Levoglucosan on Tibetan glaciers under different atmospheric circulations

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• 作者：Chao You^a ; ^b ; ^{youchao@itpcas.ac.cn} ; Tandong Yao^a ; ^b ; Chao Xu^a ; ^b ; Lili Song^c
• 关键词：Fire emissions ; Levoglucosan ; Fire tracer ; Snow chemistry ; Tibetan plateau
• 刊名：Atmospheric Environment
• 出版年：2017
• 出版时间：March 2017
• 年：2017
• 卷：152
• 期：Complete
• 页码：1-5
• 全文大小：1191 K
• 卷排序：152

文摘

Tibetan glaciers are natural documents of the specific biomass burning biomarker levoglucosan from regions around. However, knowledge about the characteristics of levoglucosan distributions on Tibetan glaciers under the different climate systems is poorly understood. In this study, we detected levoglucosan in snow samples from the Zuoqiupu (ZQP) Glacier affected by the Indian summer monsoon and the Muji (MJ) Glacier dominated by the westerlies. Results found that the ZQP Glacier was more heavily affected by fire emissions than the MJ Glacier, caused by stronger emission sources on the windward direction and shorter transport distances. Elevations for the appearance of levoglucosan maxima on glacier surfaces are roughly around the equilibrium line altitudes. However, levoglucosan displays a wider distribution range on the MJ glacier than on the ZQP glacier due to weaker summer melt. Injection height of fire smokes and glacial melt can affect the altitudinal distribution of levoglucosan. Black carbon and levoglucosan show different temporal variations in snow-pit samples on those two glaciers. The post-depositional effects, e.g. the melting and refreezing processes, can modulate the vertical distribution of levoglucosan in snow/ice layers. Our results are helpful for understanding the geochemical behaviors of levoglucosan happened on Tibetan glacier surfaces.