State Key Laboratory of Cryosphere Science, Northwest Institute of Eco-Environment and Resources, , Chinese Academy of Sciences, Lanzhou 730000, China; Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control (AEMPC), School of Environmental Sciences and Engineering, Nanjing University of Information Science and Technology, 219 Ningliu Road, Nanjing 210044, China.
State Key Laboratory of Cryosphere Science, Northwest Institute of Eco-Environment and Resources, , Chinese Academy of Sciences, Lanzhou 730000, China; CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing 100101, China.
Sci Total Environ. 2017 Jan 1;574:889-900. doi: 10.1016/j.scitotenv.2016.09.114. Epub 2016 Oct 14.
Melting of high-elevation glaciers can be accelerated by the deposition of light-absorbing aerosols (e.g., organic carbon, mineral dust), resulting in significant reductions of the surface albedo on glaciers. Organic carbon deposited in glaciers is of great significance to global carbon cycles, snow photochemistry, and air-snow exchange processes. In this work, various snow and ice samples were collected at high elevation sites (4300-4850masl) from Mt. Yulong on the southeastern Tibetan Plateau in 2015. These samples were analyzed for water-soluble organic carbon (DOC), total nitrogen (TN), and water-soluble inorganic ions (WSIs) to elucidate the chemical species and compositions of the glaciers in the Mt. Yulong region. Generally, glacial meltwater had the lowest DOC content (0.39mgL), while fresh snow had the highest (2.03mgL) among various types of snow and ice samples. There were obvious spatial and temporal trends of DOC and WSIs in glaciers. The DOC and TN concentrations decreased in the order of fresh snow, snow meltwater, snowpit, and surface snow, resulting from the photolysis of DOC and snow's quick-melt effects. The surface snow had low DOC and TN depletion ratios in the melt season; specifically, the ratios were -0.79 and -0.19mgLd, respectively. In the winter season, the ratios of DOC and TN were remarkably higher, with values of -0.20mgLd and -0.08mgLd, respectively. A reduction of the DOC and TN content in glaciers was due to snow's quick melt and sublimation. Deposition of these light-absorbing impurities (LAPs) in glaciers might accelerate snowmelt and even glacial retreat.
高海拔冰川的融化会因吸收光的气溶胶（例如有机碳、矿物粉尘）的沉积而加速，从而导致冰川表面反照率显著降低。沉积在冰川中的有机碳对全球碳循环、雪光化学和空气-雪交换过程具有重要意义。在这项工作中，于 2015 年在青藏高原东南部的玉龙雪山的高海拔地点（4300-4850masl）收集了各种冰雪样本。对这些样本进行了水溶性有机碳（DOC）、总氮（TN）和水溶性无机离子（WSIs）的分析，以阐明玉龙山地区冰川的化学物质和组成。一般来说，冰川融水中的 DOC 含量最低（0.39mgL），而各种冰雪样本中，新鲜雪中的 DOC 含量最高（2.03mgL）。DOC 和 WSIs 在冰川中有明显的时空趋势。DOC 和 TN 浓度按新鲜雪、雪融水、雪坑和表面雪的顺序降低，这是由于 DOC 的光解和雪的快速融化作用所致。在融雪季节，表面雪的 DOC 和 TN 耗竭率较低，分别为-0.79mgLd 和-0.19mgLd。在冬季，DOC 和 TN 的比值明显较高，分别为-0.20mgLd 和-0.08mgLd。冰川中 DOC 和 TN 含量的减少是由于雪的快速融化和升华。这些吸收光的杂质（LAPs）在冰川中的沉积可能会加速融雪甚至冰川退缩。
