State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, CAS, Lanzhou, 730000, China.
Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity, Xi'an, 710127, China; Institute of Earth Surface System and Hazards, Northwest University, Xi'an, 710127, China; College of Urban and Environmental Sciences, Northwest University, Xi'an, 710127, China.
Environ Pollut. 2019 Jan;244:209-217. doi: 10.1016/j.envpol.2018.10.037. Epub 2018 Oct 10.
Cryoconite is a dark, dusty aggregate of mineral particles, organic matter, and microorganisms transported by wind and deposited on glacier surfaces. It can accelerate glacier melting and alter glacier mass balances by reducing the surface albedo of glaciers. Biomass burning in the Tibetan Plateau, especially in the glacier cryoconites, is poorly understood. Retene, levoglucosan, mannosan and galactosan can be generated by the local fires or transported from the biomass burning regions over long distances. In the present study, we analyzed these four molecular markers in cryoconites of seven glaciers from the northern to southern Tibetan Plateau. The highest levels of levoglucosan and retene were found in cryoconites of the Yulong Snow Mountain and Tienshan glaciers with 171.4 ± 159.4 ng g and 47.0 ± 10.5 ng g dry weight (d.w.), respectively. The Muztag glacier in the central Tibetan Plateau contained the lowest levels of levoglucosan and retene with mean values of 59.8 ng g and 0.4 ± 0.1 ng g d.w., respectively. In addition, the vegetation changes and the ratios of levoglucosan to mannosan and retene indicate that combustion of conifers significantly contributes to biomass burning of the cryoconites in the Yulong Snow Mountain and Tienshan glacier. Conversely, biomass burning tracers in cryoconites of Dongkemadi, Yuzhufeng, Muztag, Qiyi and Laohugou glaciers are derived from the combustion of different types of biomass including softwood, hardwood and grass.
冰碛是一种由矿物质颗粒、有机物和微生物组成的黑色尘埃状混合物，通过风的运输而沉积在冰川表面。它可以通过降低冰川表面反照率来加速冰川融化并改变冰川质量平衡。青藏高原的生物质燃烧，特别是在冰川冰碛中，仍知之甚少。萜烯、左旋葡聚糖、甘露聚糖和半乳糖醛酸聚糖可以由当地火灾产生，也可以从长距离运输的生物质燃烧区输送而来。在本研究中，我们分析了来自青藏高原北部到南部的 7 个冰川的冰碛中的这四种分子标记物。在玉龙雪山和天山冰川的冰碛中，左旋葡聚糖和 Retene 的含量最高，分别为 171.4±159.4ng g 和 47.0±10.5ng g 干重（d.w.）。位于青藏高原中部的木孜塔格冰川的左旋葡聚糖和 Retene 含量最低，平均值分别为 59.8ng g 和 0.4±0.1ng g d.w.。此外，植被变化和左旋葡聚糖与甘露聚糖和 Retene 的比值表明，针叶树的燃烧对玉龙雪山和天山冰川冰碛的生物质燃烧有重要贡献。相反，在东柯马里、玉珠峰、木孜塔格、七一和老虎沟冰川的冰碛中，生物质燃烧示踪剂来源于不同类型的生物质燃烧，包括软木、硬木和草。
