Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research , Chinese Academy of Sciences , Beijing 100101 , China.
University of Chinese Academy of Sciences , Beijing 100049 , China.
Environ Sci Technol. 2018 Jul 3;52(13):7203-7211. doi: 10.1021/acs.est.8b01251. Epub 2018 Jun 19.
Humic-like substances (HULIS) are major components of light-absorbing brown carbon that play an important role in Earth's radiative balance. However, their concentration, optical properties, and sources are least understood over Tibetan Plateau (TP). In this study, the analysis of total suspended particulate (TSP) samples from central of TP (i.e., Nam Co) reveal that atmospheric HULIS are more abundant in summer than that in winter without obvious diurnal variations. The light absorption ability of HULIS in winter is 2-3 times higher than that in summer. In winter, HULIS are mainly derived from biomass burning emissions in South Asia by long-range transport. In contrast, the oxidation of anthropogenic and biogenic precursors from northeast part of India and southeast of TP are major sources of HULIS in summer.
类腐殖质物质（HULIS）是吸光棕色碳的主要成分，在地球辐射平衡中起着重要作用。然而，在青藏高原（TP）地区，HULIS 的浓度、光学性质和来源了解最少。在这项研究中，对青藏高原中部（即纳木错）的总悬浮颗粒物（TSP）样品的分析表明，大气 HULIS 在夏季比冬季更为丰富，且没有明显的日变化。冬季 HULIS 的光吸收能力是夏季的 2-3 倍。在冬季，HULIS 主要是通过长距离传输，由南亚的生物质燃烧排放物形成的。相比之下，夏季 HULIS 的主要来源是来自印度东北部和青藏高原东南部的人为和生物前体的氧化。
