM) imaging also demonstrated that calcium and silicon rich particles in ILAIs dominate over biological, quartz and flying ash particles in the cryoconite, providing additional constraints on the sources of dust-in-snow and can facilitate better understanding of the physicochemical properties and climatic effects of particles in the glacial cryoconite. 

This study has been published in the Atmospheric Research in an article entitled “Measurements of Light-Absorbing Impurities in Snow over Four Glaciers on the Tibetan Plateau”. 

Contact: 

NIU Hewen 

E-mail: niuhw@lzb.ac.cn 

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