Progress in research on glacial black carbon in southeastern Tibet, where the Tibetan Plateau is located

The black carbon emitted from the combustion of biomass and fossil fuels in South Asia can be transported to the glaciers on the Qinghai-Tibet Plateau under the influence of the westerly jet and the Indian monsoon. The black carbon deposited in snow and ice generates radiative forcing on the snow-ice surface, thus becoming an important factor in the melting of glaciers.

Xu Baiqing, Research Fellow at the Institute of Tibetan Plateau Research, Chinese Academy of Sciences (Assistant Researcher Wang Mowei as the first author) analyzed the historical changes of the structure of combustion emission sources through the analysis of the black carbon in the Puer glaciers of the Gangzhan Bushan in southeastern Tibet. The CAM5 climate model was used to elucidate the main contribution of South Asian emissions to black carbon deposition in the southeastern Tibet, and the SNICAR model was used to quantitatively evaluate the impact of black carbon deposition on the radiative forcing of the snow-ice surface.

The main achievements of this study include: (1) South Asian emissions have the largest contribution to black carbon deposition in southeastern Tibet (an average of 74% per year), followed by East Asia (14%), while contributions from Central and Southeast Asia are very small (both And 1%); (2) Black carbon in glaciers in southeastern Tibet has shown an upward trend in the past 50 years, especially since 1980, the black carbon content has increased 2-3 times compared with 1956-1979. The historical emissions of black carbon in South Asia and the changing trends of coal and biomass combustion are consistent; (3) The radiative forcing of black and white carbon (including BC and OC) on the snow-ice surface of southeastern Tibet was between 1956 and 1979. At 0.95 Wm-2, it increased to 2.79 Wm-2 between 1980 and 2006.

The results of this research are published in Atmospheric Chemistry and Physics.